An Analysis for the Imperial Irrigation District...Imperial Irrigation District RAMON MIRAGE S.C.E. IID I.V. SUB. 30 mo. 24 mo. 36 mo. 36 mo 30 mo. 30 mo. Proposed Major Transmission

Transitional Cluster Study

PDS Consulting, PLC Tempe AZ 85282

An Analysis for the Imperial Irrigation District

~ FINAL REPORT~ 01-28-2010

Imperial Irrigation District: Transitional Cluster Study Report

PDS Consulting, PLC 5063764

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EXECUTIVE SUMMARY

This section provides a summary of the transitional cluster study results for integrating about 2183 MW of generation resources to the Imperial Irrigation District (IID) transmission system. Detailed study results can be found in the subsequent sections of the report. Disclaimer

This report does not constitute an offer of transmission service nor confer upon the Interconnection Customer, any right to receive transmission service from IID. IID and its neighboring interconnected utilities may not have the Available Transmission Capacity to deliver to any customer or Point of Delivery. It must also be noted that the study results for the analysis presented in this report are highly dependent upon the data provided by the interconnection customers such as machine models, points of interconnection and timing of proposed projects. Any modification to the data provided in the interconnection application invalidates the results of this study. Although IID will share the study results with the other neighboring utilities, at this time the impact of the proposed generation projects on the affected systems are unknown.

Overview

IID is currently processing a large volume of active Interconnection Requests (IRs). IID clustered all pending IRs into a common Transitional Cluster Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These proposed projects plan to deliver power to IID and other neighboring utilities in the 2010-2015 timeframe. Specifically, the Cluster Study contained the following active interconnection requests:

Project Code Capacity Point of Interconn. In-service Date A-1-1 70 MW Midway 230 kV 07/01/2012 A-1-2 70 MW Midway 230 kV 11/01/2012 A-1-3 70 MW Midway 230 kV 04/01/2013 A-2-4 70 MW Midway 230 kV 04/01/2014 A-2-5 70 MW Midway 230 kV 01/01/2015 A-2-6 70 MW Midway 230 kV 10/01/2015 A-3 36.1 MW ―EO‖ 92 kV line 11/01/2011 A-4 225 MW Midway 230 kV 05/01/2014 A-5 55 MW Niland 161 kV 01/01/2010 A-6 99 MW Plaster City 92 kV 12/31/2011 A-7-1 47 MW ―KS‖ 230 kV 07/01/2012 A-7-2 47 MW ―KS‖ 230 kV 10/01/2013



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A-8 80 MW ―N‖ line 1 05/30/2011 A-9 100 MW Dixieland 230 kV 09/01/2011 A-10-1 200 MW Dixieland 230 kV 06/01/2012 A-10-2 200 MW Dixieland 230 kV 07/01/2013 A-11 130 MW ―R‖ line 09/01/2011 A-12 250 MW ―L‖ line 2 09/01/2011 A-13 50 MW ―L‖ line 12/01/2011 A-14-1 25 MW ―L‖ line 3 06/30/2012 A-14-2 50 MW ―L‖ line 12/31/2012 A-14-3 50 MW ―L‖ line 06/30/2013 A-15 119 MW Anza 92 kV 09/01/2012

To determine the impact of the proposed projects on the IID Transmission System and the neighboring transmission systems, IID contracted with PDS Consulting, PLC (PDS) to perform the Cluster Study. The Cluster Study was conducted using Western Electricity Coordination Council’s (WECC) approved heavy summer and light winter power flow models with detailed IID system representation incorporated. Studies performed included power flow, transient stability, post transient stability and short circuit analyses. PDS performed the transient and post-transient analyses portions of the Cluster Study while IID Transmission Planning conducted the power flow and short circuit analyses. Study Approach In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. For projects with different phases of implementation, the entire project output was considered operational in the year in which the first phase commences operation. Table I depicts the projects in each group and the WECC base model used for studying the group.

Group Projects WECC Base Model

2010

A-5 (55 MW) 2010 heavy summer and light winter models

2011

A-3 (36.1 MW), A-6 (99 MW), A-8 (80 MW), A-9 (100 MW), A-11 (130 MW), A-12 (250 MW) & A-13 (50 MW)

2011 heavy summer and 2010 light winter models

2012

A-1-1 (70 MW), A-1-2 (70 MW), A-1-3 (70 MW), A-7-1 (47 MW), A-7-2 (47 MW), A-10-1 (200 MW), A-10-2 (200 MW), A-14-1 (25 MW), A-14-2 (50 MW) , A-14-3 (50 MW) & A-15 (119 MW)


1 Project A-8 was connected to the IID ―KN‖ line between Midway and Coachella Valley Substations in lieu

of the requested ―N‖ line due to capacity limitation and huge cost of upgrading the ―N‖ line. 2 Due to capacity limitations on the ―L‖ line, A-12 was connected to the proposed Bannister to Dixieland

230 kV line. 3 A-14 was connected to Bannister via a radial 230 kV line



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2014

A-2-4 (70 MW) A-2-5 (70 MW) & A-2-6 (70 MW) & A-4 (225 MW)


TABLE I: Grouping of Projects for Transitional Cluster Study

The output from all the generation projects in each group were dispatched and delivered as indicated in each project’s interconnection application. Power flow, transient stability, post-transient stability, and short circuit analyses were conducted on each group. The adequacy of the study results were evaluated using WECC/NERC reliability and the IID planning standards. Impacts of each group to the IID system were determined and mitigation plans recommended. The mitigation plans were designed to ensure cost is contained and development is coordinated with IID future transmission plan objectives.

IID Transmission System Impacts The studies described in this report showed that the interconnection of proposed generation projects created new transmission overloads under normal operating conditions as well as single and credible double element outage conditions. In particular, the addition of the Group 2010 Cluster projects caused two (2) IID transmission facilities to overload under single element outage conditions. The interconnection of the Group 2011 Cluster projects caused ten (10) transmission facilities to overload under single element outages and another eight (8) facilities to overload during double element outages. In some instances the proposed point of interconnection of some of the projects were modified in order to minimize the impact of the projects on the existing transmission system. The detail impact of each cluster group can be found in the ―Study Results‖ section of each cluster group study. The addition of the proposed projects also had some impact on the voltage performance of the IID transmission system. The post-transient stability analysis showed that the interconnection of the proposed project caused the reactive margins at most of the IID buses monitored to shrink marginally. Each project would therefore be expected to ensure at a minimum zero reactive power exchange between its project and the IID transmission system at the point of interconnection. The study showed that a minimum of 632 MVAR of reactive power resources (a combination of controllable and non-controllable shunt capacitors) would be needed to maintain acceptable voltage performance on the IID transmission system. The results of the transient stability analysis showed that system performance was significantly impacted following the addition of the cluster projects. In particular, the addition of the Group 2011 cluster projects caused self-sustaining system swings and WECC system performance criteria violations. With the observed system performance criteria violations in 2011 resolved, subsequent cluster project additions in 2012 and 2014 resulted in a well-damped transient stability performance with no performance criteria violations. The short circuit analysis showed that the interconnection of the proposed cluster projects would cause forty-one (41) IID breakers to exceed their interrupting capabilities.



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Recommended Mitigation Plan, Cost and Construction Timelines To mitigate the identified impacts to IID transmission system following the addition of the cluster projects, IID developed an iterative process that ensured that any mitigation plan designed meets the following objectives:

It ensures that WECC/NERC reliability standards are met

It fits into IID long term transmission expansion plans

It is cost effective. Based on these objectives, the mitigation plan provided in TABLES II-V portions of which is depicted graphically in FIGURE I, is recommended as the appropriate transmission network reinforcements needed for resolving the identified thermal and transient stability criteria violations attributable to the cluster projects. It is estimated that the recommended network upgrades and its implementation would cost $ 507 Million (2009 Dollars). This estimate excludes a direct assignment cost of $ 133 Million (2009 Dollars) for interconnecting the proposed projects to the IID transmission system. The estimated construction timelines for each of the upgrades is provided in TABLES II-V.

FIGURE I: Recommended Major Transmission Network Upgrades

S.C.E.DEVERS

ECSS

AVE 58

MIDWAY

I.V. SUB.

COACHELLA VALLEY

BANNISTER SS

NILAND

HIGHLINE

DROP 4

DIXIELAND

Transitional Cluster Study

Imperial Irrigation District

RAMON

MIRAGES.C.E.

IID I.V. SUB.

30 mo.

24 mo.

36 mo.

36 mo

30 mo. 30 mo.

Proposed Major Transmission Network Upgrades

to Blythe

to Blythe

to Palo Verde

to North Gila

to Pilot Knob

CC - Existing single161kV line upgraded to double circuit

230kV

DD - Existing 161/92kV line upgraded to double circuit

230kV

AA - New double circuit 230kV line using new ROW

BB - New single circuit 230kV line using new ROW

LEGEND

500kV line

230kV line

Proposed 230kV line upgrade

Existing 230kV Switching Stations

New 230kV Switching Stations

161kV line


92kV line


to La Rosita (CFE)

to Miguel (SDG&E)

36 mo.

24 mo.

CC

AA

BB

EE

DD

AA

New

230/161 KV

225MVAIID Approved Project

30 mo.

30 m

o.



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TABLE II: Recommended Mitigation Plan & Associated Cost for Group 2010 Cluster Projects

Overloaded Faci l i ties Cri tica l OutageAppl icable

RatingsLoadings Recom m ended M itigation

Cost

Estim ate ($

M i l l ion)

Construction

Tim e L ines

(M onths) Notes

AVENUE 58 – JEFERSON 92 KV LINEN. LA QUINTA – AVENUE 42 92 KV LINE

"CD"132 MVA 127%

Rebuild line using 191 MVA, 900 MCM

ACSS ConductorIID Budget 18

N. LA QUINTA – AVENUE 42 92 KV LINE

"CD"AVENUE 58 – JEFERSON 92 KV LINE 132 MVA 126%



MIDWAY #1 230/92 KV TRANSFORMER MIDWAY #2 230/92 KV TRANSFORMER 300 MVA 150% 12


RAMON – MIRAGE 230 KV LINE COACHELLA - DEVERS 230 KV LINE 389 MVA 118%Upgrade 0.1 miles to 2-1033.5

ACSS/TW conductor 0.18 18

CVSUB – JACKSON 92 KV LINE 132 MVA 121% 9.27 24

EDOM – RAMON 92 KV LINE 91 MVA 133% IID Budget 12

CITAP1 – COACHELA 92 KV LINE 152 MVA 115%

CITAP1- VANBUREN 92 KV LINE 152 MVA 115%

CMTAP2 – VANBUREN 92 KV LINE 132 MVA 112%

CMTAP2 – SHAHILLS 92 KV LINE 123 MVA 112%

AVENUE 58 161/92 KV TRANSFORMER COACHELLA 161/92 KV TRANSFORMER 125 MVA 113%Replace unit with 225 MVA 161/92 kV

transformerIID Budget 24

Though overloads are due to Group

2010 Cluster projects, IID has aplanned budget for this upgrade

COACHELLA - DEVERS 230 KV LINE RAMON - MIRAGE 230 KV LINE 389 MVA 112% 23.00

CV - RAMON 230 KV LINE COACHELLA - DEVERS 230 KV LINE 389 MVA 109% 23.00

Install 104.4 MVAR capacitor banks 3.41

0.50

247.92

Network Upgrades Attributable to Group 2010 Cluster Pro jects

These transmission lines

share the same tower and

needed to be upgraded at the

Upgrade transmission line to 779 MVA,

2-1033 MCM ACSR30

Existing Transm ission System Upgrades

These network upgrades are not

due to the addition of the cluster

projects. However, the upgrades

are needed prior to the

integration of the proposed

projects. IID have some of the

upgrades already planned and

budgeted.

Implement Remedial Action Scheme

to trip generation at Midway 92 kV

Rebuild transmission lines using 191

MVA, 900 MCM ACSS Conductor

CVSUB - COACHELLA #1 &2 92 KV LINES

AVENUE 58 – JEFERSON 92 KV &

AVENUE 58 - AVENUE 48 92 KV LINES



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TABLE III: Recommended Mitigation Plan & Associated Cost for Group 2011 Cluster Projects



Cost

Estim ate

($ M i l l ion)

Construction

Tim e L ines

(M onths)

Notes

NONE N/A N/A N/A

40 Breaker Replacements at El Centro 92 kV

switching station 13.60 12 Short Circuit Study

ELCENTSW – IMPERIAL VALLEY 230 KV LINE 370 MVA 148%

Rebuild line using 786 MVA, 2-1033 MCM

ACSS Conductor and also rebuild the ECSS

230.

58.94 30 None

ELCENTSW 230/92 KV TRANSFORMER 332 MVA 114%

USNAF – ELTERMIN 92 KV LINE 132 MVA 112%

USNAF – DIXIELAN 92 KV LINE 132 MVA 112%

COACHELLA 161/92 KV TRANSFORMER AVENUE 58 161/92 KV TRANSFORMER 125 MVA 178% Replace CV transformer with 300 MVA rating 8.32 24 None

DIXPRI1 – DIXPRI 92 KV LINE 132 MVA 147%

DIXIELAN – DIXPRI2 92 KV LINE 132 MVA 147%

DIXPRI – DIXPRI2 92 KV LINE 132 MVA 147%

RTAP2 – RTP1 92 KV LINE 57 MVA 149%

RTP1 – DIXIELAND 92 KV LINE 51 MVA 102%

RAMON 230/92 KV TRANSFORMER 225 MVA 142%

N. VIEW – AVE42 92 KV LINE 132 MVA 137%

N. VIEW – RAMON 92 KV LINE 132 MVA 132%

AVE42 – FRANWAY 92 KV LINE 132 MVA 130%

FRANWAY – EDOM 92 KV LINE 132 MVA 128%

COACHELA #1 230/92 KV TRANSFORMER 150 MVA 116%


ELCENTSW 161/92 KV TRANSFORMER

COACHELA – DEVERS 230 KV & MIRAGE –

RAMON 230 KV LINES 125 MVA 112%

New 230 kV substation at Dixieland 20.77

332 MVA 230/92 kV transformer at Dixieland

and a transmission line (circuit #1) from

Dixieland to IID's Imperial Valley Switching

Station

IID Budget

New 92 kV line from Avenue 58 to Coachella

through Kohl Ranch (KM line)9.15 24

New 230 kV line (circuit #2) from Dixieland

to Imperial Valley Sw. Station28.28 24

Install 105 MVAR of reactive power

resources (Shunt capacitors)3.41 24

New 19-mile, 786 MVA, 2-1033 MCM bundled

230 kV line from Highline to El Centro. Install

Remedial Action Scheme (RAS) to mitigate

the marginal transmission overloads.

Upgrade Highline Sub., Upgrade "E" line 3.4

miles.

Rebuild "R" line uisng 191 MVA, 900 MCM

ACSS Conductor from Dixieland to Anza and

to Central

36

30

None

DIXIELAND – IMPERIAL VALLEY 230 KV LINE

IMPERIAL VALLEY – EL CENTRO 230 KV LINE

New Network faci l i ties for In tegrating Group 2011 Cluster Pro jects

24


47.08

32.59

New 22-mile, 786 MVA, 2-1033 MCM ACSR

bundled 230 kV line from Dixieland to El

Centro. Rebuild 9-mile El Centro to L-TAPA-12

161 kV line using double circuit 554 MVA,

1033 ACSR conductor

52.80

NONE N/A N/A N/A

These projects are needed in

order to integrate Group 2011 Cluster Projecs in Dixieland area.

None

None

DIXIELAND 230/92 KV TRANSFORMER

COACHELA – DEVERS 230 KV &

COACHELA – RAMON 230 KV LINES 30



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TABLE IV: Recommended Mitigation Plan & Associated Cost for Group 2012 Cluster Projects



Cost

Estim ate ($

M i l l ion)

Construction

Tim e L ines

(M onths) Notes


resources (Shunt capacitors)3.41 24 None

One Breaker replacement at

Coachella Valley 92 kV substation 0.13 N/A

Installation cost for

replacing the breaker

New 8.5-mile 230 kV line from Midway

– Hudson RanchIID Budget 24

Upgrade Midway 230 kV Substation 10.41 30

New 24-mile 230 kV line from Hudson

Ranch to Bannister44.70 30

Rebuild "L" line between Bannister

and A121P tap and BTAP-DTP 15.5

miles with 2 circuits of 2-1033 ACSR

35.65 36

Install 225 MVA, 230/161 kV

transformer and build Bannister

substation

21.37 30

AVE48 – AVE58 92 KV LINE AVE58 – JEFERSN 92 KV LINE 132 MVA 121%Reconductor line using 191 MVA, 900

MCM ACSS 92 kV Conductor5.85 18 None

RTAP2 – RTP3ANZA 92 KV LINE RTP3ANZA– RTP5DSTS 92 KV LINE 91 MVA 126%Rebuild line using 191 MVA, 900 MCM

ACSS 92 kV Conductor6.21 30 None

NILAND – COACHELA 161 KV LINE 165 MVA 119%

RTP3ANZA – RTP4SLTN 92 KV LINE 132 MVA 122%

RTP4SLTN – RTP5DSTS 92 KV LINE 132 MVA 116%

RTP5DSTS – RTP6OASS 92 KV LINE 132 MVA 111%

COACHELA – MIDWAY 230 KV &

COACHELA– A-8 230 KV LINES

Implement a Remedial Action Scheme

to trip generation at MidwayN/A

NORMAL OPERATIONS (N-0)

12Already included in 2011

Budget

165 MVA 103%

None N/A N/A N/A

None


A-13 (POI) – AVENUE 58 161 KV LINE



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TABLE V: Recommended Mitigation Plan & Associated Cost for Group 2014 Cluster Projects

Overloaded Facilities Critical OutageApplicable

RatingsLoadings Recommended Mitigation

Cost Estimate

($ Million)

Construction Time

Lines (Months)Notes

Implement Breaker-and-one half

configuration at Coachella Valley

substation

13.49 18




Install a second 225 MVA transformer at

Ramon8.35 24





24

None

Network Upgrades Attributable to Group 2014 Cluster Projects


COACHELA– RAMON KV LINES Rebuild lines using 191 MVA, 900

ACSS Conductor

5.39

6.65

NONE N/A N/A N/A



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TABLE OF CONTENTS

EXECUTIVE SUMMARY ............................................................................................... i STUDY OVERVIEW ..................................................................................................... 1 STUDY METHODOLOGY AND EVALUATED CRITERIA ............................................. 2

Power Flow Analysis ................................................................................................................................................. 3 Transient Stability Analysis..................................................................................................................................... 3 Post-Transient Stability Analysis .......................................................................................................................... 6 Short Circuit Analysis ................................................................................................................................................ 7

GROUP 2010 CLUSTER STUDY ................................................................................. 8 A.1 INTRODUCTION .................................................................................................... 9 A.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS ................................... 9

A.2.1 Base Case Assumptions ............................................................................................................................. 9 A.2.2 Base Cases Studied ................................................................................................................................... 10 A.2.3 Load and Resources ................................................................................................................................... 10 A.2.4 Dynamic Models ........................................................................................................................................... 11 A.2.5 Short Circuit Data ......................................................................................................................................... 11

A.3 STUDY RESULTS ................................................................................................ 12 A.3.1 Power Flow Analysis Findings ................................................................................................................ 12

A.3.1.1 Heavy Summer Pre-Cluster Base Case .................................................................................. 12 A.3.1.2 Heavy Summer Post-Cluster Base Case ................................................................................ 12 A.3.1.3 Light Winter Pre-Cluster Base Case .......................................................................................... 15 A.3.1.4 Light Winter Post-Cluster Base Case........................................................................................ 15

A.3.2 Transient Stability Analysis Findings ................................................................................................... 17 A.3.3 Post-Transient Stability Analysis Findings ......................................................................................... 18 A.3.4 Short Circuit Analysis Findings ............................................................................................................... 18

A.4 MITIGATION PLANS ............................................................................................ 19 A.4.1 Mitigation Plans for Existing Overloads .............................................................................................. 19 A.4.2 Mitigation Plans for Overloads Caused by Group 2010 Cluster Projects .............................. 21

A.5 COST AND CONSTRUCTION TIMELINES .......................................................... 21 GROUP 2011 CLUSTER STUDY ............................................................................... 37 B.1 INTRODUCTION .................................................................................................. 38 B.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS ................................. 38

B.2.1 Base Case Assumptions ........................................................................................................................... 38 B.2.2 Base Cases Studied ................................................................................................................................... 39 B.2.3 Load and Resources ................................................................................................................................... 40 B.2.4 Dynamic Models ........................................................................................................................................... 40 B.2.5 Short Circuit Data ......................................................................................................................................... 41

B.3 STUDY RESULTS ................................................................................................ 42 B.3.1 Power Flow Analysis Findings ................................................................................................................ 42

B.3.1.1 Heavy Summer Pre-Cluster Base Case .................................................................................. 42 B.3.1.2 Heavy Summer Post-Cluster Base Case ................................................................................ 42 B.3.1.3 Light Winter Pre-Cluster Base Case .......................................................................................... 45 B.3.1.4 Light Winter Post-Cluster Base Case........................................................................................ 46

B.3.2 Transient Stability Analysis Findings ................................................................................................... 48 B.3.3 Post-Transient Stability Analysis Findings ......................................................................................... 49 B.3.4 Short Circuit Analysis Findings ............................................................................................................... 49



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B.4 MITIGATION PLANS ............................................................................................ 50 B.4.1 Mitigation Plans for Overloads Caused by Group 2011 Cluster Study ................................... 50

B.5 COST AND CONSTRUCTION TIMELINES .......................................................... 51 GROUP 2012 CLUSTER STUDY ............................................................................... 78 C.1 INTRODUCTION .................................................................................................. 79 C.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS ................................. 79

C.2.1 Base Case Assumptions ........................................................................................................................... 79 C.2.2 Base Cases Studied ................................................................................................................................... 80 C.2.3 Load and Resources ................................................................................................................................... 81 C.2.4 Dynamic Models ........................................................................................................................................... 81 C.2.5 Short Circuit Data ......................................................................................................................................... 82

C.3 STUDY RESULTS ................................................................................................ 83 C.3.1 Power Flow Analysis Findings ................................................................................................................ 83

C.3.1.1 Heavy Summer Pre-Cluster Base Case .............................................................................. 83 C.3.1.2 Heavy Summer Post-Cluster Base Case ............................................................................ 83 C.3.1.3 Light Winter Pre-Cluster Base Case ..................................................................................... 85 C.3.1.4 Light Winter Post-Cluster Base Case ................................................................................... 86

C.3.2 Transient Stability Analysis Findings ................................................................................................... 88 C.3.3 Post-Transient Stability Analysis Findings ......................................................................................... 89 C.3.4 Short Circuit Analysis Findings ............................................................................................................... 89

C.4 MITIGATION PLANS ............................................................................................ 90 C.4.1 Mitigation Plans for Overloads Caused by Group 2012 Cluster Study ................................... 90

C.5 COST AND COSTRUCTION TIMELINES ............................................................. 91 GROUP 2014 CLUSTER STUDY ............................................................................. 115 D.1 INTRODUCTION ................................................................................................ 116 D.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS ............................... 116

D.2.1 Base Case Assumptions ......................................................................................................................... 116 D.2.2 Base Cases Studied ................................................................................................................................. 117 D.2.3 Load and Resources ................................................................................................................................. 118 D.2.4 Dynamic Models ......................................................................................................................................... 118 D.2.5 Short Circuit Data ....................................................................................................................................... 118

D.3 STUDY RESULTS .............................................................................................. 119 D.3.1 Power Flow Analysis Findings .............................................................................................................. 119

D.3.1.1 Heavy Summer Pre-Cluster Base Case ............................................................................ 119 D.3.1.2 Heavy Summer Post-Cluster Base Case .......................................................................... 119 D.3.1.3 Light Winter Pre-Cluster Base Case ................................................................................... 121 D.3.1.4 Light Winter Post-Cluster Base Case ................................................................................. 122

D.3.2 Transient Stability Analysis Findings ................................................................................................. 124 D.3.3 Post-Transient Stability Analysis Findings ....................................................................................... 124 D.3.4 Short Circuit Analysis Findings ............................................................................................................. 125

D.4 MITIGATION PLANS .......................................................................................... 126 D.4.1 Mitigation Plans for Overloads Caused by Group 2014 Cluster Study ................................. 126

D.5 COST AND CONSTRUCTION TIMELINES ........................................................ 126



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LIST OF APPENDICES

Group 2010 Cluster Study Appendix A1 – Power Flow Maps Appendix A2 – Summary of Power Flow Analysis Results Appendix A3 – Heavy Summer Post-Transient Stability Analysis Results Group 2011 Cluster Study Appendix B1 – Power Flow Maps Appendix B2 – Summary of Power Flow Analysis Results Appendix B3 – Heavy Summer Post-Transient Stability Analysis Results Group 2012 Cluster Study Appendix C1 – Power Flow Maps Appendix C2 – Summary of Power Flow Analysis Results Appendix C3 – Heavy Summer Post-Transient Stability Analysis Results Group 2014 Cluster Study Appendix D1 – Power Flow Maps Appendix D2 – Summary of Power Flow Analysis Results Appendix D3 – Heavy Summer Post-Transient Stability Analysis Results



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LIST OF ATTACHMENTS Attachment A – Group 2010 Cluster Study Transient Stability Plots Attachment B – Group 2011 Cluster Study Transient Stability Plots Attachment C – Group 2012 Cluster Study Transient Stability Plots Attachment D – Group 2014 Cluster Study Transient Stability Plots



1

STUDY OVERVIEW

Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Transitional Cluster Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These proposed projects plan to deliver power to IID and other neighboring utilities in the 2010-2015 timeframe. The Cluster Study contained the following active interconnection requests:

Project Code Capacity Point of Interconn. In-service Date A-1-1 70 MW Midway 230 kV 07/01/2012 A-1-2 70 MW Midway 230 kV 11/01/2012 A-1-3 70 MW Midway 230 kV 04/01/2013 A-2-4 70 MW Midway 230 kV 04/01/2014 A-2-5 70 MW Midway 230 kV 01/01/2015 A-2-6 70 MW Midway 230 kV 10/01/2015 A-3 36.1 MW ―EO‖ 92 kV line 11/01/2011 A-4 225 MW Midway 230 kV 05/01/2014 A-5 55 MW Niland 161 kV 01/01/2010 A-6 99 MW Plaster City 92 kV 12/31/2011 A-7-1 47 MW ―KS‖ 230 kV 07/01/2012 A-7-2 47 MW ―KS‖ 230 kV 10/01/2013 A-8 80 MW ―N‖ line 4 05/30/2011 A-9 100 MW Dixieland 230 kV 09/01/2011 A-10-1 200 MW Dixieland 230 kV 06/01/2012 A-10-2 200 MW Dixieland 230 kV 07/01/2013 A-11 130 MW ―R‖ line 09/01/2011 A-12 250 MW ―L‖ line 5 09/01/2011 A-13 50 MW ―L‖ line 12/01/2011 A-14-1 25 MW ―L‖ line 6 06/30/2012 A-14-2 50 MW ―L‖ line 12/31/2012 A-14-3 50 MW ―L‖ line 06/30/2013 A-15 119 MW Anza 92 kV 09/01/2012

To determine the impact of the proposed projects on the IID electric system and the neighboring transmission systems, IID contracted with PDS Consulting, PLC (PDS) to perform the Cluster Study. The Cluster Study was conducted using Western Electricity Coordination Council’s (WECC) approved heavy summer and light winter power flow models with detailed IID system representation incorporated. Studies performed included power flow, transient stability, post transient stability and short circuit analyses.

4 Project A-8 was connected to the IID ―KN‖ line in lieu of the requested ―N‖ line interconnected due to

capacity limitation and huge cost of upgrading the ―N‖ line. 5 Due to capacity limitations on the ―L‖ line, A-12 was connected to Dixieland 230 kV via a radial 13-mile

1033 MCM ACSR bundle 230 kV conductor. 6 A-14 was connected to Bannister via a radial 230 kV line



2

PDS performed the transient and post-transient analyses portions of the Cluster Study while IID Transmission Planning conducted the power flow and short circuit analyses. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. For projects with different phases of implementation, the entire project output was considered operational in the year in which the first phase commences operation. Table 1 depicts the projects in each group and the WECC base model used for studying the group. The study description, methodology and findings of each group are provided in this report. For example, Group 2010 Cluster Study of this report details the study findings of projects in Group 2010.

Group Projects WECC Base Model

2010

A-5 (55 MW) 2010 heavy summer and light winter models

2011

A-3 (36.1 MW), A-6 (99 MW), A-8 (80 MW), A-9 (100 MW), A-11 (130 MW), A-12 (250 MW) & A-13 (50 MW)


2012

A-1-1 (70 MW), A-1-2 (70 MW), A-1-3 (70 MW), A-7-1 (47 MW), A-7-2 (47 MW), A-10-1 (200 MW), A-10-2 (200 MW), A-14-1 (25 MW), A-14-2 (50 MW) , A-14-3 (50 MW) & A-15 (119 MW)


2014

A-2-4 (70 MW) A-2-5 (70 MW) & A-2-6 (70 MW) & A-4 (225 MW)


Table 1: Groupings of Projects for Transitional Cluster Study

The output from all the generation projects in each group were dispatched and delivered as indicated in each project’s interconnection application. IID and its neighboring interconnected utilities may not have the Available Transmission Capacity to deliver to any customer or Point of Delivery.

STUDY METHODOLOGY AND EVALUATED CRITERIA In performing the analyses, the proposed projects were grouped according to each project’s in-service year. Two operating conditions (heavy summer and light winter) were studied for each cluster group independent of the season that a project plans to start commercial operation. This enabled IID to determine the impact of the group as a whole and facilitated cost sharing for mitigating the identified impact. The analyses performed in this study included power flow, transient stability, post-transient stability and short circuit. This section provides a summary of the methods and the evaluation criteria used for analyzing the results of the studies.



3

Power Flow Analysis

Power flow analysis was conducted on all the pre- and post-cluster base cases developed for the Cluster Study. Power flow analysis considers a snapshot in time where tap changing transformers, Static Var Devices (SVD) and phase-shifters have had time to adjust. In addition, a swing generator balances generation and load (plus losses) on the system during each contingency scenario. The power flow analysis was conducted with version 16 of General Electric’s PSLF software. Power flow results were monitored and reported for the IID and the neighboring control areas. Thermal and voltage performance of the system was evaluated under normal (N-0), single element outage (N-1) and select double element outage (N-2) conditions. Thermal loadings were reported when a modeled transmission component is loaded to 100% or more of its continuous MVA rating (as provided in the power flow database). Transmission voltage violations for N-0 conditions were reported when per unit voltages were less than 0.95 or greater than 1.05. Transmission voltage violations following N-1 or N-2 outage were reported when per unit voltage was less than 0.90 or greater than 1.05. Additionally, voltage deviations between the pre- and post-contingency conditions were recorded whenever these deviations were greater than 5% for single contingencies and 10% for double contingencies. In summary, the following WECC/NERC reliability criteria were used to assess the adequacy of the power flow study results:

Pre-disturbance bus voltage must be between 0.95 per unit and 1.05 per unit. (an IID-specific requirement)

Allowable voltage deviation of five (5) percent for N-1 Contingencies (deviation from pre-disturbance voltage).

Allowable voltage deviation of ten (10) percent for N-2 contingencies (deviation from pre-disturbance voltage).

Post-transient bus voltage must be at least 0.90 per unit (an IID-specific requirement)

Pre- and post-disturbance loading to remain within the emergency ratings of all equipment and line conductors. The emergency ratings are determined by the owner/operator of each equipment item.

As applied in the analysis, all tables and results for loading criteria were based on the normal or continuous rating (Rating 1) for all lines in service conditions and the emergency rating (Rating 2) for outage conditions. Transient Stability Analysis Transient stability analysis is a time-based simulation that assesses the performance of the power system shortly before, during, and after a contingency. Transient stability studies were performed on both the pre- and post-cluster base cases to verify the stability of the system following a system fault.



4

Transient stability analysis was performed based on WECC Disturbance-Performance Criteria for selected system contingencies using version 16 of General Electric’s PSLF software. Transient stability contingencies were simulated for 10 seconds, excluding one (1) second of pre-disturbance data. All simulated faults, unless specified, were assumed to be three-phase with a 4 cycle breaker clearing time. System damping was assessed visually with the aid of stability plots. Selected critical contingencies were simulated. Provided below are the outages simulated.

Imperial Valley-Miguel 500 kV line outage

Palo Verde-Devers 500 kV line outage

N. Gila-Imperial Valley 500 kV line outage

Imperial Valley-El Centro 230 kV line outage

Ramon–Mirage 230 kV line outage

Coachella –Devers 500 kV line outage

ELSTM2 and REPU2 generator outages

Ramon –Mirage 230 kV and Coachella – Devers 230 kV lines outage

Imperial Valley–El Centro #1 &2 230 kV lines (Group 2014 Cluster Study only)

Imperial Valley–Dixieland #1 &2 230 kV lines (Group 2014 Cluster Study only) The following WECC transient voltage dip and transient frequency criteria were used to evaluate the impact of the project. A summary of the transient stability analysis evaluation criteria is provided in Table 2 and depicted graphically in Figure 1.

WECC transient voltage dip criteria: The transient voltage dip must not exceed 25% at load buses or 30% at non-load buses for N-1 contingency. For N-2 contingency, the transient voltage dip must not exceed 30% at any bus. The maximum duration of the voltage dip of 20% at load buses must not exceed 20 cycles for N-1 contingency or 40 cycles for N-2 contingency.

WECC transient frequency criteria: The minimum transient frequency for N-1 contingency is 59.6 Hz; if below 59.6 Hz, the duration must not exceed 6 cycles at load bus. For N-2 contingencies, the minimum transient frequency is 59.0 Hz; if below 59.0 Hz, the duration should not exceed 6 cycles at load bus.

The following parameters were plotted on the stability plots:

Bus Voltage Bus voltage plots provide a means of detecting out-of-step conditions and are useful to assess the magnitude and duration of post disturbance voltage dips and peak-to-peak voltage oscillations. The voltage plots also indicate system damping response and the expected bus voltage following the disturbance.

Bus Frequency Bus frequency plots provide expected magnitude and duration of post-disturbance frequency swings as well as indicating possible over-frequency or under-frequency conditions.

Six (6) critical buses which provide a representative illustration of the transmission system performance following each of the critical outages studied were monitored. The



5

monitored buses included: COACHELLA 230 kV, RAMON 230 kV, EL CENTRO 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVENUE 42 92 kV.

NERC and WECC Categories

Outage Frequency Associated with the Performance Category (outage/year)

Transient Voltage Dip Standard

Minimum Transient Frequency Standard

Post Transient Voltage Deviation Standard

A System normal

Not Applicable Nothing in addition to NERC

B One element out-of-service

0.33

Not to exceed 25% at load buses or 30% at non-load buses. Not to exceed 20% for more than 20 cycles at load buses.

Not below 59.6Hz for 6 cycles or more at a load bus.

Not to exceed 5% at any bus.

C Two or more elements out-of-service

0.033 – 0.33

Not to exceed 30% at any bus. Not to exceed 20% for more than 40 cycles at load buses.

Not below 59.0Hz for 6 cycles or more at a load bus.

Not to exceed 10% at any bus.

D Extreme multiple-element outages

< 0.033 Nothing in addition to NERC

Table 2: Stability and Post-transient Analysis Evaluation Criteria

Figure 1: Graphical Representation of Stability Analysis Evaluation Criteria



6

Post-Transient Stability Analysis

Post-transient stability analysis was performed on selected buses in the IID transmission system following selected critical outages. Governor power flow tools were used for the analysis. For each bus assessed, a synchronous condenser was modeled to extract reactive power till voltage collapse occurs. The maximum reactive power consumed prior to the voltage collapse is determined. The post-transient stability analysis related assumptions made are:

Loads were modeled as constant MVA during the post-transient time frame

Reactive power output of the system swing generator was limited to its maximum capability.

No manual operator intervention was allowed to increase generator MVAR flow.

Remedial actions such as generator dropping, load shedding or blocking of automatic generator control were not considered for single outages.

The list outages simulated and the buses monitored are provided below.

Imperial Valley-Miguel 500 kV line outage

Palo Verde-Devers 500 kV line outage

N. Gila-Imperial Valley 500 kV line outage

N. Laquinta–Avenue 42 92 kV line outage

Imperial Valley-El Centro 230 kV line outage

Ramon–Mirage 230 kV line outage

Coachella –Devers 230 kV line outage

ELSTM2 and REPU2 generator outages

Imperial Valley–El Centro #1 &2 230 kV lines (Group 2014 Cluster Study only)

Imperial Valley–Dixieland #1 &2 230 kV lines (Group 2014 Cluster Study only) The monitored buses included:

Avenue 58 161 kV

Coachella Valley 161 kV

N. Laquinta 92 kV

Coachella Valley 92 kV

Midway 92 kV

Niland 92 kV

El Centro 92 kV

Calexico 92 kV

Pilot Knob 92 kV

Dixieland 92 kV

For post-transient stability, positive reactive margin must be achieved at all buses. For IID transmission system the post-transient stability analysis evaluated criteria used are:

Minimum reactive power margin at any bus following N-1 outage is 100 MVAR

Minimum reactive power margin at any bus following N-2 outage is 50 MVAR



7

Short Circuit Analysis

Short circuit analysis was performed to determine the impact of the addition of the transitional cluster projects on selected IID substation breaker duties. The analysis was performed by the IID Planning Department using the ASPEN program and the machine data contained in the cluster project’s interconnection application. Fault duties were calculated for both single-phase -to- ground and three-phase faults at the selected substation buses prior to and after the interconnection of each cluster group. The incremental fault duties due to transitional cluster projects were calculated. The fault contributions from the cluster projects were compared to the available margins of the vicinity breakers to determine if a breaker’s interrupting capabilities is exceeded following the addition of the cluster projects.



8

GROUP 2010 CLUSTER STUDY



A.1 INTRODUCTION

Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Cluster System Impact Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned interconnection points in the IID service area were included in the Cluster Study. These projects plan to deliver power to IID and several IID neighboring utilities in the 2010-2015 timeframe. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. Projects with different phases of implementation were grouped in the year in which the first phase becomes operational. This section of the report details the study assumptions, methodology and results of Group 2010 Cluster Study. The Group 2010 Cluster Study contains one (1) proposed generation project, a 55 MW photovoltaic solar project with planned interconnection at IID’s Niland 161 kV substation. This proposed 55 MW generation project is referred to as ―Project A-5‖ per this analysis. The output of Project A-5 is planned to be delivered to the Mirage/Devers 230 kV with the Los Angeles Department of Water and Power (LADWP) Balancing Authority as the receiving entity. The planned in-service date of Project A-5 is January 2010.

The Group 2010 Cluster Study was conducted using approved WECC 2010 heavy summer and light winter power flow models. Studies performed included power flow, transient stability, post-transient stability and short circuit analyses for peak (heavy summer) and off-peak (light winter) conditions.

A.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS

A.2.1 Base Case Assumptions

The Group 2010 Cluster Study was conducted using the following WECC approved power flow models as the starting base cases:

Heavy summer . . . . 10hs2sa.sav ………...Approved 10/05/2007

Light winter . . . . . . 10lw1a1.sav…………Approved 07/13/2009

Both power flow base cases were selected because they were the most recently developed and available base cases in the WECC library based on planned in-service dates of the Group 2010 Cluster projects. Pre-cluster base cases were developed from the starting base cases by incorporating IID detailed system representation. IID system loads, resources, and topology were adjusted to reflect the conditions expected in 2010 when the Group 2010 Cluster projects plan to commence operations. While it is impossible to study all IID transmission system flows and generation levels during all seasons, these two pre-cluster base cases represent extreme generation and transmission flows that will potentially expose any transmission constraints at the Group 2010 projects interconnection points.



A.2.2 Base Cases Studied

Two pre-cluster base cases were developed for the Group 2010 Cluster Study. The pre-cluster base cases were initially tested to ensure that all transmission facilities in IID control area are within their normal operating limits and this provided a benchmark for post-cluster evaluations. Two (2) post-cluster base cases were developed from the pre-cluster base cases by modeling the Group 2010 Cluster projects. The output of the Group 2010 Cluster projects which consisted of only Project A-5 was scheduled to LADWP Balancing Authority. The four (4) base cases developed and used for studying the impact of the Group 2010 Cluster Projects are summarized in Table A-1.

Season PSLF Case Name Description

2010 Heavy Summer 2010 HS Pre-Cluster Planned IID heavy summer configuration without the Group 2010 Cluster projects

2010 Heavy Summer 2010 HS Post-Cluster Planned IID heavy summer configuration with Group 2010 Cluster projects modeled and dispatched

2010 Light Winter 2010 LW Pre-Cluster Planned IID light winter configuration without the Group 2010 Cluster projects

2010 Light Winter 2010 LW Post-Cluster Planned IID light winter configuration with Group 2010 Cluster projects modeled and dispatched

Table A-1: Study Base Cases-Group 2010 Cluster Study

A.2.3 Load and Resources The IID load (including parasitic loads at the new power plants) and Resources for the four base cases studied are provided in Table A-2. Table A-2 also depicts IID transmission system losses and area interchange flows for both pre- and post- cluster base cases. The area interchange flow for the receiving entity for the Group 2010 projects power output is highlighted in Table A-2.

Load & Resources 2010 HS

Pre-Cluster 2010 HS

Post-Cluster 2010 LW

Pre-Cluster 2010 LW Post-Cluster

Load (MW) 1041 1041 227 227

Load (MVAR) 397 397 59 59

Losses (MW) 49 50 35 36

Losses (MVAR) 224 234 127 145

Interchange (MW) 32 23 542 597

Total IID Shunts (MVAR) 510 520 121 131

IID Generation (MW) 1058 1114 803 860

IID Generation (MVAR) 104 101 67 68

LADWP Interchange (MW) 1817 1872 109 54

Table A-2: Summary of Load and Resources



A.2.4 Dynamic Models

Dynamic data files ―10hs2s1.dyd‖ and ―10lw11.dyd‖ developed for use with WECC power flow models ―10hs2sa.sav― and ―10lw1a1.sav― respectively were used for the transient stability analysis. New ―motorw‖ data for the IID control area were created and added to the dynamic data files. The stability models used for the Group 2010 Cluster Study were user written algorithms provided by the owner of Project A-5 as contained in the interconnection application.

A.2.5 Short Circuit Data

The machine data used for the Group 2010 Cluster Study short circuit analysis was contained in the Project A-5 interconnection application.



A.3 STUDY RESULTS

This section provides the results obtained by applying the stated study assumptions and the general study methodology. It illustrates the findings associated with the power flow, transient stability and post-transient stability analyses for both the pre- and post-cluster base cases.

A.3.1 Power Flow Analysis Findings

This section details the findings of the power flow analysis. WECC/NERC reliability criteria were used to assess the adequacy of the study results.

A.3.1.1 Heavy Summer Pre-Cluster Base Case The pre-cluster base case was used as a benchmark for the analysis. Pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2010 Cluster projects during the heavy summer operating condition can be found at Appendix A1, Figure A1-1. Key findings from the power flow analysis using the Heavy Summer Pre-cluster Base Case included:

N-0 Findings

No transmission facility overload was identified during normal operating conditions

N-1 Findings

Four (4) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Summary of the pre-project overloaded facilities can be found at Appendix A2, Table A2-1.

No bus voltage deviation violation was observed following the selected single element outages.

N-2 Findings

Nine (9) IID transmission facilities were found to be overloaded following selected double element (N-2) outages. Summary of the pre-project overloads can be found at Appendix A2. Table A2-2.

No bus voltage deviation violation was observed following the selected double element outages.

Losses

IID system losses in the heavy summer pre-cluster base case were 49 MW

A.3.1.2 Heavy Summer Post-Cluster Base Case In the Post-cluster analysis, the Group 2010 Cluster projects were dispatched and delivered to LADWP Balancing Authority. Compared to the Pre-cluster base case, the addition of the Group 2010 Cluster projects showed approximately the same voltage and thermal loadings as noted in the Pre-cluster under normal operating conditions. The impact of the Group 2010 Cluster Projects to IID system losses during heavy summer operating condition was about 1 MW. The heavy summer post-cluster power flow map can be found at Appendix A, Figure A2-2.



To ease the comparison between pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table A-3. Table A-3 highlights the magnitude (not direction) of power flows on the selected transmission facilities.

Element (unit of measure) 2010 HS

Pre-Cluster 2010 HS

Post-Cluster

El Centro 161/230 kV Transformer (MW) 31 22


Avenue 58 161/92 kV Transformer Circuit 1 (MW) 107 111

Niland 161/92 kV Transformer Circuit 1 (MW) 13 3

Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 95 87

Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 250 261


Niland-Blythe 161 kV Line (MW) 92 80

Niland-Blythe 161 kV Line (MVAR) 29 26

Imperial Valley-El Centro SW 230 kV (MW) 66 46

Imperial Valley-El Centro SW 230 kV (MVAR) 14 13

Mirage-Ramon 230 kV Line (MW) 120 130

Mirage-Ramon 230 kV Line (MVAR) 40 41

Coachella-Devers 230 kV Line (MW) 16 24

Coachella-Devers 230 kV Line (MVAR) 34 34

Path 42 (MW) 136 154

Path 42 (MVAR) 63 65

Path 46 (MW) 5846 5898

Path 49 (MW) 5285 5296

SCIT (MW) 11739 11799

Table A-3: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the heavy summer post-cluster base case are provided below. A comparison of the impact of Group 2010 Cluster project on the IID and the interconnected transmission systems are also detailed. It must however be noted that for screening purposes IID typically uses identical continuous and emergency ratings for its facilities. Typically 110% of continuous rating is an acceptable emergency rating for 30 minutes. N-0 findings


N-1 findings

Five (5) IID transmission facilities were overloaded following selected single element (N-1) outages. Four (4) out of the 5 transmission facility overloads were existing overloads which persisted following the integration of the Group 2010



cluster projects. However, the integration of the Group 2010 Cluster projects caused the existing N-1 contingency overload on the AVENUE 58 92/161 kV transformer to exacerbate up to 8%. A summary of the transmission facility overloads following single element outages is provided in Appendix A2, Table A2-1. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table A-4.


Overloaded Transmission Facility Applicable

Rating

Worst Outage Element(s) Loadings

Pre- Cluster

Post Cluster

AVENUE 58 – JEFERSON 92 KV LINE 132 MVA N.LAQUIN – AVENUE 42 92 KV LINE 127% 127%

N.LAQUIN – AVENUE 42 92 KV LINE 132 MVA JEFERSON – AVENUE58 92 KV LINE 126% 126%

AVENUE 58 161/92 KV TRANSFORMER

125 MVA CVSUB161 161/92 KV TRANSFORMER

105% 113%

MIDWAY #1 230/92 KV TRANSFORMER

300 MVA MIDWAY #2 230/92 KV TRANSFORMER

150% 150%



150% 150%

Table A-4: Single Element Outage Transmission Facility Overloads

N-2 findings

Nine (9) IID transmission facilities were overloaded following selected double element (N-2) outages. All the overloads were existing overloads that persisted or exacerbated following the integration of the Group 2010 Cluster projects. A summary of the transmission facility overloads following the double element outages is provided in Appendix A2, Table A2-2. Provided in Table A-5 are the identified overloads which exceeded 110% of facility’s continuous rating and warrants mitigation.



Rating


Pre- Cluster

Post Cluster

CVSUB – JACKSON 92 KV LINE 132 MVA

CVSUB – COACHELA #1 &2 92 KV LINES

121% 121%


125 MVA 131% 133%

EDOM – RAMON 92 KV LINE 91 MVA 133% 126%

AVE58– JEFERSON 92 KV LINE 132 MVA AVE42 – N.LAQUIN 92 KV & AVE42- SHIELDS 92 KV LINES

131% 131%

N.LAQUIN – AVENUE 42 92 KV LINE 132 MVA

AVE58 – JEFFERSN 92 KV & AVE58 - AVE48 92 KV LINES

130% 130%

CITAP1 – COACHELA 92 KV LINE 152 MVA 115% 117%

CITAP1- VANBUREN 92 KV LINE 152 MVA 115% 117%

CMTAP2 – VANBUREN 92 KV LINE 132 MVA 112% 114%

CMTAP2 – SHAHILLS 92 KV LINE 123 MVA 112% 114%

Table A-5: Double Element Outage Transmission Facility Overloads



Losses

IID system losses in the heavy summer post-cluster base case were 50 MW

A.3.1.3 Light Winter Pre-Cluster Base Case

The pre-cluster base case was used as a benchmark for the analysis. Key findings from the power flow analysis using the light winter pre-cluster base case are:

N-0 Findings

No transmission facility overload was identified during normal operating conditions. The pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2010 Cluster projects during the light winter operating conditions with all transmission lines in-service can be found at Appendix A, Figure A3.

N-1 Findings

Three (3) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. A summary of the power flow analysis results can be found at Appendix A2, Table A2-3.


N-2 Findings

No transmission facility overload was identified following selected double element (N-2) outages.


Losses

IID system losses in the heavy summer pre-project case were 35 MW

A.3.1.4 Light Winter Post-Cluster Base Case

In the post-cluster analysis, the Group 2010 Cluster projects were dispatched and delivered to LADWP Balancing Authority. Compared to the Pre-cluster base case, the addition of the Group 2010 Cluster projects showed approximately the same voltage and thermal loadings as noted in the Pre-cluster under normal operations. The impact of the Group 2010 Cluster Projects to IID system losses was about 1 MW. The light summer post-cluster power flow map can be found at Appendix A, Figure A1-4.

To ease the comparison between light winter pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table A-6. Table A-6 highlights the magnitude (not direction) of the power flow on the selected transmission facilities.



Element (unit of measure) 2010 LW

Pre-Cluster 2010 LW

Post-Cluster



Avenue 58 161/92 kV Transformer Circuit 1 (MW) 37 42

Niland 161/92 kV Transformer Circuit 1 (MW) 7 18

Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 12 19




Niland-Blythe 161 kV Line (MVAR) 18 16

Imperial Valley-El Centro SW 230 kV (MW) 138 159

Imperial Valley-El Centro SW 230 kV (MVAR) 10 9

Mirage-Ramon 230 kV Line (MW) 298 309

Mirage-Ramon 230 kV Line (MVAR) 1 1

Coachella-Devers 230 kV Line (MW) 193 200

Coachella-Devers 230 kV Line (MVAR) 31 32

Path 42 (MW) 489 507


Path 46 (MW) 5054 5106

Path 49 (MW) 3608 3609

SCIT (MW) 4250 4305

Table A-6: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the light winter post-cluster base case are: N-0 Findings


N-1 Findings

Four (4) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Three (3) out of the 4 transmission facility overloads were existing overloads which persisted or exacerbated following the addition of the Group 2010 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix A2, Table A2-3. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table A-7.





Rating


Pre- Cluster

Post Cluster

RAMON – MIRAGE 230 KV LINE 389 MVA COACHELA – DEVERS 230 KV LINE 118% 123%

COACHELA – DEVERS 230 KV LINE 389 MVA RAMON – MIRAGE 230 KV LINE 107% 112%



149% 149%



149% 149%

Table A-7: Single Element Outage Transmission Facility Overloads

N-2 Findings

No transmission facility overload was identified following selected double element (N-2) outages.


Losses

IID system losses in the heavy summer post-cluster base case were 36 MW

A.3.2 Transient Stability Analysis Findings

Stable and adequately damped transient stability performances were achieved following most of the outages simulated. A visual look at the stability plots (both bus voltage and frequency) for the Path 42 outage (with RAS), Mirage- Ramon 230 kV line outage and the Coachella – Devers 230 kV line outage reveals that the system swings following the three outages are self-sustaining and not adequately damped. However no transient voltage dip violation or transient frequency violation was observed following any of the three outages. The system performance following any of the three outages was not due to the integration of the Group 2010 Cluster projects but rather the large angular difference created between the IID and SCE transmission systems following each of the 3 outages. Key findings from the transient stability analysis using both the heavy summer and light winter pre- and post-cluster base cases are:

No transient voltage dip violations were observed per WECC/NERC transient voltage dip for all the outages simulated.

No transient frequency criteria violations were observed for all the outages simulated.

Transient voltage and frequency plots at selected critical buses following each of the critical outages studied can be found in Attachment B. The critical buses monitored included: COACHELA 230 kV, RAMON 230 kV, ELCENTSW 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVE42 92 kV.



A.3.3 Post-Transient Stability Analysis Findings

Post-transient stability analysis was performed on the heavy summer pre- and post-cluster base cases. The post-transient stability analysis showed that for both cases and for all the outages simulated positive reactive margins were achieved at all the buses monitored. However, for most of the outages simulated using both the pre- and post-cluster base cases, the reactive margins at the N. LAQUIN 92 kV and MIDWAY 92 kV buses were below IID’s acceptable minimum reactive margins. In general, the study showed that the integration of the Group 2010 Cluster Projects resulted in marginal reductions in the reactive power margins at most of the buses monitored. Detailed results of the post-transient stability analysis can be found at Appendix A3.

A.3.4 Short Circuit Analysis Findings

The results of the Group 2010 Cluster Short Circuit Analysis is provided in Table A-8. The maximum incremental fault duty was 2,887 A. The available margins at the vicinity breakers indicate that the interconnection of the Group 2010 Cluster projects will not cause any IID breaker to exceed its interruption capabilities.

Table A-8: Summary of Short Circuit Analysis Results

Bus Name IID Substation Name kV

Breaker

Rating

(A)

Pre- Cluster Max

(3LG, 1LG) Fault

Current (A)

Available

Margins

(A)

Post-Cluster

Max (3LG, 1LG)

Fault Current (A)

Project

Contribution

(A)

AVE-52 AVE. 52 92 40,000 15,044 24,956 16,249 1,205

AVE.42 N.BUS AVE. 42 92 40,000 14,391 25,609 14,942 551

AVE48 AVE. 48 92 40,000 10,701 29,300 11,025 325

AVE58-161KV AVE. 58 161 40,000 5,931 34,069 8,817 2,887

AVE58-92 AVE. 58 92 40,000 12,778 27,222 13,413 635

CARREON CARREON 92 40,000 10,888 29,112 11,175 287

COACHELA COACHELLA SW STA 92 22,000 19,173 2,827 20,386 1,213

CV-161 COACHELLA VALLEY 161 40,000 6,834 33,166 7,054 220


EDOM EDOM 92 40,000 10,952 29,048 11,906 954

FRANCES WAY- FRANCES WAY 92 40,000 9,523 30,477 9,887 364

JACKSON JACKSON 92 31,500 10,140 21,360 10,384 244

JEFFERSON92 JEFFERSON 92 40,000 8,681 31,319 9,687 1,006

LAQUINTA92 LA QUINTA 92 40,000 8,982 31,018 9,679 697

MARSHALL MARSHALL 92 40,000 8,519 31,481 9,301 782

MONROE MONROE 92 40,000 11,900 28,100 12,290 391

N. LA QUINTA NORTH LA QUINTA 92 40,000 9,808 30,192 10,562 754

NEW MECCA NEW MECCA 92 40,000 5,775 34,225 5,883 109

NILAND NILAND 92 40,000 13,682 26,318 13,804 122

NILAND NILAND 161 40,000 7,350 32,650 7,614 264

NORTHVIEW NORTH VIEW 92 40,000 10,752 29,248 11,037 285

RAMON RAMON 92 40,000 13,647 26,353 13,885 238

SHADOW HILLS SHADOW HILLS 92 40,000 12,106 27,894 13,306 1,200

SHIELDS SHIELDS 92 64,000 12,574 51,426 13,081 507

VANBUREN VAN BUREN 92 40,000 12,513 27,487 13,810 1,297

Group 2010 Cluster Projects: Short Circuit Analysis Results



A.4 MITIGATION PLANS

This section details the recommended transmission upgrade projects required to mitigate both existing and new overloads created following the integration of the Group 2010 Cluster Projects. The recommended upgrades have been tested and found to mitigate all the overloads identified. Post-transient stability analysis of the post-cluster base case with the recommended transmission plans incorporated can be found in Appendix A3. Similarly, transient stability analysis was performed on the post-cluster base case with the recommended transmission plans incorporated and the system was found to be stable and adequately damped with no WECC/NERC criteria violations.

A.4.1 Mitigation Plans for Existing Overloads

Table A-9 details the existing transmission facility overloads and the associated recommended mitigation plans.



Worst Outage Overloaded Facility

Applicable

Rating

Pre- Cluster

Loadings Recommended Mitigation Notes

SINGLE ELEMENT OUTAGE (N-1)

N.LAQUIN – AVENUE 42 92 KV LINE

AVENUE 58 – JEFERSON 92 KV LINE

132 MVA 127% Rebuild line using 191 MVA, 900 MCM ACSS Conductor

Existing transmission facility overloads not attributable to Group 2010 Cluster Study.

JEFERSON – AVENUE58 92 KV LINE

N.LAQUIN – AVENUE 42 92 KV LINE

132 MVA 126% Rebuild line using 191 MVA, 900 MCM ACSS Conductor



300 MVA 150% Utilize existing Remedial Action Scheme to trip generation at Midway 92 kV MIDWAY #1 230/92 KV

TRANSFORMER MIDWAY #2 230/92 KV TRANSFORMER

300 MVA 150%

COACHELA – DEVERS 230 KV LINE

RAMON – MIRAGE 230 KV LINE

389 MVA 118% Upgrade 0.1 miles to 2-1033.5 ACSS/TW conductor

DOUBLE ELEMENT OUTAGES (N-2)

CVSUB – COACHELA #1 &2 92 KV LINES

CVSUB – JACKSON 92 KV LINE

132 MVA 121%

Rebuild transmission lines using 191 MVA, 900 MCM ACSS Conductor

Existing transmission facility overloads not attributable to Group 2010 Cluster Study.

EDOM – RAMON 92 KV LINE

91 MVA 133%

AVE58 – JEFFERSN 92 KV & AVE58 – AVE48 92 KV LINES

CITAP1 – COACHELA 92 KV LINE

152 MVA 115%

CITAP1- VANBUREN 92 KV LINE

152 MVA 115%

CMTAP2 – VANBUREN 92 KV LINE

132 MVA 112%

CMTAP2 – SHAHILLS 92 KV LINE

123 MVA 112%

Table A-9: Recommended Mitigation Plans for Existing Transmission Overloads



A.4.2 Mitigation Plans for Overloads Caused by Group 2010 Cluster Projects

Table A-9 depicts overloads attributable solely to the integration of the Group 2010 Cluster Projects and their associated recommended mitigation plans. It should be noted the addition of the Group 2010 Cluster projects also caused existing transmission overloads to exacerbate. A.5 COST AND CONSTRUCTION TIMELINES The estimated cost for the recommended network upgrades for mitigating the impact of the Group 2010 Cluster Projects is $ 67.3 Million. The detail network upgrade cost and the construction timelines for implementing the upgrades are provided in Table A-10.




Applicable

Rating

Post- Cluster



CVSUB161 161/92 KV TRANSFORMER


125 MVA 113% Replace unit with 225 MVA 161/92 kV transformer

Overloads attributable solely to the Group 2010 Cluster project RAMON – MIRAGE 230 KV LINE


389 MVA 112% Upgrade transmission line to 779 MVA, 2-1033 MCM ACSR

Table A-9: Recommended Mitigation Plans Group 2010 Cluster Projects

Table A-10: Recommended Mitigation Plan & Associated Cost for Group 2010 Cluster Projects



Cost

Estim ate ($

M i l l ion)

Construction

Tim e L ines

(M onths) Notes

AVENUE 58 – JEFERSON 92 KV LINEN. LA QUINTA – AVENUE 42 92 KV LINE

"CD"132 MVA 127%



N. LA QUINTA – AVENUE 42 92 KV LINE

"CD"AVENUE 58 – JEFERSON 92 KV LINE 132 MVA 126%





RAMON – MIRAGE 230 KV LINE COACHELLA - DEVERS 230 KV LINE 389 MVA 118%Upgrade 0.1 miles to 2-1033.5

ACSS/TW conductor 0.18 18

CVSUB – JACKSON 92 KV LINE 132 MVA 121% 9.27 24

EDOM – RAMON 92 KV LINE 91 MVA 133% IID Budget 12

CITAP1 – COACHELA 92 KV LINE 152 MVA 115%

CITAP1- VANBUREN 92 KV LINE 152 MVA 115%

CMTAP2 – VANBUREN 92 KV LINE 132 MVA 112%

CMTAP2 – SHAHILLS 92 KV LINE 123 MVA 112%

AVENUE 58 161/92 KV TRANSFORMER COACHELLA 161/92 KV TRANSFORMER 125 MVA 113%Replace unit with 225 MVA 161/92 kV

transformerIID Budget 24

Though overloads are due to Group

2010 Cluster projects, IID has aplanned budget for this upgrade

COACHELLA - DEVERS 230 KV LINE RAMON - MIRAGE 230 KV LINE 389 MVA 112% 23.00

CV - RAMON 230 KV LINE COACHELLA - DEVERS 230 KV LINE 389 MVA 109% 23.00

Install 104.4 MVAR capacitor banks 3.41

0.50

247.92


These transmission lines

share the same tower and

needed to be upgraded at the

Upgrade transmission line to 779 MVA,

2-1033 MCM ACSR30

Existing Transm ission System Upgrades

These network upgrades are not

due to the addition of the cluster

projects. However, the upgrades

are needed prior to the

integration of the proposed

projects. IID have some of the

upgrades already planned and

budgeted.

Implement Remedial Action Scheme

to trip generation at Midway 92 kV

Rebuild transmission lines using 191

MVA, 900 MCM ACSS Conductor

CVSUB - COACHELLA #1 &2 92 KV LINES

AVENUE 58 – JEFERSON 92 KV &

AVENUE 58 - AVENUE 48 92 KV LINES



Appendix A1

Power flow Maps: Group 2010 Cluster Study



Figure A1-1: Power flow Map—2010 Heavy Summer Pre-Cluster Base Case



Figure A1-2: Power flow Map—2010 Heavy Summer Post-Cluster Base Case



Figure A1-3: Power flow Map—2010 Light Winter Pre-Cluster Base Case



Figure A 1-4: Power flow Map—2010 Light Winter Post-Cluster Base Case



Appendix A2

Summary of Power Flow Analysis Results: Group 2010 Cluster Study



Table A2-1: Summary of 2010 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads

From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-Cluster Outage description

8279 CVSUB 92 8312 COACHELA 92 1 Line 8 155 B92_L002 105% 103% Line CVSUB 92.0 to COACHELA 92.0 Circuit 2

8279 CVSUB 92 8312 COACHELA 92 2 Line 8 155 B92_L001 105% 103% Line CVSUB 92.0 to COACHELA 92.0 Circuit 1

8279 CVSUB 92 8312 COACHELA 92 2 Line 8 155 B92_L024A 105% 103% Line CVSUB 92.0 to AVE 52 92.0 Circuit 1

8281 AVE58 92 8285 JEFERSN 92 1 Line 8 132 B92_L014 127% 127% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1

8285 JEFERSN 92 8354 MARSHALL 92 1 Line 8 132 B92_L014 102% 102% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1

8292 N.LAQUIN 92 8309 AVE42 92 1 Line 8 132 B92_L007 126% 126% Line AVE58 92.0 to JEFERSN 92.0 Circuit 1

8311 COACHELA 230 8695 RAMON 230 1 Line 8 389 line_221 110% 110% line DEVERS to MIRAGE 230 ck 1

8281 AVE58 92 8805 AV58 161 1 Tran 8 125 B230_T003 101% 104% Tran RAMON92 92.00 .0to RAMON230 230.00 Circuit 1

8281 AVE58 92 8805 AV58 161 1 Tran 8 125 B161_T001 105% 113% Tran CVSUB 92.00 to CVSUB161 161.00 Circuit 1

8281 AVE58 92 8805 AV58 161 1 Tran 8 125 B92_L008 100% 104% Line AVE58 92.0 to COACHELA 92.0 Circuit 1

8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 150% 150% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2


Summary of 2010 Heavy Summer Power Flow Analaysis Results--Thermal Overloads



Table A2-2: Summary of 2010 Heavy Summer Power Flow Analysis Results— N-2 Thermal Overloads


8279 CVSUB 92 8349 JACKSON 92 1 Line 8 132 C92_L012 121% 121% Loss of CVSUB - COACHELLA(CL) 92kV CK1 & CVSUB - COACHELLA 92kV LINES

8281 AVE58 92 8285 JEFERSN 92 1 Line 8 132 C92_L014 131% 131% Loss of AVE42 - N.LAQ(CD) 92kV & AVE42 - SHIELDS(CS) 92kV LINES

8285 JEFERSN 92 8354 MARSHALL 92 1 Line 8 132 C92_L014 105% 105% Loss of AVE42 - N.LAQ(CD) 92kV & AVE42 - SHIELDS(CS) 92kV LINES

8292 N.LAQUIN 92 8309 AVE42 92 1 Line 8 132 C92_L013 130% 130% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 - AVE48(CS) 92kV LINES

8301 CITAP1 92 8312 COACHELA 92 1 Line 8 152 C92_L013 115% 117% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 - AVE48(CS) 92 kV LINES

8301 CITAP1 92 8389 VANBUREN 92 1 Line 8 152 C92_L013 115% 117% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 - AVE48(CS) 92kV LINES

8302 CARREON 92 8308 CITP4 92 1 Line 8 132 C92_L012 103% 102% Loss of CVSUB - COACHELLA(CL) 92kV CK1 & CVSUB - COACHELLA 92kV LINES

8304 CITP2 92 8308 CITP4 92 1 Line 8 132 C92_L012 103% 102% Loss of CVSUB - COACHELLA(CL) 92kV CK1 & CVSUB - COACHELLA 92kV LINES

8304 CITP2 92 8349 JACKSON 92 1 Line 8 132 C92_L012 103% 102% Loss of CVSUB - COACHELLA(CL) 92kV CK1 & CVSUB - COACHELLA 92kV LINES

8307 CMTAP2 92 8389 VANBUREN 92 1 Line 8 132 C92_L013 112% 114% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 - AVE48(CS) 92kV LINES

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_T001 102% 101% Tran CVSUB 92.00 - COACHELA 230.00 CK1 & CK2

8330 EDOM 92 8640 RAMON92 92 1 Line 8 91 C230_T001 133% 126% Tran CVSUB 92.00 - COACHELA 230.00 CK1 & CK2

8309 AVE42 92 8406 SHAHILLS 92 1 Line 8 132 C92_L013 101% 103% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 to AVE48(CS) 92 kV LINES

8406 SHAHILLS 92 8307 CMTAP2 92 1 Line 8 132 C92_L013 112% 114% Loss of AVE58 - JEFFERSON(CD)92kV & AVE58 - AVE48(CS) 92kV LINES

8281 AVE58 92 8805 AV58 161 1 Tran 8 125 C92_L010 103% 106% Loss of AVE58 - RTP5DSTS(R)92kV & Ave 58 - COACHELLA 92 kV LINES

8281 AVE58 92 8805 AV58 161 1 Tran 8 125 C92_L012 131% 133% Loss of CVSUB - COACHELLA(CL)92kV CK1 & CVSUB - COACHELLA 92kV LINES

8281 AVE58 92 8805 AV58 161 1 Tran 8 125 C92_L014 107% 109% Loss of AVE42 - N.LAQ(CD)92kV & AVE42 - SHIELDS(CS)92kV LINES

8281 AVE58 92 8805 AV58 161 1 Tran 8 125 C92_L020 98% 102% Loss of AVE42 - MONROE(CW)92kV & AVE42 - SHAHILLS(CI)92kV LINES

Summary of 2010 Heavy Summer Power Flow Analysis Results--N-2 Thermal Overloads



Table A2-3: Summary of 2010 Light Winter Power Flow Analysis Results— N-1 Thermal Overloads


8311 COACHELA230 8695 RAMON 230 1 Line 8 389 B230_L001 106% 109% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1

8311 COACHELA230 24804 DEVERS 230 1 Line 8 389 B230_L003 107% 112% Line RAMON230 230.0 to MIRAGE 230.0 Circuit 1

8695 RAMON 230 24806 MIRAGE 230 1 Line 8 389 B230_L001 118% 123% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1



Summary of 2010 Light Winter Power Flow Analysis Results--Thermal Overloads



Appendix A3

Heavy Summer Post-Transient Stability Analysis Results: Group 2010 Cluster Study



Table A3-1: Summary of 2010 Heavy Summer Post-Transient Stability Analysis Results

Outage

Monitored Bus Reactive Power Margin (MVar)

Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/ mitigation

N.LAQUIN-AVE42 92 kV LINE

8805 AV58 161 kV 182 180 140

8808 CVSUB161 161 kV 174 172 198

8292 N.LAQUIN 92 kV 59 59 57

8312 COACHELA 92 kV 212 209 219

8700 MIDWAY 92 kV 100 100 96

8361 NILAND 92 kV 251 252 250

8335 ELSTEAMP 92 kV 442 441 437

8397 CLX92 92 kV 261 262 259

8369 PILOTKNB 92 kV 177 177 176

8319 DIXIELAN 92 kV 215 215 213

ELSTM 2 & REPU 2 GENERATOR OUTAGE

8805 AV58 161 kV 212 211 207

8808 CVSUB161 161 kV 231 229 222

8292 N.LAQUIN 92 kV 159 159 159

8312 COACHELA 92 kV 241 241 241

8700 MIDWAY 92 kV 103 103 99

8361 NILAND 92 kV 248 249 246

8335 ELSTEAMP 92 kV 414 414 409

8397 CLX92 92 kV 242 243 240

8369 PILOTKNB 92 kV 177 176 175

8319 DIXIELAN 92 kV 204 204 202



Table A3-2: Summary of 2010 Heavy Summer Post-Transient Stability Analysis Results (Continued)

Outage


Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation

PALO VERDE - DEVERS kV LINE

8805 AV58 161 kV 198 196 192

8808 CVSUB161 161 kV 216 213 205

8292 N.LAQUIN 92 kV 148 147 147

8312 COACHELA 92 kV 215 213 228

8700 MIDWAY 92 kV 96 96 92

8361 NILAND 92 kV 250 251 248

8335 ELSTEAMP 92 kV 445 456 452

8397 CLX92 92 kV 261 261 258

8369 PILOTKNB 92 kV 177 177 176

8319 DIXIELAN 92 kV 216 216 214

N.GILA-IMPERIAL VALLEY 500 kV LINE

8805 AV58 161 kV 206 206 201

8808 CVSUB161 161 kV 223 223 215

8292 N.LAQUIN 92 kV 150 151 151

8312 COACHELA 92 kV 223 224 224

8700 MIDWAY 92 kV 92 93 89

8361 NILAND 92 kV 251 252 248

8335 ELSTEAMP 92 kV 434 432 438

8397 CLX92 92 kV 253 253 250

8369 PILOTKNB 92 kV 177 177 176

8319 DIXIELAN 92 kV 213 212 210




Outage



IMPERIAL VALLEY - MIGUEL kV LINE

8805 AV58 161 kV 204 202 198

8808 CVSUB161 161 kV 223 220 212

8292 N.LAQUIN 92 kV 153 152 152

8312 COACHELA 92 kV 232 232 232

8700 MIDWAY 92 kV 100 100 95

8361 NILAND 92 kV 254 254 252

8335 ELSTEAMP 92 kV 450 460 457

8397 CLX92 92 kV 263 264 261

8369 PILOTKNB 92 kV 178 178 177

8319 DIXIELAN 92 kV 218 218 215

IMPERIAL VALLEY – ELCENTRO 230 kV LINE

8805 AV58 161 kV 212 210 206

8808 CVSUB161 161 kV 231 229 221

8292 N.LAQUIN 92 kV 158 158 158

8312 COACHELA 92 kV 242 231 242

8700 MIDWAY 92 kV 103 103 99

8361 NILAND 92 kV 257 258 256

8335 ELSTEAMP 92 kV 458 467 452

8397 CLX92 92 kV 266 267 264

8369 PILOTKNB 92 kV 178 178 177

8319 DIXIELAN 92 kV 220 220 218




Outage



RAMON – MIRAGE 230 kV LINE

8805 AV58 161 kV 138 139 124

8808 CVSUB161 161 kV 142 143 128

8292 N.LAQUIN 92 kV 104 105 97

8312 COACHELA 92 kV 122 123 113

8700 MIDWAY 92 kV 70 70 62

8361 NILAND 92 kV 245 246 240

8335 ELSTEAMP 92 kV 430 430 410

8397 CLX92 92 kV 265 265 260

8369 PILOTKNB 92 kV 178 178 176

8319 DIXIELAN 92 kV 218 218 214

COACHELA – DEVERS 230 kV LINE

8805 AV58 161 kV 155 154 142

8808 CVSUB161 161 kV 158 156 144

8292 N.LAQUIN 92 kV 123 123 116

8312 COACHELA 92 kV 138 137 128

8700 MIDWAY 92 kV 64 64 58

8361 NILAND 92 kV 247 247 243

8335 ELSTEAMP 92 kV 437 436 428

8397 CLX92 92 kV 262 263 259

8369 PILOTKNB 92 kV 178 177 176

8319 DIXIELAN 92 kV 217 217 214






B.1 INTRODUCTION

Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Cluster System Impact Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These projects plan to deliver power to IID and several IID neighboring utilities in the 2010-2015 timeframe. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. Projects with different phases of implementation were grouped in the year in which the first phase becomes operational. This section of the report details the study assumptions, methodology and results of Group 2011 Cluster Study. The Group 2011 Cluster Study contains seven proposed generation projects totaling 745.1 MW. Provided below are the projects and their interconnection information.

Project Code Capacity POI In-service Date A-3 36.1 MW “EO” 92 kV line 11/01/2011 A-6 99 MW Plaster City 92 kV 12/31/2011 A-8 80 MW “N” line 05/30/2011 A-9 100 MW Dixieland 230 kV 09/01/2011 A-11 130 MW “R” line 09/01/2011 A-12 250 MW “L” line 7 09/01/2011 A-13 50 MW “L” line 12/01/2011

The Group 2011 Cluster Study was conducted using approved WECC 2011 heavy summer and light winter power flow models. Studies performed included power flow, transient stability, post-transient stability and short circuit analyses for peak (heavy summer) and off-peak (light winter) conditions. B.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS

B.2.1 Base Case Assumptions The Group 2011 Cluster Study was performed using the following WECC approved power flow models as the starting base cases:

Heavy summer . . . . 11hs1b.sav ………...Approved 01/12/2007

Light winter . . . . . . 10lw1a1.sav…………Approved 07/13/2009

Both power flow base cases were selected because they were the most recently developed and available base cases in the WECC library based on planned in-service dates of the Group 2011 Cluster Projects. Pre-cluster base cases were developed from the starting base cases by incorporating IID detailed system representation. IID system loads, resources, and topology were adjusted to reflect the conditions expected in 2011

7 Due to capacity limitations on the ―L‖ line, A-12 was connected to Dixieland 230 kV via a radial 13-mile

1033 MCM ACSR bundle 230 kV conductor



when the Group 2011 Cluster projects plan to initiate operations. Group 2010 Cluster projects and other queued generation projects with planned interconnection to IID transmission system prior to summer 2011 were modeled in the pre-cluster base cases. The following 12 transmission projects which were recommended for upgrade as part of the Group 2010 Cluster Study were incorporated into the 2011 pre-cluster base cases:

AVENUE 58 – JEFERSON 92 kV line (191 MVA, 900 MCM ACSS)

N. LAQUIN – AVENUE 42 kV line (191 MVA, 900 MCM ACSS)

RAMON – MIRAGE 230 kV line (779 MVA, 2-1033 MCM ACSR)

CVSUB – JACKSON 92 kV line (191 MVA, 900 MCM ACSS)

EDOM – MIRAGE 92 kV line (191 MVA, 900 MCM ACSS)

CITAP1 – COACHELLA 92 kV line (191 MVA, 900 MCM ACSS)

CITAP1 – VANBUREN 92 kV line (191 MVA, 900 MCM ACSS)

CMTAP2 – VANBUREN 92 kV line (191 MVA, 900 MCM ACSS)

CMTAP2 – SHAHILLS 92 kV line (191 MVA, 900 MCM ACSS)

COACHELLA – DEVERS 230 kV line (779 MVA, 2-1033 MCM ACSR)

COACHELLA – RAMON 230 kV line (779 MVA, 2-1033 MCM ACSR)

AVENUE 58 161/92 kV transformer (250 MVA) While it is impossible to study all IID transmission system flows and generation levels during all seasons, these two pre-cluster base cases represent extreme generation and transmission flows that will potentially expose any transmission constraints at the Group 2011 projects interconnection points.

B.2.2 Base Cases Studied

Two (2) pre-cluster base cases were developed for the Group 2011 Cluster Study. The pre-cluster base cases were initially tested to ensure that all transmission facilities in IID control area are within their normal operating limits and this provided a benchmark for post-cluster evaluations. Two post-cluster base cases were developed from the pre-cluster base cases by modeling the Group 2011 Cluster projects. Due to the capacity of the IID ―N‖ line, Project A-8 was connected to the IID ―KN‖ line in lieu of the requested interconnection point of ―N‖ line. In order to integrate the Group 2011 cluster projects in the Dixieland area to the IID transmission system, the following transmission facilities were modeled in the post-project base case:

DIXIELAND 230/92 KV transformer (332 MVA)

DIXIELAND – IMPERIAL VALLEY 230 kV line (786 MVA, 1033 MCM ACSR). The output of the Group 2011 Cluster projects were dispatched and scheduled according to the information provided on each projects interconnection application. The four base cases developed and used for studying the impact of the Group 2010 Cluster Projects are summarized in Table B-1.






2011 Light Winter 2011 LW Pre-Cluster Planned IID light winter configuration without the Group 2011Cluster projects


Table B-1: Study Base Cases-Group 2011 Cluster Study

B.2.3 Load and Resources The IID load and Resources for the four base cases studied are provided in Table B-2. Table B-2 also depicts IID transmission system losses and area interchange flows for both pre- and post- cluster base cases. The area interchange flows for the receiving entities for the Group 2011 projects power outputs are highlighted in Table B-2.


Pre-Cluster 2011 HS

Post-Cluster 2011 LW


Load (MW) 1065 1079 253 267

Load (MVAR) 410 419 73 81

Losses (MW) 57 77 41 62

Losses (MVAR) 299 562 218 531

Interchange (MW) 318 1041 803 1543




SCE Interchange (MW) 7644 7980 320 656

SDG&E Interchange (MW) 2430 2759 1348 1676

Table B-2: Summary of Load and Resources

B.2.4 Dynamic Models

Dynamic data files ―11hs11.dyd‖ and ―10lw11.dyd‖ developed for use with WECC power flow models ―11hs1b.sav― and ―10lw1a1.sav― respectively were used for the transient stability analysis. New ―motorw‖ data for the IID control area were created and added to the dynamic data files. The stability models used for the Group 2011 Cluster Study were user written algorithms and other dynamic data contained in each project’s interconnection application.



B.2.5 Short Circuit Data

The machine data used for the Group 2011 Cluster Study short circuit analysis were contained in each project’s interconnection application.



B.3 STUDY RESULTS

This section provides the results obtained by applying the stated study assumptions and the general study methodology. It illustrates the findings associated with the power flow, transient stability and post-transient stability analyses for both Group 2011 Cluster Study pre- and post-cluster base cases.

B.3.1 Power Flow Analysis Findings

This section details the findings of the power flow analysis. WECC/NERC reliability criteria were used to assess the adequacy of the study results.

B.3.1.1 Heavy Summer Pre-Cluster Base Case

The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. Pre-cluster power flow map that depicts the power flow distribution at the points of interconnections of the Group 2011 Cluster projects during the heavy summer operating condition can be found at Appendix B1, Figure B1-1. Key findings from the power flow analysis using the Heavy Summer Pre-cluster Base Case include:

N-0 Findings


N-1 Findings

Two (3) IID transmission facilities were found overloaded following selected single element (N-1) outages. Summary of the pre-project overloaded facilities can be found at Appendix B2, Tables B2-1 and B2-2.

One (1) bus voltage deviation violation was observed following the selected single element outages. A summary of the bus voltage deviation violations using the 2011 heavy summer base cases can be found at Appendix B2, Table B2-3.

N-2 Findings

One (1) IID transmission facility was overloaded following selected double element (N-2) outages. Summary of the pre-project overloads can be found at Appendix B2. Tables B2-4.


Losses


B.3.1.2 Heavy Summer Post-Cluster Base Case

In the Post-cluster analysis, the 745 MW net Group 2011 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2011 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group



2011 Cluster Projects to IID system losses was about 20 MW. The heavy summer post-cluster power flow map can be found at Appendix B1, Figure B1-2.

To ease the comparison between pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table B-3. Table B-3 highlights the magnitude (not direction) of flow.


Pre-Cluster 2011 HS

Post-Cluster



Avenue 58 161/92 kV Transformer Circuit 1 (MW) 126 172 Niland 161/92 kV Transformer Circuit 1 (MW) 53 57

Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 60 103 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 376 620 Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 189 311


Niland-Blythe 161 kV Line (MVAR) 25 9 Imperial Valley-El Centro SW 230 kV (MW) 98 254

Imperial Valley-El Centro SW 230 kV (MVAR) 18 1 Imperial Valley – Dixieland 230 kV (MW) N/A 285 Imperial Valley – Dixieland 230 kV (MVAR) N/A 58 Mirage-Ramon 230 kV Line (MW) 184 283 Mirage-Ramon 230 kV Line (MVAR) 27 44 Coachella-Devers 230 kV Line (MW) 123 215 Coachella-Devers 230 kV Line (MVAR) 25 30

Path 42 (MW) 306 496 Path 42 (MVAR) 49 78

Path 46 (MW) 6832 7178

Path 49 (MW) 6082 6011

SCIT (MW) 14754 15150

Table B-3: Comparison Flows on Critical Lines/Paths

Key findings from the power flow analysis using the heavy summer post-cluster base case are provided below. A comparison of the impact of Group 2011 Cluster projects on the IID and the interconnected transmission systems are also detailed. It must however be noted that IID, for screening purposes, typically uses identical continuous and emergency ratings for its facilities. Typically 110% of continuous rating is an acceptable emergency rating for 30 minutes.

N-0 Findings

No transmission facility overload was identified during normal operating conditions.



N-1 Findings

Nine (9) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Three (3) out of the 9 transmission facility overloads were existing overloads which persisted or exacerbated following the integration of the Group 2011 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix B2, Table B2-1. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table B-4.

Two (2) bus voltage deviation violations were observed following the selected single element outages.


Rating


Pre- Cluster

Post Cluster

DIXPRI1 – DIXPRI 92 KV LINE 132 MVA IMPERIAL VALLEY – ELCENTSW 230 KV LINE

20% 131%

DIXPRI2 – DIXIELAN 92 KV LINE 132 MVA 17% 128%

DIXPRI2 – DIXPRI 92 KV LINE 132 MVA 17% 128%

DIXIELAN – RTP1 92 KV LINE 51 MVA DIXIE230-DIXIELAN 230/92 KV TRANSFORMER

79% 145%

RTAP2 – RTP1 92 KV LINE 57 MVA DIXIE230 - IMPERIAL VALLEY 230 KV LINE

70% 149%

IMPERIAL VALLEY – ELCENTSW 230 KV LINE

370 MVA N. GILA – IMPERIAL VALLEY 500 KV LINE

110% 127%


125 MVA AVENUE 58 161/92 KV TRANSFORMER

118% 178%



149% 149%



149% 149%

Table B-4: Single Element Outage Transmission Facility Overloads

N-2 Findings

Ten (10) IID transmission facilities were found to be overloaded following selected double element (N-2) outages. One (1) out of the10 overloads were existing overloads that persisted or exacerbated following the integration of the Group 2011 Cluster projects. A summary of the transmission facility overloads following the double element outages is provided in Appendix B2, Table B2-5. Provided in Table B-5 are the identified overloads which exceeded 110% of facility’s continuous rating and warrants mitigation.





Rating


Pre- Cluster

Post Cluster

NILAND - CVSUB161 161 KV LINE 165 MVA

ELCENTSW –IMPERIAL VALLEY 230 kV & ELCENTSW – AVE58 KV 161 KV LINES

101% 133%


DIXPRI2 – DIXIELAN 92 KV LINE 132 MVA 21% 145%


DIXIE230-DIXIELAN 230/92 KV TRANSFORMER

300 MVA N/A 119%

DIXIELAN – RTP1 92 KV LINE 51 MVA 118% 130%


125 MVA ELCENTSW – AVE58 161 KV & CVSUB – AVE58 161 KV LINES

99% 128%


RTAP2 – RTP1 92 KV LINE 57 MVA 92% 123%

CVSUB – COACHELA #1 92 KV LINE 150 MVA RAMON – MIRAGE 230 KV & COACHELA – DEVERS 230 KV LINES (W/RAS)

85% 114%

CVSUB – COACHELA #2 92 KV LINE 150 MVA 85% 114%

Table B-5: Double Element Outage Transmission Facility Overloads

Losses

IID transmission system losses in the heavy summer post-cluster base case were 77 MW

B.3.1.3 Light Winter Pre-Cluster Base Case

The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. Key findings from the power flow analysis using the light winter pre-cluster base case are:

N-0 Findings

No transmission facility overload was identified during normal operating conditions. The pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2011 Cluster projects during the light winter operating conditions with all transmission lines in-service can be found at Appendix B1, Figure B1-4.

N-1 Findings

Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. Summary of the power flow analysis results can be found at Appendix B2, Table B2-6.


N-2 Findings

Two (2) transmission facility overloads were identified following selected double element (N-2) outages. Summary of the power flow analysis results can be found at Appendix B2, Table B2-8.

No bus voltage deviation violation was identified following the selected double element outages.

Losses

IID system losses in the light winter pre-project case were 41 MW



B.3.1.4 Light Winter Post-Cluster Base Case In the Post-Cluster analysis, the 745 MW net Group 2011 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2011 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group 2011 Cluster Projects to IID system losses was about 21 MW. The light winter post-cluster power flow map can be found at Appendix B1, Figure B1-5.

To ease the comparison between light winter pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table B-6. Table B-6 highlights the magnitude (not direction) of flow.


Pre-Cluster 2011 LW

Post-Cluster



Avenue 58 161/92 kV Transformer Circuit 1 (MW) 48 87 Niland 161/92 kV Transformer Circuit 1 (MW) 16 17 Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 45 95 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 139 349 Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 70 179


Niland-Blythe 161 kV Line (MVAR) 17 8 Imperial Valley-El Centro SW 230 kV (MW) 212 338 Imperial Valley-El Centro SW 230 kV (MVAR) 19 1 Imperial Valley – Dixieland 230 kV (MW) N/A 347 Imperial Valley – Dixieland 230 kV (MVAR) N/A 76 Mirage-Ramon 230 kV Line (MW) 372 468

Mirage-Ramon 230 kV Line (MVAR) 16 7 Coachella-Devers 230 kV Line (MW) 272 355 Coachella-Devers 230 kV Line (MVAR) 33 31

Path 42 (MW) 642 818 Path 42 (MVAR) 31 72

Path 46 (MW) 5298 5610

Path 49 (MW) 3001 3521

SCIT (MW) 4503 4817

Table B-6: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the light winter post-cluster base case are: N-0 Findings




N-1 Findings

Eleven (11) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Two (2) out of the 11 transmission facility overloads were existing overloads which persisted or exacerbated following the integration of the Group 2011 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix B2, Table B2-7. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table B-7.



Rating


Pre- Cluster

Post Cluster



149% 148%



149% 148%

ELCENTSW – IMPERIAL VALLEY 230 KV LINE

370 MVA

DIXIE230 – IMPERIAL VALLEY 230 KV LINE

57% 148%


332 MVA 43% 114%


USNAF – ELTERMIN 92 KV LINE 132 MVA 12% 112%

USNAF – DIXIELAN 92 KV LINE 132 MVA 11% 111%

DIXIE230 – DIXIELAN 230/92 KV TRANSFORMER

300 MVA


N/A 139%


DIXIELAN – DIXPRI2 92 KV LINE 132 MVA 12% 147%

DIXPRI – DIXPRI2 92 KV LINE 132 MVA 12% 147%

Table B-7: Single Element Outage Transmission Facility Overloads

N-2 Findings

Nineteen (19) transmission facilities were overloaded following selected double element (N-2) outages. Two (2) out of the 19 overloaded facilities are attributable to the addition of the Group 2011 cluster projects. A summary of the transmission facility overloads following double element outages is provided in Appendix B2, Table B2-8. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table B-8.

Fifty-five (55) bus voltage deviation violations were observed following the selected double element outages. A summary of the bus voltage deviation violations following selected double element outages can be found at Appendix B2, Tables B2-9 and B2-10.




Rating


Pre- Cluster

Post Cluster

USNAF – ELTERMIN 92 KV LINE 132 MVA

ELCENTSW – IMPERIAL VALLEY 230 KV & ELCENTSW – AVENUE 161 KV LINES

22% 121%

USNAF – DIXIELAN 92 KV LINE 132 MVA 21% 121%


DIXIELAN – DIXPRI2 92 KV LINE 132 MVA 14% 160%

DIXPRI – DIXPRI2 92 KV LINE 132 MVA 14% 160%

DIXIE230 – DIXIELAN 230/92 KV TRANSFORMER

300 MVA N/A 147%

RAMON 230/92 KV TRANSFORMER 225 MVA

COACHELA – DEVERS 230 KV & COACHELA – RAMON 230 KV LINES (W/ RAS)

98% 142%

N. VIEW – AVE42 92 KV LINE 132 MVA 91% 137%

N. VIEW – RAMON 92 KV LINE 132 MVA 88% 132%

AVE42 – FRANWAY 92 KV LINE 132 MVA 86% 130%

FRANWAY – EDOM 92 KV LINE 132 MVA 85% 128%

COACHELA #1 230/92 KV TRANSFORMER

150 MVA 85% 116%


150 MVA 85% 116%


225 MVA

COACHELA – DEVERS 230 KV & MIRAGE – RAMON 230 KV LINES (W/ RAS)

85% 119%


370 MVA 126% 164%


125 MVA 21% 112%

COACHELA 161/92 KV TRANSFORMER

225 MVA 116% 79&


RTAP2 – RTP1 92 KV LINE 57 MVA 87% 146%

Table B-8: Double Element Outages Transmission Facility Overloads

Losses

IID system losses in the light winter post-cluster base case were 62 MW

B.3.2 Transient Stability Analysis Findings Stable and adequately damped transient stability performances were achieved following Six (6) out of the eight (8) critical outages simulated using both the pre- and post-cluster base cases. A visual look at the stability plots (both bus voltage and frequency) for the Mirage- Ramon 230 kV line outage and the Coachella – Devers 230 kV line outage reveals that the system swings following the two outages are self-sustaining and not adequately damped. The observed system swings following the two outages were pre-existing which exacerbated following the integration of the Group 2011 Cluster projects. There were also bus voltage criteria violations following the Path 42 outage (with RAS). These criteria violations are attributable to the integration of the Group 2011 Cluster projects. Key findings from the transient stability analysis using both the heavy summer and light winter pre- and post-cluster base cases are:



Transient voltage dip violations were observed per WECC/NERC transient voltage dip for the Path 42 outage (with RAS).


System swings following 2 out of the 8 outages were not adequately damped. Transient voltage and frequency plots at selected critical buses which provide a representative illustration of the transmission system response following each of the critical outages studied can be found in Attachment A. The critical buses monitored included: COACHELA 230 kV, RAMON 230 kV, ELCENTSW 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVE42 92 kV. With the implementation of all the IID system upgrades proposed to mitigate the mentioned unstable conditions on the 2011 scenario, stable and adequately damped transient stability performances were achieved following all of the critical outages simulated using both the pre- and post-cluster base cases.

B.3.3 Post-Transient Stability Analysis Findings

Post-transient stability analysis was performed on the heavy summer pre- and post-cluster base cases. The post-transient stability analysis showed that for both cases and for all the outages simulated positive reactive margins were achieved at all the buses monitored. However, for 3 out of the 8 outages simulated using both the pre- and post-cluster base cases, the reactive margins at the N. LAQUIN 92 kV and MIDWAY 92 kV buses were below IID’s acceptable minimum reactive margins. In general, the study showed that the integration of the Group 2011 Cluster Projects resulted in marginal reductions in the reactive power margins at some of the buses monitored. Other monitored buses recorded improvements following the addition of the Group 2011 Cluster projects. Detailed results of the post-transient stability analysis can be found at Appendix B3.

B.3.4 Short Circuit Analysis Findings

The results of the Group 2011 Cluster Short Circuit Analysis is provided in Table B-9. The maximum incremental fault duty following the integration of the Group 2011 Cluster projects was 14,909 A at the El Centro 230 kV switching station. The available margins at the vicinity breakers as depicted in Table B-9 indicate that the interconnection of the Group 2011 Cluster projects will cause the El Centro 92 kV breakers to be within 120 A of their interruption capabilities. While the Group 2011 Cluster projects contributed 7189 A to the fault duty at the El Centro 92 kV breakers, the available margins on the breakers are 7308 A. Thus, the 40, 000 A breakers at the El Centro 92 kV substation would have to be replaced with a 63, 000 A rated breakers. In all, there are 40 breakers at the El Centro 92 kV substation.



Table B-9: Summary of Short Circuit Analysis Results

B.4 MITIGATION PLANS This section details the recommended transmission upgrade projects required to mitigate overloads created following the integration of the Group 2011 Cluster Projects. The recommended upgrades have been tested and found to mitigate all the overloads identified (See Appendix B2 for power flow results). The results of the post-transient stability analysis using the post-cluster base case with the recommended transmission plans incorporated can be found in Appendix B3. Similarly, transient stability analysis was performed on the post-cluster base case with the recommended transmission plans incorporated and the transmission system was found stable and adequately damped with no WECC/NERC criteria violations (See Attachment B). B.4.1 Mitigation Plans for Overloads Caused by Group 2011 Cluster Study To mitigate the both the N-1 and N-2 overloads attributable solely to the integration of the Group 2010 Cluster Projects, the following transmission facilities are recommended:


Breaker

Rating

(A)

Pre- Cluster Max

(3LG, 1LG) Fault

Current (A)

Available

Margins

(A)

Post-Cluster

Max (3LG, 1LG)

Fault Current (A)

Project

Contribution

(A)

ATEN ATEN 92 40,000 15,442 24,558 17,956 2,514

AVE58-92 AVE. 58 92 40,000 13,413 26,587 14,547 1,133

BRAVO 92 KV. BRAVO 92 40,000 11,749 28,251 13,697 1,948

CALEXICO CALEXICO 92 40,000 10,147 29,853 11,424 1,277

CENTRAL CENTRAL 92 40,000 12,085 27,915 14,925 2,840

CLARK CLARK 92 40,000 14,661 25,339 16,829 2,168

COACHELA COACHELLA SW STA 92 22,000 20,386 1,614 21,633 1,247


CV-230 COACHELLA VALLEY 230 40,000 15,392 24,608 17,605 2,213


DAHLIA DAHLIA 92 64,000 14,629 49,371 16,839 2,210

DIXIE-PRISON DIXIELAND PRISON 92 40,000 7,027 32,973 13,543 6,516

DIXIELAND DIXIELAND 92 40,000 7,479 32,521 19,044 11,565

ELCENTSW EL CENTRO SW STA 92 40,000 32,692 7,308 39,881 7,189


EUCLID EUCLID 92 64,000 15,794 48,206 18,449 2,655

GATEWAY-92 GATEWAY 92 40,000 9,363 30,637 11,319 1,956

HEBER HEBER 92 40,000 12,497 27,503 14,012 1,516

HEBERSCE HGC PLANT (HEBER SCE) 92 20,000 12,463 7,537 13,974 1,511

HIGHLINE230 HIGHLINE 230 40,000 5,407 34,593 17,492 12,084


HOLTVILLE HOLTVILLE 92 40,000 11,995 28,005 13,911 1,916

MIDWAY230 MIDWAY 230 40,000 7,967 32,033 13,758 5,791

MIDWAY92 MIDWAY 92 40,000 14,547 25,453 17,377 2,831

NAVY BASE NAVY BASE 92 40,000 9,734 30,266 13,877 4,143

PLASTER-CITY PLASTER CITY 92 40,000 5,410 34,590 9,548 4,138

TERMINAL 92 TERMINAL 92 37,000 23,568 13,433 30,257 6,690




New 22-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV transmission line from Dixieland to El Centro

New 8-mile, 786 MVA, 1033 MCM ACSR bundled 230 kV transmission line from Dixieland to Imperial Valley

Rebuild 19-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV transmission lines from Highline to El Centro.

Rebuild the 18.1 miles El Centro - Imperial Valley 230 kV line using 786 MVA, 2-1033 MCM ACSR bundled transmission line.

Replace Coachella 161/92 kV transformer with a 250 MVA transformer.

Rebuild 1 mile DIXPRI1 –DIXPRI 92 kV line using 191 MVA, 900 ACSS conductor

Rebuild 2.5 mile DIXPRI2 –DIXIELAN 92 kV line to 191 MVA, 900 ACSS conductor

Rebuild 1-mile DIXPRI –DIXPRI2 92 kV line using 191 MVA, 900 ACSS conductor

Rebuild 7.4-mile DIXIELAN – RTP1 92 kV line using 191 MVA, 900 ACSS conductor

Rebuild 20-mile RTP1 – RTAP2 92 kV line using 191 MVA, 900 ACSS conductor

Rebuild the 9-mile, 161 KV line section from ELCENTSW to L-TAPA-12 to double circuit 554 MVA, 1033 ACSR conductor.

New 332 MVA, 230/92 kV transformer at Dixieland.

New 8- mile CVSUB – KOHLRANCH - AVENUE 58 92 kV line to 191 MVA, 900 ACSS conductor

It is also recommended to interconnect Project A-12 to the proposed Dixieland 230 kV substation via a radial 13-mile line in lieu of the Customer’s requested interconnection point of ―L‖ line due to capacity and cost implications. Summary of the overloaded transmission facilities and the associated recommended transmission facilities are also provided in Tables B-10 & B-11. B.5 COST AND CONSTRUCTION TIMELINES The estimated cost for the recommended network upgrades for mitigating the impact of the Group 2011 Cluster Projects is $ 258.7 Million. The detail network upgrade cost and the construction timelines for implementing the upgrades are provided in Table B-12.




Applicable

Rating

Post- Cluster


NORMAL CONDITION (N-0 )

ALL LINES IN SERVICE

N/A N/A N/A Interconnect A-8 to ―KN‖ line in lieu of ―N‖ line

Change of interconnection points results in increased reliability and reduced cost N/A N/A N/A

Interconnect A-12 to Dixieland 230 kV line in lieu of ―L‖ line

N/A N/A N/A New 332 MVA, 230/92 KV transformer at Dixieland

Needed in order to integrate projects in Dixieland area

N/A N/A N/A New 8-mile, 786 MVA, 1033 MCM ACSR bundled 230 kV line from Dixieland to Imperial Valley

N/A N/A N/A New 8-mile, 191 MVA, 900 MCM ACSS 92 kV line from Avenue 58 through Kohl Ranch to Coachella

Required to lower Coachella area 92 kV transmission line flows following single element outages




370 MVA 148% Rebuild 18.1-mile line using 786 MVA, 2-1033 ACSR bundled 230 kV line and rebuild the ECSS 230

Other N-1 outages such as N. Gila- Imperial Valley 500 kV line caused this line to overload


332 MVA 114% New 22-mile, 786 MVA, 1033 MCM ACSR bundled 230 kV line from Dixieland to El Centro Rebuild 9-mile El Centro to L-TAPA-12 161 kV line using Double Circuit 554 MVA 1033 ASCR Conductor

Needed to close the loop and prevent the Dixieland area power from overloading the underlying system during outages

USNAF – ELTERMIN 92 KV LINE

132 MVA 112%

USNAF – DIXIELAN 92 KV LINE

132 MVA 112%


COACHELLA 161/92 KV TRANSFORMER

125 MVA 178% Replace CV transformer with 300 MVA rating

None


DIXPRI1 – DIXPRI 92 KV LINE

132 MVA 147% Rebuild 1-mile line using 191 MVA, 900 MCM ACSS Conductor

Several other N-1 & N-2 outages caused these lines to overload

DIXIELAN – DIXPRI2 92 KV LINE

132 MVA 147% Rebuild 2.5-mile line using 191 MVA, 900 MCM ACSS Conductor

DIXPRI – DIXPRI2 92 KV LINE

132 MVA 147% Rebuild 1-mile line using 191 MVA, 900 MCM ACSS Conductor


RTAP2 – RTP1 92 KV LINE 57 MVA 149% Rebuild 20-mile line using 191 MVA, 900 MCM ACSS Conductor

RTP1 – DIXIELAND 92 KV LINE


Table B-10: Summary of Transmission Facility Overloads and Associated Mitigation Plan




Applicable

Rating

Post- Cluster


DOUBLE ELEMENT OUTAGES (N-2)

COACHELA – DEVERS 230 KV & COACHELA – RAMON 230 KV LINES (W/ RAS)

RAMON 230/92 KV TRANSFORMER

225 MVA 142%

New 19-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV line from Highline to El Centro. Upgrade Highline Substation. Upgrade ―E‖ Line 3.4 Miles.

Need to mitigate for the observed several bus voltage deviation violations were observed

N. VIEW – AVE42 92 KV LINE

132 MVA 137%

N. VIEW – RAMON 92 KV LINE

132 MVA 132%

AVE42 – FRANWAY 92 KV LINE

132 MVA 130%

FRANWAY – EDOM 92 KV LINE

132 MVA 128%


150 MVA 116%


150 MVA 116%

COACHELA – DEVERS 230 KV & MIRAGE – RAMON 230 KV LINES (W/ RAS)


125 MVA 112%

Transient stability performance of the transmission system following this outage was inadequately damped. There were transient stability criteria violations.

Table B-11: Summary of Transmission Facility Overloads and Associated Mitigation Plan (Continued)



Table B-12: Recommended Mitigation Plan & Associated Cost for Group 2011 Cluster Projects



Cost

Estim ate

($ M i l l ion)

Construction

Tim e L ines

(M onths)

Notes

NONE N/A N/A N/A

40 Breaker Replacements at El Centro 92 kV

switching station 13.60 12 Short Circuit Study

ELCENTSW – IMPERIAL VALLEY 230 KV LINE 370 MVA 148%

Rebuild line using 786 MVA, 2-1033 MCM

ACSS Conductor and also rebuild the ECSS

230.

58.94 30 None

ELCENTSW 230/92 KV TRANSFORMER 332 MVA 114%

USNAF – ELTERMIN 92 KV LINE 132 MVA 112%

USNAF – DIXIELAN 92 KV LINE 132 MVA 112%

COACHELLA 161/92 KV TRANSFORMER AVENUE 58 161/92 KV TRANSFORMER 125 MVA 178% Replace CV transformer with 300 MVA rating 8.32 24 None

DIXPRI1 – DIXPRI 92 KV LINE 132 MVA 147%

DIXIELAN – DIXPRI2 92 KV LINE 132 MVA 147%

DIXPRI – DIXPRI2 92 KV LINE 132 MVA 147%

RTAP2 – RTP1 92 KV LINE 57 MVA 149%

RTP1 – DIXIELAND 92 KV LINE 51 MVA 102%









COACHELA – DEVERS 230 KV & MIRAGE –

RAMON 230 KV LINES 125 MVA 112%

New 230 kV substation at Dixieland 20.77

332 MVA 230/92 kV transformer at Dixieland

and a transmission line (circuit #1) from

Dixieland to IID's Imperial Valley Switching

Station

IID Budget

New 92 kV line from Avenue 58 to Coachella

through Kohl Ranch (KM line)9.15 24

New 230 kV line (circuit #2) from Dixieland

to Imperial Valley Sw. Station28.28 24



New 19-mile, 786 MVA, 2-1033 MCM bundled

230 kV line from Highline to El Centro. Install

Remedial Action Scheme (RAS) to mitigate

the marginal transmission overloads.

Upgrade Highline Sub., Upgrade "E" line 3.4

miles.

Rebuild "R" line uisng 191 MVA, 900 MCM

ACSS Conductor from Dixieland to Anza and

to Central

36

30

None



New Network faci l i ties for In tegrating Group 2011 Cluster Pro jects

24


47.08

32.59

New 22-mile, 786 MVA, 2-1033 MCM ACSR

bundled 230 kV line from Dixieland to El

Centro. Rebuild 9-mile El Centro to L-TAPA-12

161 kV line using double circuit 554 MVA,

1033 ACSR conductor

52.80

NONE N/A N/A N/A

These projects are needed in

order to integrate Group 2011 Cluster Projecs in Dixieland area.

None

None



COACHELA – RAMON 230 KV LINES 30



Appendix B1

Power flow Maps



Figure B1-1: Power flow Map—2011 Heavy Summer Pre-Cluster Base Case



Figure B1-2: Power flow Map—2011 Heavy Summer Post-Cluster Base Case



Figure B1-3: Power flow Map—2011 Heavy Summer Post-Cluster w/ Mitigation Base Case



Figure B1-4: Power flow Map—2011 Light Winter Pre-Cluster Base Case



Figure B1-5: Power flow Map—2011 Light Winter Post-Cluster Base Case



Figure B1-6: Power flow Map—2011 Light Winter Post-Cluster w/Mitigation Base Case



Appendix B2

Summary of Power Flow Analysis Results



Table B2-1: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads

From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster

w/MitigationOutage Description

8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 149% 149% 149% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2


8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 line_211 96% 111% 101% line PALOVRDE to DEVERS 500 ck 1

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B161_L005 86% 112% 101% Line AV58 161.0 to ELCENTSW 161.0 Circuit 1

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B161_C010 73% 112% 101% Line A-13-IP 161.0 to AVE58 161.0 Circuit 1

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B92_L031 88% 103% 100% Line NILAND 92.0 to NEW MECCA 92.0 Circuit 1

8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 B161_T002 118% 178% 83% Tran AVE58 92.00 to AV58 161.00 Circuit 1

8639 A-13-IP 161 8806 AV58TP1 161 1 Line 8 165 line_211 N/A 110% 78% line PALOVRDE to DEVERS 500 ck 1

8639 A-13-IP 161 8806 AV58TP1 161 1 Line 8 165 B230_L004 N/A 104% 65% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 line_210 11% 117% 61% line N.GILA to IMPRLVLY 500 ck 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_T101 20% 112% 61% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 line_210 8% 113% 59% line N.GILA to IMPRLVLY 500 ck 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 line_210 8% 113% 59% line N.GILA to IMPRLVLY 500 ck 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B230_T101 16% 109% 58% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B230_T101 16% 109% 58% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 line_206 9% 106% 58% line HASSYAMP to N.GILA 500 ck 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 line_206 6% 102% 55% line HASSYAMP to N.GILA 500 ck 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 line_206 6% 102% 55% line HASSYAMP to N.GILA 500 ck 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L055 44% 104% 54% Line USNAF 92.0 to ELTERMIN 92.0 Circuit 1

8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 B161_L006 86% 106% 54% Line AV58 161.0 to CVSUB 161.0 Circuit 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_L004 20% 131% 53% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 line_211 81% 119% 53% line PALOVRDE to DEVERS 500 ck 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L054 40% 102% 53% Line USNAF 92.0 to DIXIELAN 92.0 Circuit 1

8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 B92_L031 67% 106% 52% Line NILAND 92.0 to NEW MECCA 92.0 Circuit 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B230_L004 17% 128% 51% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B230_L004 17% 128% 51% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_C005 79% 145% 44% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B230_C005 70% 130% 44% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_211 107% 137% 44% line PALOVRDE to DEVERS 500 ck 1

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 line_211 96% 123% 44% line PALOVRDE to DEVERS 500 ck 1

8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 B230_L004 63% 104% 42% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_L005 92% 125% 41% Line AV58 161.0 to ELCENTSW 161.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_C010 79% 125% 41% Line A-13-IP 161.0 to AVE58 161.0 Circuit 1

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B161_C010 70% 112% 41% Line A-13-IP 161.0 to AVE58 161.0 Circuit 1

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B161_L005 82% 112% 41% Line AV58 161.0 to ELCENTSW 161.0 Circuit 1

8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 B230_L004 N/A 106% 40% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_207 90% 119% 40% line IMPRLVLY to MIGUEL 500 ck 1

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 line_207 81% 107% 40% line IMPRLVLY to MIGUEL 500 ck 1




Table B2-2: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads (Continued)



8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_T002 98% 126% 40% Tran AVE58 92.00 to AV58 161.00 Circuit 1

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B161_T002 87% 113% 40% Tran AVE58 92.00 to AV58 161.00 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L031 88% 109% 38% Line NILAND 92.0 to NEW MECCA 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T003 86% 106% 37% Tran RAMON92 92.00 .0to RAMON230 230.00 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L004 82% 104% 37% Line CVSUB 92.0 to COLMAC 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L032A 83% 104% 37% Line NILAND 92.0 to CCAP 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T001 83% 102% 37% Tran CVSUB 92.00 to COACHELA 230.00 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T002 83% 102% 37% Tran CVSUB 92.00 to COACHELA 230.00 Circuit 2

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_231 84% 105% 37% line J.HINDS to EAGLEMTN 230 ck 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T101 90% 104% 36% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_265 84% 104% 36% line BLYTHESC to BLYTHE 161 ck 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L006 81% 102% 36% Line EDOM 92.0 to RAMON92 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_C001 79% 167% 36% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B230_C001 70% 149% 36% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L008 83% 103% 36% Line AVE58 92.0 to COACHELA 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L014 81% 103% 36% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_232 81% 102% 36% line J.HINDS to MIRAGE 230 ck 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_T004 82% 102% 36% Tran NILAND 161.00 to NILAND 92.00 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_L006 83% 102% 36% Line AV58 161.0 to CVSUB 161.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L003 81% 102% 36% Line CVSUB 92.0 to JACKSON 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L072 83% 105% 36% Line MW1TAP 92.0 to MIDWAY 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L071 82% 104% 36% Line MIDWAY 92.0 to VULCAN 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L0070 82% 103% 36% Line MIDWAY 92.0 to MINPLNT 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T005 82% 104% 35% Tran HIGHLINE 230.00 to HIGHLINE 92.00 Circuit 1

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 line_210 110% 127% 29% line N.GILA to IMPRLVLY 500 ck 1

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 line_206 80% 105% 26% line HASSYAMP to N.GILA 500 ck 1

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 B230_C001 27% 116% 12% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1




Table B2-3: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-1 Voltage Deviation Violations

Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster


8292 N.LAQUIN 92 8 B92_L014 5.1% 5.5% 4.3% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1

8286 LAQUINTA 92 8 B92_L014 4.9% 5.3% 4.2% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1

Summary of 2011 Heavy Summer Power Flow Analysis--N-1 Bus Voltage Deviation Violations



Table B2-4: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-2 Thermal Overloads


w/ MitigationOutage Description

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C230_L007 101% 133% 101% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8279 CVSUB 92 8311 COACHELA 230 1 Tran 8 150 230_L004 85% 114% 78% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS


8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 C161_L001 99% 128% 62% Loss of Transmission ELCENTSW to AVE58(L) 161kV & AVE58 to CVSUB(L)161kV

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C230_L007 24% 148% 56% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 C92_L013 76% 116% 55% Loss of Transmission from AVE58 to JEFFERSON(CD)92kV & from AVE58 to AVE48(CS)92

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 C230_L007 21% 145% 54% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 C230_L007 21% 145% 54% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C92_L003 44% 104% 54% Loss of Transmission from ELTERMINAL to USNAF(LW)92kV & from ELTERMINAL to EUCLI

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C230_L006 14% 103% 53% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C161_L001 103% 138% 42% Loss of Transmission ELCENTSW to AVE58(L) 161kV & AVE58 to CVSUB(L)161kV

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 C161_L001 92% 123% 42% Loss of Transmission ELCENTSW to AVE58(L) 161kV & AVE58 to CVSUB(L)161kV

8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 C230_L007 N/A 119% 42% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_L007 118% 130% 40% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 C230_L007 106% 117% 40% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_T001 97% 111% 40% Tran CVSUB 92.00 to COACHELA 230.00 CK1 & CK2

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_L001 82% 104% 37% Line HIGHLINE 230.0 to MIDWAY 230.0 Circuit 1&2

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C92_L012 89% 110% 36% Loss of Transmission from CVSUB to COACHELLA(CL)92kV CK1 & from CVSUB to COACHEL

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C92_L014 84% 103% 36% Loss of Transmission from AVE42 to N.LAQ(CD)92kV & from AVE42 to SHIELDS(CS)92kV

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C92_L020 82% 103% 36% Loss of Transmission from AVE42 to MONROE(CW)92kV & from AVE42 to SHAHILLS(CI)92

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_T002 89% 112% 36% Tran MIDWAY 230.00 to MIDWAY 92.00 Ck1 & CK2

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 C230_L006 48% 104% 20% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8282 USNAF 92 8337 ELTERMIN 92 1 Line 8 132 C230_L007 41% 109% 14% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8282 USNAF 92 8319 DIXIELAN 92 1 Line 8 132 C230_L007 36% 104% 9% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

Summary of 2011 Heavy Summer Power Flow Analysis Results---N-2 Thermal Overloads



Table B2-5: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-2 Bus Voltage Deviation Violations

Summary of 2011 Heavy Summer Power Flow Analysis Results--N-2 Bus Voltage Deviation Violations

Bus Name kV Area Outage Pre-Cluster Post-Cluster Post-Cluster w/

Mitigation Outage Description

NONE



Table B2-6: Summary of 2011 Light Winter Power Flow Analysis Results— N-1 Thermal Overloads


w/MitigationOutage description



8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 B230_T101 N/A 107% 72% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_T101 10% 120% 63% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B230_T101 10% 120% 63% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B230_T101 10% 120% 63% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L060 6% 107% 60% Line USGYPS 92.0 to DIXIELAN 92.0 Circuit 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B92_L060 6% 106% 60% Line USGYPS 92.0 to DIXIELAN 92.0 Circuit 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B92_L060 6% 106% 60% Line USGYPS 92.0 to DIXIELAN 92.0 Circuit 1

8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 B230_L004 N/A 137% 59% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 line_210 6% 107% 56% line N.GILA to IMPRLVLY 500 ck 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 line_210 6% 107% 56% line N.GILA to IMPRLVLY 500 ck 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 line_210 6% 107% 56% line N.GILA to IMPRLVLY 500 ck 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_T004 8% 102% 55% Tran ELCENTSW 161.00 to ELCENTSW 230.00 Circuit 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_L004 12% 147% 55% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B230_L004 12% 147% 54% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B230_L004 12% 147% 54% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L055 17% 108% 54% Line USNAF 92.0 to ELTERMIN 92.0 Circuit 1

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L054 17% 108% 54% Line USNAF 92.0 to DIXIELAN 92.0 Circuit 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B92_L055 17% 108% 53% Line USNAF 92.0 to ELTERMIN 92.0 Circuit 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B92_L055 17% 108% 53% Line USNAF 92.0 to ELTERMIN 92.0 Circuit 1

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B92_L054 16% 108% 53% Line USNAF 92.0 to DIXIELAN 92.0 Circuit 1

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B92_L054 16% 108% 53% Line USNAF 92.0 to DIXIELAN 92.0 Circuit 1

8332 ELCENTSW 230 8335 ELSTEAMP 92 1 Tran 8 332 B230_C001 43% 114% 46% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 line_210 98% 114% 24% line N.GILA to IMPRLVLY 500 ck 1

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 B230_C005 57% 133% 23% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 line_206 80% 102% 22% line HASSYAMP to N.GILA 500 ck 1

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 B230_C001 57% 148% 20% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 B92_L058 57% 102% 19% Line DIXIELAN 92.0 to DIXPRI 92.0 Circuit 1

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_C001 28% 112% 17% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1

8282 USNAF 92 8337 ELTERMIN 92 1 Line 8 132 B230_L004 18% 103% 5% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8282 USNAF 92 8319 DIXIELAN 92 1 Line 8 132 B230_L004 18% 102% 5% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1

8331 ELCENTSW 161 8335 ELSTEAMP 92 1 Tran 8 125 B230_T004 18% 102% 4% Tran ELCENTSW 161.00 to ELCENTSW 230.00 Circuit 1

8282 USNAF 92 8319 DIXIELAN 92 1 Line 8 132 B230_C001 11% 111% 3% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1

8282 USNAF 92 8337 ELTERMIN 92 1 Line 8 132 B230_C001 12% 112% 1% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1

Summary of 2011 Light Winter Power Flow Analysis Results-- N-1 Thermal Overloads



Table B2-7: Summary of 2011 Light Winter Power Flow Analysis Results— N-1 Voltage Deviation Violations



Summary of 2011 Light Winter Power Flow Analysis Results--N-1 Bus Voltage Deviation Violations

NONE



Table B2-8: Summary of 2011 Light Winter Power Flow Analysis Results— N-2 Thermal Overloads



8640 RAMON92 92 8695 RAMON 230 1 Tran 8 225 230_L004 98% 142% 89% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8289 N.VIEW 92 8309 AVE42 92 1 Line 8 132 230_L004 91% 137% 83% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8289 N.VIEW 92 8640 RAMON92 92 1 Line 8 132 230_L004 88% 132% 79% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8309 AVE42 92 8310 FRANWAY 92 1 Line 8 132 230_L004 86% 130% 78% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8310 FRANWAY 92 8330 EDOM 92 1 Line 8 132 230_L004 85% 128% 76% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 C230_L006 N/A 135% 74% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 230_L004 N/A 104% 63% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8330 EDOM 92 8640 RAMON92 92 1 Line 8 156 230_L004 69% 104% 62% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8335 ELSTEAMP 92 8720 WSTBIOTP 92 2 Line 8 132 C230_L006 81% 105% 61% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 C230_L007 N/A 147% 60% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C230_L007 14% 161% 56% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 C230_L007 14% 160% 56% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 C230_L007 14% 160% 56% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C230_L006 16% 124% 55% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 C230_L006 16% 124% 55% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 C230_L006 16% 124% 55% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 230_L004 4% 110% 54% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C92_L003 17% 108% 54% Loss of Transmission from ELTERMINAL to USNAF(LW)92kV & from ELTERMINAL to EUCLI

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 230_L004 4% 109% 54% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 230_L004 4% 109% 54% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 C92_L003 17% 108% 53% Loss of Transmission from ELTERMINAL to USNAF(LW)92kV & from ELTERMINAL to EUCLI

8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 C92_L003 17% 108% 53% Loss of Transmission from ELTERMINAL to USNAF(LW)92kV & from ELTERMINAL to EUCLI

8331 ELCENTSW 161 8332 ELCENTSW 230 1 Tran 8 225 C230_L006 85% 119% 47% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 C230_L006 126% 164% 34% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS



8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 230_L004 80% 121% 25% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8279 CVSUB 92 8311 COACHELA 230 1 Tran 8 150 C230_L006 87% 106% 21% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8279 CVSUB 92 8311 COACHELA 230 2 Tran 8 150 C230_L006 87% 106% 21% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_L006 97% 163% 10% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 C230_L006 87% 146% 10% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8282 USNAF 92 8337 ELTERMIN 92 1 Line 8 132 C230_L007 22% 121% 9% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8282 USNAF 92 8319 DIXIELAN 92 1 Line 8 132 C230_L007 21% 121% 9% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV

8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 225 C230_L006 116% 79% 3% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

8331 ELCENTSW 161 8335 ELSTEAMP 92 1 Tran 8 125 C230_L006 21% 112% 2% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS

Summary of 2011 Light Winter Power Flow Analysis Results--N-2 Thermal Overloads



Table B2-9: Summary of 2011 Light Winter Power Flow Analysis Results— N-2 Bus Voltage Deviation Violations

Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster w/

MitigationOutage Description

8311 COACHELA 230 8 230_L004 1.8% 17.1% 2.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8008 A-8-IP 230 8 230_L004 N/A 18.3% 1.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8630 A-8 230 8 230_L004 N/A 18.3% 1.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8699 MIDWAY 230 8 230_L004 2.1% 18.2% 1.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8700 MIDWAY 92 8 230_L004 1.9% 18.4% 1.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8678 HUDSONTA 230 8 230_L004 1.9% 18.6% 1.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8675 HUDSON23 230 8 230_L004 1.8% 18.7% 1.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8723 VULCAN 92 8 230_L004 1.1% 18.0% 1.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8673 EARTHE2 92 8 230_L004 0.9% 17.6% 1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8702 REG1EX 92 8 230_L004 0.8% 17.4% 1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8279 CVSUB 92 8 230_L004 -0.2% 14.7% 0.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8732 COLMAC 92 8 230_L004 -0.2% 14.8% 0.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8670 MW1TAP 92 8 230_L004 1.2% 19.2% 0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8355 MECCA 92 8 230_L004 -0.1% 11.5% 0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8393 KTP2 92 8 230_L004 -0.2% 12.2% 0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8807 AV58TP2 161 8 230_L004 -0.3% 11.8% 0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8385 THERMAL 92 8 230_L004 -0.3% 13.7% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8358 AVE 52 92 8 230_L004 -0.4% 14.4% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8312 COACHELA 92 8 230_L004 -0.4% 14.7% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8306 CMTAP1 92 8 230_L004 -0.4% 14.7% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8303 SKY VLY 92 8 230_L004 -0.4% 14.7% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8805 AV58 161 8 230_L004 -0.6% 12.0% 0.4% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8690 HIGHLINE 230 8 230_L004 1.8% 18.0% 0.4% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8691 HIGHLINE 92 8 230_L004 0.8% 17.0% 0.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8912 GEM23 92 8 230_L004 0.8% 17.1% 0.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8363 OASIS 92 8 230_L004 -1.0% 12.4% 0.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8380 RTP6OASS 92 8 230_L004 -1.0% 12.4% 0.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8652 SIGCTAP 92 8 230_L004 0.7% 16.1% 0.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8900 PRUETTAP 92 8 230_L004 0.7% 16.1% 0.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8287 RTAP8 92 8 230_L004 -1.0% 14.4% 0.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8960 SIGC92 92 8 230_L004 0.5% 15.1% 0.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8301 CITAP1 92 8 230_L004 -1.2% 15.4% -0.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8703 MINPLNT 92 8 230_L004 0.3% 20.1% -0.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS




Table B2-10: Summary of 2011 Light Winter Power Flow Analysis Results— N-2 Bus Voltage Deviation Violations (Continued)



8311 COACHELA 230 8 230_L004 1.8% 17.1% 2.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8008 A-8-IP 230 8 230_L004 N/A 18.3% 1.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8630 A-8 230 8 230_L004 N/A 18.3% 1.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8281 AVE58 92 8 230_L004 -1.4% 14.1% -0.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8389 VANBUREN 92 8 230_L004 -1.6% 15.7% -0.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8285 JEFERSN 92 8 230_L004 -1.8% 14.8% -0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8349 JACKSON 92 8 230_L004 -1.7% 15.9% -0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8307 CMTAP2 92 8 230_L004 -1.8% 15.8% -0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8354 MARSHALL 92 8 230_L004 -2.0% 15.2% -0.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8304 CITP2 92 8 230_L004 -2.0% 16.0% -0.9% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8406 SHAHILLS 92 8 230_L004 -2.1% 16.0% -0.9% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8308 CITP4 92 8 230_L004 -2.2% 16.1% -1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8291 AVE48 92 8 230_L004 -2.2% 15.5% -1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8315 CWTAP2 92 8 230_L004 -2.2% 15.5% -1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8302 CARREON 92 8 230_L004 -2.3% 16.1% -1.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8286 LAQUINTA 92 8 230_L004 -2.3% 15.6% -1.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8292 N.LAQUIN 92 8 230_L004 -2.3% 15.7% -1.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8357 MONROE 92 8 230_L004 -2.5% 16.2% -1.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8316 SHIELDS 92 8 230_L004 -2.5% 16.0% -1.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8309 AVE42 92 8 230_L004 -2.6% 16.2% -1.4% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8289 N.VIEW 92 8 230_L004 -3.1% 16.4% -1.9% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8310 FRANWAY 92 8 230_L004 -3.4% 16.3% -2.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8330 EDOM 92 8 230_L004 -4.0% 15.2% -2.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8640 RAMON92 92 8 230_L004 -4.0% 14.7% -2.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS




Appendix B3

Heavy Summer Post-Transient Stability Analysis Results



Table B3-1: Summary of 2011 Heavy Summer Post-Transient Stability Analysis Results

Outage




8805 AV58 161 kV 208 144 233

8808 CVSUB161 161 kV 212 178 238

8292 N.LAQUIN 92 kV 72 57 76

8312 COACHELA 92 kV 266 182 252

8700 MIDWAY 92 kV 120 122 201

8361 NILAND 92 kV 290 280 294

8335 ELSTEAMP 92 kV 485 529 658

8397 CLX92 92 kV 276 278 313

8369 PILOTKNB 92 kV 149 160 161

8319 DIXIELAN 92 kV 224 368 388


8805 AV58 161 kV 240 215 267

8808 CVSUB161 161 kV 254 244 284

8292 N.LAQUIN 92 kV 192 173 206

8312 COACHELA 92 kV 288 282 345

8700 MIDWAY 92 kV 123 127 206

8361 NILAND 92 kV 290 286 297

8335 ELSTEAMP 92 kV 459 522 651

8397 CLX92 92 kV 259 266 303

8369 PILOTKNB 92 kV 167 162 162

8319 DIXIELAN 92 kV 215 367 387



Table B3-2: Summary of 2011 Heavy Summer Post-Transient Stability Analysis Results (Continued)

Outage




8805 AV58 161 kV 199 138 195

8808 CVSUB161 161 kV 212 160 208

8292 N.LAQUIN 92 kV 166 122 156

8312 COACHELA 92 kV 252 191 250

8700 MIDWAY 92 kV 117 108 163

8361 NILAND 92 kV 270 238 262

8335 ELSTEAMP 92 kV 450 436 546

8397 CLX92 92 kV 267 265 298

8369 PILOTKNB 92 kV 158 128 148

8319 DIXIELAN 92 kV 216 351 364


8805 AV58 161 kV 212 212 270

8808 CVSUB161 161 kV 223 238 286

8292 N.LAQUIN 92 kV 166 168 206

8312 COACHELA 92 kV 232 265 346

8700 MIDWAY 92 kV 95 110 205

8361 NILAND 92 kV 264 273 295

8335 ELSTEAMP 92 kV 405 470 620

8397 CLX92 92 kV 241 249 297

8369 PILOTKNB 92 kV 132 163 163

8319 DIXIELAN 92 kV 203 325 368



Table B3-3: Summary of 2011 Heavy Summer Post-Transient Stability Results (Continued)

Outage




8805 AV58 161 kV 218 171 236

8808 CVSUB161 161 kV 232 195 239

8292 N.LAQUIN 92 kV 177 141 174

8312 COACHELA 92 kV 267 225 286

8700 MIDWAY 92 kV 114 107 177

8361 NILAND 92 kV 286 263 280

8335 ELSTEAMP 92 kV 485 498 607

8397 CLX92 92 kV 276 275 307

8369 PILOTKNB 92 kV 165 152 154

8319 DIXIELAN 92 kV 224 365 378


8805 AV58 161 kV 237 206 259

8808 CVSUB161 161 kV 251 235 277

8292 N.LAQUIN 92 kV 190 167 200

8312 COACHELA 92 kV 285 272 337

8700 MIDWAY 92 kV 122 124 202

8361 NILAND 92 kV 295 285 297

8335 ELSTEAMP 92 kV 497 544 671

8397 CLX92 92 kV 279 281 315

8369 PILOTKNB 92 kV 167 161 142

8319 DIXIELAN 92 kV 228 372 390



Table B3-4: Summary of 2011 Heavy Summer Post-Transient Stability Analysis Results (Continued)

Outage




8805 AV58 161 kV 181 183 244

8808 CVSUB161 161 kV 187 199 261

8292 N.LAQUIN 92 kV 141 141 184

8312 COACHELA 92 kV 170 188 296

8700 MIDWAY 92 kV 95 97 198

8361 NILAND 92 kV 291 285 299

8335 ELSTEAMP 92 kV 495 533 652

8397 CLX92 92 kV 279 279 315

8369 PILOTKNB 92 kV 150 160 160

8319 DIXIELAN 92 kV 228 370 389


8805 AV58 161 kV 198 183 246

8808 CVSUB161 161 kV 202 197 261

8292 N.LAQUIN 92 kV 160 147 190

8312 COACHELA 92 kV 184 186 295

8700 MIDWAY 92 kV 88 88 191

8361 NILAND 92 kV 290 282 295

8335 ELSTEAMP 92 kV 494 528 645

8397 CLX92 92 kV 278 279 314

8369 PILOTKNB 92 kV 167 141 160

8319 DIXIELAN 92 kV 227 369 389






C.1 INTRODUCTION

Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Transitional Cluster Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These projects plan to deliver power to IID and several IID neighboring utilities in the 2010-2015 timeframe. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. Projects with different phases of implementation were grouped in the year in which the first phase becomes operational. This section of the report details the study assumptions, methodology and results of Group 2012 Cluster Study. The Group 2012 Cluster Study contains eleven proposed generation projects totaling 948 MW. Provided below are the projects and their interconnection information.

Project Code Capacity POI In-service Date A-1-1 70 MW Midway 230 kV 07/01/2012 A-1-2 70 MW Midway 230 kV 11/01/2012 A-1-3 70 MW Midway 230 kV 04/01/2013 A-7-1 47 MW ―KS‖ 230 kV 07/01/2012 A-7-2 47 MW ―KS‖ 230 kV 10/01/2013 A-10-1 200 MW Dixieland 230 kV 06/01/2012 A-10-2 200 MW Dixieland 230 kV 07/01/2013 A-14-1 25 MW ―L‖ line 06/30/2012 A-14-2 50 MW ―L‖ line 12/31/2012 A-14-3 50 MW ―L‖ line 06/30/2013 A-15 119 MW Anza 92 kV 09/01/2012

The Group 2012 Cluster Study was conducted using approved WECC 2012 heavy summer and 2013 light winter power flow models. Studies performed included power flow, transient stability, post-transient stability and short circuit analyses for peak (heavy summer) and off-peak (light winter) conditions. C.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS

C.2.1 Base Case Assumptions


Heavy summer . . . . 12hs2a1.sav ………...Approved 11/14/2007

Light winter . . . . . . 13lw1sa1.sav…………Approved 01/07/2009

Both power flow base cases were selected because they were the most recently developed and available base cases in the WECC library based on planned in-service dates of the Group 2012 Cluster Projects. Pre-cluster base cases were developed from



the starting base cases by incorporating IID detailed system representation. IID system loads, resources, and topology were adjusted to reflect the conditions expected in 2012 when the Group 2012 Cluster projects plan to initiate operations. Group 2011 Cluster projects and other queued generation projects with planned interconnection to IID transmission system prior to summer 2012 were modeled in the pre-cluster base cases. The following 13 new and existing transmission projects which were recommended for upgrade as part of the Group 2011 Cluster Study were incorporated into the 2012 pre-cluster base cases:

New 22-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV transmission line from Dixieland to El Centro

New 8-mile, 786 MVA, 1033 MCM ACSR bundled 230 kV transmission line from Dixieland to Imperial Valley

New 19-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV transmission lines from Highline to El Centro.

Rebuild the 18.1 miles El Centro - Imperial Valley 230 kV line using 786 MVA, 2-1033 MCM ACSR bundled transmission line.

Replace Coachella 161/92 kV transformer with a 250 MVA transformer.

Rebuild 1 mile DIXPRI1 –DIXPRI 92 kV line using 191 MVA, 900 ACSS conductor

Rebuild 2.5 mile DIXPRI2 –DIXIELAN 92 kV line to 191 MVA, 900 ACSS conductor

Rebuild 1-mile DIXPRI –DIXPRI2 92 kV line using 191 MVA, 900 ACSS conductor

Rebuild 7.4-mile DIXIELAN – RTP1 92 kV line using 191 MVA, 900 ACSS conductor

Rebuild 20-mile RTP1 – RTAP2 92 kV line using 191 MVA, 900 ACSS conductor

Rebuild the 9-mile, 161 KV line section from ELCENTSW to L-TAPA-12 to double circuit 554 MVA, 1033 ACSR conductor.

New 332 MVA, 230/92 kV transformer at Dixieland.

Rebuild 8- mile CVSUB – KOHLRANCH - AVENUE 58 92 kV line to 191 MVA, 900 ACSS conductor

While it is impossible to study all IID transmission system flows and generation levels during all seasons, these two pre-cluster base cases represent extreme generation and transmission flows that will potentially expose any transmission constraints at the Group 2012 projects interconnection points. C.2.2 Base Cases Studied The two pre-cluster base cases developed for the Group 2012 Cluster Study were initially tested to ensure that all transmission facilities in IID control area are within their normal operating limits and this provided a benchmark for post-cluster evaluations. Two post-cluster base cases were developed from the pre-cluster base cases by modeling the Group 2012 Cluster projects. The output of the Group 2012 Cluster projects were dispatched and scheduled according to the information provided on each projects interconnection application. In the heavy summer post-cluster base case, the net output



of the Group 2012 Cluster projects was 932 MW while the net output of the Group 2012 Cluster projects during the light winter operating condition was 948 MW. The four base cases developed and used for studying the impact of the Group 2012 Cluster Projects are summarized in Table C-1.




2012 Light Winter 2012 LW Pre-Cluster Planned IID light winter configuration without the Group 2012 Cluster projects


Table C-1: Study Base Cases-Group 2012 Cluster Study

C.2.3 Load and Resources The IID load and Resources for the four base cases studied are provided in Table C-2. Table C-2 also depicts IID transmission system losses and area interchange flows for both pre- and post- cluster base cases. The area interchange flows for the receiving entities for the Group 2012 projects power outputs are highlighted in Table C-2.


Pre-Cluster 2012 HS

Post-Cluster 2012LW


Load (MW) 1102 1118 282 298

Load (MVAR) 427 437 81 91

Losses (MW) 71 92 43 68

Losses (MVAR) 504 827 299 601

Interchange (MW) 1026 1936 1534 2452





SDG&E Interchange (MW) 1631 2366 1831 2566

Table C-2: Summary of Load and Resources C.2.4 Dynamic Models Dynamic data files ―12hs21.dyd‖ and ―13lw1s1.dyd‖ developed for use with WECC power flow models ―12hs2a1.sav ― and ―13lw1sa1.sav― respectively were used for the transient stability analysis. New ―motorw‖ data for the IID control area were created and added to the dynamic data files. The stability models used for the Group 2012 Cluster



Study were user written algorithms and other dynamic data contained in each project’s interconnection application. C.2.5 Short Circuit Data The machine data used for the Group 2012 Cluster Study short circuit analysis were contained in each project’s interconnection application.



C.3 STUDY RESULTS This section provides the results obtained by applying the stated study assumptions and the general study methodology. It illustrates the findings associated with the power flow, transient stability and post-transient stability analyses for both the pre- and post-cluster base cases. C.3.1 Power Flow Analysis Findings This section details the findings of the power flow analysis. WECC/NERC reliability criteria were used to assess the adequacy of the study results.

C.3.1.1 Heavy Summer Pre-Cluster Base Case

The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. Pre-cluster power flow map that depicts the power flow distribution at the points of interconnections of the Group 2012 Cluster projects during the heavy summer operating condition can be found at Appendix C1, Figure C1-1. Key findings from the power flow analysis using the Heavy Summer Pre-cluster Base Case include:

N-0 Findings


N-1 Findings

Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. A summary of the transmission facility overloads is provided in Appendix C2, Table C2-1.


N-2 Findings

One (1) IID transmission facility was overloaded following selected double element (N-2) outages. A summary of the transmission facility overloads is provided in Appendix C2, Table C2-3.


Losses


C.3.1.2 Heavy Summer Post-Cluster Base Case

In the Post-Cluster analysis, the 932 MW net Group 2012 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2012 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group 2012 Cluster Projects to IID system losses was about 21 MW. The heavy summer post-cluster power flow map can be found at Appendix C1, Figure C1-2.



To ease the comparison between pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table C-3. Table C-3 highlights the magnitude (not direction) of flow.


Pre-Cluster 2012 HS

Post-Cluster





Niland-Blythe 161 kV Line (MVAR) 10 3 Imperial Valley-El Centro SW Circuit 1 &2 230 kV (MW) 80 201 Imperial Valley-El Centro W Circuit 1&2 230 kV (MVAR) 60 72 Imperial Valley – Dixieland 230 kV (MW) 396 886 Imperial Valley – Dixieland 230 kV (MVAR) 19 70 Mirage-Ramon 230 kV Line (MW) 327 472 Mirage-Ramon 230 kV Line (MVAR) 42 50 Coachella-Devers 230 kV Line (MW) 186 293 Coachella-Devers 230 kV Line (MVAR) 38 61

Path 42 (MW) 512 761 Path 42 (MVAR) 79 132

Path 46 (MW) 6401 6668

Path 49 (MW) 5035 4964

SCIT (MW) 15137 15415

Table C-3: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the heavy summer post-cluster base case are provided below. A comparison of the impact of Group 2012 Cluster projects on the IID and the interconnected transmission systems are also detailed. It must however be noted that IID, for screening purposes, typically uses identical continuous and emergency ratings for its facilities. Typically 110% of continuous rating is an acceptable emergency rating for 30 minutes.

N-0 Findings

One (1) transmission facility overload was identified during normal operating conditions. In particular, the line section from Project A-13 interconnection point to Avenue 58 161 kV substation (A-13-IP – AVE58 161 kV line) was overloaded up to 103% of the line’s rating under normal operating condition.



N-1 Findings

Four (4) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Two (2) out of the 4 transmission facility overloads are attributable to the integration of the Group 2012 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix C2, Table C2-1. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table C-4.



Rating


Pre- Cluster

Post Cluster

AVE48 – AVE58 92 KV LINE 132 MVA AVE58 – JEFERSN 92 KV LINE 92% 118%

RTAP2 – RTP3ANZA 92 KV LINE 91 MVA RTP3ANZA– RTP5DSTS 92 KV LINE 4% 122%



149% 150%



149% 150%

Table C-4: Single Element Outage Transmission Facility Overloads

N-2 Findings

Four (4) IID transmission facilities were overloaded following selected double element (N-2) outages. Three (3) out of the 4 transmission facility overloads were attributable to the integration of the Group 2012 Cluster projects. A summary of the transmission facility overloads following the double element outages is provided in Appendix C2, Tables C2-3. Provided in Table C-5 are the identified overloads which exceeded 110% of facility’s continuous rating and warrants mitigation.



Rating


Pre- Cluster

Post Cluster

NILAND – COACHELA 161 KV LINE 165 MVA

COACHELA – MIDWAY 230 KV & COACHELA – A-8 230 KV LINES

111% 119%

RTP3ANZA – RTP4SLTN 92 KV LINE 132 MVA 70% 122%

RTP4SLTN – RTP5DSTS 92 KV LINE 132 MVA 64% 116%

RTP5DSTS – RTP6OASS 92 KV LINE 132 MVA 60% 111%

Table C-5: Double Element Outage Transmission Facility Overloads

Losses


C.3.1.3 Light Winter Pre-Cluster Base Case




N-0 Findings

No transmission facility overload was identified during normal operating conditions. The pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2012 Cluster projects during the light winter operating conditions with all transmission lines in-service can be found at Appendix C1, Figure C1-4.

N-1 Findings

Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. Summary of the power flow analysis results can be found at Appendix C2, Table C2-5.


N-2 Findings

No IID transmission facility overload was identified following selected double element (N-2) outages.


Losses


C.3.1.4 Light Winter Post-Cluster Base Case In the Post-cluster analysis, the 948 MW net Group 2012 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2012 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The addition of the Group 2012 Cluster Projects caused IID system losses to increase by 25 MW. The light winter post-cluster power flow map can be found at Appendix C1, Figure C1-5.

To ease the comparison between light winter pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table C-6. Table C-6 highlights the magnitude (not direction) of the power flow on the selected facilities.




Pre-Cluster 2012 LW

Post-Cluster



Avenue 58 161/92 kV Transformer Circuit 1 (MW) 58 77 Niland 161/92 kV Transformer Circuit 1 (MW) 58 60

Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 59 73 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 582 848 Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 292 426


Niland-Blythe 161 kV Line (MVAR) 7 14 Imperial Valley-El Centro SW #1 &2 230 kV (MW) 254 357

Imperial Valley-El Centro SW #1 &2 230 kV (MVAR) 49 68 Imperial Valley – Dixieland #1 &2 230 kV (MW) 536 1000 Imperial Valley – Dixieland #1 &2 230 kV (MVAR) 5 58 Mirage-Ramon 230 kV Line (MW) 383 564 Mirage-Ramon 230 kV Line (MVAR) 39 27 Coachella-Devers 230 kV Line (MW) 215 350 Coachella-Devers 230 kV Line (MVAR) 9 13

Path 42 (MW) 597 910 Path 42 (MVAR) 50 72

Path 46 (MW) 4209 4533

Path 49 (MW) 3472 3408

SCIT (MW) 5170 5504

Table C-6: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the light winter post-cluster base case are: N-0 Findings


N-1 Findings

Three (3) IID transmission facilities were overloaded following selected single element (N-1) outages. Two (2) out of the 3 transmission facility overloads were existing overloads which persisted following the integration of the Group 2012 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix C2, Table C2-5. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table C-7.

No bus voltage deviation violation was identified following the selected single element outages.




Rating


Pre- Cluster

Post Cluster



148% 148%



148% 148%

RTAP2 – RTP3ANZA 92 KV LINE 91 MVA RTP3ANZA– RTP5DSTS 92 KV LINE 4% 125%

Table C-7: Single Element Outage Transmission Facility Overloads

N-2 Findings

One (1) IID transmission facilities was overloaded following selected double element outages. The transmission facility overload is attributable to the addition of Group 2012 Cluster projects. A summary of the transmission facility overloads following double element outages is provided in Appendix C2, Table C2-7. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table C-8.



Rating


Pre- Cluster

Post Cluster

RTAP2 – RTP3ANZA 92 KV LINE 91 MVA AVE58– RTP5DSTS 92 KV & AVE58 – COACHELA 92 KV LINES

5% 123%

Table C-8: Double Element Outages Transmission Facility Overloads

Losses


C.3.2 Transient Stability Analysis Findings

With the modeling of all the IID system upgrades proposed to mitigate the unstable conditions found for the scenario 2011, stable and adequately damped transient stability performances were achieved following all of the critical outages simulated using both the pre- and post-cluster base cases. Key findings include:



Transient voltage and frequency plots at selected critical buses which provide a representative illustration of the transmission system response following each of the critical outages studied can be found in Attachment C. The critical buses monitored included: COACHELA 230 kV, RAMON 230 kV, ELCENTSW 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVE42 92 kV.



C.3.3 Post-Transient Stability Analysis Findings Post-transient stability analysis was performed on the heavy summer pre- and post-cluster base cases. The post-transient stability analysis showed that for both cases and for all the outages simulated positive reactive margins were achieved at all the buses monitored. However, the reactive power margins at the N. LAQUIN 92 kV bus following the outage of the N. LAQUIN – AVE42 92 kV line were below IID’s acceptable minimum reactive margins. In general, the study showed that the integration of the Group 2012 Cluster Projects resulted in marginal reductions in the reactive power margins at most of the buses monitored. Detailed results of the post-transient stability analysis can be found at Appendix C3. C.3.4 Short Circuit Analysis Findings The results of the Group 2012 Cluster Short Circuit Analysis is provided in Table C-9. The maximum incremental fault duty following the integration of the Group 2012 Cluster projects was 3,956 A at the Midway 230 kV substation. The available margins at the vicinity breakers as depicted in Table C-9 showed that the interconnection of the Group 2012 Cluster projects will cause the El Centro 92 kV and the Coachella Switching Station 92 kV breakers to exceed their interruption capabilities by 649 A and 31 A respectively. Therefore, the 40, 000 A breakers at the El Centro 92 kV substation and the 22,000 A breakers at Coachella 92 kV switching station would have to be replaced with a 63, 000 A and 40,000 A respectively rated breakers prior to the interconnection of the Group 2012 Cluster projects. There are forty (40) breakers with interruption capability of 40,000 A at the El Centro 92 kV substation and one (1) breaker with interruption capability of 22,000 A at Coachella Switching Station.



Table C-9: Summary of the Short Circuit Analysis Results

C.4 MITIGATION PLANS This section details the recommended transmission upgrade projects required to mitigate overloads created following the integration of the Group 2012 Cluster Projects. The recommended upgrades have been tested and found to mitigate all the overloads identified (See Appendix C2 for power flow results). The results of the post-transient stability analysis using the post-cluster base case with the recommended transmission plans incorporated can be found in Appendix C3. Similarly, transient stability analysis was performed on the post-cluster base case with the recommended transmission plans incorporated and the system was found to be stable and adequately damped with no WECC/NERC criteria violations (See Attachment C). C.4.1 Mitigation Plans for Overloads Caused by Group 2012 Cluster Study The following transmission upgrade projects are recommended for mitigating the identified transmission overloads caused by the integration of the Group 2012 Cluster projects to the IID transmission system.


Breaker

Rating

(A)

Pre- Cluster Max

(3LG, 1LG) Fault

Current (A)

Available

Margins

(A)

Post-Cluster

Max (3LG, 1LG)

Fault Current (A)

Project

Contribution

(A)

ANZA ANZA 92 30,000 3,019 26,981 6,553 3,534

CARREON CARREON 92 40,000 11,386 28,614 11,532 146

CENTRAL CENTRAL 92 40,000 14,925 25,075 15,114 190

CLARK CLARK 92 40,000 16,829 23,171 17,016 187

CLPT-PRISON CALIPATRIA PRISON 92 40,000 10,887 29,113 10,928 40

COACHELA COACHELLA SW STA 92 22,000 21,633 367 22,031 398




DAHLIA DAHLIA 92 64,000 16,839 47,161 17,029 189

DESERT SHORE DESERT SHORES 92 40,000 4,129 35,871 5,266 1,137

DIXIE-PRISON DIXIELAND PRISON 92 40,000 13,543 26,457 13,974 430

DIXIELAND DIXIELAND 92 40,000 19,044 20,956 19,983 939

DROP4 DROP 4 92 40,000 14,757 25,243 14,847 90

ELCENTSW EL CENTRO SW STA 92 40,000 39,881 119 40,649 768

ELCENTSW EL CENTRO SW STA 161 16,000 10,305 5,695 10,933 628


ELMORE-92 k (CALENERGY) ELMORE 92 31,500 7,107 24,393 7,169 62

EUCLID EUCLID 92 64,000 18,449 45,551 18,679 230

FRANCES WAY- FRANCES WAY 92 40,000 10,027 29,973 10,049 22

GATEWAY-92 GATEWAY 92 40,000 11,319 28,681 11,377 58

HEBER HEBER 92 40,000 14,012 25,988 14,117 105

HEBERSCE HGC PLANT (HEBER SCE) 92 20,000 13,974 6,026 14,077 103


HIGHLINE92 HIGHLINE 92 40,000 20,391 19,609 20,705 315

MIDWAY230 MIDWAY 230 40,000 13,758 26,242 17,713 3,956

MIDWAY92 MIDWAY 92 40,000 17,377 22,623 19,328 1,951

SANFELIP SAN FELIPE 92 10,000 2,188 7,813 2,888 701

SHIELDS SHIELDS 92 64,000 13,426 50,574 13,619 193




Replace the existing Avenue 58 – Avenue 48 92 kV line with a 191 MVA, 900 MCM ACSS conductor

Rebuild the RTP3ANZA – RTP5DSTS 92 kV line with a 191 MVA, 900 MCM ACSS conductor

New 8.5-mile, 560 MVA, 2-1590 MCM ACSS bundled 230 kV line from Midway to Hudson Ranch

New 24-mile, 560 MVA, 2-1590 MCM ACSS bundled 230 kV line from Hudson Ranch to Banister

Replace the existing Avenue 58 – El Centro 161 kV line (24.5-mile Bannister to El Centro section) with 2-1033 MCM ACSR bundled 230 kV conductors. Terminate one circuit at El Centro. Extend the other circuit to Dixieland to from Bannister- Dixieland 230 kV line.

Install a new 225 MVA, 230/161 kV transformer at Bannister

Implement a Special Protection System to trip generation at Midway 92 kV. Summary of the overloaded transmission facilities and the associated recommended transmission facilities are also provided in Tables C-10. C.5 COST AND COSTRUCTION TIMELINES The estimated cost for the recommended network upgrades for mitigating the impact of the Group 2012 Cluster Projects is $ 127.6 Million. The detail network upgrade cost and the construction timelines for implementing the upgrades are provided in Table C-11.



Worst Outage Element (s) Overloaded Facility

Applicable

Rating

Post- Cluster


NORMAL OPERATIONS (N-0 )

ALL LINES IN SERVICE A-13-IP – AVENUE 58 161 KV LINE

165 MVA 103%

New 8.5-mile , 230 kV line from Midway to Hudson Ranch using 560 MVA, 2-1590 MCM ACSS bundled conductors These new transmission

lines and interconnection points help to mitigate the costly upgrade of the Avenue 58 – El Centro 161 kV line. These upgrades also ameliorate the reliability of the entire transmission system following selected double element outages from Midway to SCE transmission system

New 24-mile 230 kV line from Hudson Ranch to Bannister using 560 MVA, 2-1590 MCM ACSS bundled conductors

Rebuild ―L‖ line between Bannister and A121P tap and BTAP-DTP 15.5 Miles with 2 circuits of 2-1033 ACSR

Install 225 MVA, 230/161 kV transformer at Bannister

Interconnect Project A-8 to Banister 230 kV substation

Interconnect Project A-12 to the new Bannister – Dixieland 230 kV line

Interconnect Project A-1 to Hudson Ranch 230 kV substation

SINGLE ELEMENT OUTAGE (N-1

AVE58 – JEFERSN 92 KV LINE AVE48 – AVE58 92 KV LINE 132 MVA 121% Reconductor the 6.5-mile using 191 MVA, 900 MCM ACSS 92 kV Conductor

None

RTP3ANZA– RTP5DSTS 92 KV LINE

RTAP2 – RTP3ANZA 92 KV LINE


DOUBLE ELEMENT OUTAGE (N-2)

COACHELA – MIDWAY 230 KV & COACHELA– A-8 230 KV LINES

NILAND – COACHELA 161 KV LINE

165 MVA 119%

Implement a Special Protection Scheme to trip generation at Midway 92 kV and the new cluster projects at Midway

None

RTP3ANZA – RTP4SLTN 92 KV LINE

132 MVA 122%

RTP4SLTN – RTP5DSTS 92 KV LINE

132 MVA 116%

RTP5DSTS – RTP6OASS 92 KV LINE

132 MVA 111%

Table C-10: Summary of Transmission Facility Overloads and Associated Mitigation Plan



Table C-11: Recommended Mitigation Plan & Associated Cost for Group 2012 Cluster Projects



Cost

Estim ate ($

M i l l ion)

Construction

Tim e L ines

(M onths) Notes


resources (Shunt capacitors)3.41 24 None

One Breaker replacement at

Coachella Valley 92 kV substation 0.13 N/A

Installation cost for

replacing the breaker

New 8.5-mile 230 kV line from Midway

– Hudson RanchIID Budget 24

Upgrade Midway 230 kV Substation 10.41 30

New 24-mile 230 kV line from Hudson

Ranch to Bannister44.70 30

Rebuild "L" line between Bannister

and A121P tap and BTAP-DTP 15.5

miles with 2 circuits of 2-1033 ACSR

35.65 36

Install 225 MVA, 230/161 kV

transformer and build Bannister

substation

21.37 30

AVE48 – AVE58 92 KV LINE AVE58 – JEFERSN 92 KV LINE 132 MVA 121%Reconductor line using 191 MVA, 900

MCM ACSS 92 kV Conductor5.85 18 None

RTAP2 – RTP3ANZA 92 KV LINE RTP3ANZA– RTP5DSTS 92 KV LINE 91 MVA 126%Rebuild line using 191 MVA, 900 MCM

ACSS 92 kV Conductor6.21 30 None

NILAND – COACHELA 161 KV LINE 165 MVA 119%

RTP3ANZA – RTP4SLTN 92 KV LINE 132 MVA 122%

RTP4SLTN – RTP5DSTS 92 KV LINE 132 MVA 116%

RTP5DSTS – RTP6OASS 92 KV LINE 132 MVA 111%

COACHELA – MIDWAY 230 KV &

COACHELA– A-8 230 KV LINES

Implement a Remedial Action Scheme

to trip generation at MidwayN/A

NORMAL OPERATIONS (N-0)

12Already included in 2011

Budget

165 MVA 103%

None N/A N/A N/A

None


A-13 (POI) – AVENUE 58 161 KV LINE



Appendix C1

Power flow Maps



Figure C1-1: Power flow Map—2012 Heavy Summer Pre-Cluster Base Case



Figure C1-2: Power flow Map—2012 Heavy Summer Post-Cluster Base Case



Figure C1-3: Power flow Map—2012 Heavy Summer Post-Cluster w/ Mitigation Base Case



Figure C1-4: Power flow Map—2012 Light Winter Pre-Cluster Base Case



Figure C1-5: Power flow Map—2012 Light Winter Post-Cluster Base Case



Figure C1 6: Power flow Map—2012 Light Winter Post-Cluster w/Mitigation Base Case



Appendix C2




Table C2-1: Summary of 2012 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads



8639 A-13-IP 161 8806 AV58TP1 161 1 Line 8 165 Base 65% 103% 71% No outage (N-0)



8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_C005 60% 108% 112% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1


8378 RTP4SLTN 92 8379 RTP5DSTS 92 1 Line 8 132 B230_C005 55% 103% 106% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1

8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_C017 53% 99% 104% Line COACHELA 230.0 to A-8 230.0 Circuit 1

8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_L007 53% 99% 104% Line COACHELA 230.0 to MIDWAY 230.0 Circuit 1

8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B161_C009 55% 104% 103% Line AV58TP1 161.0 to A-13-IP 161.0 Circuit 1

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B161_C009 101% 110% 103% Line AV58TP1 161.0 to A-13-IP 161.0 Circuit 1

8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_C018 52% 97% 102% Line Midway 230.0 to A-8 230.0 Circuit 1

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B92_L030 94% 95% 102% Line NEW MECCA to AVE 52 92.0 Circuit 1

8074 DIXIE230 230 22356 IMPRLVLY 230 2 Line 8 786 B230_C001 57% 105% 87% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1

8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 250 B161_T002 83% 102% 73% Tran AVE58 92.00 to AV58 161.00 Circuit 1

8291 AVE48 92 8281 AVE58 92 1 Line 8 132 B92_L007 92% 118% 64% Line AVE58 92.0 to JEFERSN 92.0 Circuit 1

8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 B92_L028 4% 122% 59% Line RTP3-ANZA 92.0 to Desert Shores 92.0 Circuit 1

Summary of 2012 Heavy Summer Power Flow Analysis Results-- N-1 Thermal Overloads



Table C2-2: Summary of 2012 Heavy Summer Power Flow Analysis Results— N-1 Voltage Deviation Violations



Summary of 2012 Heavy Summer Power Flow Analysis--N-1 Voltage Deviation Violations

None



Table C2-3: Summary of 2012 Heavy Summer Power Flow Analysis Results— N-2 Thermal Overloads



8291 AVE48 92 8281 AVE58 92 1 Line 8 132 C92_L020 81% 105% 69% Loss of Transmission from AVE42 to MONROE(CW)92kV & from AVE42 to SHAHILLS(CI)92

8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 C230_C007 70% 122% 126% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C230_C007 111% 119% 126% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit

8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 C230_C008 67% 119% 123% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C230_C008 107% 115% 122% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit

8378 RTP4SLTN 92 8379 RTP5DSTS 92 1 Line 8 132 C230_C007 64% 116% 120% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit

8378 RTP4SLTN 92 8379 RTP5DSTS 92 1 Line 8 132 C230_C008 61% 112% 117% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit

8379 RTP5DSTS 92 8380 RTP6OASS 92 1 Line 8 132 C230_C007 60% 111% 115% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit

8379 RTP5DSTS 92 8380 RTP6OASS 92 1 Line 8 132 C230_C008 57% 108% 112% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit

8082 RKMTAP 92 8380 RTP6OASS 92 1 Line 8 132 C230_C007 48% 99% 103% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C92_L011A 93% 94% 101% Loss of Transmission from AVE58 to COACHELLA(R)92kV & from MECCA to COACHELLA(NE

8691 HIGHLINE 92 8093 HIGH161 161 1 Tran 8 125 C230_C007 53% 102% 99% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit

8301 CITAP1 92 8312 COACHELA 92 1 Line 8 191 C92_L013 93% 108% 71% Loss of Transmission from AVE58 to JEFFERSON(CD)92kV & from AVE58 to AVE48(CS)92

8301 CITAP1 92 8389 VANBUREN 92 1 Line 8 191 C92_L013 93% 108% 71% Loss of Transmission from AVE58 to JEFFERSON(CD)92kV & from AVE58 to AVE48(CS)92

8690 HIGHLINE 230 8105 A-7TAP1 230 1 Line 8 389 C230_C007 N/A 104% 55% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit

8105 A-7TAP1 230 8019 A-7 230 1 Line 8 393 C230_C007 N/A 103% 55% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit

8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 C92_L010 16% 107% 52% Loss of Transmission from AVE58 TO RTP5DSTS(R)92kV & from Ave 58 to COACHELLA(R)

8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 C230_C007 104% 45% 25% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit




Table C2-4: Summary of 2012 Heavy Summer Power Flow Analysis Results— N-2 Voltage Deviation Violations



Summary of 2012 Heavy Summer Power Flow Analysis Results--N-2 Bus Voltage Deviation Violations

NONE



Table C2-5: Summary of 2012 Light Winter Power Flow Analysis Results— N-1 Thermal Overloads






8695 RAMON 230 24806 MIRAGE 230 1 Line 8 779 B230_L001 77% 102% 93% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1

8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 B92_L028 4% 125% 61% Line RTP3-ANZA 92.0 to Desert Shores 92.0 Circuit 1

8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 B92_L026 5% 123% 60% Line AVE58 92.0 to OASIS 92.0 Circuit 1




Table C2-6: Summary of 2012 Light Winter Power Flow Analysis Results— N-1 Voltage Deviation Violations



Summary of 2012 Light Winter Power Flow Analysis Results-- N-1 Bus Voltage Deviation Violations

NONE



Table C2-7: Summary of 2012 Light Winter Power Flow Analysis Results— N-2 Thermal Overloads



8361 NILAND 92 8059 NILTAP92 92 1 Line 8 132 C230_C007 81% 79% 104% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit

8361 NILAND 92 8059 NILTAP92 92 1 Line 8 132 C230_C008 78% 77% 101% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit

8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 C92_L010 5% 123% 60% Loss of Transmission from AVE58 TO RTP5DSTS(R)92kV & from Ave 58 to COACHELLA(R)

8690 HIGHLINE 230 8699 MIDWAY 230 2 Line 8 389 C230_L003 49% 104% 48% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1, COACHELA 230 to RAMON Circuit 1




Table C2-8: Summary of 2012 Light Winter Power Flow Analysis Results— N-2 Voltage Deviation Violations



Summary of 2012 Light Winter Power Flow Analysis Results--N-2 Voltage Deviation Violations

NONE



Appendix C3




Table C3-1: Summary of 2012 Heavy Summer Post-Transient Stability Analysis Results

Outage




8805 AV58 161 kV 232 203 207

8808 CVSUB161 161 kV 276 243 248

8292 N.LAQUIN 92 kV 80 68 70

8312 COACHELA 92 kV 335 297 306

8700 MIDWAY 92 kV 207 234 243

8361 NILAND 92 kV 318 296 298

8335 ELSTEAMP 92 kV 707 637 643

8397 CLX92 92 kV 324 304 305

8369 PILOTKNB 92 kV 153 141 142

8319 DIXIELAN 92 kV 468 437 439


8805 AV58 161 kV 270 236 242

8808 CVSUB161 161 kV 302 271 277

8292 N.LAQUIN 92 kV 217 194 208

8312 COACHELA 92 kV 364 330 340

8700 MIDWAY 92 kV 211 238 247

8361 NILAND 92 kV 325 303 306

8335 ELSTEAMP 92 kV 697 641 647

8397 CLX92 92 kV 315 296 297

8369 PILOTKNB 92 kV 155 145 145

8319 DIXIELAN 92 kV 465 438 440



Table C3-2: Summary of 2012 Heavy Summer Post-Transient Stability Analysis Results (Continued)

Outage




8805 AV58 161 kV 244 206 213

8808 CVSUB161 161 kV 272 237 243

8292 N.LAQUIN 92 kV 197 171 184

8312 COACHELA 92 kV 330 290 300

8700 MIDWAY 92 kV 195 224 234

8361 NILAND 92 kV 310 287 290

8335 ELSTEAMP 92 kV 690 617 625

8397 CLX92 92 kV 321 300 300

8369 PILOTKNB 92 kV 151 140 140

8319 DIXIELAN 92 kV 463 431 433


8805 AV58 161 kV 280 246 252

8808 CVSUB161 161 kV 312 283 288

8292 N.LAQUIN 92 kV 224 203 216

8312 COACHELA 92 kV 377 345 354

8700 MIDWAY 92 kV 220 245 253

8361 NILAND 92 kV 334 316 318

8335 ELSTEAMP 92 kV 728 665 672

8397 CLX92 92 kV 326 308 309

8369 PILOTKNB 92 kV 162 154 154

8319 DIXIELAN 92 kV 471 440 443




Outage




8805 AV58 161 kV 244 198 205

8808 CVSUB161 161 kV 272 228 234

8292 N.LAQUIN 92 kV 197 164 177

8312 COACHELA 92 kV 330 279 288

8700 MIDWAY 92 kV 194 218 228

8361 NILAND 92 kV 310 278 281

8335 ELSTEAMP 92 kV 683 578 589

8397 CLX92 92 kV 321 296 297

8369 PILOTKNB 92 kV 150 136 137

8319 DIXIELAN 92 kV 461 422 424


8805 AV58 161 kV 263 227 233

8808 CVSUB161 161 kV 293 261 266

8292 N.LAQUIN 92 kV 212 188 201

8312 COACHELA 92 kV 356 319 329

8700 MIDWAY 92 kV 208 235 244

8361 NILAND 92 kV 323 302 304

8335 ELSTEAMP 92 kV 718 653 660

8397 CLX92 92 kV 325 306 308

8369 PILOTKNB 92 kV 153 142 142

8319 DIXIELAN 92 kV 471 442 444




Outage




8805 AV58 161 kV 245 229 236

8808 CVSUB161 161 kV 271 259 266

8292 N.LAQUIN 92 kV 189 182 195

8312 COACHELA 92 kV 300 293 302

8700 MIDWAY 92 kV 203 239 248

8361 NILAND 92 kV 324 309 311

8335 ELSTEAMP 92 kV 699 639 647

8397 CLX92 92 kV 326 309 309

8369 PILOTKNB 92 kV 151 137 137

8319 DIXIELAN 92 kV 471 444 446


8805 AV58 161 kV 250 215 222

8808 CVSUB161 161 kV 277 247 252

8292 N.LAQUIN 92 kV 201 176 189

8312 COACHELA 92 kV 324 291 301

8700 MIDWAY 92 kV 197 227 237

8361 NILAND 92 kV 319 296 299

8335 ELSTEAMP 92 kV 697 625 634

8397 CLX92 92 kV 324 303 305

8369 PILOTKNB 92 kV 152 139 139

8319 DIXIELAN 92 kV 468 435 438






D.1 INTRODUCTION

Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Cluster System Impact Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These projects plan to deliver power to IID and several IID neighboring utilities in the 2010-2015 timeframe. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. Projects with different phases of implementation were grouped in the year in which the first phase becomes operational. This section of the report details the study assumptions, methodology and results of Group 2014 Cluster Study. The Group 2014 Cluster Study contains four proposed generation projects totaling 435 MW. Provided below are the projects and their interconnection information.

Project Code Capacity POI In-service Date A-2-4 70 MW Midway 230 kV 04/01/2014 A-2-5 70 MW Midway 230 kV 01/01/2015 A-2-6 70 MW Midway 230 kV 10/01/2015 A-4 225 MW Midway 230 kV 05/01/2014

The Group 2014 Cluster Study was performed using approved WECC 2014 heavy summer and 2013 light winter power flow models. Studies performed included power flow, transient stability, post-transient stability and short circuit analyses. D.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS

D.2.1 Base Case Assumptions


Heavy summer . . . . 14hs2sa.sav ………...Approved 07/23/2008

Light winter . . . . . . 13lw1sa1.sav…………Approved 01/07/2009

Both power flow base cases were selected because they were the most recently developed and available base cases in the WECC library based on planned in-service dates of the Group 2014 Cluster Projects. Pre-cluster base cases were developed from the starting base cases by incorporating IID detailed system representation. IID system loads, resources, and topology were adjusted to reflect the conditions expected in 2014 when the Group 2014 Cluster projects plan to initiate operations. It was noted that existing generation resources at Imperial Valley were operating at a very low output level (78 MW) in the pre-cluster base case. The outputs of the Imperial Valley generation resources were maintained at the pre-cluster level. Cluster projects and other queued generation projects with planned interconnection to IID transmission system prior to summer 2014 were modeled in the pre-cluster base cases.



The following new and existing transmission projects which were recommended for mitigating the Group 2012 Cluster projects impacts were incorporated into the 2014 pre-cluster base cases:

AVENUE 58 – AVENUE 48 92 kV line (191 MVA, 900 MCM ACSS)

RTP3ANZA – RTP5DSTS 92 kV line (191 MVA, 900 MCM ACSS )

New MIDWAY – HUDSON RANCH 230 KV LINE (560 MVA, 2-1590 MCM ACSS)

New HUDSON RANCH – BANNISTER 230 kV line (560 MVA, 2-1590 MCM ACSS)

New BANNISTER – EL CENTRO 230 kV line (786 MVA, 2-1033 MCM ACSR)

New BANNISTER – DIXIELAND 230 kV line (786 MVA, 2-1033 MCM ACSR)

New 225 MVA, 230/161 kV transformer at Bannister While it is impossible to study all IID transmission system flows and generation levels during all seasons, these two pre-cluster base cases represent extreme generation and transmission flows that will potentially expose any transmission constraints at the Group 2014 projects interconnection points. D.2.2 Base Cases Studied Two pre-cluster base cases were developed for the Group 2014 Cluster Study. The pre-cluster base cases were initially tested to ensure that all transmission facilities in IID control area are within their normal operating limits and this provided a benchmark for post-cluster evaluations. Two post-cluster base cases were developed from the pre-cluster base cases by modeling the Group 2014 Cluster projects. Project A-2 (which comprises of A-2-4, A-2-5 and A-2-6) was interconnected to Hudson Ranch 230 kV substation in lieu of Midway 230 kV substation due to the transmission reconfiguration recommended following the Group 2012 Cluster Study. The output of the Group 2014 Cluster projects were dispatched and scheduled according to the information provided on each projects interconnection application. The four base cases developed for studying the impact of the Group 2014 Cluster Projects are summarized in Table D-1.




2014 Light Winter 2014 LW Pre-Cluster Planned IID light winter configuration without the Group 2014Cluster projects


Table D-1: Study Base Cases-Group 2014 Cluster Study



D.2.3 Load and Resources The IID load and Resources for the four base cases studied are provided in Table D-2. Table D-2 also depicts IID transmission system losses and area interchange flows for both pre- and post- cluster base cases. The area interchange flows for the receiving entities for the Group 2014 projects power outputs are highlighted in Table D-2.


Pre-Cluster 2014 HS

Post-Cluster 2014LW


Load (MW) 1179 1195 311 326

Load (MVAR) 460 470 97 106

Losses (MW) 82 100 68 89

Losses (MVAR) 724 942 643 897

Interchange (MW) 1888 2287 2446 2854





LADWP Interchange (MW) 1780 1984 189 21 Table D-2: Summary of Load and Resources

D.2.4 Dynamic Models Dynamic data files ―14hs2s1.dyd‖ and ―13lw1s1.dyd‖ developed for use with WECC power flow models ―14hs2sa.sav― and ―13lw1sa1.sav― respectively were used for the transient stability analysis. New ―motorw‖ data for the IID control area were created and added to the dynamic data files. The stability models used for the Group 2014 Cluster Study were user written algorithms and other dynamic data contained in each project’s interconnection application. D.2.5 Short Circuit Data The machine data used for the Group 2014 Cluster Study short circuit analysis were contained in each project’s interconnection application.



D.3 STUDY RESULTS This section provides the results obtained by applying the stated study assumptions and the general study methodology. It illustrates the findings associated with the power flow, transient stability and post-transient stability analyses for both the pre- and post-cluster base cases. D.3.1 Power Flow Analysis Findings This section details the findings of the power flow analysis. WECC/NERC reliability criteria were used to assess the adequacy of the study results.

D.3.1.1 Heavy Summer Pre-Cluster Base Case

The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. A pre-cluster power flow map that depicts the power flow distribution at the points of interconnections of the Group 2014 Cluster projects during the heavy summer operating condition can be found at Appendix D1, Figure D1-1. Key findings from the power flow analysis using the Heavy Summer Pre-cluster Base Case include:

N-0 Findings


N-1 Findings

Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. Summary of the pre-project overloaded facilities can be found at Appendix D2, Table D2-1.

Two (2) bus voltage deviation violations were observed following the selected single element outages. A summary of the voltage deviation violations can be found at Appendix D2, Table D2-2.

N-2 Findings

No IID transmission facility was overloaded following selected double element (N-2) outages.


Losses

IID system losses in the heavy summer pre-cluster base case were 82 MW.

D.3.1.2 Heavy Summer Post-Cluster Base Case

In the Post-cluster analysis, the Group 2014 Cluster project’s output were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the integration of the Group 2014 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group 2014 Cluster Projects to IID system losses during heavy summer operating condition was about



18 MW. The heavy summer post-cluster power flow map can be found at Appendix D1, Figure D1-2.

To ease the comparison between pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table D-3. Table D-3 highlights the magnitude (not direction) of the power flow on the selected transmission facilities.


Pre-Cluster 2014 HS

Post-Cluster



Avenue 58 161/92 kV Transformer Circuit 1 (MW) 130 135 Niland 161/92 kV Transformer Circuit 1 (MW) 53 59 Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 114 117 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 578 703



Niland-Blythe 161 kV Line (MVAR) 11 6 Imperial Valley-El Centro SW #1 &2 230 kV (MW) 422 546 Imperial Valley-El Centro SW #1 &2 230 kV (MVAR) 37 11 Imperial Valley – Dixieland #1 &2 230 kV (MW) 918 1016

Imperial Valley – Dixieland #1 &2 230 kV (MVAR) 58 30 Mirage-Ramon 230 kV Line (MW) 353 449 Mirage-Ramon 230 kV Line (MVAR) 67 19 Coachella-Devers 230 kV Line (MW) 223 301 Coachella-Devers 230 kV Line (MVAR) 1 24

Path 42 (MW) 575 747


Path 46 (MW) 8586 8833

Path 49 (MW) 6854 6870

SCIT (MW) 14645 14909

Table D-3: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the heavy summer post-cluster base case are provided below. A comparison of the impact of Group 2014 Cluster projects on the IID and the interconnected transmission systems are also detailed. It must however be noted that IID, for screening purposes, typically uses identical continuous and emergency ratings for its facilities. Typically 110% of continuous rating is an acceptable emergency rating for 30 minutes.

N-0 Findings

No transmission facility overload was identified during normal operating conditions.



N-1 Findings

Three (3) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Two (2) out of the 3 transmission facility overloads were existing overloads which persisted following the integration of the Group 2014 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix D2, Table D2-1. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table D-4.

Two (2) bus voltage deviation violations were observed following the selected single element outages. The bus voltage violations were pre-existing violations which persisted following the interconnection and subsequent dispatch of the Group 2014 cluster projects. A summary of the voltage deviation violations can be found at Appendix D2, Table D2-2.


Rating


Pre- Cluster

Post Cluster



149% 149%



149% 149%

IMPERIAL VALLEY – DIXIELAND #1 230 KV LINE

786 MVA IMPERIAL VALLEY – DIXIELAND #1 230 KV LINE

100% 111%

Table D-4: Single Element Outage Transmission Facility Overloads

N-2 findings

No transmission facility overload was identified following selected double element outages.


Losses


D.3.1.3 Light Winter Pre-Cluster Base Case


N-0 Findings

No transmission facility overload was identified during normal operating conditions. The pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2014 Cluster projects during the light winter operating conditions with all transmission lines in-service can be found at Appendix D1, Figure D1-4.



N-1 Findings

Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. A summary of the power flow analysis results can be found at Appendix D2, Table D2-5.


N-2 Findings

No transmission facility overloads was identified following selected double element (N-2) outages.


Losses


D.3.1.4 Light Winter Post-Cluster Base Case In the Post-Cluster analysis, the Group 2014 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2014 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group 2014 Cluster Projects to IID system losses during light winter operating condition was about 21 MW. The light winter post-cluster power flow map can be found at Appendix D1, Figure D1-5.

To ease the comparison between light winter pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in TableD-5. Table D-5 highlights the magnitude (not direction) of flow.

Element (unit of measure) 2014LW

Pre-Cluster 2014 LW

Post-Cluster





Niland-Blythe 161 kV Line (MVAR) 10 14 Imperial Valley-El Centro SW 230 kV (MW) 454 557 Imperial Valley-El Centro SW 230 kV (MVAR) 54 31 Imperial Valley – Dixieland 230 kV (MW) 961 1059 Imperial Valley – Dixieland 230 kV (MVAR) 69 48

Mirage-Ramon 230 kV Line (MW) 513 524 Mirage-Ramon 230 kV Line (MVAR) 29 72 Coachella-Devers 230 kV Line (MW) 314 395 Coachella-Devers 230 kV Line (MVAR) 22 36



Path 42 (MW) 824 1004 Path 42 (MVAR) 74 154

Path 46 (MW) 4488 4739

Path 49 (MW) 3401 3399

SCIT (MW) 5411 5699

Table D-5: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the light winter post-cluster base case are: N-0 Findings


N-1 Findings

Four (4) IID transmission facilities were overloaded following selected single element (N-1) outages. Two (2) out of the 4 transmission facility overloads were existing overloads which persisted or exacerbated following the integration of the Group 2014 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix D2, Table D2-5. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table D-6.



Rating


Pre- Cluster

Post Cluster



148% 148%



148% 148%

DIXIE230 – IMPERIAL VALLEY #2 230 KV LINE

786 MVA DIXIE230 – IMPERIAL VALLEY #1 230 KV LINE

105% 117%

RAMON – MIRAGE 230 KV LINE 779 MVA COACHELA – DEVERS 230 KV LINE 92% 114%

Table D-6: Single Element Outage Transmission Facility Overloads

N-2 Findings

Five (5) transmission facilities were overloaded following selected double element (N-2) outages. A summary of the transmission facility overloads following double element outages is provided in Appendix D2, Table D2-7. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table D-7.





Rating


Pre- Cluster

Post Cluster

RAMON 230/92 KV TRANSFORMER 225 MVA

COACHELA – DEVERS 230 KV & COACHELA – RAMON 230 KV LINES (W/RAS)

107% 132%

N. VIEW – AVE42 92 KV LINE 132 MVA 97% 121%

N. VIEW – RAMON 92 KV LINE 132 MVA 93% 116%

AVE42 – FRANWAY 92 KV LINE 132 MVA 92% 114%

FRANWAY – EDOM 92 KV LINE 132 MVA 90% 112%

Table D-7: Double Element Outages Transmission Facility Overloads

Losses


D.3.2 Transient Stability Analysis Findings

Stable and adequately damped transient stability performances were achieved following all of the critical outages simulated using both the pre- and post-cluster base cases. Key findings include:



Transient voltage and frequency plots at selected critical buses which provide a representative illustration of the transmission system response following each of the critical outages studied can be found in Attachment C. The critical buses monitored included: COACHELA 230 kV, RAMON 230 kV, ELCENTSW 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVE42 92 kV.

D.3.3 Post-Transient Stability Analysis Findings

Post-transient stability analysis was performed on the heavy summer pre- and post-cluster base cases. The post-transient stability analysis showed that for both cases and for all the outages simulated positive reactive margins were achieved at all the buses monitored. However, the reactive power margins at the N. LAQUIN 92 kV bus following the outage of the N. LAQUIN – AVE42 92 kV line were below IID’s acceptable minimum reactive margins. In general, the study showed that the integration of the Group 2014 Cluster Projects resulted in marginal reductions in the reactive power margins at most of the buses monitored. Detailed results of the post-transient stability analysis can be found at Appendix D3.



D.3.4 Short Circuit Analysis Findings The results of the Group 2012 Cluster Short Circuit Analysis is provided in Table D-8. It was assumed in this analysis that the 40,000 A El Centro 92 kV breakers and the 22,000 A Breaker at Coachella Switching Station have been replaced with 63,000 A Breakers and 40,000 A Breaker respectively. The maximum incremental fault duty following the integration of the Group 2014 Cluster projects was 7,039 A at the Ramon 230 kV substation. The available margins at the vicinity breakers as depicted in Table D-8 indicate that the interconnection of the Group 2012 Cluster projects will not cause any IID breakers to exceed their interruption capabilities.

Table D-8: Summary of the Short Circuit Analysis Results


Breaker

Rating

(A)

Pre- Cluster Max

(3LG, 1LG) Fault

Current (A)

Available

Margins

(A)

Post-Cluster

Max (3LG, 1LG)

Fault Current (A)

Project

Contribution

(A)

AVE-52 AVE. 52 92 40,000 17,293 22,707 17,857 564

AVE.42 N.BUS AVE. 42 92 40,000 15,243 24,757 17,053 1,810

AVE48 AVE. 48 92 40,000 11,871 28,129 12,648 776

AVE58-161KV AVE. 58 161 40,000 10,296 29,704 10,529 233

AVE58-92 AVE. 58 92 40,000 15,464 24,536 16,216 752

CARREON CARREON 92 40,000 11,532 28,468 12,304 772

COACHELA COACHELLA SW STA 92 40,000 22,031 17,970 22,635 605

COLMAC92 COLMAC 92 40,000 8,577 31,423 8,669 92




EDOM EDOM 92 40,000 12,082 27,918 16,624 4,542




FRANCES WAY- FRANCES WAY 92 40,000 10,049 29,951 11,534 1,485

HEBERSCE HGC PLANT (HEBER SCE) 92 20,000 14,077 5,923 14,097 20

HIGHLINE230 HIGHLINE 230 40,000 19,697 20,303 20,655 958

JACKSON JACKSON 92 31,500 10,757 20,743 11,289 532

JEFFERSON92 JEFFERSON 92 40,000 10,383 29,618 10,834 451

LAQUINTA92 LA QUINTA 92 40,000 10,084 29,916 10,659 575

MARSHALL MARSHALL 92 40,000 9,801 30,199 10,268 467

MIDWAY230 MIDWAY 230 40,000 17,713 22,287 21,071 3,358

MIDWAY92 MIDWAY 92 40,000 19,328 20,672 20,195 867

MONROE MONROE 92 40,000 12,664 27,336 13,725 1,061

N. LA QUINTA NORTH LA QUINTA 92 40,000 10,941 29,059 11,696 755

NILAND NILAND 92 40,000 15,489 24,511 15,641 152

NILAND NILAND 161 40,000 8,826 31,174 9,533 707

NORTHVIEW NORTH VIEW 92 40,000 11,244 28,756 13,030 1,786

RAMON RAMON 92 40,000 14,063 25,937 21,102 7,039

RAMON RAMON 230 40,000 25,710 14,290 26,335 626

SHADOW HILLS SHADOW HILLS 92 40,000 12,474 27,526 13,236 762

SHIELDS SHIELDS 92 64,000 13,619 50,381 14,925 1,306

VANBUREN VAN BUREN 92 40,000 12,808 27,192 13,451 644




D.4 MITIGATION PLANS This section details the recommended transmission upgrade projects required to mitigate overloads created following the integration of the Group 2014 Cluster Projects. The recommended upgrades have been tested and found to mitigate all the overloads identified (See Appendix D2 for power flow results). The results of the post-transient stability analysis for the post-cluster base case with the recommended transmission plans incorporated can be found in Appendix D3. Similarly, transient stability analysis was performed on the post-cluster base case with the recommended transmission plans incorporated and the transmission system was found to be stable and adequately damped with no WECC/NERC criteria violations (See Attachment D).

D.4.1 Mitigation Plans for Overloads Caused by Group 2014 Cluster Study

The following transmission upgrade projects are recommended for mitigating the identified transmission overloads caused by the integration of the Group 2014 Cluster projects to the IID transmission system.

Construct 8-mile Dixieland – Imperial Valley 230 kV lines with a 887 MVA, 2-1033 MCM ACSS conductor

Construct 8-mile Ramon – Mirage 230 kV line with a 887 MVA, 2-1033 MCM ACSS conductor

Install a second 225 MVA 230/92 kV transformer at Ramon

Rebuild the 11.6-mile from Avenue 42 to N. view to Ramon using a 191 MVA, 900 MCM ACSS 92 kV conductor

Rebuild the 13.7-mile from Avenue 42 to Francis Way to Edom using a 191 MVA, 900 MCM ACSS 92 kV conductor

Implement Breaker-and-Half configuration at Coachella. Summary of the overloaded transmission facilities and the associated recommended transmission facilities are also provided in Tables D-9. D.5 COST AND CONSTRUCTION TIMELINES The estimated cost for the recommended network upgrades for the Group 2014 Cluster Projects is $ 37.3 Million. The detail network upgrade cost and the construction timelines for implementing the upgrades are provided in Table D-10.



Worst Outage Element (s) Overloaded Facility

Applicable

Rating

Post- Cluster


NORMAL CONDITION (N-0)

ALL LINES IN SERVICE N/A N/A N/A Implement Breaker-and-Half Configuration at Coachella Valley

This will ensure that under double element outages of

Coachella – Devers & Coachella –Ramon 230 kV

lines, both Coachella 230/92 kV transformers will be in

service.

SINGLE ELEMENT (N-1 )

DIXIELAND – IMPERIAL VALLEY #1 230 KV LINE


786 MVA 117% Construct the 8-mile Dixieland – Imperial Valley 230 kV lines using 887 MVA, 2-1033 MCM ACSS 230 kV Conductor

These lines have already been recommended for upgrades in 2010-2011. Build lines using higher ampacity conductors



786 MVA 117%


RAMON – MIRAGE 230 KV LINE

779 MVA 114%

Construct the 8-mile Ramon – Mirage 230 kV line using 887 MVA, 2-1033 MCM ACSS 230 kV Conductor

DOUBLE ELEMENT OUTAGE (N-2)

COACHELA – DEVERS 230 KV & COACHELA– RAMON 230 KV LINES (W/ RAS)

RAMON 230/92 KV TRANSFORMER

225 MVA 132% Install a second 225 MVA, 230/92 kV transformer at RAMON

None

N. VIEW – AVE42 92 KV LINE

132 MVA 121% Rebuild 11.6-mile line from Avenue 42- N. View - Ramon using 191 MVA, 900 ACSS 92 kV Conductor

None N. VIEW – RAMON 92 KV LINE

132 MVA 116%

AVE42 – FRANWAY 92 KV LINE

132 MVA 114% Rebuild 13.7-mile line from Avenue 42- Francis Way - Edom using 191 MVA, 900 ACSS92 kV Conductor

None FRANWAY – EDOM 92 KV LINE

132 MVA 112%

Table D-9: Summary of Transmission Facility Overloads and Associated Mitigation Plan



Table D-10: Recommended Mitigation Plan & Associated Cost for Group 2014 Cluster Projects

Overloaded Facilities Critical OutageApplicable

RatingsLoadings Recommended Mitigation

Cost Estimate

($ Million)

Construction Time

Lines (Months)Notes

Implement Breaker-and-one half

configuration at Coachella Valley

substation

13.49 18




Install a second 225 MVA transformer at

Ramon8.35 24





24

None

Network Upgrades Attributable to Group 2014 Cluster Projects


COACHELA– RAMON KV LINES Rebuild lines using 191 MVA, 900

ACSS Conductor

5.39

6.65

NONE N/A N/A N/A



Appendix D1

Power flow Maps



Figure D1-1: Power flow Map—2014 Heavy Summer Pre-Cluster Base Case



Figure D1-2: Power flow Map—2014 Heavy Summer Post-Cluster Base Case



Figure D1-3: Power flow Map—2014 Heavy Summer Post-Cluster w/ Mitigation Base Case



Figure D1-4: Power flow Map—2014 Light Winter Pre-Cluster Base Case



Figure D1 5: Power flow Map—2014 Light Winter Post-Cluster Base Case



Figure D1 6: Power flow Map—2014 Light Winter Post-Cluster w/Mitigation Base Case



Appendix D2




Table D2-1: Summary of 2014 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads






8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_C005 106% 108% 108% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 line_265 104% 104% 104% line BLYTHESC to BLYTHE 161 ck 1

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B161_C009 103% 104% 103% Line AV58TP1 161.0 to A-13-IP 161.0 Circuit 1

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B92_L030 103% 103% 103% Line NEW MECCA to AVE 52 92.0 Circuit 1

8378 RTP4SLTN 92 8379 RTP5DSTS 92 1 Line 8 132 B230_C005 100% 102% 102% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1


Summary of 2014 Heavy Summer Power Flow Analysis Results-- N-1 Thermal Overloads



Table D2-2: Summary of 2014 Heavy Summer Power Flow Analysis Results— N-1 Voltage Deviation Violations



8286 LAQUINTA 92 8 B92_L014 5.42% 5.69% 5.71% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1

8292 N.LAQUIN 92 8 B92_L014 5.63% 5.90% 5.93% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1

Summary of 2014 Heavy Summer Power Flow Analysis--N-1 Voltage Deviation Violations



Table D2-3: Summary of 2014 Heavy Summer Power Flow Analysis Results— N-2 Thermal Overloads



8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C92_L011A 102% 102% 102% Loss of Transmission from AVE58 to COACHELLA(R)92kV & from MECCA to COACHELLA(NE)

8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C230_T001 102% 102% 99% Tran CVSUB 92.00 to COACHELA 230.00 CK1 & CK2







Summary of 2014 Heavy Summer Power Flow Analysis Results--N-2 Voltage Deviation Violations

NONE



Table D2-5: Summary of 2014 Light Winter Power Flow Analysis Results— N-1 Thermal Overloads






8695 RAMON 230 24806 MIRAGE 230 1 Line 8 779 B230_L001 92% 114% 72% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1







Summary of 2014 Light Winter Power Flow Analysis Results-- N-1 Voltage Deviation Violations

NONE



Table D2-7: Summary of 2014 Light Winter Power Flow Analysis Results— N-2 Thermal Overloads



8640 RAMON92 92 8695 RAMON 230 1 Tran 8 225 230_L004 107% 132% 80% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8289 N.VIEW 92 8309 AVE42 92 1 Line 8 132 230_L004 97% 121% 100% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8289 N.VIEW 92 8640 RAMON92 92 1 Line 8 132 230_L004 93% 116% 97% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8309 AVE42 92 8310 FRANWAY 92 1 Line 8 132 230_L004 92% 114% 75% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS

8310 FRANWAY 92 8330 EDOM 92 1 Line 8 132 230_L004 90% 112% 74% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS







Summary of 2014 Light Winter Power Flow Analysis Results--N-2 Voltage Deviation Violations

NONE



Appendix D3




Table D3-1: Summary of 2014 Heavy Summer Post-Transient Stability Analysis Results

Outage




8805 AV58 161 kV 168 175 221

8808 CVSUB161 161 kV 208 215 271

8292 N.LAQUIN 92 kV 64 67 70

8312 COACHELA 92 kV 291 216 339

8700 MIDWAY 92 kV 249 266 266

8361 NILAND 92 kV 317 309 327

8335 ELSTEAMP 92 kV 638 602 619

8397 CLX92 92 kV 305 287 288

8369 PILOTKNB 92 kV 158 172 172

8319 DIXIELAN 92 kV 366 303 304


8805 AV58 161 kV 241 244 262

8808 CVSUB161 161 kV 277 281 303

8292 N.LAQUIN 92 kV 201 207 232

8312 COACHELA 92 kV 324 330 381

8700 MIDWAY 92 kV 253 269 270

8361 NILAND 92 kV 322 313 331

8335 ELSTEAMP 92 kV 634 598 613

8397 CLX92 92 kV 296 278 279

8369 PILOTKNB 92 kV 160 155 155

8319 DIXIELAN 92 kV 367 303 305



Table D3-2: Summary of 2014 Heavy Summer Post-Transient Stability Analysis Results (Continued)

Outage



PALO VERDE – DEVERS 500 kV LINE

8805 AV58 161 kV 206 207 224

8808 CVSUB161 161 kV 237 239 260

8292 N.LAQUIN 92 kV 172 176 199

8312 COACHELA 92 kV 287 288 319

8700 MIDWAY 92 kV 236 253 253

8361 NILAND 92 kV 305 296 315

8335 ELSTEAMP 92 kV 610 577 596

8397 CLX92 92 kV 297 279 281

8369 PILOTKNB 92 kV 157 171 171

8319 DIXIELAN 92 kV 352 289 292


8805 AV58 161 kV 252 259 276

8808 CVSUB161 161 kV 286 295 317

8292 N.LAQUIN 92 kV 207 217 241

8312 COACHELA 92 kV 333 356 392

8700 MIDWAY 92 kV 254 272 272

8361 NILAND 92 kV 321 315 335

8335 ELSTEAMP 92 kV 597 565 579

8397 CLX92 92 kV 292 275 276

8369 PILOTKNB 92 kV 184 163 181

8319 DIXIELAN 92 kV 345 283 283




Outage



IMPERIAL VALLEY – MIGUEL 500 kV LINE

8805 AV58 161 kV 205 204 221

8808 CVSUB161 161 kV 237 236 258

8292 N.LAQUIN 92 kV 171 174 197

8312 COACHELA 92 kV 277 283 316

8700 MIDWAY 92 kV 233 249 250

8361 NILAND 92 kV 304 292 311

8335 ELSTEAMP 92 kV 585 545 568

8397 CLX92 92 kV 293 275 277

8369 PILOTKNB 92 kV 157 170 151

8319 DIXIELAN 92 kV 342 279 281


8805 AV58 161 kV 234 236 254

8808 CVSUB161 161 kV 269 273 295

8292 N.LAQUIN 92 kV 196 201 226

8312 COACHELA 92 kV 326 322 365

8700 MIDWAY 92 kV 250 267 267

8361 NILAND 92 kV 323 316 334

8335 ELSTEAMP 92 kV 654 617 633

8397 CLX92 92 kV 308 289 291

8369 PILOTKNB 92 kV 176 172 154

8319 DIXIELAN 92 kV 371 308 309




Outage




8805 AV58 161 kV 234 248 263

8808 CVSUB161 161 kV 267 283 300

8292 N.LAQUIN 92 kV 190 205 223

8312 COACHELA 92 kV 291 308 343

8700 MIDWAY 92 kV 254 274 275

8361 NILAND 92 kV 333 332 348

8335 ELSTEAMP 92 kV 651 621 635

8397 CLX92 92 kV 310 293 294

8369 PILOTKNB 92 kV 176 171 152

8319 DIXIELAN 92 kV 373 312 312


8805 AV58 161 kV 226 229 246

8808 CVSUB161 161 kV 260 264 285

8292 N.LAQUIN 92 kV 188 193 217

8312 COACHELA 92 kV 306 310 349

8700 MIDWAY 92 kV 245 263 263

8361 NILAND 92 kV 322 314 331

8335 ELSTEAMP 92 kV 641 603 619

8397 CLX92 92 kV 306 287 288

8369 PILOTKNB 92 kV 176 171 171

8319 DIXIELAN 92 kV 367 301 303




Outage



IMPERIAL VALLEY – ELCENTRO #1 &2 230 kV LINES

8805 AV58 161 kV 223 220 237

8808 CVSUB161 161 kV 258 255 276

8292 N.LAQUIN 92 kV 188 188 212

8312 COACHELA 92 kV 312 308 347

8700 MIDWAY 92 kV 242 256 256

8361 NILAND 92 kV 317 305 323

8335 ELSTEAMP 92 kV 606 566 583

8397 CLX92 92 kV 304 283 285

8369 PILOTKNB 92 kV 156 150 169

8319 DIXIELAN 92 kV 359 289 290

IMPERIAL VALLEY – DIXIELAND #1 &2 230 kV LINES

8805 AV58 161 kV 202 201 220

8808 CVSUB161 161 kV 234 232 255

8292 N.LAQUIN 92 kV 171 173 198

8312 COACHELA 92 kV 278 280 314

8700 MIDWAY 92 kV 230 247 248

8361 NILAND 92 kV 291 279 299

8335 ELSTEAMP 92 kV 432 407 429

8397 CLX92 92 kV 273 256 259

8369 PILOTKNB 92 kV 150 162 144

8319 DIXIELAN 92 kV 254 221 224

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