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Q219 Generator
Interconnection Project
System Impact Study
APS Contract No. 52698
By
Arizona Public Service Company
Transmission Planning
June 5, 2015 Version 3.1
Prepared by Jason Spitzkoff Arizona Public Service Company
Ben Stephenson, P.E. Utility System Efficiencies, Inc.
Page 1
Q219 SYSTEM IMPACT STUDY
TABLE OF CONTENTS
EXECUTIVE SUMMARY .................................................................................................................................. 4
1 Study Description and Assumptions ................................................................................................. 7
1.1 Study Cases ................................................................................................................................... 9
1.2 Interconnection Modeling .......................................................................................................... 13
1.3 Dynamic Data .............................................................................................................................. 14
1.4 Reliability Criteria ........................................................................................................................ 14
1.4.1 Power Factor Criteria ....................................................................................................... 14
1.4.2 (Steady State) Power Flow Criteria ............................................................................... 14
1.4.3 Transient Stability Criteria ............................................................................................... 15
2 Study Methodology ......................................................................................................................... 16
2.1 Power Factor Requirements ....................................................................................................... 16
2.2 Power Flow ................................................................................................................................. 16
2.3 Post-Transient ............................................................................................................................. 17
2.4 Transient Stability ....................................................................................................................... 17
2.5 Short Circuit ................................................................................................................................ 18
3 Results and Findings ........................................................................................................................ 18
3.1 Power Factor Capability Results ................................................................................................. 18
3.2 Peak Load Thermal Results ......................................................................................................... 19
3.3 Light Load Thermal Results ......................................................................................................... 20
3.4 Follow-Up Scenario Thermal Results .......................................................................................... 22
3.5 Affected Systems Review ............................................................................................................ 22
3.6 Voltage Results ............................................................................................................................ 23
3.7 Transient Stability Analysis ......................................................................................................... 23
3.8 Short Circuit / Fault Duty Analysis .............................................................................................. 25
3.9 Results & Findings Summary ....................................................................................................... 26
3.10 Network Resource Interconnection Service ............................................................................... 28
4 Cost & Construction Time Estimates .............................................................................................. 28
4.1 Network Upgrades ...................................................................................................................... 28
4.2 Transmission Provider’s Interconnection Facilities (TPIF) .......................................................... 31
4.3 Project Estimate Summary .......................................................................................................... 32
LIST OF APPENDICES Appendix A – List of Contingencies Appendix B – Power Flow Diagrams Appendix C – Dynamic Data Appendix D – Transient Stability Plots Appendix E – Supplemental Mitigation Study
Page 2
List of Acronyms
ACC Arizona Corporation Commission ACSS Aluminum Conductor Steel Supported ANPP Arizona Nuclear Power Project APS Arizona Public Service ASLD Arizona State Land Department ATC Available Transfer Capability CAISO California Independent System Operator Corporation CAWCD Central Arizona Water Conservation District CCVT Coupling Capacitor Voltage Transformer COD Commercial Operation Date COO Change of Ownership CSP Concentrated Solar Power CT Combustion Turbine or Current Transformer DCTL Double-Circuit Tower Line EA Environmental Assessment EPE El Paso Electric EPNG El Paso Natural Gas ER Energy Resource ERIS Energy Resource Interconnection Service FaS Facilities Study FERC Federal Energy Regulatory Commission FeS Feasibility Study GT Gas Turbine IC Interconnection Customer IID Imperial Irrigation District IR Interconnection Request LADWP Los Angeles Department of Water and Power LGIA Large Generator Interconnection Agreement NEC Navopache Electric Cooperative NEPA National Environmental Policy Act NERC North American Electric Reliability Corporation NR Network Resource NRIS Network Resource Interconnection Service NTUA Navajo Tribal Utility Authority OASIS Open Access Same Time Information System OATT Open Access Transmission Tariff PG&E Pacific Gas & Electric PNM Public Service Company of New Mexico POI Point Of Interconnection PPA Purchase Power Agreement PSLF/PSDS/SCSC Positive Sequence Load Flow/Positive Sequence Dynamic
Simulation/Short-Circuit Saturation Curve PST Phase-Shifting Transformer PV Photovoltaic RAS Remedial Action Scheme (also known as SPS) RFP Request for Proposal ROW Right-of-Way SCE Southern California Edison Company SDG&E San Diego Gas & Electric Company
Page 3
SIS System Impact Study SLG fault Single Line-to-Ground fault SPS Special Protection System (also known as RAS) SRP Salt River Project SSVEC Sulphur Springs Valley Electric Cooperative, Inc. SVC Static VAR Compensator SVD Static VAR Device SWTC Southwest Transmission Cooperative TEP Tucson Electric Power TPIF Transmission Provider’s Interconnection Facilities WAPA or Western Western Area Power Administration WECC Western Electricity Coordinating Council
Q219 System Impact Study APS Contract No. 52698
Page 4
EXECUTIVE SUMMARY
This section summarizes the System Impact Study (SIS) results for a proposed generator interconnection facility connected to the Arizona Public Service (APS) proposed future Jojoba 230 kV bus. The gas-powered facility is planned to be completed in 2018 and capable of 577 MW in the summer and 626 MW in the winter. The customer has requested the project be studied as both a Network and as an Energy Resource. The results of this SIS indicate that the addition of Q219 creates overloads to the following facilities:
Gila River 500/230 kV transformer
Liberty-Rudd 230 kV line
Jojoba-TS4 230 kV line
TS4-Liberty 230 kV line
Gillespie-Patterson 69 kV line
Patterson-Komatke 69 kV line Due to the already-constrained 69 kV network, the project may interconnect up to 5 MW without any network upgrade. Table E-1 summarizes the network upgrades required to achieve full output of the project. Two transmission network upgrade alternatives are evaluated for consideration. Alternative 1 is to add a new Jojoba 500/230 kV transformer
1. Alternative 2 is to construct a second circuit from Jojoba to
TS4. Alternative 2 will also require a RAS to trip the Q219 project in the unlikely event of a double circuit tower line outage between Jojoba and TS4. This study found that neither Alternative alone is sufficient. Additional miscellaneous network upgrades are also required as listed.
Table E-1. Network Upgrades for Q219
Upgrades Required
Gillespie-Patterson 69 kV Upgrade
Patterson-Komatke 69 kV Upgrade
Jojoba-TS4-Liberty 230 kV Upgrade
Liberty-Rudd 230 kV Mitigation and/or Upgrade
Alternative 1: Jojoba 500/230 kV Transformer
Alternative 2: Jojoba-TS4 #2 230 kV Line, Q219 RAS
The results of both Alternatives are shown throughout the report. Both options give similar reliability benefits. However, after investigating both options the feasibility of constructing Alternative 2 has significantly more risk along with a longer timeframe and higher cost. Alternative 1 will be the mitigation APS is proposing for this interconnection and will be the option estimated in Section 4 of this report. Short Circuit studies for Palo Verde and Hassayampa switchyards are currently being performed by
ANPP owners. At this point of time, any conclusions with regard of fault duties at Palo Verde and
Hassayampa are premature. The interconnector Q219 is to be aware that high costs associated with
mitigation of short circuit problems are probable and might be imposed on the interconnector.
Additional information and specific details of the project's impact on the surrounding transmission system can be found in the “Results and Findings Summary” Section 3.7 of this report. Western Area Power Administration (Western) and Salt River Project (SRP) have been identified as Affected Systems. A copy of this study report was provided to them for review and comment. Their
1 This option will require an interconnection request to ANPP; the joint owners of the Jojoba 500 kV
switchyard.
Q219 System Impact Study APS Contract No. 52698
Page 5
comments have been incorporated into this report along with the need for further follow-up by the IC with both companies.
Disclaimer Nothing in this report constitutes an offer of transmission service or confers upon the Interconnection Customer (IC or customer) any right to receive transmission service. APS and other interconnected utilities may not have the Available Transmission Capacity (ATC) to support the interconnection described in this report. It should also be noted that all results for the SIS are highly dependent upon the assumed topology and timing of new projects in the vicinity of the interconnection, which are subject to change. Background: APS received a valid large generator interconnection request for a proposed interconnection to the location of a potential future 230kV substation; Jojoba 230 kV bus
2. Currently, APS has no commitment to
build this 230kV substation. This site is only identified in APS’s plans as the potential site of a future substation if system conditions warrant its construction. On behalf of, and with the oversight of APS, Utility System Efficiencies, Inc. (USE) performed this SIS under the APS Tariff. Power flow, post-transient, transient stability, and short circuit analysis are performed for this study. Machine parameters and characteristics provided by the customer are applied to the power flow, dynamic, and short circuit models. This study considers the interconnection under anticipated 2018 summer peak and light load conditions with various sensitivity scenarios applied. Select contingencies which stress the transmission system to various degrees are simulated for all analyses. Results are monitored for APS, SRP, WAPA, and other neighboring systems. Figure E-2 illustrates this proposed generator interconnection location and the nearby transmission facilities.
2 APS is currently in the process of construction a 69 kV substation at this site which was recently
renamed as the Komatke switchyard. The 230 kV portion of the yard may be alternatively referred to in various documents as Komatke or Jojoba.
Q219 System Impact Study APS Contract No. 52698
Page 6
Figure E-2. Q219 and Nearby Transmission Facilities
Nearby generation interconnection projects in the APS queue of interest are:
APS Q192 – 20 MW of solar at Komatke 69 kV as ER. Non-FERC Gila Bend Interconnection Projects
Gila Bend: 36 MW at the Gila Bend 12.47 kV buses - planned in-service in 2014.
Gillespie: 10 MW at the Gillespie 12.47 kV bus - planned in-service in 2015.
Lukefield: 10 MW at the Lukefield 12.47 kV bus - planned in-service in 2015.
System performance criteria used in the study: The criteria applied in this study are consistent with NERC/WECC Reliability Criteria. For more detailed information on the criteria used for each analysis see section 1.4 “Reliability Criteria.” The APS Open Access Transmission Tariff (OATT) policy regarding power factor requires all Interconnection Customers, with the exception of wind generators, to maintain an acceptable power factor (typically near unity) at the Point of Interconnection (POI), subject to system conditions. The APS OATT also requires Interconnection Customers to be able to achieve +/- 0.95 power factor at the POI, with the maximum "full-output" reactive capability available at all outputs. Furthermore, APS requires Interconnection Customers to have dynamic voltage control and maintain the voltage as specified by the transmission operator within the limitation of +/- 0.95 power factor, as long as the Project is online and generating. If the Project’s equipment is not capable of this type of response, a dynamic reactive device will be required. APS has the right to disconnect the Project if system conditions dictate the need to do so in order to maintain system reliability.
Gila River 500 kV
#1-11
CT CT CT CT CT CT
Q#219 577 MW (S) 626 MW (W)
230 kV
#1 #2
(Hassayampa)
Panda
500 kV Jojoba
230 kV Solana
230 kV Gila Bend
(69 kV)
230 kV
(Pinal West)
(Kyrene)
(Liberty) (Palm Valley)
TS4
Q219 System Impact Study APS Contract No. 52698
Page 7
1 Study Description and Assumptions
This section of the report provides details pertaining to the power flow case development and an overview of the major study assumptions. All power flow, post-transient, and transient stability study work is performed using General Electric’s Positive Sequence Load Flow (GE-PSLF), version 18.1_02. The 2018 Heavy Summer APS detailed planning case “sm18#14.sav” is used for this study. This case has undergone review and updates by all of the Arizona utilities including: SRP, APS, WAPA, SWTC, and TEP. The case originates from the WECC 2018 HS2A approved base case. The corresponding dynamic data file is used for transient stability analysis. The light load case is derived from the heavy summer case. Transmission Projects Assumed In-Service For All Scenarios The following nearby transmission projects are modeled in all cases:
Hassayampa-North Gila #2 500kV line planned for 2015.
Delaney-Sun Valley 500kV line planned for 2016.
Palo Verde-Delaney 500kV line planned for 2016.
Sun Valley-Trilby Wash 230kV line planned for 2016.
Trilby Wash-Palm Valley 230kV line planned for 2015.
Sun Valley-Morgan 500 kV line planned for 2018. Generation Assumed Online For All Scenarios The following nearby generation interconnection projects are modeled in all cases:
APS Q192 – 20 MW of solar at Komatke 69 kV as ER. Non-FERC Gila Bend Interconnection Projects
County Line: 17 MW at the County Line 12.47 kV bus #1 - in-service.
County Line: 18 MW at the County Line 12.47 kV bus #2 - in-service.
Cotton Center: 18 MW at the Cotton Center 12.47 kV bus #1 - in-service.
Cotton Center: 18 MW at the Cotton Center 12.47 kV bus #2 - in-service.
Saddle Mountain: 15 MW at the Saddle Mountain 12.47 kV bus - in-service.
Gila Bend: 36 MW at the Gila Bend 12.47 kV buses - planned in-service in 2014.
Badger: 15 MW at the Badger 12.47 kV bus - in-service.
Gillespie: 15 MW at the Gillespie West 12.47 kV bus - in-service.
Gillespie: 10 MW at the Gillespie 12.47 kV bus - planned in-service in 2015.
Lukefield: 10 MW at the Lukefield 12.47 kV bus - planned in-service in 2015.
Generation Dispatch Assumptions Sensitivity cases are run to assess the impacts of offsetting Q219 at various locations:
Offset output of Q219 within the APS network or resources APS currently has contracts for. The generation is offset at Gila River and Arlington in the heavy summer case. The generation is offset at Rocking Chair East and West, Yucca CT 5 and 6, Cholla 1, and the remaining 278.8 MW is offset in CA in the light load case.
Offset output of Q219 throughout the AZ and adjacent systems as described in Table 1-1.
All new generation added to the cases are offset throughout the AZ and adjacent systems proportionally according to load as follows:
Q219 System Impact Study APS Contract No. 52698
Page 8
Table 1-1. Generation System Distribution
Area 2018 Case
Load Allocation
Area 10 (NM) 3,169 3%
Area 11 (EPE) 2,113 2%
Area 14 (AZ) 22,113 19%
Area 18 (NV) 6,817 6%
Area 21 (IID) 1,188 1%
Area 22 (SDG&E) 5,656 5%
Area 24 (SCE) 25,003 21%
Area 26 (LADWP) 7,740 7%
Area 30 (PG&E) 28,941 25%
Area 70 (CO) 8,299 7%
Area 73 (WAPA RM) 5,736 5%
The generation reduction will be distributed across each area according to their generation output. Base loaded units will be ignored.
Q219 System Impact Study APS Contract No. 52698
Page 9
1.1 Study Cases
A total of 16 initial cases and 5 follow-up cases are necessary to evaluate the potential network upgrade projects required to allow full output of Q219 under both peak load and light load conditions. The impact of ER interconnection (generation offset distributed to the system) and NR interconnection (generation offset within the APS network) are evaluated. The sufficiency of the following network upgrade projects are evaluated under NR/ER and heavy/light load conditions:
Panda-Jojoba-TS4-Liberty 230 kV line upgrade to 3000 A
Gillespie-Patterson-Komatke 69 kV line upgrade to 1600 A
Jojoba 500/230 kV transformer (as a sensitivity; Alternative 1)
Jojoba-TS4 #2 230 kV line (as a sensitivity; Alternative 2)
Table 1-2. Study Case Summary
# Scenario Description Pan
da-J
ojo
ba-T
S4-L
ibe
rty U
pg
rad
e
Gille
sp
ie-P
att
ers
on
-Ko
matk
e U
pg
rad
e
Alt
. 1:
Jo
job
a 5
00/2
30 k
V T
ran
sfo
rmer
Alt
. 2:
Jo
job
a-T
S4 #
2 2
30 k
V L
ine
Q192
Offset
AP
S N
etw
ork
Syste
m
2018 Heavy Summer (peak)
1. Pre-Project √
2. Post-Project √ √
3. Post-Project, upgrades √ √ √ √
4. Post-Project, upgrades √ √ √ √
5. Post-Project, upgrades, JJ 500/230 kV xfmr √ √ √ √ √
6. Post-Project, upgrades, JJ 500/230 kV xfmr √ √ √ √ √
7. Post-Project, upgrades, JJ-TS4 230 kV #2 √ √ √ √ √
8. Post-Project, upgrades, JJ-TS4 230 kV #2 √ √ √ √ √
2018 Light Load (off-peak)
9. Pre-Project √
10. Post-Project √ √
11. Post-Project, upgrades √ √ √ √
12. Post-Project, upgrades √ √ √ √
13. Post-Project, upgrades, JJ 500/230 kV xfmr √ √ √ √ √
14. Post-Project, upgrades, JJ 500/230 kV xfmr √ √ √ √ √
15. Post-Project, upgrades, JJ-TS4 230 kV #2 √ √ √ √ √
16. Post-Project, upgrades, JJ-TS4 230 kV #2 √ √ √ √ √
2018 Follow-Up Scenarios
20. Pre-Project, JJ 500/230 kV xfmr (peak) √ √
21. Post-Project, JJ 500/230 kV xfmr (peak) √ √ √
22. Post-Project, JJ 500/230 kV xfmr, 69 kV upgrades (peak) √ √ √ √
23. Post-Project, JJ 500/230 kV xfmr, 230 kV upgrades (peak) √ √ √ √
24. Post-Project, JJ 500/230 kV xfmr (off-peak) √ √ √
The resulting power flow attributes observed in the case described above are listed in Tables 1-3 and 1-4
on the following pages.
Q219 System Impact Study APS Contract No. 52698
Page 10
Table 1-3. Heavy Summer Study Case Attributes
Major Branch Flows (MW)
Base Scenario With 230 kV & 69 kV Upgrades
With 230 kV & 69 kV Upgrades Jojoba 500/230
With 230 kV & 69 kV Upgrades Jojoba-TS4 #2
Pre-Project
Post-Project
(Sys)
Post-Project
(Sys)
Post-Project (APS)
Post-Project
(Sys)
Post-Project (APS)
Post-Project
(Sys)
Post-Project (APS)
Path 46: West of River 5,108 5,359 5,358 5,115 5,358 5,116 5,359 5,118
Path 49: East of River 2,378 2,691 2,690 2,383 2,690 2,382 2,691 2,383
Path 50: Cholla-Pinnacle Peak 704 686 685 699 685 700 683 698
Palo Verde East + Delaney-SV 8,070 8,101 8,062 7,701 8,083 7,735 7,960 7,604
Delaney-Sun Valley 500 kV Line 694 690 686 651 688 655 675 640
Palo Verde-Delaney 500 kV Line 695 691 687 652 689 655 675 641
Sun Valley-Morgan 500 kV Line 368 402 403 370 403 370 403 371
N.Gila-Imperial Valley 500 kV Line 1,386 1,454 1,454 1,378 1,454 1,379 1,451 1,376
Hassayampa-Qx #1 500 kV Line 510 549 549 505 549 505 547 503
Hoodoo Wash-N.Gila 500 kV Line 1,012 1,051 1,051 1,007 1,051 1,007 1,049 1,005
Hassayampa-N.Gila #2 500 kV Line 597 634 634 592 634 592 632 590
Hassayampa-Pinal West 500 kV Line 1,217 1,224 1,222 1,198 1,223 1,200 1,217 1,193
Hassayampa-Jojoba 500 kV Line -170 -319 -290 96 -305 71 -212 170
Jojoba-Kyrene 500 kV Line 1,943 1,983 1,972 1,842 1,979 1,853 1,943 1,814
Gila River-Jojoba #1 500 kV Line 1,059 1,154 1,133 874 1,128 865 1,079 823
Gila River-Jojoba #2 500 kV Line 1,059 1,154 1,133 874 1,128 865 1,079 823
Gila River 500/230 kV Xfmr 97 -94 -53 -89 -42 -71 55 14
Panda-Gila Bend 230 kV Line 59 70 67 62 66 62 57 53
Panda-Jojoba 230 kV Line 317 115 160 128 171 147 277 240
Jojoba-TS4 #1 230 kV Line 313 692 736 704 715 669 426 408
TS4-Liberty 230 kV Line 149 433 465 433 449 408 555 519
TS4-Palm Valley 230 kV Line 161 244 262 263 257 254 292 291
Liberty-Rudd 230 kV Line 147 252 264 269 257 258 300 304
Alt 1: Jojoba 500/230 kV Xfmr 0 0 0 0 -33 -54 0 0
Alt 2: Jojoba-TS4 #2 230 kV Line 0 0 0 0 0 0 426 408
Arizona Area 14 (incl. WALC)
Arizona Load 21,275 21,282 21,282 21,282 21,282 21,282 21,282 21,282
Arizona Losses 833 837 830 831 830 830 825 826
Arizona Generation 27,498 27,978 27,970 27,504 27,970 27,503 27,965 27,499
Arizona Interchange 5,390 5,858 5,858 5,391 5,859 5,390 5,858 5,390
Case 1 2 3 4 5 6 7 8
Q219 System Impact Study APS Contract No. 52698
Page 11
Table 1-4. Light Load Study Case Attributes
Major Branch Flows (MW)
Base Scenario With 230 kV & 69 kV Upgrades
With 230 kV & 69 kV Upgrades Jojoba 500/230
With 230 kV & 69 kV Upgrades Jojoba-TS4 #2
Pre-Project
Post-Project
(Sys)
Post-Project
(Sys)
Post-Project (APS)
Post-Project
(Sys)
Post-Project (APS)
Post-Project
(Sys)
Post-Project (APS)
Path 46: West of River 5,139 5,431 5,431 5,358 5,429 5,356 5,432 5,359
Path 49: East of River 2,399 2,756 2,756 2,596 2,753 2,594 2,756 2,596
Path 50: Cholla-Pinnacle Peak 492 472 472 433 474 435 471 432
Palo Verde East + Delaney-SV 3,897 3,921 3,894 3,860 3,123 3,999 3,808 3,774
Delaney-Sun Valley 500 kV Line 276 272 269 261 285 277 259 251
Palo Verde-Delaney 500 kV Line 276 272 269 261 285 277 259 251
Sun Valley-Morgan 500 kV Line 91 128 128 120 128 120 129 121
N.Gila-Imperial Valley 500 kV Line 1,308 1,387 1,387 1,404 1,390 1,408 1,385 1,402
Hassayampa-Qx #1 500 kV Line 460 504 504 543 506 545 503 542
Hoodoo Wash-N.Gila 500 kV Line 962 1,006 1,006 1,045 1,008 1,047 1,005 1,043
Hassayampa-N.Gila #2 500 kV Line 549 591 591 628 593 630 589 627
Hassayampa-Pinal West 500 kV Line 900 903 902 908 908 914 898 904
Hassayampa-Jojoba 500 kV Line 307 141 160 167 55 61 226 233
Jojoba-Kyrene 500 kV Line 975 1,016 1,008 1,016 1,048 1,057 983 991
Gila River-Jojoba #1 500 kV Line 334 438 424 425 383 384 379 380
Gila River-Jojoba #2 500 kV Line 334 438 424 425 383 384 379 380
Gila River 500/230 kV Xfmr -117 -324 -297 -298 -215 -216 -206 -208
Panda-Gila Bend 230 kV Line -25 -13 -15 -16 -18 -19 -23 -24
Panda-Jojoba 230 kV Line 187 -32 -3 -4 82 82 96 95
Jojoba-TS4 #1 230 kV Line 185 594 623 622 481 478 361 361
TS4-Liberty 230 kV Line 133 441 462 459 358 354 538 534
TS4-Palm Valley 230 kV Line 51 141 155 157 119 121 181 183
Liberty-Rudd 230 kV Line 52 167 175 179 129 133 205 210
Alt 1: Jojoba 500/230 kV Xfmr 0 0 0 0 -227 -229 0 0
Alt 2: Jojoba-TS4 #2 230 kV Line 0 0 0 0 0 0 361 361
Arizona Area 14 (incl. WALC)
Arizona Load 13,509 13,517 13,517 13,517 13,517 13,517 13,517 13,517
Arizona Losses 581 586 581 578 578 574 579 575
Arizona Generation 19,480 20,038 20,033 19,764 20,030 19,760 20,030 19,761
Arizona Interchange 5,390 5,935 5,935 5,669 5,935 5,669 5,935 5,669
Case 9 10 11 12 13 14 15 16
Q219 System Impact Study APS Contract No. 52698
Page 12
Table 1-5. Follow-Up Study Case Attributes
Major Branch Flows (MW)
wJJ Xfmr wJJ Xfmr 69 kV Upg
wJJ Xfmr 230 kV Upg
wJJ Xfmr Off-Peak
Pre-Project
Post-Project
(Sys)
Post-Project
(Sys)
Post-Project (APS)
Post-Project
(Sys)
Path 46: West of River 5,110 5,357 5,357 5,358 5,428
Path 49: East of River 2,380 2,690 2,690 2,690 2,753
Path 50: Cholla-Pinnacle Peak 703 686 686 685 475
Palo Verde East + Delaney-SV 7,958 8,143 8,142 8,087 4,072
Delaney-Sun Valley 500 kV Line 681 695 695 689 289
Palo Verde-Delaney 500 kV Line 682 696 696 689 289
Sun Valley-Morgan 500 kV Line 369 402 402 403 127
N.Gila-Imperial Valley 500 kV Line 1,383 1,455 1,455 1,454 1,391
Hassayampa-Qx #1 500 kV Line 508 550 550 549 507
Hoodoo Wash-N.Gila 500 kV Line 1,011 1,052 1,052 1,051 1,009
Hassayampa-N.Gila #2 500 kV Line 595 635 635 634 593
Hassayampa-Pinal West 500 kV Line 1,212 1,226 1,226 1,223 910
Hassayampa-Jojoba 500 kV Line -83 -351 -350 -308 24
Jojoba-Kyrene 500 kV Line 1,912 1,997 1,997 1,980 1,060
Gila River-Jojoba #1 500 kV Line 1,095 1,141 1,141 1,134 391
Gila River-Jojoba #2 500 kV Line 1,095 1,141 1,141 1,134 391
Gila River 500/230 kV Xfmr 24 -69 -69 -54 -231
Panda-Gila Bend 230 kV Line 62 69 71 67 -17
Panda-Jojoba 230 kV Line 242 140 140 158 64
Jojoba-TS4 #1 230 kV Line 430 647 647 709 436
TS4-Liberty 230 kV Line 234 401 400 445 327
TS4-Palm Valley 230 kV Line 189 233 233 255 103
Liberty-Rudd 230 kV Line 184 238 238 256 117
Alt 1: Jojoba 500/230 kV Xfmr 190 -69 -69 -25 -254
Alt 2: Jojoba-TS4 #2 230 kV Line 0 0 0 0 0
Arizona Area 14 (incl. WALC)
Arizona Load 21,275 21,282 21,282 21,282 13,517
Arizona Losses 834 836 835 830 580
Arizona Generation 27,499 27,976 27,976 27,970 20,032
Arizona Interchange 5,390 5,858 5,858 5,858 5,935
Case 20 21 22 23 24
Q219 System Impact Study APS Contract No. 52698
Page 13
1.2 Interconnection Modeling
APS Q219 connects to a 230 kV bus at the Jojoba location. The detailed power flow model of the project is depicted in Figure 1-6 below. The project is comprised of six combustion turbines (CT) that total 577 MW net. Each CT unit has a dedicated 13.8/230 kV Generator Step-Up (GSU) transformer. Each GSU connects to a common 230 kV bus that is then connected to the Jojoba 230 kV bus. The gross power capability for each CT unit is 97.5 MW in the summer and 105.7 MW in the winter. The reactive power capability for each CT unit is +60.4/-35.8 MVAr in the summer and +65.6/-38.8 MVAr in the winter. The project is required to be capable of +/- 0.95 power factor at the Point of Interconnection.
Figure 1-6. Q219 Power Flow Model
Power flow diagrams of the transmission system along with the new generation interconnection are provided in Appendix A.
Jojoba 230 kV
Q219
Gross Pmax: 585 (S)/634.2 (W)
Net Pmax: 577 (S)/626 (W)
13.8 kV
Each CTG
155.059 MVA
Pmax: 97.5 MW (S) 105.7 MW (W)
Qmin/max: +60.4/-35.8 MVAr (S) +65.6/-38.8 MVAr (W)
MVAbase: 75
Rating: 125
235/13.8 kV
Z: 10%
X/R: 34
230 kV
Q219 System Impact Study APS Contract No. 52698
Page 14
1.3 Dynamic Data
Appendix C provides details of the dynamic model used to model the project. Modeling for the new generation utilizes machine characteristics provided by the Applicant in the Large Generator Interconnection Application (LGIA). The exciter model parameters required adjustment in order to achieve a flat run. Specifically, "Kp" the exciter field voltage source gain was adjusted to 11.3724 from 32.6746, and "Kd" the exciter internal reactance was adjusted to 1.623 from 5.866. Additionally, the inertia constant, "H," was adjusted from 1.1 to 1.99 after follow up interaction with the customer. All changes were agreed upon between APS and the Q219 customer. Transient stability plots of the outages simulated are provided in Appendix D.
1.4 Reliability Criteria
In general, an evaluation of the system reliability investigates the system’s thermal loading capability, voltage performance (not too high or low), and transient stability (the system should not oscillate excessively and generators should remain synchronized). The evaluation of these criteria must be conducted for credible ‘emergency’ conditions, such as loss of a single (TPL-002) or double circuit (TPL-003) line, a transformer, or a generator. Performance of the transmission system and neighboring Control Areas are measured against the Western Electricity Coordinating Council (WECC) Reliability Standards and the North American Electric Reliability Corporation (NERC) Planning Standards described in the following subsections. The criteria for Category A (TPL-001, “All lines in service”), Category B (TPL-002, single element outage), and Category C (TPL-003, multiple element outage) conditions are explicitly applied both internally (within APS system) and to external Control Areas. Select Category D (TPL-004, catastrophic outage) are selectively applied to the transient stability portion of the study.
1.4.1 Power Factor Criteria
The study applies APS power factor criteria which state that a generator must be capable of providing dynamic reactive support within the range of +/-0.95 power factor at the POI.
1.4.2 (Steady State) Power Flow Criteria
Normal conditions
All line loadings must be less than 100% of the continuous (normal) thermal ratings.
All transformer loadings must be less than 100% of the continuous (normal) ratings. Contingency Conditions
For TPL-002, a single (N-1) contingency or TPL-003, a double (N-2) contingency, no transmission element will be loaded above the emergency rating.
Depending upon the type of analysis and applied case/sensitivity, applicable criteria for system performance will be identified. In some instances, resulting local circuit overloads and/or voltage deviations may be deemed acceptable per local criteria; as long as the local system’s post-contingency performance does not result in cascading outages.
Established loading limits and voltage performance for other neighboring utilities will be monitored.
Voltage deviations at any bus must be no more than 5% for TPL-002, N-1 contingencies, and no more than 10% for TPL-003, N-2 contingencies.
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1.4.3 Transient Stability Criteria
The study applies reliability criteria contained within the WECC disturbance-performance table of allowable effects on other systems. Table 1-7 and Figure 1-8 are excerpts from the WECC Reliability Criteria.
Table 1-7. WECC Disturbance-Performance Table of Allowable Effects on Other Systems
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
(TPL-001) Not Applicable Nothing in addition to NERC
B One element out-of-service
(TPL-002)
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
(TPL-003)
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
(TPL-004)
< 0.033 Nothing in addition to NERC
Figure 1-8. NERC/WECC Voltage Performance Parameters
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2 Study Methodology
This section summarizes the methods used to derive the power factor requirements, power flow, post transient, transient stability, and fault duty results. Appendix A lists the details of the contingencies run for the study.
2.1 Power Factor Requirements
The APS Open Access Transmission Tariff (OATT) policy regarding power factor requires all Interconnection Customers, with the exception of wind generators, to maintain an acceptable power factor (typically near unity) at the Point of Interconnection (POI), subject to system conditions. The APS OATT also requires Interconnection Customers to be able to achieve +/- 0.95 power factor at the POI, with the maximum "full-output" reactive capability available at all outputs. Furthermore, APS requires Interconnection Customers to have dynamic voltage control and maintain the voltage as specified by the transmission operator within the limitation of +/- 0.95 power factor, as long as the project is online and generating. If the project’s equipment is not capable of this type of response, a dynamic reactive device will be required. APS has the right to disconnect the project from the power grid if system conditions dictate the need to do so in order to maintain system reliability. The method for determining whether or not the generator meets these requirements is to first record the pre-project POI bus voltage. Next, model the project online at full output with zero reactive capability. All shunt devices are turned off. Two fictitious synchronous condensers are added to the case with infinite reactive capability. One is placed at the terminal bus of each generating unit set to regulate the bus voltage to 1.0 pu. The second is placed one bus away from the POI regulating the POI to the pre-project voltage level. The amount of plant losses is determined by recording the MVAR flow at the POI and adding that value to the sum of the synchronous condenser output. Based on the maximum output of the plant, determine the minimum reactive capabilities required to meet the +/-0.95 power factor range. The sum of the two numbers determines the maximum amount of reactive support the project must provide.
2.2 Power Flow
Power flow analysis considers a snapshot in time where the transformer tap changers, and phase shifters have not adjusted, and the system swing bus balances the system during each contingency scenario. SVDs are allowed to adjust. All power flow analysis is conducted with version 18.1_01 of General Electric’s PSLF/PSDS/SCSC software. Power flow results are monitored and reported for APS and other neighboring systems, including TEP and SRP. Pre-project issues (if any) are addressed with the appropriate entity. Traditional power flow analysis is used to evaluate the thermal and voltage performance of the system under Category A (TPL-001, all elements in service), Category B (TPL-002, N-1, single contingency), and select Category C (TPL-003, multiple contingency) conditions. The applicable WECC reliability planning criteria is listed below.
Changes in bus voltages from pre- to post-contingency must be less than 5% for single contingencies.
All equipment loadings must be below their normal ratings under normal conditions.
All equipment loadings must be below their emergency ratings for single contingencies.
Depending upon the type of analysis and applied case/sensitivity, applicable criteria for system performance is identified. In some instances, resulting local circuit overloads and/or voltage deviations may be deemed acceptable per local criteria; as long as the local system’s post-contingency performance does not result in cascading outages.
Thermal loading is reported when a modeled transmission element is loaded over 98% of its appropriate MVA rating modeled in the power flow database, and when the incremental change in loading between Pre-Project and Post-Project case exceeded 1%.
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Transmission voltage violations for Category A (TPL-001, no contingency) conditions are reported where per unit voltages are less than 0.95 or greater than 1.05. For Category B outages (TPL-002, N-1) the voltage violations are reported when the post-contingency voltage deviation is greater than 5%.
2.3 Post-Transient
Post-transient analysis determines if the voltage deviations at critical buses meet the maximum allowable voltage deviation criteria, and if any transmission elements exceed their maximum rating for selected Category B (TPL-002, N-1) disturbances. This snapshot focuses on the first few minutes following an outage where the transformer tap changers, and phase shifters, have not adjusted, and all of the system generation reacts by governor control to balance the system during each contingency scenario. SVDs are allowed to adjust. All loads are modeled as constant power during the Post-Transient time frame. Generator reactive limits are modeled as a constant single value for each generator since the reactive power capability curve will not be modeled in the power flow program.
2.4 Transient Stability
Transient stability analysis is a time-based simulation that assesses the performance of the power system during (and shortly following) a contingency. Dynamic simulations are performed to verify the system stability following a critical fault on the system. Prior to finalization of the power flow and dynamic data set, a flat–run is used to ensure true power system behavior is not masked by any remote dynamic modeling anomalies. Transient stability analysis is performed based on WECC Disturbance-Performance Criteria for selected system contingencies. Dynamic simulation is modeled out to 11 seconds to ensure a damped system performance. Most simulated faults are assumed to be three-phase unless otherwise noted. Table 2-1 identifies the breaker clearing times for faults on different voltage levels.
Table 2-1. Breaker Clearing Times
Voltage Level Breaker
clearing times
69 kV 7-cycles
115/161 kV 6-cycles
345/230 kV 5-cycles
500 kV 4-cycles
All transient stability simulations are conducted using version 18.1_02 of General Electric’s PSLF/PSDS/SCSC software. The Worst Condition Analysis (WCA) tool, available in the PSDS software package, tracks and records the transient stability behavior of all output channels contained within the binary output file of a transient stability simulation. The monitoring of channel output is initiated two cycles after fault clearing, to ensure that all post-fault stability behavior is captured. System damping is assessed visually with the aid of stability plots.
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Parameters Monitored to Evaluate System Stability Performance: Rotor Angle
Rotor angle plots provide a measure for determining how the proposed generation unit would swing with respect to other generating units in the area. This information is used to determine if a machine would remain in synchronism or go out-of-step from the rest of the system following a disturbance.
Bus Voltage
Bus voltage plots, in conjunction with the relative rotor angle plots, provide a means of detecting out-of-step conditions. The bus voltage plots are useful in assessing the magnitude and duration of post-disturbance voltage dips and peak-to-peak voltage oscillations. Bus voltage plots also give an indication of system damping and the level to which voltages are expected to recover in the steady state conditions.
Bus Frequency
Bus frequency plots provide information on magnitude and duration of post-fault frequency swings with the new project(s) in service. These plots indicate the extent of possible over-frequency or under-frequency excursions, which can occur due to an area’s imbalance between load and generation.
Other plotted Parameters
Real Power Output
2.5 Short Circuit
Short Circuit Analysis is performed by the APS Transmission Planning Department using the CAPE program and parameters supplied by the applicant. Fault duties are calculated for both single phase to ground and three phase faults at substation busses in the immediate surrounding area before and after the proposed generator interconnection. If fault currents are of such magnitude that series capacitors are removed from the system, they are removed from the modeling.
3 Results and Findings
This section provides the results obtained by applying the previously-discussed assumptions and methodology. It illustrates all findings associated with the impact of the interconnection.
3.1 Power Factor Capability Results
The project satisfies the minimum power factor requirement. A minimum of +/- 189.65 MVAr capability in the summer and +/- 205.76 MVAr in the winter at the POI is required to meet the +/- 0.95 power factor requirement. The calculated plant losses are 86.9 MVAr in the summer and 100.8 MVAr in the winter. The gross dynamic reactive capability of the project is +362.4/-214.8 MVAr in the summer and +393.6/-232.8 MVAr in the winter. The resulting net power factor capability of the project after accounting for losses is +0.902/-0.886 in the summer and +0.906/-0.883. No additional reactive support is required to meet the APS power factor requirement.
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3.2 Peak Load Thermal Results
Base Scenario (Cases 1-2) Addition of Q219 without any network upgrade causes a pre-contingency overload of the Jojoba-TS4 230 kV line and numerous post-contingency overloads. The most severe outage results are listed in Table 3-1 below. The worst post-contingency loading of the Jojoba-TS4 230 kV is caused by an outage of the Jojoba-Kyrene 500 kV line. An outage of the Jojoba-Liberty-Palm Valley 230 kV line overloads the Gillespie-Patterson 69 kV line, Patterson-Komatke 69 kV line, Jojoba-Panda 230 kV line, and Gila River 500/230 kV transformer. The Gillespie-Patterson and Patterson-Komatke 69 kV lines are also overloaded following an outage of the Lower River-Gillespie 69 kV line (with 9 MW of PV generation tripping at Gillespie).
Table 3-1. Heavy Summer Thermal Results (Summer Rating Applied)
Base Scenario With 230 kV & 69 kV Upgrades
With 230 kV & 69 kV Upgrades Jojoba 500/230
With 230 kV & 69 kV Upgrades Jojoba-TS4 #2
Contingency Description Overloaded Element Rating Pre-
Project Post-
Project (Sys)
Post-Project
(Sys)
Post-Project
(AZ)
Post-Project
(Sys)
Post-Project
(AZ)
Post-Project
(Sys)
Post-Project
(AZ)
0 All Lines in Service Jojoba-TS4 230 kV1
1097 Amps
70.2 154.5 60.32 57.6
2 58.7
2 54.9
2 34.8
2 33.3
2
12 N-1 Jojoba-Kyrene 500 kV Jojoba-TS4 230 kV1
1367 Amps
76.0 144.8 70.82 67.2
2 77.5
2 72.2
2 40.7
2 38.7
2
58 N-1 Gila River 500/230 kV Jojoba-TS4 230 kV1
1367 Amps
41.3 138.9 64.22 64.3
2 60.0
2 57.1
2 32.8
2 32.8
2
25 N-1 Jojoba-Liberty- Palm Valley 230 kV
Gillespie-Patterson 69 kV1
536 Amps
92.7 125.3 42.12 40.5
2 32.9
2 31.4
2 26.3
3 25.3
3
Patterson-Komatke 69 kV
1
536 Amps
81.9 115.2 37.82 37.0
2 29.4
2 27.9
2 22.6
3 21.6
3
Jojoba-Panda 230 kV
1367 Amps
1.4 104.4 104.4 104.4 11.2 12.7 28.73 23.0
3
Gila River 500/230 kV
725 MVA
26.9 101.7 102.1 103.1 32.7 35.0 7.33 12.4
3
45 N-1 Lower R-Gillespie 69 kV (Trip 9 MW of Gillespie PV Gen) Gillespie-Patterson 69 kV
1
536 Amps
99.4 111.1 35.92 34.6
2 35.8
2 34.4
2 32.6
2 31.5
2
Patterson-Komatke 69 kV
1
536 Amps
88.4 100.1 32.22 30.9
2 32.1
2 30.7
2 28.9
2 27.8
2
16 N-1 Palo Verde-Rudd 500 kV Jojoba-TS4 230 kV1
1367 Amps
72.3 139.8 68.3 65.5 73.1 69.1 39.3 37.7
Liberty-Rudd 230 kV
1600 Amps
81.4 95.7 97.6 97.6 99.9 99.3 102.6 102.4
17 Open Sun Valley-Hassy Tap 230 kV Liberty-Rudd 230 kV 1600 Amps
74.2 89.3 91.3 91.4 94.1 93.6 96.7 96.6
81 N-2 Jojoba-TS4 230 kV 1 and 2
Gila River 500/230 kV 725 MVA
N/A N/A N/A N/A N/A N/A 101.9 102.9
Case 1 2 3 4 5 6 7 8
Note 1: Numerous Outages were shown to have overloaded the facility; only the worst are shown. Note 2: Facility Upgraded; Percent loading reflects new rating. Note 3: Network Upgrade deems contingency invalid; comparable contingency result listed
With 230 kV and 69 kV Upgrades Scenario (Cases 3-4) The overloads noted above trigger the need to upgrade the Panda-Jojoba 230 kV line
3, Jojoba-Liberty-
Palm Valley 230 kV line, Gillespie-Patterson 69 kV line, and Patterson-Komatke 69 kV line. It is assumed that these facilities will be re-conductored. The challenging constraint that remains is the overload of the Gila River 500/230 kV transformer. An outage of the Jojoba-Liberty-Palm Valley 230 kV line overloads the transformer to 103.1 % beyond its 725 MVA short term (30 minute) emergency rating.
3 The upgrade of this line section is not required with the addition of the recommended Jojoba 500/230 kV
transformer.
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Mitigation of the Gila River 500/230 kV transformer overload requires a more significant network upgrade project. The effectiveness of two potential upgrades was evaluated: (Alternative 1) Add a 500/230 kV transformer at Jojoba, and (Alternative 2) Add a second 230 kV line between Jojoba and TS4. The results of both options are described below. Both options give similar reliability benefits and mitigate the Gila River transformer overload. However, after investigating both options the feasibility of actually constructing Alternative 2 has significantly more risk along with a longer timeframe and higher cost. Alternative 1 is the mitigation APS is proposing for this interconnection and is the option estimated in Section 4 of this report. Alternative 1: Jojoba 500/230 kV Transformer Scenario (Cases 5-6) The Gila River 500/230 kV transformer overload is fully-mitigated by the addition of the Jojoba 500/230 kV transformer. The Liberty-Rudd 230 kV line is heavily loaded with the addition of Q219. After the Jojoba transformer addition the loading on the Liberty-Rudd 230 kV line following an outage of the Palo Verde-Rudd 500 kV line goes right up to 99.9%. This loading level is close enough to the emergency rating to consider that as an overload requiring mitigation. Two SPS projects could be used as an interim project. Reducing the output of the Q219 project would relieve the loading concern. Also, opening the planned Sun Valley-Hassayampa Tap 230 kV line would mitigate the line loading. An increase in the Liberty-Rudd 230 kV line will need to be investigated as a long term solution. The 230 kV line is owned by SRP, with the Liberty substation being owned by Western and the Rudd substation being jointly owned by APS and SRP, but operated by SRP. All parties will need to coordinate in determining what would be required to increase the rating of the line. Alternative 2: Jojoba-TS4 230 kV Line #2 Scenario (Cases 7-8) The addition of a second Jojoba-TS4 230 kV line has a similar impact as the Jojoba 500/230 kV transformer, however the Liberty-Rudd 230 kV line is overloaded. The second line section will require an additional upgrade. One option is the addition of an automatic scheme that opens the Sun Valley-Hassayampa Tap 230 kV line following an outage of the Palo Verde-Rudd 500 kV line in order to sufficiently mitigate the Liberty-Rudd 230 kV line overload. It is assumed that the second Jojoba-TS4 230 kV line will be a double-circuit tower line (DCTL) installed when the #1 line is upgraded for the segment of the line that runs generally north from Jojoba. Once the line turns east the existing line is already the second circuit on 500/230 kV double circuit poles. Therefore, the second Jojoba-TS4 230 kV circuit is assumed in a new corridor as it heads to TS4. This configuration creates a new potential for a common tower N-2 outage of both Jojoba-TS4 230 kV lines. This TPL-003 outage causes an overload of the Gila River 500/230 kV transformer. A generator tripping scheme will need to be in place to trip or ramp back Q219 generation should the DCTL outage occur
4.
3.3 Light Load Thermal Results
The light load scenario models Q219 at the winter capacity of 626 MW (net) and applies the winter rating. Base Scenario (Cases 9-10) Addition of Q219 without any network upgrade causes a pre-contingency overload of the TS4-Liberty 230 kV line. All outage results are listed in Table 3-2 on the following page. The worst post-contingency loading of the TS4-Liberty 230 kV line is caused by an outage of the Gila River 500/230 kV transformer. An outage of the Jojoba-Liberty-Palm Valley 230 kV line overloads the Gila River 500/230 kV transformer. With 230 kV and 69 kV Upgrades Scenario (Cases 11-12) As with the peak load result, the constraint that remains after upgrading the 230 kV and 69 kV lines, is the overload of the Gila River 500/230 kV transformer. An outage of the Jojoba-Liberty-Palm Valley 230 kV line overloads the transformer to 122.6% beyond its 725 MVA short term emergency rating.
4 The ultimate mitigation will need to be coordinated with the owner of the transformer; Gila River Plant.
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Jojoba 500/230 kV Transformer Scenario (Cases 13-14)
The addition of the Jojoba 500/230 kV transformer fully-mitigates the Gila River 500/230 kV transformer loading concerns without creating any new overloads in the light load condition. Jojoba-TS4 230 kV Line #2 Scenario (Cases 15-16) The addition of a second Jojoba-TS4 230 kV line has a similar impact as the Jojoba 500/230 kV transformer. The new common tower N-2 outage of both Jojoba-TS4 230 kV lines causes an overload of the Gila River 500/230 kV transformer, similar to the peak scenario. A generator tripping scheme will need to be in place to trip or ramp back Q219 generation should the DCTL outage occur
3.
Table 3-2. Light Load Thermal Results (Winter Rating Applied)
Base Scenario With 230 kV & 69 kV Upgrades
With 230 kV & 69 kV Upgrades Jojoba 500/230
With 230 kV & 69 kV Upgrades Jojoba-TS4 #2
Contingency Description Overloaded Element Rating Pre-
Project Post-
Project (Sys)
Post-Project
(Sys)
Post-Project
(AZ)
Post-Project
(Sys)
Post-Project
(AZ)
Post-Project
(Sys)
Post-Project
(AZ)
0 All Lines in Service TS4-Liberty 230 kV 1099 Amps
29.9 100.1 38.22 37.9
2 29.6
2 29.2
2 44.2
2 43.9
2
25 N-1 Jojoba-Liberty- Palm Valley 230 kV
Gila River 500/230 kV 725 MVA
40.0 122.1 122.5 122.6 48.2 48.2 41.43 41.6
3
58 N-1 Gila River 500/230 kV TS4-Liberty 230 kV 1368 Amps
37.6 119.2 54.62 54.4
2 34.4
2 34.1
2 55.7
2 55.5
2
75 N-2 Jojoba-Gila River 500 kV 1 and 2 (with RAS)
TS4-Liberty 230 kV 1368 Amps
36.1 117.7 53.92 53.7
2 31.6
2 31.3
2 55.0
2 54.8
2
81 N-2 Jojoba-TS4 230 kV 1 and 2
Gila River 500/230 kV 725 MVA
N/A N/A N/A N/A N/A N/A 122.4 122.4
Case 9 10 11 12 13 14 15 16
Note 2: Facility Upgraded; Percent loading reflects new rating. Note 3: Network Upgrade deems contingency invalid; comparable contingency result listed.
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3.4 Follow-Up Scenario Thermal Results
Follow-up scenarios evaluated at the request of the customer demonstrate that both the 69 kV and the 230 kV line upgrades are necessary with the Jojoba 500/230 kV transformer in-service during peak load conditions. No off-peak overload concerns are observed in the off-peak condition. Case 20 demonstrates that the addition of the Jojoba 500/230 kV transformer alone creates overloads in both the 230 kV and 69 kV systems without the Q219 project online. It is critical that the 230 kV and 69 kV facilities be re-enforced prior to placing the transformer into service.
Table 3-3. Heavy Summer Thermal Results (Summer Rating Applied)
wJJ Xfmr wJJ Xfmr wJJ Xfmr 69 kV Upg
wJJ Xfmr 230 kV Upg
Contingency Description Overloaded Element Rating Pre-
Project Pre-
Project Post-
Project (Sys)
Post-Project
(Sys)
Post-Project
(Sys)
0 All Lines in Service Jojoba-TS4 230 kV1
1097 Amps
70.2 96.9 154.3 145.2 58.32
12 N-1 Jojoba-Kyrene 500 kV Jojoba-TS4 230 kV1
1367 Amps
76.0 113.4 154.2 154.1 76.92
TS4-Liberty 230 kV
1367 Amps
44.5 72.6 104.9 104.9 52.22
58 N-1 Gila River 500/230 kV Jojoba-TS4 230 kV1
1367 Amps
41.3 76.4 120.8 120.6 59.92
25 N-1 Jojoba-Liberty- Palm Valley 230 kV
Gillespie-Patterson 69 kV 536
Amps 92.7 86.2 98.1 34.6
2 98.1
Patterson-Komatke 69 kV
536 Amps
81.9 75.4 87.5 30.92 87.5
45 N-1 Lower R-Gillespie 69 kV (Trip 9 MW of Gillespie PV Gen)
Gillespie-Patterson 69 kV 536
Amps 99.4 102.4 110.1 38.3
2 107.8
Patterson-Komatke 69 kV
536 Amps
88.4 91.4 99.1 34.62 96.8
50 Watson-Valencia-Baseline-Lower R 69 kV Line
Gillespie-Patterson 69 kV 536
Amps 90.5 93.2 100.1 35.1
2 98.1
16 N-1 Palo Verde-Rudd 500 kV Jojoba-TS4 230 kV1
1367 Amps
72.3 106.8 145.3 145.3 72.52
Liberty-Rudd 230 kV
1600 Amps
81.4 89.4 96.9 96.9 99.6
17 Open Sun Valley-Hassy Tap 230 kV Liberty-Rudd 230 kV 1600 Amps
74.2 83.1 90.9 90.9 93.8
Case 1 20 21 22 23
Note 1: Numerous Outages were shown to have overloaded the facility; only the worst are shown. Note 2: Facility Upgraded; Percent loading reflects new rating.
3.5 Affected Systems Review
As part of this interconnection study, SRP and Western have been identified as affected systems. A coordinated meeting with APS, SRP, Western and the IC was held to discuss the results identified in APS’s initial SIS. Western identified some network upgrades they will require. They also indicated they do not require any additional studies to be performed. Western provided the following statement:
Western staff is concerned that the near-overloads on the Liberty-Rudd 230 kV line and the Liberty 230 kV fault current could increase if different dispatch
scenarios or planning horizon years beyond 2018 were modeled. However, the
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study performed is thorough, and as along long as some margin is provided on these facilities, Western staff is comfortable with the simulation results.
Therefore, no further analysis is needed as long as we agree that a conclusion of the study is that the Liberty 230 kV buswork, three disconnects, and two breakers
need upgrades to accommodate this project SRP was concerned about the interconnection’s effect on the metro Phoenix Maximum Load Serving Capability (MLSC). SRP performed a short MLSC study and found that the Phoenix MLSC would drop by 2000 MW with the existing rating of the Liberty-Rudd 230kV line. If the Liberty-Rudd 230kV line rating is upgraded so that the emergency rating becomes the conductor rating of 2090 A there is no impact on MLSC.
3.6 Voltage Results
Results indicate that the addition of Q219 does not create any voltage concerns under peak load and light load conditions.
3.7 Transient Stability Analysis
Seventy-two (72) outages were selected for transient stability evaluation. Results indicate that the project does not create any transient stability issues beyond its own facilities, as is discussed in this section. The in-service Agua Caliente project is observed to trip post-contingency for the following outage outages:
Palo Verde-Colorado River 500 kV Line
Hassayampa-Qx 500 kV Line
Qx-Hoodoo Wash 500 kV Line
Hassayampa-N.Gila 500 kV Line
Palo Verde-Rudd 500 kV Line The generator trips in both the pre-project and post-project cases; the Q219 project appears to have little bearing on the performance of the Agua Caliente project. Addition of either the Jojoba 500/230 kV transformer or of the Jojoba-TS4 #2 230 kV line causes Q43 to remain online for the Palo Verde-Rudd 500 kV contingency. Due to the pre-existing nature of this event, this generator tripping is not attributed to the Q219 project and will not be discussed further in this report
5.
Base Scenario (Cases 1-2 and 9-10) An unacceptable transient frequency dip is observed at each of the six Q219 generation terminals following an outage of the Jojoba-Liberty-Palm Valley 230 kV line under heavy summer and light load conditions. An additional unacceptable frequency dip is observed following an outage of the Panda-Jojoba 230 kV line under light load conditions only. With 230 kV and 69 kV Upgrades Scenario (Cases 3-4 and 11-12) The frequency dip following the Jojoba-Liberty-Palm Valley 230 kV line is still detected after applying the 230 kV and 69 kV upgrades. The light load frequency dip following the Panda-Jojoba 230 kV line outage is no longer detected. Jojoba 500/230 kV Transformer Scenario (Cases 5-6 and 13-14) No transient stability violations detected.
5 This performance has not been observed in other studies and is likely a modeling anomaly in this power
flow case. These results will be examined in more detail outside this SIS to determine if it is a modeling issue or if there is a reliability concern.
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Jojoba-TS4 230 kV Line #2 Scenario (Cases 7-8 and 15-16)
No transient stability violations detected. Slow Voltage Recovery (SVR) was observed at the Valencia #3 12.0 kV bus following an outage of the Buckeye-Liberty 230 kV line in the heavy summer condition. SVR is not a criteria violation. Figure 3-4 illustrates the frequency dip violation and demonstrates the mitigation of the violation by adding either the Jojoba 500/230 kV transformer or the Jojoba-TS4 #2 230 kV line. Results of the heavy summer condition with the project offset by the system resources (cases 3, 5, and 7) is used to plot the impact. Similar impact is observed in the light load and AZ offset scenarios.
Figure 3-4. Transient Frequency Response of Q219 Unit 1 During an Outage of the Jojoba-Liberty-Palm Valley 230 kV Line
Appendix D contains transient stability plots of all contingencies that provide a representative illustration of the transmission system’s pre-project and post-project transient response.
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3.8 Short Circuit / Fault Duty Analysis
Short-circuit analysis of the proposed generator was performed by the APS Transmission Planning Department, using the CAPE program and parameters supplied by the Applicant. Fault duties were calculated for both single-phase–to-ground and three-phase faults at substation busses in the immediate surrounding area before and after the proposed generator installation. The results presented here assume a “worst-case” scenario. The results show an increase in the fault currents at Liberty. The fault currents are under the minimum breaker rating, but they are over 90% of their rated fault current
6. Western has indicate the IC should plan
to replace two 230kV breakers at Liberty which are rated at 40 kA. As the Transmission Operator and Planning Coordinator for Palo Verde and Hassayampa SRP, in coordination with the other participants, is in the process of performing a detailed analysis. At this point of time, any conclusions with regard of fault duties at Palo Verde and Hassayampa are premature. The interconnector Q219 is to be aware that high costs associated with mitigation of short circuit problems are probable and might be imposed on the interconnector. Table 3-5 describes the short-circuit results.
Table 3-5. Short-Circuit Analysis Results - 1.05 Pre-Fault Voltage
Station
Pre-Project including
Q62 & Q90 Post-Project (W/500/230xfmr)
Min
Brkr.
Rating
(kA) 3 Ph. (kA) Ph-G (kA) 3 Ph. (kA) ΔI
Ph-G
(kA) ΔI
Q219 230kV N/A N/A 20.5 N/A 24.0 N/A TBD
Jojoba 230kV N/A N/A 22.5 N/A 26.1 N/A TBD
Kyrene 500kV 21.7 19.2 22.3 0.6 19.7 0.5 40
Gila River 500kV 29.2 28.6 29.8 0.6 29.4 0.8 63
Panda 230kV 16.0 16.2 17.4 1.4 17.5 1.3 40
Gila Bend 230kV 10.9 10.0 11.5 0.6 10.5 0.5 N/A2
Liberty 230kV 34.4 28.1 37.0 2.6 30.3 2.2 40
Rudd 230kV 49.9 42.2 50.2 0.3 42.3 0.1
Palm Valley 230kV 22.8 16.6 23.7 0.9 17.4 0.8 63
Notes: 1. Values in red are >90% of minimum breaker rating
2. There are no 230kV breakers at Gila Bend.
6 Western is the owner and operator of the Liberty substation and is identified as an affected system.
Western has identified the threshold for breaker replacement as 90% of the rated interrupting current.
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3.9 Results & Findings Summary
As discussed in Section 3.3, the results of the SIS indicate that the addition of Q219 creates post-contingency thermal loading concerns at multiple facilities within the AZ network. Facilities of concern include the following:
Gillespie-Patterson 69 kV line
Patterson-Komatke 69 kV line
Jojoba-TS4 230 kV line
TS4-Liberty 230 kV line
Gila River 500/230 kV transformer
Liberty-Rudd 230 kV line In addition to the thermal loading concerns, Q219 also experiences unacceptable transient frequency dips at full output prior to Alternative 1 or Alternative 2, as discussed in Section 3.5. The following briefly describes the network upgrade projects required to adequately mitigate the reliability concerns noted above. Gillespie-Patterson-Komatke 69 kV Upgrade This project assumes that the existing Gillespie-Patterson-Komatke 69 kV line can be re-conductored with 795 ACSS conductor capable of 1600 Amps normal and emergency. Jojoba-TS4-Liberty 230 kV Upgrade This project assumes that the existing Jojoba-TS4 and TS4-Liberty 230 kV line sections can be re-conductored with 2156 ACSS conductor capable of 3000 Amps normal and emergency. Most of the TS4-Palm Valley 230 kV line section is already 2156 ACSS. The first two spans beyond TS4 are smaller conductor and the limiting elements of the line and would be upgraded at the same time the Jojoba-TS4 and TS4-Liberty 230 kV line sections. Liberty-Rudd 230 kV Mitigation There are a few projects that address this line overload. One project is an automatic scheme that trips the Hassayampa Tap-Sun Valley 230 kV line following an outage of the Palo Verde-Rudd 500 kV line. This scheme can monitor the status of the Palo Verde-Rudd 500 kV line and/or the loading of the Liberty-Rudd 230 kV line to initiate. Another option is an SPS to trip some amount of generation from the Q219 project to mitigate the overload. An SPS would generally be used as a temporary solution until a system upgrade can be completed. A long-term solution would be to upgrade the Liberty-Rudd 230 kV line. Coordination with SRP and Western has determined that the Liberty 230kV bus work and three limiting disconnect switches should be planned to be upgraded. The upgrades would yield a rating of about 1900 A. SRP identified a desire to upgrade the line up to the conductor limit of 2090 A. This may require the replacement of additional equipment at Liberty; the jumpers from the Transmission line to the CT, the CT to the rigid bus, the bushing CT, one disconnect switch on the transfer bus. An estimate of these upgrades is not included in this report. The IC will be required to coordinate these upgrades with SRP and Western. Alternative 1: New Jojoba 500/230 kV Transformer
This project assumes that a new 500/230 kV transformer will be added that ties the existing SRP-operated 500 kV bus to the proposed APS-owned Jojoba 230 kV bus. It is assumed that the transformer is a 600 MVA transformer similar to the APS standard 500/230 kV transformers. The facility will have a 600 MVA normal rating and a 896 MVA emergency rating. This network upgrade is required to mitigate the Q219 transient frequency dips and Gila River 500/230 kV transformer overload. The frequency dips are more limiting than the thermal overload concerns. In addition, this alternative would preclude the requirement to upgrade the Panda-Jojoba portion of the existing 230 kV line. Follow-up scenario analysis demonstrates that both the 230 kV and 69 kV upgrades are required prior to allowing the new Jojoba 500/230 kV transformer to be placed into service regardless of the status of the
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Q219 project. Installation of a facility and generator tripping scheme would allow approximately 40 MW of generation online without the 230 kV upgrades. The scheme would be required to trip the new Jojoba 500/230 kV transformer even without the generator online. Alternative 2: New Jojoba-TS4 #2 230 kV Line This project assumes that a second line can be constructed from Jojoba to TS4 as a double-circuit tower line when the existing line is re-conductored. It is assumed that this second line is also 2156 ACSS conductor capable of 3000 Amps. This second line will require TS4 to be upgraded to a ring bus in order to accommodate a fourth termination. The second line segment is only required from Jojoba to TS4 and is not required to extend to Liberty or Palm Valley. This network upgrade is required to mitigate the Q219 transient frequency dips and Gila River 500/230 kV transformer overload. The frequency dips are more limiting than the thermal overload concerns.
Alternative 2: Q219 RAS Applicable only under Alternative 2 conditions where a second Jojoba-TS4 230 kV line is constructed, an automatic generation shedding scheme is required to trip either the entire project or the portion above 440 MW (limited by the light load condition) following the simultaneous outage of both Jojoba-TS4 230 kV lines. The following Tables 3-6 and 3-7 show the generator output at which each project is required.
Table 3-6. Heavy Summer Upgrade Requirements to Achieve Full Output
Peak Load
Upgrade Required NR
(APS) ER
(Sys)
0 0 Gillespie-Patterson 69 kV Upgrade
188-382 188-382 Patterson-Komatke 69 kV Upgrade
Jojoba-TS4-Liberty 230 kV Upgrade
Alternative 1: Jojoba 500/230 kV Transformer
382-577 382-577 Jojoba 500/230 kV Xfmr
577 577 Liberty-Rudd 230 kV Mitigation
Alternative 2: Jojoba-TS4 #2 230 kV Line
382-470 382-460 Jojoba-TS4 #2 230 kV Line
470-555 460-555 Liberty-Rudd 230 kV Mitigation
555-577 555-577 Q219 RAS
Table 3-7. Light Load Upgrade Requirements to Achieve Full Output
Light Load
Upgrade Required NR
(APS) ER
(Sys)
0-382 0-382 None
Alternative 1: Jojoba 500/230 kV Transformer
382-626 382-626 Jojoba 500/230 kV Xfmr
Alternative 2: Jojoba-TS4 #2 230 kV Line
382-440 382-440 Jojoba-TS4-Liberty 230 kV Upgrade
Jojoba-TS4 #2 230 kV Line
440-626 440-626 Q219 RAS
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3.10 Network Resource Interconnection Service
This interconnection request requested to be studied with both Energy Resource Interconnection Service (ERIS) and Network Resource Interconnection Service (NRIS). The results and mitigation projects discussed in sections 3.1 thru 3.7 of this report identify the requirements for ERIS. In order for Q219 to receive NRIS all of the projects identified in those sections would need to be completed. At the requested POI there would be two possible paths for the project to deliver its output to APS’s retail load. One possible path would be through the 500/230 kV transformer that is one of the proposed mitigation projects. However, APS does not have any ATC to be able to deliver the power from the Jojoba 500 kV bus to our load. A second path would be from the POI back to Panda. That line section is rated at 437 MVA. That line section would have to be rebuilt to accommodate the full output of the Q219 project. Plus, if that line is rebuilt to a higher capacity APS still would not be able to deliver the power from the Panda substation to retail load. At Panda even if there is enough ATC to go up the 500/230 kV transformer to the Gila River 500kV bus there is only one path from there and that is to the Jojoba 500 kV bus. As stated above, APS does not have ATC to deliver the power from the Jojoba 500 kV bus to our load. Another option at Panda is the 230 kV line to Gila Bend and that line section is fully scheduled. The third possible path from the Jojoba 230 kV substation would be the Jojoba-TS4-Liberty-Palm Valley 230 kV line. Currently, the Panda-TS4-Liberty-Palm Valley 230 kV line is fully scheduled. However, one of the mitigation projects identified is to rebuild that line. Once the line is rebuilt there would be enough scheduling capacity to deliver the output of Q219 into APS’s retail load. Therefore, the 230kV line upgrade identified as one of the mitigation projects is required to achieve NRIS. The 500/230 kV transformer is also required as this would protect for contingency conditions and would enable the rebuilt 230 kV line to achieve its full rating.
4 Cost & Construction Time Estimates
The cost and time estimates represent good faith estimates necessary to interconnect to the system. The information in this section refers to the Network Upgrades and Transmission Provider’s Interconnection Facilities (TPIF). This section does not contain estimates for mitigations that are identified on affected systems. Network Upgrades refer to upgrades on the APS transmission system due to voltage, capacity and/or stability issues and are identified as mitigations in the prior section of this report. TPIF refer to facilities within an APS substation/switchyard for the sole use of connecting a particular generator project(s). The non-binding, good faith cost and time estimates are detailed and tabulated in the sections below.
4.1 Network Upgrades
Gillespie-Patterson-Komatke 69 kV Line Upgrade These projects are to rebuild the existing 69 kV lines using 795 ACSS conductor. Approximately 6.5 miles of the 69 kV lines need to be rebuilt. The two lines are longer than 6.5 miles, however portions of the lines have already been or are scheduled to be rebuilt for other projects. Those sections are not included in this estimate. Both lines have multiple sections with 12 kV underbuild. The 12 kV lines will need to be transferred along with the dips, taps and line equipment. No substation upgrades at Gillespie, Patterson, or Komatke substations would be required to achieve the 1600A rating. This rebuild also assumes the line will be rebuilt with OPGW. The estimate assumes the work will be done so that it is capable of being released back to operation daily. There may be windows where longer outage windows are possible, but this estimate assumes a worst case cost. The existing Rights-Of-Way (ROW) with the lines are 10 feet at its narrowest point, crossing the El Paso Natural Gas (EPNG) pipeline, and 35 feet at its widest point within Arizona State Land Department (ASLD) property. It is assumed the line would be rebuilt in the existing rights-of-way, however APS’s
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current standard for 69 kV infrastructure is 40 feet. Given this standard additional ROW will need to be acquired. The average width of ROW acquisition is 28 feet. The ROW in this area includes small segments of ASLD property, but is otherwise privately owned or municipally owned. The estimate for the line rebuild is $6.3 million. The estimate for the additional ROW needed is $200,000. The ROW estimates were obtained without the benefit of any appraisals. The estimate could increase or decrease based on future market values. It is also estimated that this upgrade would take approximately 36-42 months to complete; 18-24 months for ROW acquisition, 6 months for design and engineering, and 12 months for construction. This timeline assumes that the ROW acquisition will not involve condemnation proceedings.
Table 4-1. Gillespie-Patterson-Komatke 69 kV Line Upgrade
Cost Estimate Time Estimate
6.5 miles of 69 kV line Rebuild $6.3 M 18 months
ROW Acquisition $200,000 18-24 months
Total $6.5 M 36-42 months
Jojoba-TS4-Liberty 230 kV Upgrade This project is to rebuild the existing 230 kV line using 2156 ACSS conductor. Approximately 21 miles of line would be rebuilt to achieve a 3000 Amp rating. This is the portion of the Panda-TS4-Liberty 230 kV from the proposed Jojoba 230kV substation to the TS4 tap point and from the TS4 tap point into the Liberty 230kV substation. This also includes a few spans of the 230 kV line leaving the TS4 tap point to Palm Valley which are limiting the rating of that section of line. The estimate also includes replacing some switches and CTs in the Liberty substation. This rebuild also assumes the line will be rebuilt with OPGW. The estimate for the line rebuild is $21.4 million. It is also estimated that this portion of the upgrade would take approximately 24 months to complete. The existing ROW associated with the Liberty-Jojoba-Panda 230 kV varies in width from 50’ to 120’. Because the 230 kV transmission line towers are to be replaced, additional ROW will be required and have to be obtained in the areas where the ROW is less than 100’. The majority of the 50’ ROW is located along the north-south alignment between W. Lower Buckeye Road and the Arlington Canal and totals approximately 5.4 miles. The ROW in this area is generally limited to private property, but includes one railroad crossing, two canal crossings, and both single-family and agricultural land uses. Some shorter segments have ROW widths varying between 50’ and 77’; these segments are located at the eastern and southern ends of the line near the Liberty and Gila Bend Substations, respectively. It should be noted that estimate values were obtained without the benefit of any appraisals. The estimates could increase or decrease based on future market values. The estimate as of this report is approximately $9.3 million. This estimate assumes the line will be rebuilt in the same alignment and not in a new corridor. In addition to the construction and ROW acquisition costs, there could be significant costs and time impact due to the possible needs of environmental studies and Arizona transmission line siting statutes. Rebuilding the existing 230 kV line will entail replacing all or most of the existing structures. There is a mix of old wood monopoles, some new steel poles, some old wood H frame structures and then the lattice USBR structures that we share. A good portion of this line is on BLM land and therefore any action will fall into a NEPA process. Depending on what they require it may be at a minimum an EA since we are replacing structures and potentially doing other land disturbing activities. If the lattice towers need work there will be some contractual issues that need to be done to allow the upgrade and it is possible that they too, as a Federal agency, could require some level of NEPA. As noted above, depending on the
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requirements of BLM and the level of NEPA, the IC’s plant and gen-tie line could get pulled into the process as well. Until a detailed design is done and we know how many structures will need to be changed/modified and the type of structures, we won’t know what action we will need to take in regards to the State Siting Statute. At a minimum we would likely have to file something informing the Arizona Corporation Commission (ACC) as to what we are doing and this could lead to an amendment to the CEC of the existing line. It is also possible, since the original CEC is so old, we could be required to obtain a new CEC due to significant changes as to what was originally certificated. If a notification to the ACC is required, including amending the old CEC and if the BLM would keep NEPA to a minimum we would be looking at 12 to 18 months and a cost of between $750k and $1M. If we get into an Environmental Assessment (EA) and we need to obtain a new CEC the cost would go up to $2.5M to $3M and we would be looking at 18 to 36 months. It is not assumed that this would go to an EIS, but it is possible especially if BLM decides to include the Plant and Gen-tie as a connected action under NEPA. If this evolves into an EIS the costs could be much higher, possibly up to $5M and the timing would be 3 to 4 years or even longer.
Table 4-2. Jojoba-TS4-Liberty 230 kV Line Upgrade
Cost Estimate Time Estimate
21 miles of 230 kV line Rebuild $21.4 M 24 months
Siting/Environmental Activities $750,000 - $5,000,000 12 months – 48 months
ROW Acquisition $9.3 M 18 months7
Total $31.45 M - $35.7 M 54 - 90 months8
Jojoba 230 kV Substation and 500/230 kV transformer This project is to build a four breaker ring bus at the APS proposed Jojoba 230kV substation site and add a 500/230 kV transformer connecting this new 230 kV bus to the existing Jojoba 500kV bus. This estimate includes the cost for cutting the Panda-TS4 230 kV line in & out of the substation, terminating the 230 kV side of the 500/230 kV transformer, a new 500/230 kV transformer
9, and termination of the
230 kV gen-tie. The estimate also includes the cost for the site prep, grading, and 230 kV control equipment. APS already owns the property and is currently planning to construct a 69 kV switchyard (Komatke) at this location. Figure 4.1 below shows the conceptual layout of the Jojoba 230 kV substation and transformer. The facilities shown in green are the network upgrades included in this estimate. The conceptual layout shows the initial substation set-up as a four breaker ring with the capability of being converted to a breaker-and-a-half layout as the substation expands. The estimate does not include the 500 kV termination equipment required to connect the transformer into the Jojoba 500 kV substation. Since the 500 kV switchyard is operated by SRP they will provide the final estimate for this portion of the project if and when a formal interconnection request is made at the Jojoba 500 kV switchyard. The estimate for this upgrade is $17 million. This estimate assumes the 500/230 kV transformer will be located within the Jojoba 230 kV yard. It includes four 230 kV breakers, 230 kV structures, switches,
7 ROW Acquisition time does not include the possibility of having to go through a condemnation
procedure, which could add significant time. 8 Some of these activities may overlap and can reduce this timeframe.
9 The new transformer is assumed to be similar to all of the new transformers APS has recently installed
and is planning to install for our planned projects. It is a three-phase 600 MVA rated transformer.
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PTs, CTs, a 230 kV control house, and all required P&C work at the site. Relay upgrades/coordination at the Panda, Palm Valley, and Liberty ends of the line are also included. It is also assumed that the site will not require significant grading and drainage activities and the soil is not contaminated which would require special provisions. It is estimated that this project would take approximately 30 months to complete. The lead time for a 500/230 kV transformer is about 24 months, plus delivery time and energizing the unit. The design and construction can overlap the procurement time.
Table 4-3. Jojoba 230 kV Substation and 500/230 kV transformer
Cost Estimate Time Estimate
Substation & transformer $17 M 30 months
Total $17 M 30 months
Liberty-Rudd 230 kV Mitigation The option to set-up either SPS option that may be required to prevent the overload of the Liberty-Rudd 230 kV line consists of relay and communications equipment, logic, and programming. The estimate for this project is $100,000 and could be completed in no more than 12 months if this is an acceptable short-term solution determined in consultation with the other affected utilities. The project to upgrade the Liberty-Rudd 230 kV line would require a Facilities Study by Western and/or SRP; Western being the owner of the Liberty substation and SRP owning the 230 kV line and the Rudd termination.
4.2 Transmission Provider’s Interconnection Facilities (TPIF)
This estimate includes the portion of the customer’s generator tie-line that APS would construct, operate and maintain. These facilities include the 230 kV line that APS would take from the Point of Interconnection (POI) at the 230 kV bus up to the first structure outside of the Jojoba substation fence, which would be the Change of Ownership (COO). This would include the 230 kV line switch, CTs, PTs, and the 230 kV structures required to bring the line from the bus structure to the COO. The TPIF are depicted in Figure 4-6 and are the facilities shown in red. The estimate for the TPIF is $881,000 and is estimated that it could be in-service at the same time as the 230 kV substation.
Table 4-4. Transmission Provider’s Interconnection Facilities
Cost Estimate Time Estimate
230 kV TPIF $881,000 < 30 months
Total $881,000 < 30 months
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4.3 Project Estimate Summary
Table 4-5 below summarizes the costs for the various mitigations required to achieve the full requested output for this interconnection request. Due to the uncertainty regarding the rebuild of the Jojoba-TS4-Libery 230 kV line the cost estimate and estimated time to complete the required upgrades is shown over a range.
Table 4-5. Estimate Summary
Upgrade Cost Estimate Time Estimate
Gillespie-Patterson-Komatke 69 kV line $6,500,000 36-42 months
Jojoba-TS4-Liberty 230 kV line $31,450,000 - $35,700,000 54-90 months
Jojoba 230 kV substation and 500/230 kV transformer
$17,000,000 30 months
Sun Valley SPS $100,000 < 30 months
TPIF $881,000 < 30 months
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Figure 4-6. Conceptual Layout of Jojoba 230 kV substation
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TPL-002 (Category B) Outages 500 kV Lines
1. N-1 N.GILA-IMPERIAL VALLEY 500kV Line 1
3 phase fault at N.Gila 500kV cleared in 4 cycles 2. N-1 PALO VERDE-COLORADO RIVER 500kV Line 1
3 phase fault at Palo Verde 500kV cleared in 4 cycles 3. N-1 PALO VERDE-DELANEY 500kV Line 1
3 phase fault at Delaney 500kV cleared in 4 cycles 4. N-1 DELANEY-SNVLY 500KV Line 1
3 phase fault at Sun Valley 500kV cleared in 4 cycles 5. N-1 MORGAN-SUN VALLEY 500KV Line 1
3 phase fault at Sun Valley 500kV cleared in 4 cycles 6. N-1 HASSAYAMPA-JOJOBA 500KV Line 1
3 phase fault at Jojoba 500kV cleared in 4 cycles 7. N-1 HASSAYAMPA-QX 500KV Line 1
3 phase fault at Hassayampa 500kV cleared in 4 cycles 8. N-1 QX-HOODOO WASH 500KV Line 1
3 phase fault at Qx 500kV cleared in 4 cycles 9. N-1 HOODOO WASH-N.GILA 500KV Line 1
3 phase fault at HOODOO WASH 500kV cleared in 4 cycles 10. N-1 HASSAYAMPA-N.GILA 500KV Line 2
3 phase fault at Hassayampa 500kV cleared in 4 cycles 11. N-1 HASSAYAMPA-PINAL WEST 500KV Line 1
3 phase fault at Hassayampa 500kV cleared in 4 cycles 12. N-1 JOJOBA-KYRENE 500KV Line 1
3 phase fault at Jojoba 500kV cleared in 4 cycles 13. N-1 KYRENE-BROWNING 500KV Line 1
3 phase fault at Kyrene 500kV cleared in 4 cycles 14. N-1 DUGAS-MORGAN 500KV Line 1
3 phase fault at Morgan 500kV cleared in 4 cycles 15. N-1 MORGAN-WESTWING 500KV Line 1
3 phase fault at Westwing 500kV cleared in 4 cycles 16. N-1 PALOVRDE-RUDD 500KV Line 1
3 phase fault at Palo Verde 500kV cleared in 4 cycles 17. N-1 PALO VERDE-RUDD 500KV Line 1 (w Hassayampa SPS) - Exploratory
3 phase fault at Palo Verde 500kV cleared in 4 cycles
Open the Sun Valley-Hassayampa Tap 230kV line in 5 cycles 18. N-1 PALO VERDE-WESTWING 500KV Line 1
3 phase fault at Palo Verde 500kV cleared in 4 cycles 19. N-1 PALO VERDE-WESTWING 500KV Line 2
3 phase fault at Palo Verde 500kV cleared in 4 cycles 20. N-1 IMPERIAL VALLEY-MIGUEL 500KV Line 1 (W SPS)
3 phase fault at Imperial Valley 500kV cleared in 4 cycles
Trip IV Gen Units 1-3 and INTB CT and ST in 8 cycles
Trip Otay Mesa-Tijuana 230kV line in 120 cycles 21. N-1 JOJOBA-GILARIVR 500KV Line 1
3 phase fault at Gila River 500kV cleared in 4 cycles 22. N-1 MORGAN-PINNACLE PEAK 500KV Line 1
3 phase fault at Morgan 500kV cleared in 4 cycles
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TPL-002 (Category B) Outages 345 kV Lines
23. N-1 PEACOCK-LIBERTY 345KV Line 1
3 phase fault at Liberty 345kV cleared in 4 cycles TPL-002 (Category B) Outages 230 kV Lines
24. N-1 PANDA-JOJOBA 230KV Line 1
3 phase fault at Jojoba 230kV cleared in 5 cycles 25. N-1 JOJOBA-TS4-LIBERTY-PALM VALLEY 230KV Line 1 (without JJ-TS4 #2)
3 phase fault at Jojoba 230kV cleared in 5 cycles 26. N-1 JOJOBA-TS4 230KV Line 1 (with JJ-TS4 #2)
3 phase fault at Jojoba 230kV cleared in 5 cycles 27. N-1 TS4-LIBERTY 230KV Line 1 (with JJ-TS4 #2)
3 phase fault at TS4 230kV cleared in 5 cycles 28. N-1 TS4-PALM VALLEY 230KV Line 1 (with JJ-TS4 #2)
3 phase fault at TS4 230kV cleared in 5 cycles 29. N-1 JOJOBA-TS4 230KV Line 2 (with JJ-TS4 #2)
3 phase fault at Jojoba 230kV cleared in 5 cycles 30. N-1 RUDD-PLMVLY 230KV Line 1
3 phase fault at Palm Valley 230kV cleared in 5 cycles 31. N-1 BUCKEYE-LIBERTY 230KV Line 1
3 phase fault at Liberty 230kV cleared in 5 cycles
Close the Buckey-Buckey2 230kV line in 5 cycles 32. N-1 BUCKEYE-LIBERTY 230KV Line 2
3 phase fault at Liberty 230kV cleared in 5 cycles 33. N-1 SUN VALLEY-TRILBY WASH 230KV Line 1
3 phase fault at Trilby Wash 230kV cleared in 5 cycles 34. N-1 SUN VALLEY-TRILBY WASH 230KV Line 1 (w Hassayampa SPS) –
Exploratory
3 phase fault at Trilby Wash 230kV cleared in 5 cycles
Open the Sun Valley-Hassayampa Tap 230kV line in 5 cycles 35. N-1 TRILBY WASH-TS2-PALM VALLEY 230KV Line 1
3 phase fault at Palm Valley 230kV cleared in 5 cycles 36. N-1 SUN VALLEY-HASSYAMPA PUMP 230KV Line 1
3 phase fault at Sun Valley 230kV cleared in 5 cycles 37. N-1 SUN VALLEY-HASSYAMPA TAP 230KV Line 1
3 phase fault at Sun Valley 230kV cleared in 5 cycles 38. N-1 HARCUVAR-HASSYAMPA TAP 230KV Line 1
3 phase fault at Hassyampa Tap 230kV cleared in 5 cycles 39. N-1 LIBERTY-HASSYAMP TAP 230KV Line 1
3 phase fault at Hassyampa Tap 230KV cleared in 5 cycles 40. N-1 LIBERTY-LONE BUTTE 230KV Line 1
3 phase fault at Liberty 230KV cleared in 5 cycles 41. N-1 LIBERTY-PHXWAPA 230KV Line 1
3 phase fault at Liberty 230KV cleared in 5 cycles 42. N-1 LIBERTY-RUDD 230KV Line 1
3 phase fault at Liberty 230KV cleared in 5 cycles 43. N-1 LIBERTY-WESTWING 230KV Line 1
3 phase fault at Liberty 230KV cleared in 5 cycles
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TPL-002 (Category B) Outages (Power flow only) 69 kV Lines
44. N-1 GILA BEND-COTTON CENTER-GILLESPIE 69KV Line 1
45. N-1 PVNGPUMP-GILLESPIE 69KV Line 1 (Trip 9 MW of Gillespie PV Generation)
46. N-1 GILLESPIE-PATTERSON-JOJOBA 69KV Line 1
47. N-1 JOJOBA-RAINBOW 69KV Line 1
48. N-1 JOJOBA-ROBBINS BUTTE-BUCKEYE 69KV Line 1
49. N-1 BUCKEYE-WATSON 69KV Line 1
50. N-1 WATSON-VALENCIA-BASELINE-PVNGPUMP 69KV Line 1
51. N-1 SADDLE MT-PHILLIPS 69KV Line 1
52. N-1 BUCKEYE-TARTESSO TEMP-DESERT SKY-BADGER 69KV Line 1
53. N-1 PHILLIPS-WINTERSBURG 69KV Line 1
54. N-1 WINTERSBURG-ARLINGTON-PVNGPUMP 69KV Line 1
55. N-1 GILA BEND-PALOMA-BUNYAN 69KV Line 1 (DROPS BUNYAN LOAD)
56. N-1 SADDLE MT-COUNTY LINE 69KV Line 1
57. N-1 COUNTY LINE-BUNYAN 69KV Line 1
TPL-002 (Category B) Outages Transformers
58. N-1 GILA RIVER 500/230KV XFMR 1
3 phase fault at Panda 230KV cleared in 4 cycles 59. N-1 GILA BEND 230/69KV XFMR 8
3 phase fault at Gila Bend 230KV cleared in 5 cycles 60. N-1 GILA BEND 230/69KV XFMR 12
3 phase fault at Gila Bend 230KV cleared in 5 cycles 61. N-1 BUCKEYE 230/69KV XFMR 1
3 phase fault at Buckeye 230KV cleared in 5 cycles 62. N-1 BUCKEYE 230/69KV XFMR 2
3 phase fault at Buckeye 230KV cleared in 5 cycles 63. N-1 PALM VALLEY 230/69KV XFMR 1
3 phase fault at Palm Valley 230kV cleared in 5 cycles 64. N-1 SNVLY 500/230KV XFMR
3 phase fault at Sun Valley 500kV cleared in 4 cycles 65. N-1 TRILBY WASH 230/69KV XFMR
3 phase fault at Trilby Wash 500kV cleared in 5 cycles 66. N-1 RUDD 500/230KV XFMR 4
3 phase fault at Rudd 500kV cleared in 4 cycles 67. N-1 WESTWING (E) 500/230KV XFMR 1
3 phase fault at Westwing 500kV cleared in 4 cycles 68. N-1 MORGAN 500/230KV XFMR 1
3 phase fault at Raceway 230kV cleared in 4 cycles 69. N-1 KYRENE 500/230KV XFMR 6
3 phase fault at Kyrene 500kV cleared in 4 cycles 70. N-1 KYRENE 500/230KV XFMR 7
3 phase fault at Kyrene 500kV cleared in 4 cycles 71. N-1 KYRENE 500/230KV XFMR 8
3 phase fault at Kyrene 500kV cleared in 4 cycles
Q219 System Impact Study APS Contract No. 52698
Page 38
72. N-1 JOJOBA 500/230KV XFMR 1 (when Modeled)
3 phase fault at Jojoba 230 kV cleared in 5 cycles TPL-002 (Category B) Outages Generators
73. N-1 Q219 Unit 1
no fault trip 74. N-1 Q219 gen tie
3 phase fault at Jojoba 230 kV cleared in 5 cycles TPL-003 (Category C) Outages 500kV Lines
75. N-2 Jojoba-Gila River 1 &2 500 kV Lines
3 phase fault at Jojoba 500 kV cleared in 4 cycles (C3)
Gila River SPS Action: Open the Gila River 500/230 kV Xfmr at 12 cycles dropping all Gila River generation
76. N-2 Palo Verde Unit 1 & Palo Verde-Westwing 500 kV Line 1
SLG fault at Palo Verde 500 kV cleared in 10 cycles (C6) 77. N-2 Palo Verde-Westwing 500 kV Line 1 & Westwing 500/230 kV Xfmr 10
SLG fault at Westwing 500 kV cleared in 10 cycles (C7) 78. N-1-1 Morgan-Pinnacle Peak 500 kV line & Avery-Raceway 230 kV line
SLG phase fault at Pinnacle Peak 500 kV cleared in 4 cycles (C3) 79. N-2 Morgan-Westwing or Dugas (failed breaker or breaker failure protection)
500 kV line & Morgan #1 500/230 kV xfmr
3-phase fault at Morgan 500 kV cleared in 4 cycles 80. N-2 IPP DC Bi-pole
No Fault DC Outage
Trip Intermountain and Adelanto shunt caps in 4 cycles
Trip Intermountain Units 1 & 2 in 10.2 cycles 81. N-2 Jojoba-TS4 1&2 230 kV Lines (When JJ-TS4 #2 is modeled)
3-phase fault at Jojoba 230 kV cleared in 5 cycles TPL-004 (Category D) Outages 500kV Lines
82. Simultaneous Outage of the Hassayampa-Jojoba & Jojoba-Kyrene 500 kV Lines
3 phase fault at Jojoba 500 kV cleared in 4 cycles (D3)
Gila River SPS Action: Open the Gila River 500/230 kV transformer at 12 cycles dropping all Gila River generation
Open the Jojoba 500/230 kV at 12 cycles (when modeled) 83. Simultaneous Outage of the Hassayampa-Jojoba 500 kV line &
Hassayampa-Pinal West 500 kV line (Category D)
SLG fault at Hassayampa 500 kV cleared in 4 cycles 84. Simultaneous Outage of the Palo Verde-Westwing #1 500 kV line &
Palo Verde-Rudd 500 kV line (Category D)
SLG fault at Palo Verde 500kV cleared in 4 cycles 85. Simultaneous Palo Verde-Westwing 500 kV Lines 1 & 2
SLG fault at Palo Verde 500 kV cleared in 4 cycles (D3)