EirGrid 10344 - PSP019 - CABLE STUDIES FOR GRID WEST

LONDON POWER ASSOCIATES LTD

London Power Associates Ltd. LPA Project Number 10344 Elizabeth House, 56-60 London Road, Staines-upon-Thames, TW18 4BQ, UK EirGrid Project Number PSP0019 Tel: +44 (0)1784 490 057, Fax: +44 (0)1784 273 860 E-mail: [email protected], Web: www.LPAworld.com

EirGrid

10344 - PSP019 - CABLE STUDIES FOR GRID WEST

Partial AC Underground Solution

APPENDIX D – 58 KM, 220 KV CABLE OPTION SUMMER VALLEY B

17th December 2014

mailto:[email protected]

http://www.lpaworld.com/

10344 - PSP019 - CABLE STUDIES FOR GRID WEST APPENDIX D – 58 KM, 220 KV CABLE OPTION SUMMER VALLEY B

London Power Associates Ltd. PAGE II OF III 17th December 2014

REPORT AUTHORISATION SHEET

Client: EirGrid

Project: 10344 - PSP019 - Cable Studies for Grid West

Report Title Appendix D – 58 km, 220 kV Cable Option Summer Valley BAppendix D – 58 km, 220 kV Cable Option Summer Valley B

Project Number 10344

Report Version Final Appendix

Report Date 17th December 2014

Prepared by:

Name: Christopher Ellis

Position: Senior Consultant

Date: 17th December 2014

Checked by:

Name: Amarjit Jhutty

Position: Managing Director


Authorised for issue:

Name: Johan Stalmans

Position: Director


Version No. Report Date Comment Author Checked Authorised

1.0 17/12/14 Initial Issue CE AJ JS


London Power Associates Ltd. PAGE III OF III 17th December 2014

Contents

1 Results .................................................................................................................................................. 1 1.1 Impedance Scans - Length 58 km – Summer Valley B ......................................................................... 1 1.2 Time Domain Simulation - Length 58 km – Summer Valley B ............................................................ 2


London Power Associates Ltd. PAGE 1 OF 6 17th December 2014

1 RESULTS Impedance scans and time domain simulations for a 58 km of 220 kV cable with sized reactors at both Flagford and North Mayo. The Grid West circuit consisted of this 58 km 220 kV cable and a further 52 km OHL to complete the entire 110 km route.

This appendix presents the results for Summer Valley B generation / demand profile. It will cover the 220 kV 58 km cable option with the circuit incorporating 58 km of UGC and 52 km of OHL. This case has failed due to a high resonance point below the 3rd harmonic of above 1000 Ohms and has also failed due to TOVs exceeding the allowable limits.1

1.1 Impedance Scans - Length 58 km – Summer Valley B Conditions for impedance scan:

1. Summer Valley B network

2. Length – 58 km 220kV Cable/52 km Overhead Line

3. Reactors – North Mayo 175 MVar/Flagford 50 MVar

Case 1: (N-2) Cashla-Flagford/Flagford-Louth Lines Out

Figure 1: SVB - Length 58 km cable / 52 km OHL - (N-2) Cashla-Flagford/Flagford-Louth Lines Out

Impedance Scan - Resonance points

Frequency (Hz) Impedance (Ω)

121.51 1132.2

417.01 2733.8

1 For the purposes of clarity , in the Time Domain Simulations shown in all the Appendices, the term ‘N-2’ shown in the graphical figure descriptions refer to an ‘N-1-1’ trip-maintenance situation.

(file FS_GW0_BASE_SVB_ASCC_58km_(N-2)_Cashla-Flagford_Flagford-Louth.pl4; x-var f) v:FLAG2A v:FLAG2B v:FLAG2C 0 200 400 600 800 1000[Hz]

0

500

1000

1500

2000

2500

3000

[ ]

Summer Valley B - 58km 220km Cable/52km Overhead Line (N-2) Cashla-Flagford/Flagford-Louth Out



1.2 Time Domain Simulation - Length 58 km – Summer Valley B Conditions for time domain simulation:

1. Summer Valley B network

2. Length 58 km cable / 52 km OHL

Case 1: (N-2) Cashla-Flagford Auto Reclose onto Fault/Flagford-Louth Lines Out

System Conditions:

1. Fault on Flagford side of Cashla - Flagford line, applied at 0.5s.

2. Reclose sequence at 0.575s, dead time 0.6s, circuit breaker closes 1.175s, point on wave closes at 90°.

3. Breaker opens at again at 1.25s.



Figure 2: SVB - Length 58 km cable / 52 km OHL - Flagford – (N-2) Cashla-Flagford Auto Reclose onto Fault/Flagford-Louth Lines Out (0-6s)

Figure 3: SVB - Length 58 km cable / 52 km OHL - Flagford – (N-2) Cashla-Flagford Auto Reclose onto Fault/Flagford-Louth Lines Out (0-2s)

Condition Maximum Value Limit Result

Switching 780.26 kV (4.344 pu) 446.375 kV (2.5 pu) Fail

Temporary Overvoltage 410.97 kV ( 2.288pu) 287.32 kV (1.6pu) Fail

(file TD_GW0_BASE_SVB_ASCC_58km_(N-2)_Cashla-Flagford_Fail_Reclose.pl4; x-var t) v:FLAG2A v:FLAG2B v:FLAG2C 0 1 2 3 4 5 6[s]

-800

-600

-400

-200

0

200

400

600

800

[kV]

Summer Valley B - 58km 220km Cable/52km Overhead Line (N-2) Cashla-Flagford Autoreclose/Flagford-Louth Out

(file TD_GW0_BASE_SVB_ASCC_58km_(N-2)_Cashla-Flagford_Fail_Reclose.pl4; x-var t) v:FLAG2A v:FLAG2B v:FLAG2C 0.0 0.4 0.8 1.2 1.6 2.0[s]

-800

-600

-400

-200

0

200

400

600

800

[kV]




Figure 4: SVB - Length 58 km cable / 52 km OHL – Cable End A – (N-2) Cashla-Flagford Auto Reclose onto Fault/Flagford-Louth Lines Out (0-6s)

Figure 5: SVB - Length 58 km cable / 52 km OHL – Cable End A – (N-2) Cashla-Flagford Auto Reclose onto Fault/Flagford-Louth Lines Out (0-2s)


Switching 510.23 kV ( 2.841 pu) 446.375 kV (2.5 pu) Fail

Temporary Overvoltage 440.65 kV (2.453 pu) 287.32 kV (1.6pu) Fail

(file TD_GW0_BASE_SVB_ASCC_58km_(N-2)_Cashla-Flagford_Fail_Reclose.pl4; x-var t) v:CABAA v:CABAB v:CABAC 0 1 2 3 4 5 6[s]

-600

-400

-200

0

200

400

600

[kV]


(file TD_GW0_BASE_SVB_ASCC_58km_(N-2)_Cashla-Flagford_Fail_Reclose.pl4; x-var t) v:CABAA v:CABAB v:CABAC 0.0 0.4 0.8 1.2 1.6 2.0[s]

-600

-400

-200

0

200

400

600

[kV]




Figure 6: SVB - Length 58 km cable / 52 km OHL – Cable End B – (N-2) Cashla-Flagford Auto Reclose onto Fault/Flagford-Louth Lines Out (0-6s)

Figure 7: SVB - Length 58 km cable / 52 km OHL – Cable End B – (N-2) Cashla-Flagford Auto Reclose onto Fault/Flagford-Louth Lines Out (0-2s)



Temporary Overvoltage 412.89 kV (2.299 pu) 287.32 kV (1.6pu) Fail

(file TD_GW0_BASE_SVB_ASCC_58km_(N-2)_Cashla-Flagford_Fail_Reclose.pl4; x-var t) v:CABBA v:CABBB v:CABBC 0 1 2 3 4 5 6[s]

-800

-600

-400

-200

0

200

400

600

800

[kV]


(file TD_GW0_BASE_SVB_ASCC_58km_(N-2)_Cashla-Flagford_Fail_Reclose.pl4; x-var t) v:CABBA v:CABBB v:CABBC 0.0 0.4 0.8 1.2 1.6 2.0[s]

-800

-600

-400

-200

0

200

400

600

800

[kV]




Figure 8: SVB - Length 58 km cable / 52 km OHL –North Mayo – (N-2) Cashla-Flagford Auto Reclose onto Fault/Flagford-Louth Lines Out (0-6s)

Figure 9: SVB - Length 58 km cable / 52 km OHL – Cable End - North Mayo – (N-2) Cashla-Flagford Auto Reclose onto Fault/Flagford-Louth Lines Out (0-2s)



Temporary Overvoltage

400.56 kV (2.230 pu) 287.32 kV (1.6pu) Fail

(file TD_GW0_BASE_SVB_ASCC_58km_(N-2)_Cashla-Flagford_Fail_Reclose.pl4; x-var t) v:CABNMA v:CABNMB v:CABNMC 0 1 2 3 4 5 6[s]

-600

-400

-200

0

200

400

600

[kV]


(file TD_GW0_BASE_SVB_ASCC_58km_(N-2)_Cashla-Flagford_Fail_Reclose.pl4; x-var t) v:CABNMA v:CABNMB v:CABNMC 0.0 0.4 0.8 1.2 1.6 2.0[s]

-600

-400

-200

0

200

400

600

[kV]


Documents

EirGrid 10344 - PSP019 - CABLE STUDIES FOR GRID WEST