1. Proposal to Remove from Service the PV-COI RAS
Justin Lee
August 2, 2017

2. Agenda Purpose Historical Background Summary of Study Results
Recommendation
08/02/2017

3. Purpose Obtain RASRS approval to remove from service the PV-COI RAS
08/02/2017

4. Historical Background
Planned upgrades of the three Palo Verde (PV) Units
Winter / Summer
PV Unit #2 – November 2003 (121MW / 92MW)
PV Unit #1 – November 2005 (121MW / 92MW)
PV Unit #3 – November 2007 (121MW / 92MW)
08/02/2017

5. Historical Background
Technical Studies showed impact on California Oregon Inter-Tie (COI)
Pre PV unit upgrades showed minimum of 134MVAR margin on COI system busses
Post PV unit upgrades study case diverged, indicated zero MVAR margin on COI system busses
Direct Load Tripping of 150MW in Phoenix Area restored MVAR margin to 139MVAR
08/02/2017

6. 08/02/2017

7. 0MW
200MVAR
400MW
0MVAR
1000MW
200MVAR
08/02/2017

8. 08/02/2017

9. Historical Background
A Direct Load Trip (DLT) scheme was designed and implemented
Scheme arms when output of any two units at Palo Verde exceeds 2550MW
Scheme operates if two Palo Verde units trip within five minutes
150MW of load armed, 120MW to trip
DLT scheme placed in service in 2004
08/02/2017

10. Historical Background
The Transmission System has Changed Since the PV-COI RAS was Installed
Series capacitors installed on John Day – Grizzly #1 and #2 500kV lines
308MVAR Shunt capacitor installed at the Slatt 500KV bus
08/02/2017

11. Historical Background
To be compliant with PRC-012 through 014- WECC-CRT-2 WR10, SRP began a project to assess the operation, coordination, and effectiveness of the PV-COI RAS
A third party consultant was hired to perform the technical analysis
08/02/2017

12. Summary of Study Results
The study results show that with the COI stressed to it limit and without the PV-COI RAS in service
The system continues to meet all power flow, voltage, stability, and transient stability criteria
There is a minimum of 472MVAR of Margin on the COI system busses, well above the 134MVAR of margin that the RAS was designed to maintain
08/02/2017

13. Recommendation
Based on the study results, SRP recommends that the PV-COI RAS be removed from service by December 31, 2017 and decommissioned at a later date.
08/02/2017