1. Presented by: LADWP November 14, 2017
Hollywood RAS
Presented by:
LADWP
November 14, 2017
Los angeles department of water and power

2. OVERVIEW

3. PURPOSE
In 2016 the Hollywood RAS was presented and approved as a Safety Net. Its initial purpose was to prevent transient instability, thermal overload, and voltage instability associated with the loss of the Toluca Substation (RS-E) or simultaneous loss of the three (3) Toluca-Hollywood parallel lines
Because of the Ten Year Planning Assessment Study from 2016, three (3) new contingencies were identified and will be added to do the following:
Protect against thermal overload of the remaining circuit for the loss of any two (2) TOL-HWD
Detection and mitigation strategy that utilizes Line Loss Detection + Power Flow

4. Overall Power System

5. System Overview

6. Planning Study

7. Planning Study Results
Study results, using approved WECC 2020 Heavy Summer base case, showed the loss of two (2) Toluca-Hollywood lines causes thermal overload on the remaining Hollywood Line
Contingency 5: Loss of TOL-HWD Line 1 and TOL-HWD Line 3
Contingency 6: Loss of TOL-HWD Line 1 and TOL-HWD Line 2
Contingency 7: Loss of TOL-HWD Line 2 and TOL-HWD Line 3

8. One Line Diagram

9. Hollywood RAS Logic: TOL-HWD Transmission Circuit Flows
The RAS logic predicts post-contingency and post-remedial MW flows on TOL-HWD transmission circuits based on the following:
Real-time, pre-contingency MW flows
Contingency and injection distribution factors obtained from power flow simulations

10. Hollywood RAS Logic: Arming
The RAS logic arms remedial action to prevent predicted post-contingency MW flows on TOL-HWD transmission circuits from exceeding emergency ratings

11. Contingency 5: Loss of TOL-HWD Line 1 & Line 3
TOL-HWD Line 2 Ratings
Sec
Description
Cont. Rating (MVA) A
Bank 1 at Toluca
272 B
One 138kV overhead transmission line
297* C1
138kV underground, overhead, and disconnect switches
182* C2
138kV underround, overhead, and disconnect switches D
Disconnect switches at Hollywood
287
Loss of TOL-HWD Line 1 and TOL-HWD Line 2
* Use the lowest rating

12. Contingency 5: Planning Flowchart
TH1=Actual TOL-HWD 1 MW flow, positive flowing into HWD
TH2=Actual TOL-HWD 2 MW flow, positive flowing into HWD
TH3=Actual TOL-HWD 3 MW flow, positive flowing into HWD
TH2’ = Calculated post-contingency MW flow on TOL-HWD 2 positive flowing into HWD

13. Contingency 5: Simplified Logic

14. Contingency 5: Post-Contingency Flow
Power Flow Results of Loss of TOL-HWD Lines 1 & 3
Lines
Pre-contingency Flow (MW)
Post-contingency Flow (MW)
TOL-HWD Line 1
232
TOL-HWD Line 2
115
389
TOL-HWD Line 3
226
To relieve the overload on TOL-HWD L2, 241 MW of load needs to be shed.

15. Contingency 6: Loss of TOL-HWD Line 1 & Line 2
TOL-HWD Line 3 Rating
Description
Continuous Rating (MVA)
One section of overhead Transmission Line and one section of underground cable
494*
Bank F at Hollywood
400
* Use the lowest rating
Loss of TOL-HWD Line 1 and TOL-HWD Line 2

16. Contingency 6: Planning Flowchart
TH1=Actual TOL-HWD 1 MW flow, positive flowing into HWD
TH2=Actual TOL-HWD 2 MW flow, positive flowing into HWD
TH3=Actual TOL-HWD 3 MW flow, positive flowing into HWD
TH3’=Calculated post-contingency MW flow on TOL-HWD 3, positive flowing into HWD

17. Contingency 6: Simplified Logic

18. Contingency 6: Post-Contingency Flow
Power Flow Results of Loss of TOL-HWD Lines 1 & 2
Lines
Pre-contingency Flow (MW)
Post-contingency Flow (MW)
TOL-HWD Line 1
232
TOL-HWD Line 2
115
TOL-HWD Line 3
226
486
To relieve the overload on TOL-HWD L3, 137 MW of load needs to be shed.

19. Contingency 7: Loss of TOL-HWD Line 2 & Line 3
TOL-HWD Line 1 Rating
Description
Continuous Rating (MVA)
One section of overhead Transmission Line and one section of underground cable
313*
Bank E at Hollywood
405
* Use the lowest rating
Flow on TOL-HWD L1 After Load-shedding at Hollywood

20. Contingency 7: Planning Flowchart
TH1=Actual TOL-HWD 1 MW flow, positive flowing into HWD
TH2=Actual TOL-HWD 2 MW flow, positive flowing into HWD
TH3=Actual TOL-HWD 3 MW flow, positive flowing into HWD
TH1’=Calculated post-contingency MW flow on TOL-HWD 1, positive flowing into HWD

21. Contingency 7: Logic

22. Contingency 7: Post-Contingency Flow
Power Flow Results of Loss of TOL-HWD Lines 2 & 3
Lines
Pre-contingency Flow (MW)
Post-contingency Flow (MW)
TOL-HWD Line 1
232
489
TOL-HWD Line 2
115
TOL-HWD Line 3
226
To relieve the overload on TOL-HWD L1, 238 MW of load needs to be shed.

23. Impacts of a Failure of a RAS to Operate
No violation of TPL-001-WECC-CRT-3
Maximum firm load loss ≤ 300 MW
Maximum generation loss ≤ 1000 MW
Contingencies 5-7 meet the LAPS criteria
Note! Contingencies 1-4 continue to be a Safety Net as previously approved.

24. RAS LOGIC

25. RAS Devices
The same devices will be utilized for new HWDRAS contingencies as previously approved for Safety Net contingencies: NO NEW HARDWARE
GE-N60 relays are used to
Gather local data
Transfer data using IEC telecommunications protocol
Perform local trips
GE-C90P relays
Process all the data and run it through logic
Use IEC to send a remedial trip to the N60s notifying them to trip local breakers

26. Line Loss Logic Detection

27. New Contingencies
Double circuit outage for Toluca-Hollywood path: Either N-2 or N-1-1
Contingency 5
Loss of Toluca-Hollywood lines 1 and 3 with Post-Contingency Toluca-Hollywood Line 2 MW >= 260 MW
Contingency 6
Loss of Toluca-Hollywood lines 1 and 2 with Post-Contingency Toluca-Hollywood Line 3 MW >= 403 MW
Contingency 7
Loss of Toluca-Hollywood Lines 2 and 3 with Post-Contingency Toluca-Hollywood Line 1 MW >= 320 MW

28. CB Assume Open
HWDRAS CB Assume Open only applied to CBs associated with Line Loss Detection
TOLUCA
TOL-HOL 1
TOL-HOL 2
TOL-HOL 3
CB-E201
CB-E202
CB-E101
CB-E102
CB-E191
CB-E192
HOLLYWOOD
HOL-FAR A
HOL-FAR B
CB-E21
CB-E22
CB-E41
CB-E42
CB-E12
CB-E13
E81
E72
FAIRFAX
E11
E12
E21
E22
NOTE! Logic for manual cb ASSUME OPEN to facilitate work on cb isolated from system via open disconnects

29. How to Set CB Assume Open
NOTE! The operator will have to Press Local Button for 5 seconds.

30. How to Set CB Assume Open
After the Relay is under a Local Command, the operator must press the pushbutton for the desired “CB Assume Open.”
After the operator presses the CB Assume Open, an alarm “CB Assume Open” will be sent to ECC indicating the station name with bay number.

31. RAS Testing & Maintence

32. RAS End-to-End Commissioning Test
Overall end-to-end test will be performed for commissioning
This is a complete test using power system simulators connected via satellite time sync
To avoid a complete system outage, outputs will be checked one terminal at a time
Block the RAS system with blocking switches
Use multiple test sets and dummy breakers to simulate a line loss
Synchronize test sets with a GPS signal
Trip test CBs one at a time

33. Commissioning Tests
The following will be checked and verified during commissioning
RAS Settings
Contingency Logic
I/O
CTs. PTs, 52a, and 52b Circuit Breaker Pallets
Contingency Operation
Contingency Time Operation
DC Circuitry Trips
Communication Channels
Wiring Prints
Annunciator Alarms
SCADA Control and Status Indications
After commissioning, the UR Engineering software will be used to extract the Master Settings file for each device

34. RAS Annual Maintenance
System Approach – Maintenance can be performed from RS-H for the entire RAS A or RAS B system
The Master Settings file will be used as a reference to verify relay settings and logic
If any unauthorized change is made to an HWDRAS device the system automatically sends an alarm to the Grid Operation Center

35. RAS Annual Maintenance Process
Use the latest software to do the following:
Compare the relay settings and logic with the Master Settings file for the device.
Verify that the settings and logic have not changed.
Perform a remote load check for each terminal to verify the integrity of the PTs and CTs.
Compare RAS A values with RAS B values.
NOTE! Communication channels, CB pallets, C90P/N60 devices, and contingencies arming are continuously monitored. If a failure event occurs, the system automatically sends an alarm to Grid Operation Center.

36. RAS 5-Year Functional Test
This is an individual circuit approach, and work will be performed on every circuit in the RAS A and B systems, one system at a time
The Functional Test combined with Annual Maintenance checks the following to ensure compliance with PRC-005
Settings and Logic
Communication Channels
Inputs and Outputs
Arming Contingencies
Communication Time Delay
System Operating Time Delay
Automatic Arming
CT and PT Integrity
CIP Alarms
52-a and 52-b CB Pallets
Trip DC Circuitry
SCADA Controls

37. HWD RAS SUMMARY

38. Conclusion
No system thermal overload after applying the RAS for the new contingency.
No violation of TPL-001-WECC-CRT-3.
Maximum firm load loss ≤ 300 MW.
Maximum generation loss ≤ 1000 MW.
No additional hardware was needed for the new contingencies 5-7.
The addition of Contingencies 5, 6, and 7 meet the criteria of a LAPS. Hence, it remains a Safety Net.

39. Summary A new set of contingencies were identified
Contingencies 5, 6, and 7 were added to protect the overload condition on the remaining TOL-HWD line for the loss of any two (2) TOL-HWD lines
LADWP requests the continued acknowledgement of the Hollywood RAS as a Safety Net.

40. QUESTIONS?

41. TIME TO VOTE!
LADWP requests the continued acknowledgement of the Hollywood RAS as a Safety Net.