1. 2018 CG MOD 33 updates CG Planning Meeting June 7, 2018

2. Review of CG MOD 33 Activities
Selection of August 8th event (3AM) in 08/17 planning meeting
Requested by CG, WECC created the mapping case in Nov. 30
CG developed WSM/Planning case mapping tool and use it for Area 40 mapping: generate 3126 branch mapping table, adjusts loads, and identify topology difference.
2/7/18, we had the 1st MOD 33 workgroup meeting, discussed preliminary MW/Mvar comparison results
4/12/18, we had the 2nd MOD 33 workgroup meeting, finished MW comparison, started case review focused on Mvar/Voltage mapping.

3. Activities since April 12
MVar/Voltage review & adjustments from Avista, Chelan, Grant, PSE and SCL
BPA, Snohomish and Tacoma indicates no further adjustments related to MVar/Voltage mapping
Lessons learned from reactive power mapping.
Type mismatch (Gen, Load, SVC, Switch shunt, Line shunt, etc)
Significant contribution from line charging and impedance difference
Topology, transformer tap, distribution feeders, load connecting points, etc
CG performed independent case review, with some corrections, all 115kV ~ 500kV bus voltage comparison (includes PACW and PGE) stays in “acceptable” range. No further adjustment or objections from members.
MOD 33 Power Flow Validation is completed, with no “unacceptable” discrepancy in our region.
A presentation given to WECC MVWG draws a lot of interests

4. Voltage Comparison

5. MVar load comparison
After load scaling and adjustment, type mismatch may show as points off.

6. Shunt Comparison
Some type mismatches, shunt vs load (gen, line shunt, etc)
Smaller shunts in distribution feeder are not exactly matched

7. Gen Mvar Output Comparison
Most members chose to align voltage set points, leave MVar output to whatever values from power flow solution

8. Voltage Comparison WSM vs. planning
All buses in Area 40 (0.6 kV ~ 500 kV)
Do not correct any voltage discrepancy bellow 115 kV

9. 500 kV

10. 230 ~ 345 kV

11. 115 kV

12. To Map Voltage
Align Generator Voltage set points, it provides supporting points throughout the network
Review branch mapping to correct impedance difference
Align Shunts
Starting from 500 kV, tracking down the voltage difference points and fix any model difference causing it.
Similar to MW mapping, sometimes need to go a little further along the path. But with the supporting points from generator voltage set point, it is not very hard.
Pay attention to the type mismatches

13. After Voltage Mapping, Line flows, MW

14. Line flows, MVar

15. Dynamic Model Validation

16. WECC Dynamic Data
Reading the DYD, WECC has made some adjustments for the dynamic data:
Netted 597 generators for the reason of: renewable, bad models, low loading, etc
84 units were in area 40, sent to members for review, feedback indicates most units should not be netted
Many other generators with bad models are switched off
A concerns of accuracy as loss of governor response and inertia.
Extra attention needed in the future for events at the boarder, where we don’t have other regions to review their generator being switch off.

17. Creating the Dynamic Base Case
Replace the composite load model with 3AM data
Model change for Coulee Condenser, confirmed by BPA & USBR
Clean up the bad data same as transient stability base cases (no switched off or netted generation)
Adopt latest model changes from members

18. Issues
WSM Measurement likes to push the generator output to the limits, even sometimes it is wrong…
Service load
Wrong MOD 32 data
Measurement error
Can’t fix everything,
no disturbance not exactly flat

19. Event Sequence
2017 8/8 3:08 am PCT event, three Colstrip units tripped
Time (MDT)
Time From Fault
Cycles From Fault
Event
04:08:18.279
00:00:00.000
0.00
A-Phase fault on Colstrip - Broadview 500 kV Line B; Z=0+ j pu 35% from Broadview
04:08:18.329
00:00:00.050
3.00
Fault cleared by opening Colstrip - Broadview 500 kV Line B
04:08:18.647
00:00:00.368
22.08
Series capacitors on the Colstrip – Broadview A line bypassed
04:08:18.687
00:00:00.408
24.48
Colstrip - Broadview 500 kV Line A opens
04:08:18.833
00:00:00.544
32.64
Colstrip Unit 3 Tripped
Colstrip Unit 4 Tripped
04:08:18.917
00:00:00.638
38.28
Colstrip Unit 1 Tripped
04:08:23.932
00:00:05.653
339.18
Broadview 500/230 kV Bank 3 tertiary reactors inserted
04:08:28.943
00:00:10.664
639.84
Broadview 500/230 kV Bank 4 tertiary reactors inserted

20. Simulation of ATR model
Contingency Name
Cycles From Fault
Event
August_8_events 37
Colstrip Unit 2 Tripped 38
Colstrip Unit 3 Tripped 41
Colstrip Unit 4 Tripped

21. Remove ATR, manually Add Tripping

22. Submitted Dynamic Measurements
PSE (DFR records in Comtrade)
5 substations measurements includes Bellingham, Bremerton, Sammamish, West Texaco, Wind Ridge
WECC (PMU data in Excel)
Malin 500kV frequency, voltage
MW flow Garrison – Taft 500kV, ckt 1 & 2
MW flow Ingledow – Custer 500kV, ckt 1 & 2
Snohomish (SCADA data in Excel)
Delta SW 115 kV frequency
Jackson 115 kV voltage
Jackson unit 2: MW, Mvar, Speed
Jackson unit 3: MW, Mvar

23. PSE Frequency Simulation dip < measurement dip
Load tripping & stall too much?
Other generation tripping elsewhere?
Simulation ramping < measurement ramping
Less generation governor response (netted)?
Load recovery too fast?

24. WECC Voltage Simulation overshoot > Measurement overshoot
500 kV power flow voltage mapping
Switching reactive source action?

25. WECC Line flow Post fault steady state value doesn’t match exactly
Unmapped neighboring power flow system has large impact in tie line flow
Netted generation in neighboring system
Flow control not modelled?

26. Snohomish

27. Next Step Stability Case will be posted/send for review
Please review stability models and send me any adjustments
Please provide DFR/PMU data for dynamic model validation, especially I am looking for
Measurements in generation and load center: Mid-C, Upper & Lower Columbia, Portland, Spokane area
Line flow measurements inside area 40
Generation terminal measurements
Switching device output measurements
Deadline: 6/29 ?

28. MOD 33 Work Plans
2018/ st MOD 33 work group meeting, focus on data checking, pass software tools to member to facilitate their data checking
After it, Both CG and member will do 2nd round MW flow review
2018/4        2nd MOD 33 work group, resolve power flow discrepancy caused between utilities, kick off the Mvar/voltage mapping process
After it, Both CG and member will do Mvar/Voltage review
2018/6         3rd MOD 33 work group, finalize Mvar/voltage mapping, kick off Dynamic mapping process
After it, CG prepare the dynamic base case, members to collect the PMU/DFR data
2018/8         4th MOD 33 work group, review and finalize dynamics mapping results and mitigate issues if any
After it, CG develop the 1st draft report
2018/10       5th MOD 33 work group, 1st draft report discussion
After it, CG revise the draft report
2018/12       6th MOD 33 work group, aim to finalize the study report.
After it, Report posted, compliance finished. 

29. Question: Bo Gong, gong@columbiagrid.org