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

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.

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

Voltage Comparison

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

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

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

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

500 kV

230 ~ 345 kV

115 kV

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

After Voltage Mapping, Line flows, MW

Line flows, MVar

Dynamic Model Validation

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.

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

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

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+ j0.0470 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

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

Remove ATR, manually Add Tripping

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

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?

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

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?

Snohomish

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 ?

MOD 33 Work Plans 2018/2 1st 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. 

Question: Bo Gong, gong@columbiagrid.org