1.Welcome, Call to Order, Introductions

TSS Meeting Minutes May 10-12, 20171

1.Welcome, Call to Order, Introductions

Philip Augustin, Technical Studies Subcommittee (TSS) Chair, called the meeting to order at 1:00p.m. A quorum was present for the conducting of business. Mr. Augustin asked attendees to introduce themselves. A list of attendees is attached as Exhibit A.

2.Antitrust Policy

Doug Tucker read aloud the WECC Antitrust Policy statement. A link to the posted Policy was provided in the meeting agenda.

3.Approve Agenda

Mr. Augustin reviewed the agenda and made some minor edits to the topics.

On a motion by Jameson Thornton,the TSS approved the agenda.

4.Review January 18-20, 2017 Minutes

Stephanie Imamovic introduced the minutes from the January 18-20, 2017 meeting.

On a motion by Ms. Imamovic, the TSS approved the Meeting #174 January 18-20, 2017 minutes.

5.TSS Chair’s Report

Planning Coordinating Committee (PCC) Update

Mr. Augustin reported that all TSS requested approval items were approved by the PCC. The PCC also approved the request from WestConnect to modify the 2017 case schedule.

Board Meeting Updates

Mr. Augustin reported the following:

• As of December 2016, WECC has performed 38 onsite audits.
• Northern Mexico (Baja area) is in the process of officially becoming part of WECC and is deciding whether to recognize the North American Electric Reliability Corporation (NERC) as their Electric Reliability Organization (ERO).
• Mexico is expecting large scale expansion of natural gas coming from El-Paso, TX.
• The Western Reliability Summit was held in Portland, Oregon on May 2-3, 2017.
• Federal Energy Regulatory Commission (FERC) is expected to look vastly different in the coming years with three new commissioners needed.
• FERC has indicated that WECC is “still not where it needs to be” with regard to implementing the recommended actions following the September 2011 Southwest outage.
• The Reliability Subcommittee has decided that it will not develop a guideline for Bulk Electric System (BES) exceptions in light of the re-organization of the subcommittees into the Reliability Assessment Committee (RAC) structure.

Joint Guidance Committee Update

Mr. Augustin reported that the Standing Committees are working on their three-year work plans; PCC and the Transmission Expansion Planning Policy Committee (TEPPC) will not because of the transition to the RAC structure expected in 2017.

6.MAXYSIS WECC Node Breaker Model

Ramu Ramathan presented on an effort that Bonneville Power Administration (BPA) is leading to develop a common WECC-wide node-breaker model. The immediate request is for utilities to respond to the WECC Node-Breaker Survey. The survey was initially sent to the Energy Management System (EMS) Work Group. Fourteen utilities have already responded. They are looking for additional utilities to respond to the survey. If a member did not receive the survey and would like a copy, or would like to submit a completed survey, contact Mr. Tucker.

Efforts are starting with a focus on operations. The first phase is to develop a requirements document for creating a WECC-wide node-breaker model by December 2018. Edison Elizah, BPA, is the Project Manager (PM) for this project. Mr. Ramathan also indicated that this project would like participation by the planners to ultimately move toward one node-breaker model for planning and operation within the Western Interconnection.

7.SRWG Report

Andrew Christensen, System Review Work Group (SRWG) Chair, provided a report on SRWG activities.

2018 DPM Change Requests

The Connector Type Change Request is intended to provide the ability for data submitters to properly characterize connections between nodes (i.e., breakers, load break disconnect, disconnect, fuse, and ground disconnect) if they are explicitly represented in the model instead of representing these types of connections as a low-impedance branch. TSS requested that the object type is changed from Breaker to Connector for clarity.

On a motion by Mr. Christensen,the TSS approved the DPM Change Request “Connector Type” with the change in terminology of the object type from Breaker to Connector with 20 Yes votes, 2 No votes, and 2 Abstain votes.

The Swing Criteria Change Request is intended to provide some guidance on how to select a generator as an Area Slack Control. It was requested to add the clarification that the dAngle/dP < 0.15 degrees/MW is suggested.

On a motion by Mr. Christensen, the TSSapproved the DPM Change Request “Swing Criteria” with the added clarification.

The Transformer Type Change Request is to add tap control codes to be able to represent disabled TCUL and Phase Shifting.

On a motion by Jameson Thornton, the TSS approved the DPM Change Request “Transformer Type.”

The Western Area Power Administration (WAPA) Area Change Request is to change the WAPA L.C. area from 14 to 19.

On a motion by Mr. Thornton, the TSS approved the DPM Change Request “WAPA Area.”

The Turbine TypeChange Requestis intended to make the turbine type codes better align with the unit types in the U.S. Energy Information Administration Form EIA-860.

On a motion by Mr. Thornton,the TSS approved the DPM Change Request “Turbine Type.”

Standard Disturbance List

The Standard Disturbance List includes seven disturbances that are simulated during the review stage and after approval of each WECC base case to test the model. The disturbance “Metcalf - Moss Landing & Tesla - Metcalf 500 kV” was replaced with the “Gates-Midway #1 & Diablo - Midway #2 500kV” disturbance. Also, an associated remedial action scheme for the “Colorado River - Red Bluff #1 & 2” disturbance was added.

On a motion by Mr. Christensen, the TSS approved the Standard Disturbance List.

Study Program Scope of Work

The Annual Study Programdescribes the annual base case compilation and data checking effort that is performed by the SRWG. It was suggested to change the name of the document to reflect the work described. The group discussed changing the document name to Annual Base Case Compilation and Data Check Scope of Work,to change the heading for the Annual Study Program to Annual Data Check of Interconnection-wide Models, and some minor edits within the document to add clarity.

On a motion by Mr. Christensen, the TSS approved the Annual Study Program Scope of Work with the changes that were discussed.

2018 Base Case Compilation Schedule

The 2018 base case compilation schedule was presented. Members provided feedback. The highlights of the changes that were discussed include:

• 29HSP1-S – Adjusted time from PST to MST for consistency. Added Northwest Hydro to Medium/High. Changed Northwest Renewable from High to Medium/High. Changed Northern California Hydro from Moderate to Medium/High. Added the interchange target for PDCI (Path 65) to be -500/-1000.
• 19LSP1-S – Adjusted time from PST to MST for consistency. Added asterisk to describe that RMR is Reliability Must Run.
• 2029HS1 – Changed the From Case to 2027-2028HW1 to be the same case as the 29HW1 case (not the Anchor Data Set(ADS)). Removed reference to ADS for the 29HS1 case (The ADS case is to be developed every other year, therefore skipping the 2018 schedule). Merged schedule for 29HW1 and 29HS1 to be the same (consistent with 29HW1 schedule).
• 2018 LSP1-S schedule shifted to start 10/5/2018 and end 2/25/2019.

On a motion by Mr. Christensen,the TSS approved the 2018 Base Case Compilation Schedule with the changes discussed.

2017 Base Case Compilation Schedule

A few changes and edits were requested to the 2017 base case compilation schedule.

One of the major changes requested was to use the 20xx-TEPPC placeholder slot for the 2028LSP-1 case. The other options considered were to replace either the 28HW1 or 21LSP1-S case and those were determined to not be acceptable. The 20xx-TEPPC placeholder slot had an abbreviated review schedule because it is the 12th case. Since the slot has an abbreviated schedule, two options were considered: 1) requester to provide a case and data submitters would review it once, or 2) data collection will be requested of submitters and the second review will not occur, resulting in a non-approved WECC case. The second option was discussed to be the preferred option. The base case description sheet for the 28LSP-1 still needs to be revised and is not yet available for approval. The starting time for the data collection will maintain the September 8, 2017 date, and the schedule will be shifted appropriately.

Another major change requested was to revise the 28HS1 case description to clarify that it is for the ADS,and that data submitters and regional planning groups need to coordinate when providing the case data.

On a motion byMr. Christensen,the TSS approved the changes that were discussed to the 2017 Base Case Compilation Schedule.

8.Annual Project Report

Mr. Tucker reviewed the list of annual progress reports. Including all the projects from all the reports in a single table takes a significant amount of time. To reduce the time to manage this information and maintain the purpose of this effort, the document will be reduced to track the submittal of annual progress reports and the list of projects that have requested and/or approved waivers. This was intended to be a tracking document.

9.The Anchor Data Set Workflow (out for Comment)

Mr. Tucker showed the ADS workflowthat is posted for comment. Comments are due by May16,2017.

10.NERC TPL-007-2 Standard Drafting Team Update

BerhanuTesema provided an update on the NERC drafting team for TPL-007-2 which focuses on Geomagnetic Disturbances (GMD). TPL-007-1 will be effective starting July 1, 2017 with an implementation plan over five years. Order No. 830 directs NERC to review TPL-007 to address Commission concerns and file by May 2018.

Commission concerns include:

• Modify the benchmark GMD event definition used for GMD vulnerability assessments so that the reference peak geoelectric field amplitude component is not based solely on spatially-averaged data, and that “local enhancements” are incorporated.
• Revise requirement R6 to require registered entities to apply spatially averaged- and non-spatially averaged-peak geoelectric field values, or some equally efficient and effective alternative, when conducting thermal impact assessments. The drafting team is proposing that no corrective action plan will be required for these supplemental analysis, but results are to be evaluated for possible mitigating steps.
• Modify requirements to transformer thermal impact assessments.
• Require deadlines for Corrective Action Plans (CAP) and GMD mitigating actions; i.e., one year for development of CAP, two years for implementing operating procedure mitigation, and four years for implementing hardware mitigation.
• Require collection of GMD-related data. NERC is directed to make data available; and
• Require new equipment Geomagnetic Induced Current (GIC) Detectors and Magnetometers to collect GMD-related data. The proposal would require one GIC detector and one magnetometers in each PC area.

Questions and comments can be shared with Mr. Tesemafor discussion with the drafting team. The next drafting team meeting is scheduled for May 15, 2017. An initial draft should be posted for comment and vote in June 2017.

11.Path 29 and Path 32 Request for Expedited Rating Process

Alex Fratkin, NV Energy (NVE), presented a summary of the request for an expedited rating process for the Path 29 and Path 32 re-study. The request was sent to the TSS, PCC and OC on May1, 2017. It included a draft study plan that will be reviewed by the Project Review Group (PRG). Those interested in being part of the PRG can send a request to Mr. Fratkin by June1,2017.

12.Path 14 Request for Expedited Rating Process

Curtis Westhoff, Idaho Power Company (IPCO), presented a summary of the request for an expedited rating process for a Path 14 rating increase in the west-to-east direction. The request was sent to the TSS, PCC and OC on May 1, 2017. It included a Comprehensive Progress Report (CPR). Comments on the CPR are due to Mr. Westhoff by June 30, 2017.

13.Modeling and Validation Work Group

Song Wang, Modeling and Validation Work Group (MVWG) Chair, presented an update on recent MVWG activities.

Load Modeling

Phase 1 of the composite load model, with the single-phase air conditioner stalling disabled, was approved in 2013. Testing of single-phase air conditioners has been performed. The proposed typical values for the air conditioner stalling parameters (motor D) are conservatively at Vstall = 0.45 pu and Tstall = 2 cycles. Simulations with the new parameters and sensitivities were performed and compared to the WECC system performance criteria. Based on the work performed, MVWG approved phase 2 of the composite load model. There were also several typical parameters that were recommended by the NERC efforts for motor A and B, which are also being requested for approval as part of the phase 2 implementation.

On a motion byMr. Wang, the TSS approved implementation of phase 2 of the composite load model (with parameters Vstall set to 0.45 pu and Tstall set to 2 cycles for the single-phase air conditioners, and adjustments of a few other protection parameters based on NERC recommendations) starting with the base cases in the 2018 base case compilation schedule.

The development of load model composition data was approved by the NERC Planning Committee in March 2017.

Renewable Energy Modeling

The WECC Battery Storage Dynamic Modeling Guideline was developed and approved by the MVWG. The document is intended to provide guidance on how to model battery energy storage systems in the interconnection-wide base cases with the use of the WECC-approved dynamic models REPC_A, REEC_C, and REGC_A. Approval tracking for the document will be added.

On a motion byMr. Wang, the TSSapproved the WECC Battery Storage Dynamic Modeling Guideline.

There was a recommendation that the next release of PTI (versions 33.1 and 34.2) include the usage of the Xa parameter in the REGC_A model. This change will ensure that all four software platforms have similar results.

In the DER_A model development, the new proposal is to include a criterion that, if voltage is below a certain level, then 100% of the distributed energy resources (DER) will go back on-line, and if frequency is below a certain level, then a percentage of the DER will return to service.

With wind power penetration increased, there are more interconnected projects on weak parts of the grid. Weak grid projects that experienced voltage oscillations can trip turbines. Therefore, a weak grid control option was applied in such projects to help stabilize the turbine response. To model this option, the Renewable Energy Modeling Task Force (REMTF) agreed to write a specification for an additional module; REEC_D.

The WECC website has a page for Help with REMTF Dynamic Models.

Additional updates were that REMTF is working on a new module for inertia based fast frequency response for wind turbine generators, developing standard Double Line Loss (DLL) interfaces for user-written models, and progressing on the DER model.

System Model Validation

The WECC Guidelines for Validation of Powerflow and Dynamic Cases for MOD-033-1 was developed and approved by MVWG. The document is intended to describe how Peak Reliability (Peak) and WECC would create cases for at least two disturbances each year and to provide guidance on how to validate the base cases. Section 5.6 Review of Steady State and Dynamic Model was revised to make the review process optional instead of a formal process. The second sentence of footnote 2 was deleted. Date and approval tracking will be added.

On a motion by Mr. Wang, the TSS approved the WECC Guidelines for Validation of Powerflow and Dynamic Cases for MOD-033-1.

Generator Modeling, Testing, and Model Validation

From wind power plant model verification studies using PMU data, there is a methodto calculate transformer tap ratio and collector system susceptance.

HVDC Modeling

For the Line Commutated Converter(LCC) High Voltage Direct Current (HVDC)model, the status of the model development is similar as the last MVWG meeting. For the Voltage-Sourced Converter (VSC) HVDC dynamic model, the status is still under code-debugging process for the concept implemented model. For the high-level documentation of Pacific DC Intertie (PDCI) and Intermountain Power Project (IPP), ABB approved to move forward with developing a high-level document plus block diagram.

RAS and Relay Modeling

There has not been much progress on the dynamic Remedial Action Scheme (RAS) modeling. The power flow RAS modeling is implemented in PowerWorld and PSLF; PSS®E RAS capability is expected in 2018.

Approved Dynamic Model List

No new models have been added to the list. In coordination with dynamics model implementation schedule, phase 1 wind models will not be accepted after June 2017 but allowed to exist in the MDF.

14.RAC Transition

Dave Angell, Reliability Assessment Committee (RAC) Chair,introduced the RAC Leadership. The RAC Governing Bodymembers are:

Mr. Angell, RAC Chair;
Bryce Freeman, Scenario Development Subcommittee (SDS) Chair;
Peter Mackin,Studies Subcommittee (StS) Chair;
Chifong Thomas, Modeling Subcommittee (MS) Chair& RAC Vice Chair; and
Stephanie Imamovic, Data Subcommittee (DS) Chair.