Western Electricity Coordinating Council

Modeling and Validation Work Group

Progress Report to TSS

August2014

The WECC Modeling and Validation Work Group (M&VWG) meeting was held in Salt Lake City, UT on June 17-19, 2014. Renewable Energy Modeling Task Force (REMTF) hosted the renewable energy workshop on June 17, and M&VWG was held on June 18-19.

The following topics were discussed at the M&VWG meeting:

  1. Next Meetings and Workshops
  2. Load Modeling
  3. Renewable Energy Modeling
  4. System Model Validation
  5. Generator Modeling, Testing, and Model Validation
  6. HVDC Modeling
  7. RAS and Relay Modeling
  8. NERC Updates
  9. WECC Project Updates
  10. Approved Dynamic Model Library and Status Update of Models
  11. Program Updates: GE PSLF, PSS®E, and PowerWorld

Meeting materials and presentations are posted on the WECC MVWG Meeting Website for the M&VWG and REMTF meetings.

I. Next Meetings and Workshops

The next MVWG meeting is planned to be at Albuquerque NM, hosted by Sandia National Labs, on November 18-20, 2014. The REMTF will be held November 18th afternoon and 19thmorning, the Load Modeling Task Force (LMTF) will be held November 19th morning, and M&VWG will be held November 19th afternoon and 20th all day.

A webinar of the PI Data Frequency Response ToolDemo is planned to be 9-11 am PST on July 22nd.

In addition, a workshop on how to use PSLF v19 to create a Model Validation Case from WSM data will be held after GE officially releases v19 in about two months. More details to follow.

II. Load Modeling

A)Composite Load Model Phase 1 Update

Dmitry Kosterev (BPA) informed the team that he has seen more PSSE users starting to use the composite load model phase 1, for example, American Electric Power, Virginia Power, and Southern Company etc. He indicated that the TF will continue the outreach to PSSE user community outside of WECC, as the TF has done in the WECC.

B)Composite Load Model Phase 2 Update

Dmitry Kosterev (BPA) indicated that the phase 2 results may be pessimistic. He also informed the team of John Undrill’s work regarding to the sensitivities to the point on wave and good analysis there.

SCE has installed PQube data on the distribution circuit and shared the FIDVR data. BPA also installed microPMU on the distribution circuit. Dmitry encourages utilities to volunteer and do the same practice so that we can have more data for FIDVR analysis. The PQube monitoring devices are free from Lawrence Berkeley National Lab, the participant just needs to deploy the devices and agree to share collected data.

Dmitry also mentioned that there is a renewed interest in the load composition of the residential and commercial buildings. DOE will have the FIDVR website, where the data will be posted and made available for entities to perform the analysis.

C)Composite Load Model – Model Specifications and Test Case

Stephanie Lu (SCL) will distribute the “WECC Composite Load Model Specifications” drafted by Bill Price (GE) for group review. This includes the new additions including the distributed generation component. Jay Senthil (Siemens) also suggested having test cases for the composite load model so that all the software vendors are consistent in model implementation. Dmitry Kosterev (BPA) will send the test case to the vendors for benchmarking across platforms to ensure consistent implementation of the composite load model.

D)Composite Load Model Monitoring Improvements in Software Implementation

When performing the study with the composite load model in PSLF, it is hard to track how muchload was lost per zone/area/owner with the existing LSMON model, so multiple users have expressed the desire to have the load trip monitoring capability in the software. Jun Wen (SCE) agreed to draft the user desired specifications, circulate among the TF for comments, and send to GE for implementation.

There are two other suggestions from the PSLF users to GE:

1)Dmitry Kosterev (BPA) brought up the issue that the user has to update the swt file that is used for dropping load when load is modeled with motorw to open the distribution transformer equivalent when load is modeled with cmpldw. This is due to the fact that the load is moved to the distribution bus equivalent with cmpldw and so the swt that was developed for motorw is no longer able tofind the load in the case that is using cmpldw.

2)Jun Wen (SCE) brought up the issue that the bus that is treated as the load bus when using motorw will be treated as the non-load bus when use cmpldw due to the fact that the load is now moved down to the lower distribution bus. Since we may want to still treat the bus where the load is modeled in the power flow as the load bus and there are different transient voltage and frequency criteria for the load bus and the non-load bus, it is better to have ways to differentiate those buses with different variable names for WCA analysis.

Jun Wen (SCE) will write up the user expectation and work with GE for potential modifications.

E)WECC-0100 Project Update and Transient Voltage Criteria

Chuck Matthews (BPA), chair of the WECC-0100 project, provided an update on the WECC-0100 project.The project team is continuing to discuss various alternatives for the transient voltage performance, voltage stability criteria, steady state voltage limits and post contingency voltage deviations. Chuck indicated that the project may need input from M&VWG on the transient voltage performance criteria. There are also some discussions around whether the transient criteria should be a regional business practice or a guideline. The majority of the project members would prefer to have this as a guideline.If there is any additional comment from M&VWG,Stephanie Lu (SCL) will providethe feedback to Chuck.

III. Renewable Energy Modeling

Pouyan Pourbeik (EPRI) provided an update of the Renewable Energy Workshop that was held on June 17, 2014. There were about 30 people in person and 10 on the webinar. The workshop covered standards, modeling guideline, dynamic model specification, user experience, and model validation tool. The recording is posted on MVWG > Documents > Seminars > Renewable Energy Modeling Workshop 2014-06-17.

A)Transition Plan for Removing Wind Phase 1 Generic Models

Eric Bakie (Idaho Power) was tasked to come up with the transition plan for removing Wind Phase 1 Generic Models from SRWGwhen the 2nd generation wind models and PV models were approved. This is also to support the last item on the MVWG implementation plan of these models. Eric presented a proposedtransition plan. The proposalis to start the transition from the next base case request, which is July 18, 2014, and remove the 1st generation wind models on June 5, 2015. To follow up,PPMDTF will then review the data again with a targeted completion date in December 2015.

In preparing the proposed time line, Eric reviewed the current data in the MDF and conducted a statistics report for the dynamic model records that have been used for wind and solar. He pointed out the issues of missing models and the use of wrong models for renewable modeling.

REMTF recommended removing wt1p and wt2p from the WECC Approved Model List immediately. Pouyan Pourbeik (EPRI) indicated that no pitch control should be used for the passive stall units, and wt1p_b should be used for active stall units. REMTF will take the action to inspect the list and give the recommendation of either deleting or replacing the wt1p and wt2p with wt1p_b. The model wt1p_b should have also been added to the WECC Approved Dynamic Model List, and will be updated to reflect this.

B)Energy Storage Modeling

Pouyan Pourbeik (EPRI)indicated that the Task Force will have the proposed structure by the next meeting. Jun Wen (SCE) commented that the three PTOs in California already received energy storage project interconnection requests and would like to see the modeling being expedited and asked if REMTF can provide an interim modeling guide. Jun also mentioned that most of the energy storage projects are battery, and there are some hybrids, either combination of PV and battery, or gas turbine and battery. Pouyan asked to have manufacturer representatives engaged early in the model development which can help expedite this effort.

C)Plant Level Control

Pouyan Pourbeik (EPRI)indicated that the Task Force will provide a proposal at the next meeting. The goal is to expand the plant controller to control multiple elements, including different types of wind turbines, SVCs or STATCOMs, and MSCs.

He also indicated a potential new item. ABB has a configuration of using VSC and TSC as a hybrid SVC. He will investigate whether SVSMO3 can model this hybrid SVC and update the team in the next meeting.

IV. System Model Validation

A)System Model Validation Efforts

Dmitry Kosterev (BPA) showed a list of large disturbance events in 2013 and 2014.

Dmitry presented two ways of performing system model validation studies:

1)Use Planning case and planning dyd

2)Use WSM case and WSM dyd

Based on Slaven Kincic (Peak RC), 95% of generation MW in WECC is mapped between the planning case and the WSM case, where the majority of the discrepancies are fromthe mapping of the windgeneration.

Dmitry Kosterev (BPA) presented the study results on the model validation of the May 16, 2014 event. The frequency and voltage have good matches, while power pickup has some offset. Overall, the simulation had a good match to the actual event. Further investigation is suggested for Kemano trip and Springerville trip. Dmitry will complete the model validation report for the May 16, 2014 event and send to the group for review. The report is expected to be getting M&VWG approval prior to the next meeting.

Dmitry mentioned that the model validation study for the May 26, 2014 event is in progress.

Dmitry indicated that at the time of the May 16thevent, a lot of wind generation is on, which is where the modeling/mapping lacks most. There are some missing wind models in SCE’s TRTP area, so are some other areas in the WECC.The issue of the missing and bad dynamic models for wind/solar in the MDF was extensively discussed. The PPMDTF Chair Kent Bolton (WECC) will take the action to create a list of wind/solar generators that have either missing models or bad data, based on the information from: 1) Dmitry’s findings from the model validation studies; 2) The list that identifies model and turbine type discrepancies found in the MDF done by Eric Bakie (Idaho Power); and 3) The TEPPC spreadsheet that has information on the type of generation. PPDMTF will then identify the owner of the data and request TP for the generator information including manufacturer, type, and vintage.In the short-term, REMTF can help to provide default data for those generators based on the collected information, for the system model validation studies, which will be better than load netting those generation. Forthe long run, the generator list will be provided to SRWG to request data submitters to correct or submit the required data in the MDF.

B)WBRTF Update

Slaven Kincic (Peak RC) provided update on WBRTF efforts. 95% of generation MW has been mapped in the WECC. He indicated that he is still waiting for some responses, and hope the work to be completed by end of the year. He will also contact Doug Tucker (WECC) to decidewhat to do with the retired units.

C)Node-Breaker Model Development

Brian Thomas (GE) presented an update on the efforts to provide the node-breaker capabilities in PSLF. The PSLF v19 will have the capability to take WSM case and WSM dynamic file which is mapped from the planning dynamic file to run the validation study. The basecase preparation time has been reduced from two weeks to one day. The beta version is available for testing for the interested working group members. The PSLF v19 is estimated to be officially released this July or August. A workshop to have hands-on training on the programis being discussed to be held after the release of the program.

D)Demo of Frequency Response Tool using PI Data

Eric Bakie (Idaho Power) provided a presentation of the frequency response tool that he has enhanced based on the tool that was developed by BPA. The tool included batch processing capability for model validation screening of multiple units and the ability to easily perform model validation screening for multiple events.

Since the March meeting, he has completed the user guide. The tool along with the validation package will be posted in the WECC MVWG > Documents > Tools folder. A webinar is planned on July 22nd for Eric to provide hands on training on how to use this tool.

V. Generator Modeling, Testing, and Model Validation

A)Power Plant Model Data Task Force

Kent Bolton (WECC) reviewed the dynamics error list. There hasn’t been much progress since last June, and M&VWG discussed how to move things along in this group. Kent will take the action to compile the data errors that have been identified by Irina Green (CAISO), Slaven Kincic (Peak RC), and Ran Xu (BPA) in their studies, as well as the wind/solar modeling issues. The PPMDTF will work with SRWG to enhance how to display the dynamic data errors. Kent will set up a meeting soon to kick-off the efforts and another meeting prior to the next M&VWG meeting to check the progress.

B)Excitation System Models

Eric Bakie (Idaho Power) shared his observation on the impacts of not modeling UEL where the generation exceeds Qmin and goes out of step. His simulations used a user-written model and is requesting for the UEL models to be implemented in the programs.

Shawn Patterson (USBR) mentioned this has also been identified as needed for FIDVR studies, and he requested to have UEL1 and UEL2 implementation at higher priority. Jay Senthil (Siemens) will send to Juan Sanchez (GE) what was implemented in PSS@E which was based on the 2005 version of IEEE 421.5 so that the implementation across the software platform will be the same. The UEL1 and UEL2 models specified in the 2005 version will not be changed with the newrevision of the standard. The IEEE 421.5 is close to going out for ballot.

C)Cross Current Compensation Model

John Undrill provided an update to the ccomp model, which is for a pair of units that have cross current compensation. The model was checked against the Dalles and John Day (ABB equipment). Pouyan Pourbeik (EPRI) asked if this will work with all equipment vendors. Pouyan will check this against a Duke case. The ccomp model is now available in PSLF dll. It is expected that Dmitry Kosterev (BPA) and Shawn Patterson (USBR) will bring the ccomp model for approval in the next meeting.

D)Hydro Turbine and Governor Models

John Undrill provided an update to the h6b model. The model has been previously approved. John identified that there is a coding error in PSLF that PSLF will fix. PowerWorld already has John’s fix and has the model available. John will also provide the code to Jay with the errors fixed.

E)Update to Typical Machine Data Document

Stephanie Lu (SCL) updatedthe Typical Machine Data document. The changes include the following:

  • Replacement of the 1st generation windmodels with the 2nd generation wind models, added the PV models, and added references to the modeling guideline documents in the Wind and PV sections.
  • Minor improvements to the hydro model section, which includes adding the accel parameter in gentpj model, and changing the ks2 parameter in pss2a model to be Tw2/(2H), same as in the thermal units.

The Typical Machine Data document wasapproved unanimously by M&VWG members.

VI. HVDC Modeling

Pouyan Pourbeik (EPRI) provided an update on HVDC modeling.

Accomplishments to date include:

  • Multi-terminal conventional HVDC powerflow model – had been there
  • Multi-terminal VSC HVDC powerflow model (Multi-terminal in PSLF, two-terminal in PSS@E and PowerWorld) - now in beta version and being tested/benchmarked
  • Conventional HVDC dynamic model - in progress
  • VSC HVDC dynamic model - in progress

The 2014 Goals are as follows:

  • Complete the testing of the VSC powerflow model and get it out in the tools
  • Complete the specification of the dynamic model for conventional HVDC and testing and hopefully have the software vendors start implementation by early 2015

Irina Green (CAISO) asked if TransBay will be asked to use the generic model once the VSC model approved. Pouyan Pourbeik (EPRI) and Ronnie Lau (PG&E) commented that the generic model is available to use, but it is up to TransBay to decide whether they will continue the user-written model or switch to the generic model.