December 2010, Updated July 2011, Updated June 2013, Updated June 2015
The following lists the M&VWG priorities in order of importance and provides a brief summary plan for meeting each priority. The items with existing or proposed WECC funding are highlighted with bold type and green color. In addition to the current and proposed WECC funding, and volunteer efforts from the
M&VWG members, significant support to WECC modeling efforts is received from equipment vendors, planning software vendors, DOE, and EPRI. This support includes participation in WECC M&VWG meetings, study work, model development work, expert advice, etc.
M&VWG plans to continue this critical effort primarily with help from volunteers from the WECC transmission planning entities, planning program vendors, and DOE funding. ( To discuss at the June meeting )
Recent Accomplishments:

WECC M&VWG has provided composite load model data files for the 2012 operating basecases in the 2012 study program, and will support the development of data files for future study program basecases (see implementation plan approved by TSS)
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WECC contract with Bill Price provided an experimental single phase motor model to try to address some perceived deficiencies with the current model
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Workshops have been conducted regarding the new composite load model between 2011 to
2013
Continuing efforts include:
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Continue model validation studies using the composite load model
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Perform system impact studies using the composite load model
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Support for the WECC-0100 project to understand the implications of criteria and standards
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Support for the Technical Studies Subcommittee efforts to implement the new models during base case development
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Maintain and enhance the tool used to estimate load composition data for summer, winter and shoulder seasons
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Support for ongoing load composition research
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Support for ongoing research regarding air conditioner stalling and tripping characteristics, including additional testing and EMTP-level modeling, and potential model improvements
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Develop a tool that detects events of Fault-Induced Delayed Voltage Recovery using synchrophasor and digital fault recording (DFR) data
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Conduct additional workshops as needed
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Support to address questions rising from composite load model studies
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Continue composite load model improvements (Composite Load Model 2 Implementation Plan) o Flexible composite load model structure (plug and play)

o Revisions to single phase AC motor model o Revisions to motor protection and control models o Updates to distributed solar generation and energy storage models o More efficient data management (eliminate repeated parameters) o Improvement to 3ph motor models
M&VWG plans to continue the efforts in the power plant modeling, model data review, and power plant model validation. In addition, M&VWG has also developed a three-year work plan to improve wind and solar plant model data and validation.
Power Plant Modeling:
Excitation Models:
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M&VWG to review the list of approved excitation models, and the updates to the IEEE standard models and determine how to reduce to a simpler set of static and rotating excitation models.
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M&VWG plans to advance modeling of Over-Excitation Limiters (OEL), Under-Excitation Limiters
(UELs), and generator protection models. These are necessary for reactive power reserve studies and the studies of Fault-Induced Delayed Voltage Recovery.
Turbine Controls:

M&VWG plans to review turbine-governor models. There are signs that the modeled frequency response is again on the optimistic side. An interim baseload flag of 2 was implemented for generators that are “baseloaded” to block governor response in both upward and downward directions. A longer-term plan is to review power plant operational information and to determine what revisions need to be made to governor models to correctly represent
“baseloaded” practices.
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Conversion to Kaplan models must be completed for generating units in lower-, mid-Columbia, and lower Snake Rivers.
Power Plant Data Review:
There is a clear need to review the power plant model data. Data checks on the synchronous machine and exciter models showed thousands of errors. Inspection of excitation and turbine control models raises many questions. It is clear that the WECC Generating Unit Model Validation Policy is somewhat deficient in assuring data quality, and replacement of the Policy with the less stringent MOD-026 and
MOD-027 standards will make the problem worse. The Power Plant Model Data Task Force was created in 2011 to help ensure the quality of the power plant modeling data in grid simulation databases and to improve coordination between Generator Owners (GO) and Transmission Planners (TP). Some data issues have been resolved but there are many more to address. M&VWG will continue to identify and address the data errors and feed the information to SRWG.
Power Plant Model Validation:

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M&VWG continues to develop Generator Model Validation Tools for WECC and interested utilities for power plant model verification using synchro-phasor data. The tool and processes are also one of the deliverables under WISP. Some tools developed by BPA and are being modified to expedite the process.
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M&VWG plans to help Wind and Solar model data and validation (see PPMVDTF Roadmap for
Wind and Solar Model Data and Validation)
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M&VWG plans to conduct workshops on MOD-025, 26 and 27, and PRC-024 NERC Standards.
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M&VWG plans to continue to conduct workshops on generator testing, model development and validation.
WECC-0101 Generator Validation standards:

M&VWG recommended to the WECC Standards Committee (WSC) to draft a regional variance to
MOD-026 and MOD-027 to preserve some fundamental attributes of the WECC Model
Validation Policy. There is tangible evidence that the existing WECC Policy and associated documents have greatly contributed to improvement in the WECC models and the new NERC
MOD standards are less stringent and will result in lower quality models and simulation accuracy. M&VWG will support the WSC as needed.
M&VWG plans to continue the development of a common format RAS model for transient stability studies. Event-driven RAS is estimated to be around 70-80% of the total number of RAS in the WECC system, and therefore, is targeted for development first. Upon the completion of Event-driven RAS, the work will expand to include other RASs in WECC, such as power swing separation scheme, under-voltage and under-frequency separation scheme, and over-current generation drop and separation scheme.
M&VWG will continue to support and approve the user specific models as appropriate. This will at least include the following:
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Colstrip Acceleration Trend Relay (ATR)
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Jim Bridger RAS
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Pacific HVDC RAS
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Fast AC Reactive Insertion (FACRI)
M&VWG will support the relay model development per TSS direction and approve models as appropriate.
M&VWG efforts at system model validation provided an example for the industry, but recent efforts have been limited. System model validation is essential to ongoing model improvement efforts. With current methods, creation of a base case to represent a disturbance is a significant effort. The WECC west wide system model (WSM) could provide significant assistance to WECC members in creating cases to represent disturbances, but currently there is no smooth method to transfer information available in the WSM to an environment that can be used for stability studies.

Two approaches are being pursued by WECC. The first approach is to create a dynamic data file compatible with WSM, and then simulate disturbances using WSM case. The second approach is to map generation and critical line statuses from WSM onto the WECC planning case, and then simulate disturbances in the planning environment. This is the most viable solution in the interim since it would allow validation of WECC basecase (powerflow) together with dynamic model validation.
Recent Accomplishments:

M&VWG issued a contract with GE to develop and demonstrate process whereby information from WSM is linked to WECC dynamic database and WSM powerflow model (pre-disturbance snapshot from Peak Reliability) is used in node breaker (full topology) format to run dynamic simulation. Contract was supported by WECC and Peak Reliability and executed by GE
Consulting. Newly developed capability is implemented in PSLF V19 so PSLF V19 can run dynamic simulation from SE snapshot using WSM and WECC dynamic database.
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Series of event has been simulated (April 2014 Brake Insertion, May 16 th 2014, May 26 th 2014,
October 18th 2014, April 28 th 2015, etc) to test validity of WSM and newly developed capability of PSLF. Results shows relatively good matching in between PMUs and simulation indicating that
WSM and PSLF could be used for dynamic model validation in the near future. The development of case can be accomplished in less than one day what represents significant improvement
(currently to develop a case event using WECC basecase takes more than a month).
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Supported NERC Modeling Working Group to define power flow and dynamic system model validation methods.
Continuing efforts include:
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Continue to work with Peak RC on improvements to WSM cases through the WBRTF (WSM and
Base Case Reconciliation Task Force) o Current mapping of the units between WSM and WECC basecase (and dynamic file) is around 95% MW capacity. The remaining 5% does not have mapping one to one and Peak
Reliability is working on remodeling some of the units in WSM. Some of the units needs to be remodeled in WECC basecase as well. o WSM does not use composite load model and there is need to create another project that will map load between WSM and WECC nasecase and add composite load model to dyd file adapted to use with WSM.
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Continue to perform system model validation studies using both approaches and provide recommendations on modeling and system practices, etc.
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Develop a WECC system model validation procedure document as an effort to support MOD-
033.
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Look into the possibility of establishing a new Task Force to support MOD-033.
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Select a set of PMU signals across interconnection (frequencies, MW, MVAR and voltages) that will be continually benchmarked for different system events.

M&VWG plans to continue to provide review and oversight of efforts in modeling renewable generation.
DOE and others (such as EPRI) are providing significant ongoing funding for these efforts while WECC funding in this area is limited. Collaborative research done in this area by EPRI, has also helped to further the work in this area.
Recent Accomplishments:

Completed the model specifications of all the 2 nd generation (phase 2) wind and utility scale PV models (renewable energy system models) in late 2013
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The major software vendors in North America made great effort to implement the models and testing was done within the REMTF. The models were thus officially approved and released in
WECC in 2014.
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A WECC workshop was held in Salt Lake City on June 17, 2014 to roll out the models and explain both the models, the model usage and validation. The slides and webinar recordings are available at WECC MVWG page.
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In late 2014 and early 2015 a generic model for battery energy storage was developed, specified, tested and even validated with one set of data. It was approved at the March
2015M&VMG meeting and is now available in the three major commercial tools used in WECC.
Continuing efforts include:

Continue to support dynamic model validation at the wind plant level; this will require installation of monitoring equipment at the interconnection points
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Revise and improve the distributed generation models proposed particular for PV; these models need further revision and collaboration between the REMTF and LMTF
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Continue efforts on modeling guides for modeling distributed generation (wind and photovoltaic) in power flow models, and a wind dynamic modeling guide.
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Continue efforts on modeling validation guides for Central Station PV and Wind plants.
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Assist as appropriate and possible with the transition of the 1 st generation generic wind turbine models to the new, improved and approved 2 nd generation generic renewable energy system models now on the WECC approved list, in order to phase out the old 1 st generation models.
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Conduct workshops on modeling renewable generation (phase 2 wind and solar) to help with model deployment.
Through WECC M&VWG efforts and efforts by the program and equipment vendors, generic static var system (SVS) models are available in the major programs in use in WECC. EPRI has also contributed significantly to this effort. Approval was obtained for the SVSMO1, SVSMO2 and SVSMO3 models at the
July 2011 M&VWG meeting and at the August 2011 TSS meeting. Many of the resources that have been focusing on SVS models have shifted their efforts to HVDC models, but will continue to support use of models as needed.

A high voltage DC modeling task force (HVDCTF) was formed and there was a kick-off meeting at the July
2011 M&VWG meeting. EPRI continues to contribute to this effort as well as the commercial software and equipment vendors.
Recent Accomplishments:

Specification of a standard power flow model structure for Voltage Source Converter (VSC)
HVDC technology. This was completed in 2014 and implemented by the three major commercial software vendors in WECC. Some validation cases were simulated and compared across the platforms.
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Specifications have been developed for two simple dynamic models for line-commutated converter (LCC) HVDC technology. The models were written in epcl (by EPRI) and tested using a simple CIGRE benchmark test case. The commercial software vendors are presently starting to look at implementing the models as a beta version. There after they will be tested and then put up for approval by the M&VWG.
Continuing efforts include:
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Complete the implementation and approval of the LCC dynamic models.
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Continue work on developing a similar simple dynamic models for VSC for planning studies.
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Review and provide guidance as appropriate and necessary on the models being developed and submitted to WECC by transmission owner/operators of the large HVDC projects in WECC, namely the PDCI upgrades, the IPP upgrade and the Transbay Cable.