MVWG 2015-5 Report to TSS - WECC



Western Electricity Coordinating Council

Modeling and Validation Work Group

Progress Report to TSS

May 2015

The WECC Modeling and Validation Work Group (M&VWG) meeting, Renewable Energy Modeling Task Force (REMTF), and Load Modeling Task Force (LMTF) meetings were held in Salt Lake City, UT on March 17-19, 2015. REMTF was held the afternoon of Mar 17 and the morning of Mar 18, LMTF was held the morning of Mar 18, and M&VWG was held the afternoon of Mar 18 and all day of Mar 19.

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

I. Next Meetings and Workshops

II. Load Modeling

III. Renewable Energy Modeling

IV. System Model Validation

V. Generator Modeling, Testing, and Model Validation

VI. HVDC Modeling

VII. RAS and Relay Modeling

VIII. NERC Updates

IX. WECC Project Updates

X. SRWG Updates

XI. Approved Dynamic Model Library and Status Update of Models

XII. Program Updates

XIII. Others

Next Meetings and Workshops

The next MVWG meeting is planned to be at Salt Lake, UT on June 16-18, 2015. The REMTF will be held the afternoon of June 16 and the morning of June 17, the LMTF will be held the morning of June 17, and M&VWG will be held the afternoon of June 17 and 18 all day.

A renewable model and model validation workshop will be held in conjunction with the REMTF meeting in June. A WSM workshop was also discussed with the date yet to be determined.

Load Modeling

A) Composite Load Model – Model Specifications

Bill Price went over the CMPLDW Model Specifications Document. The WECC Dynamic Composite Load Model (CMPLDW) Specifications Document, dated January 27, 2015, was unanimously approved.

B) Integrating DGs in Composite Load Model – Model Specifications

It was agreed by REMTF and LMTF to have the DGs in the Composite Load Model. Bill Price (GE) presented the WECC Specifications for Modeling Distributed Generation in Power Flow and Dynamics. The WECC Specifications for Modeling Distributed Generation in Power Flow and Dynamics, dated February 27, 2015, was unanimously approved. The Composite Load Model with DG is named as CMPLDWG. CMPLDW will be retired upon implementation and approval of CMPLDWG.

Song Wang (PacificCorp) will coordinate the benchmark testing among the three vendors for CMPLDWG. The target is to present the results in the Nov 2015 meeting.

C) Composite Load Model – Future Development

There are 130+ parameters in the Composite Load Model to manage. Software vendors are moving towards the modular structure for better data management.

Bill Price showed a new version of CMPLDW with simplified data input, which was implemented in PSLF version 19, called CMPLDWX. It uses several “data management” models to input the data for the sub-models, which can be recognized by the “_” as the first character of the model name.

James Weber (PowerWorld) also showed how to model load models with better data management by creating load model groups and distribution equivalent types. With better data management, there are 45 times fewer records to maintain.

In addition to the data management, Pouyan Pourbeik (EPRI) questioned about the load model data assumptions, for example, modifying feeder impedance when the local bus voltage falls below 0.95 per unit. He suggested to re-visit the parameter assumptions in the Phase 2 implementation.

Abe Ellis (Sandia) indicated that REMTF would want the flexibility to connect different DGs to the Composite Load Model, which was also conveyed by Dmitry in a load modeling discussion prior to the MVWG meeting.

Stephanie Lu (SCL) suggested that all three vendors should keep the consistency for future implementation.

It was agreed that the next version of Composite Load Model will move towards a modular structure and with the capability to have the hooks to the stand-alone DG models. LMTF will take it for further discussion regarding the modular structure, the capability of the hooks, and the data assumptions, and come back with a proposal.

D) Composite Load Model Monitoring Improvements in Software Implementation

GE provided an update on the load monitoring feature improvements, etc. that was requested by users from the prior discussions:

• A new model was implemented to report total load being tripped per area/zone/owner.

• DYTOOLS-HD was updated to be able to automatically detect Composite Load Model and associated substation transformer and feeder and would trip them all when specified to drop load.

• The in-run transient violation detection feature was updated so that it would treat the high side bus associated with the Composite Load Model as the load bus when checking for voltage and frequency violations.

The updates will be part of PSLF version 19.0_01, which is expected to release in early April.

E) Phase 1, Phase 2 Studies and WECC-0100 Project

Jeni Mistry (SRP) presented SRP Phase 2 study results, and indicated slow recovery being observed with the Phase 2 models.

Jun Wen (SCE) presented SCE study results on Phase 1, Phase 2, and sensitivity studies. The Phase 1 study showed additional voltage dip violation could be seen when compared to using the motorw. The phase 2 study showed that the voltage dip can go below 30%, the voltage recovery to pre-fault voltage typically takes 20 seconds, and the post-voltage recovery can be as high as up to 120%. The sensitivity studies examined the motor protection trip/reconnect settings. The differences are typically small but when on the boundary can push the system to instability.

DOE awarded MEPPI to perform WECC load model sensitivity study. Joe Eto (LBNL) had MEPPI team to the LMTF meeting and kicked off the project. PG&E, PacificCorp, SCE, and SRP are four participating utilities. The objective of this project is to conduct a parametric set of simulations that explore the sensitivity of WECC’s planning models to uncertainties in the composition and behavior of loads. The results of the simulations are expected to provide guidance that planners can follow in refining the composition of loads used to conduct future planning studies. MEPPI will have a presentation at the next LMTF meeting in June with proposed set of key sensitivity parameters and metrics with test runs, then perform production studies with agreed large set of sensitivities post June. MEPPI will meet with individual utilities between now and then to work towards that.

WECC-0100 project is looking for MVWG on more studies to support the voltage recovery criteria so they can get approval by the end of the year. Baj Agrawal (APS) who is on the draft team specifically asked for model validation studies. Jun Wen (SCE), Jeni Mistry (SRP), and Eric Bakie (Idaho Power) agreed to take the action and report back to the next MVWG meeting.

F) Phase 2 model improvements

Phase 2 composite load model may include significant revisions.

Dmitry Kosterev (BPA) updated the analytic study that was done by Bernie Lesieutre (University of Wisconsin) of sensitivity of AC motor stalling with respect to a point on wave where a fault is applied and a rate of voltage decline. The results are consistent with earlier observation made by John Undrill. AC motor stalls fast because of large electric braking torque when an instantaneous fault is applied at voltage zero crossing. Applying an instantaneous fault at a waveform crest or a voltage decline over a half to one cycle seems to reduce the braking torque and improves motor’s chances to ride through short-duration faults. The study implied that the existing performance model is very conservative. If continuing with performance model, it is likely that we need a curve for (Vstall, Tsall), and not just a single point.

Dmitry Kosterev (BPA) also updated on PSCAD modeling work done at BPA. Jeff Johnson has been working with John Undrill on developing a “detailed” feeder model with several commercial-type and residential-type loads. The model is subjected to transmission level faults of various magnitude, duration and point-on-wave, to determine the impact on single-phase compressor motor stalling. The model will be used for benchmarking Phase 2 composite load model.

The feeder equivalent structure may be revised based on the PSCAD studies and the need to integrate various types of DGs.

Three-phase motor models may need improvement also, including protection and control models.

John Kueck presented the table he compiled for commercial building motor load response. Both “drop out” and recovery characteristic for typical motor loads were provided. He also mentioned the BPA and SCE testing of VFD will be a complementary information to what he has compiled.

Renewable Energy Modeling

Abe Ellis (Sandia) provided an update of the REMTF work.

A) Energy Storage Modeling

A WECC REMTF Ad-hoc group on Battery Energy Storage System (BESS) led by Shengli Huang (PSE) has actively worked with REMTF on the BESS since the Nov 2014 MVWG meeting. A new model was proposed, called REEC_C, to be added to the set of recently approved renewable energy models. The REEC_C model is essential based on the REEC_A model, and when incorporated with the REGC_A model can then be used to represent an energy storage system. Furthermore, the plant controller model can also be used with these models to allow emulate various functionalities such as frequency regulation. Since the last MVWG, the group has met and conducted several discussions. A model specification document has been developed, beta version has been implemented in PSLF, PSSE, and PowerWorld and tested. Pouyan Pourbeik (EPRI) has also conducted one model validation study, the results of which are included in the final model specification sent to the REMTF and MVWG chairs.

The Simple Model Specification REEC_C for Battery Energy Storage System was unanimously approved.

The new model REEC_C was unanimously approved to be added to the WECC approved dynamic model list.

This model is implemented in all three software vendors:

• PowerWorld – version 18 batch, expect to be released late March, early April

• PSLF – version 19.0_01, expect to be released early April.

• PSSE – version 34, expect to be released early April. (Also available in version 33)

B) Enhanced Plant Level Control

The enhanced high-level plant controller work is in progress. The REPC_B model will have additional new features, including interface with multiple WTGs, interface with reactive support devices, and plant level power factor control option. The REPC_B model specification and model are expected for approval at the next meeting. A draft specification, prepared by EPRI, has already been circulated, based upon which the software vendors are developing the beta version of the model for testing.

C) Enhanced Inverter-based DG

Driven by increasing interest in deploying PV inverters with grid support functionality and standards activity (e.g., California Smart Inverter Working Group and Rule 21 effort, IEEE Standard 1547 revisions), REMTF is considering to develop a new DG model that can model the additional advanced features that are required. The new model will be named as PVD2, and would include the following features: additional active power controls, addition of time dimension to trip functions, auxiliary input for other functionality. It is expected that the PVD2 model specification and model will be ready for approval at the Nov MVWG meeting.

REMTF also recommended to add hooks in the Composite Load Model to allow different DG models (Please see Load Modeling section).

D) PV Model Validation Guide

The existing MDB on the renewable models is deficient. Almost none of the wind/PV data in the MDB has been validated. REMTF is developing model validation guide to help improve the modeling and validation of the renewable models. The PV Plant Model Validation Guide (drafted by Sandia) is under development, and is expected for approval at the next meeting. The Wind Plant Model Validation Guide will be the next. REMTF is also planning a model validation webinar in the summer of 2015.

E) Transition Plan for Renewable Models

The target completion date to remove the Phase 1 models is June 5, 2015. Eric Bakie (Idaho Power) who is also a member of SRWG indicated that the WECC transition is underway, but it will not be completed by June 2015 as planned last year. There are discussions on how REMTF can help the transition. Pouyan Pourbeik (EPRI) commented that REMTF can help provide the mapping between the 1st and 2nd generation renewable models which the software vendors can take to implement the conversion routines. This tool will help the conversion of the models without changing the functions. The Generator Owner and Transmission Planner still hold the responsibility for the data. REMTF and SRWG will report back at the next meeting on the progress.

Phase 2 renewable generation models are not well understood outside REMTF, and REMTF needs to conduct webinars to educate model users on the model structure, data, including data differences between various manufactures.

It was also discussed that the missing renewable models are of higher concern than the transition, Jun Wen (SCE) will relay it to John Gross (Avista).

F) White paper on limitations of generic models

The generic models deployed in the positive sequence program like any other model have limitation, for example they are not applicable to very low short-circuit ratio scenarios. Pouyan Pourbeik (EPRI) had agreed to take the lead in helping within REMTF to develop a white paper on the generic model limitations. The white paper is expected for approval at the next meeting.

System Model Validation

A) JSIS Update

Dmitry Kosterev (BPA) provided an update on the JSIS activities. The presentations are available at

Nothing major after the last Nov MVWG meeting. The significant events detected by PMUs between Nov. 1 2014 and March 19, 2015 are listed below:

[pic]

B) Model Validation Studies

Dmitry Kosterev (BPA) indicated that the validation studies for May 26 2014 DC RAS event was in progress, and plan for approval at the next MVWG meeting.

Hamody Hindi (BPA) provided an update on the Chief Joseph Brake modeling, which was still under testing. He will provide a presentation at the next MVWG meeting.

Slaven Kincic (Peak RC) and Brian Thomas (GE) presented the node-breaker validation study on Oct 18 2014 Colstrip event. The simulation results showed optimistic frequency response than in reality. As the next steps, Dmitry suggested to perform governor dead-band sensitivity study. In addition to the dead-band, Brian suggested to focus on the performance of hydro units and the impact of station service loads. The work will be conducted under the Power Plant Model Validation and Data Task Force. It was also discussed the use of node-breaker case for WECC planning case validation.

C) MOD-033

After last Nov MVWG meeting, a small group of MVWG members have discussed on how WECC can help to comply with MOD-033. Kent Bolton (WECC) drafted a guide on how WECC is currently performing the system wide model validation, which can be leveraged by PC for local event model validation. This was discussed and reviewed at the MVWG meeting. More work is needed. Jun Wen (SCE) will work with Kent on the guide.

It was mentioned that NATF also has a working group on MOD-033 that MVWG may be interested at coordinating with. Joseph Gillette (SMUD) provided an update on the NATF model validation field trial. The major turn-out was that a process flow chart was added to the MWG procedure, and a template was developed. Joseph also shared SMUD’s experience on power flow model validation. They can do local matches well with tie represented with equivalents. Their planning case and state estimation case match exactly so they can prepare a planning case for a local event within 4 hours.

Generator Modeling, Testing, and Model Validation

A) Cross Current Compensation Model

Pouyan Pourbeik (EPRI) and Shawn Patterson (USBR) briefed the group that the Cross Current Compensation should really use reactive current. The total current is used historically due to technology limitations. Pouyan completed the memo of the proposed new Cross Current Compensation model. The new model, named as CCOMP4, will use the reactive current for feedback, and allow up to four units. The CCOMP4 model specification and model are expected for final approval at the next MVWG meeting once the software vendors have implemented it. Pouyan will work with Baj Agrawal (APS) who offered to provide data to test/validate the new model.

B) Excitation System Models

Shawn Patterson (USBR) provided an update on the IEE 421.5, which is still in progress, close to go out for ballot. The new target is to complete before the July IEEE PES General Meeting. Shawn also brought up the reactive current feedback to IEEE 421.5. The IEEE working group agreed to discuss and probably put some explanation to the total current feedback, but not likely to change it.

C) Power Plant Testing and Model Validation

Steve Yang (BPA) presented the Power Plant Model Validation tool that was developed by BPA. The tool is available for other interested members to use. Some set up work is initially required for the tool to work, and Steve is willing to help.

Brandon Bouwman (Army Corps) presented testing results of all the units at Dalles. One unit, which had some damage had different parameter (Kis was 5% different from its sister units). This is a good example of testing all units instead of just one of the sister units.

D) Power Plant Model Validation and Data Task Force

It was discussed to expand the scope of the Power Plant Model Data Task Force to become the Power Plant Model Validation and Data Task Force with the additional tasks on power plant model validation. The charter of the Power Plant Model Validation and Data Task Force was unanimously approved.

Kent Bolton (WECC) reviewed the dynamics error list. Kent also showed the data error list that was generated from John Undrill’s data checker tool, and there were over 6600 suspected data errors. Ken indicated that the Task Force will prioritize and take some of the identified errors here to build into the dynamics error list. The renewable model checking was also planned to be added to the dynamics error list.

As discussed during REMTF meeting, PPMVDTF drafted a roadmap for implementing models of wind and solar power plants. Because models are not well understood and have had limited use outside REMTF, a phased approach is more appropriate, similar to work done with load models.

PPMVDTF developed an epcl for extracting wind and solar power plant model data from WECC base case and dynamic data file. For 2015 light summer operating case:

- WECC case has close to 29 GW of total wind and solar generation

- 100 MW of generation connected at 69, 115, and 138-kV levels

- 74 plants with 5 GW of generating capacity are connected at 24 to 35-V level, and therefore have no collector system representation, as required by WECC Data Preparation Manual, mainly Alberta and Colorado

- 94 plants with 5.2 GW of generating capacity have no dynamic models, mainly in Southern California and Alberta

- 54 plants with 2.8 GW of generating capacity are modeled with inappropriate dynamic models – “motor1”, “gentpf”, “genrou”, mainly in BC and Alberta

Looks like significant opportunity for model improvement.

HVDC Modeling

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

The LCC power flow model has always been available. There are some questions from GE and PowerWorld yet to address. The LCC dynamics point-to-point model specification is complete, the prototype is done, and the codes and specs have been sent by EPRI to the software vendors for beta testing. The goal is to have the LCC model specification and model for approval in the Nov MVWG meeting.

The VSC power flow model is completed in all three software tools now, the interface with the dynamic model still needs to be decided and finalized.

The current status of WECC base case models for PDCI, IPP DC, and TBC was also discussed.

PDCI is going through an upgrade. It is expected that the model specification and model will look for approval early 2016. All at the meeting agreed that WECC does not accept black box modeling. Thus, the MVWG chair requested that the new open source user-written model for the PDCI HVDC being worked on by BPA, in collaboration we assume with the equipment vendor, should be submitted to MVWG through the HVDC TF. The HVDC TF offered to take a first look at the model and model documentation. Hamody Hindi (BPA) took the action to pass this message back to the BPA contact person for this project.

IPP DC also has an upgrade project. The current model is a user-written epcl with hidden code. Saw Linn (LADWP) will also pass the WECC non-hidden code requirement to the vendor and report back to the group with the upgrade information.

TBC has a user-written model as well. Ronnie Lau (PG&E) will send the latest code and documentation to Pouyan (HVDC TF chair). Pouyan (with the HVDC TF) will review and check to see if TBC can be represented with the generic VSC model that is under development. It is realized that this is all a matter of timing, as the TF VSC model is still under discussion.

Ras and Relay modeling

James O’Brien (Peak RC) gave a presentation on where we are regarding the RAS modeling. A WECC RAS standard format for power flow studies has been approved and in place. Currently, only PowerWorld can read and write in this format. The target for PSLF to implement is by the end of 2015. Talks are also in place with PSSE for implementation. For RAS modeling in transient stability, James indicated that RAS engineers are the ones who typically know the details, and asked for members to understand their RAS and bring the information to him so that a common format can be developed.

James Weber (PowerWorld) informed the group that a WECC RAS modeling webinar has been scheduled on Apr 2nd, and an in-person workshop has been scheduled on May 27-29.

Eric Bahr (NWE) provided an overview of the Colstrip ATR scheme and the model specifications. The rough draft has been sent to MVWG. The ATR model specification and model approval will be postponed to the next MVWG meeting. Eric is currently performing more validation cases, and working with PowerWorld to clean up model specification. Eric will also share draft model specification with PSLF and PSSE so they can start working on it.

NERC Updates

Eric Allen (NERC) provided an update on the NERC standards and NERC MWG group activities.

• The Disturbance Monitoring Equipment standard PRC-002 was filed and pending regulatory approval.

• NERC MWG has drafted a report to address the third step of the node-breaker implementation plan; this step is the development of power system analysis software with the capability of using “node-breaker” representation. The fourth step is to look for pilot program.

• A new TF was approved under MWG for turbine control modeling.

• The revision of MWG Model Validation Procedure is planned to be posed around end of 2015.

• The event data sharing obstacle was also briefly discussed.

WECC Project Updates

Shawn Patterson (USBR) briefed the team that WECC-0101 project (Generator Validation Conversion) has been up for comments three times. The project is to decide if WECC is just to follow MOD-026, MOD-027 or turn the existing WECC policy into a regional variation. Either way, the WECC Policy will be withdrawn. Comments and feedback have been light. He encouraged more MVWG member involvement since the Policy is a MVWG creation.

Shawn also provided an update on the WECC-0107 project (PSS Design and Performance), which is an effort to convert WECC policy on PSS into a standard. Elements currently under discussion are documenting when PSS should be operational and grandfathering existing units.

SRWG Updates

SRWG chair John Gross (Avista) provided an update on SRWG activities.

MOD-032 shifts the data preparation responsibility from TP to PC, there were discussions on how PC and TP are coordinated. The DPM was revised for preparation of the implementation of MOD-032 R1 by July 2015, John will provide MVWG the updates to which one is the approved version when applicable.

The case data checks are going out with base case reviews, both power flow and dynamics.

SRGW is working on collecting TPL-007 GMD data, no support was requested from MVWG.

TPL-001-4 requires monitoring voltage ride through. PowerWorld is capable of using lhvrt structure to convert dynamic data into power flow. John encouraged PSLF and PSSE users to request the functions if they want it.

Eric Bakie (Idaho Power) asked for the capability of automatic capacitor/reactor switching. James Weber (PowerWorld) suggested that Eric make a request to both MVWG and vendors for quicker implementation.

Approved Dynamic Model Library and Status Update of Models

The REEC_C model will be added to the Approved Dynamic Model list.

Program Updates

GE PSLF, PTI PSS®E, PowerWorld, and PowerTech provided program updates.

Others

MVWG members again raised concern that it is very hard to locate MVWG documents at the new WECC website. Kent Bolton (WECC) updated the group that he was able to get the MVWG page, the next steps would be to upload the documents to the MVWG page. It was also discussed that MVWG will obtain a share drive as what SRWG has done. Kent took the action and will report back at the next meeting.

Stephanie Lu (SCL) announced new MVWG chair and TF chairs:

• MVWG chair: Stephanie Lu (SCL) will be the outgoing chair, and Jun Wen (SCE) will be the incoming chair.

• Load Modeling Task Force (LMTF): Jeni Mistry (SRP) will be the outgoing chair, and Hamody Hindi (BPA) will the incoming chair.

• Power Plant Model Validation and Data Task Force (PPMVDTF): Kent Bolton (WECC) will be the outgoing chair, and Steve Yang (BPA) will be the incoming chair.

Jun Wen (SCE) reviewed the status of MVWG model, documents, and tools document. This document will be available on the MVWG page and serve as a reference document of the available documents and tools for MVWG members.

Jun Wen (SCE) reviewed the MVWG action item log. The MVWG charter and priority, as suggested by Stephanie Lu (SCL), will be reviewed at the June MVWG meeting.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download