1. MVWG Report to TSS August 2011
Stephanie Lu
Puget Sound Energy

2. Presentation Overview
Charter
Priorities and Work Plan
SVC Modeling
System Model Validation
Load Modeling
Renewable Generation Modeling
Synchronous Generation Modeling
HVDC Modeling
Modeling Workshop

3. MVWG Charter MVWG reviewed the charter at the July 2011 meeting
Only one change is proposed – to change the review periodicity from annual to biennial
Document: M&VWGCharter2010April29_rev date 2011July15.docx
Motion: Approve the recommended change to the TSS and supporting work group charters, changing the review periodicity from annual to biennial, or as needed.

4. Priorities and Work Plan
Created in December Updated in July 2011
Priorities:
Load Model Deployment
System Model Validation
Power Plant Modeling
Renewable Generation Models
SVC and HVDC Modeling
Document: 2011JulyMVWGPriorities2011July21.docx

5. Priorities – Load Modeling
Complete the report on WECC Composite Load Model
Support ongoing load composition research, such as for air conditioner stalling
Develop a tool that detects events of Fault Induced Delayed Voltage Recovery using synchro-phasor and DFR data
Develop a tool to estimate load composition data
Perform model validation and system impact studies
Support Reliability Subcommittee efforts to understand the implications of criteria and standards
Support TSS efforts to implement the new models during base case development
Provide composite load model data files for base cases starting with the 2012 study program

6. Priorities – System Model Validation
Create cases to represent disturbances, using data available from the west wide system (WSM) cases.
Work with WECC RC to improve WSM cases. While the network topology representation is accurate, generation and load representation are significantly deficient.
M&VWG issued an RFP, evaluated proposals, and is working to contract with a vendor to provide tools and translation tables to link dynamic data to WECC power flow base cases.
System model validation is one of the deliverables under the Western Interconnection Synchro-phasor Program (WISP). M&VWG intends to perform as much as three model validation studies in CY 2012 to support the WISP efforts.
Participate in efforts by the NERC Model Validation Task Force to define power flow and dynamic system model validation methods.

7. Priorities – Power Plant Modeling
Implement a task force to review power plant data in the MDF
Verify power plant models
Conduct workshops on MOD-025, 26 and 27, and PRC-024 NERC Standards following their approval.
Deploy Generator Model Validation Tools at WECC offices and interested utilities for power plant model verification using synchro-phasor data.
Improve Synchronous Machine Models
As approved by TSS, WECC Staff translated gensal model data to gentpj model to better represent saturation effects and posted the revised master dynamics data file. There are 17 gensal models that need resolution. Translate all “gensal” models to “gentpj” models in MDF by November 2012.

8. Priorities – Power Plant Modeling (cont.)
Improve Excitation Models
Review whether 20 approved excitation models is appropriate, and whether the models can be reduced to a simpler set of static and rotating excitation models.
A 2011 contract with John Undrill will provide a tool to translate exciter data in WECC databases from old exciter models to similar new exciter models that will support over-excitation limiters.
Advance modeling of Over-Excitation Limiters (OEL), Under-Excitation Limiters (UELs), and generator protection models.
Review and Develop Turbine Controls
Review turbine-governor models. No such review was done since There are signs that the modeled frequency response is again on the optimistic side.
Conversion to Kaplan models must be completed for generating units in lower-, mid-Columbia, and lower Snake rivers.

9. Priorities – Renewable Generation Models
Obtain additional default data for various types of wind generators.
Complete Phase 2 of the WECC wind modeling effort to develop improved models (especially for Type 3 wind generators) that better represent various manufacturers’ wind generators.
Explore feasibility of dynamic model validation at the wind plant level; this will require installation of monitoring equipment at the interconnection points.
Develop methods and power flow/dynamic models for representing solar photovoltaic installations.

10. Priorities – SVC and HVDC Modeling
Approval was obtained for the SVSMO1 model.
Obtain approval for the SVSMO2 and SVSMO3 models. Validation cases have been run and a report generated.
A High Voltage DC modeling Task Force (HVDCTF) has been formed and there was a kick-off meeting at the July 2011 M&VWG meeting.

11. Priorities and Work Plan
Motion: Approve and support the “M&VWG Priorities and Work Plan” as stated.

12. SVC Modeling 12

13. SVC Models
SVSMO1 – SVC model with TSC/TCR is implemented in PSLF and PSS®E – approved
SVSMO2 – SVC model with TSC/TSR
SVSMO3 – STATCOM model
Presentation: SVC_Approval_JKPPSL_ pdf
Report: GenericStaticVarSystemModelsforWECC.pdf
Motion: Approve SVSMO2 and SVSMO3 models and add to the approved model list. Approve the SVS Model report titled ‘Generic Static Var System Models for the Western Electricity Coordinating Council’. 13

14. System Model Validation14

15. System Model Validation Studies
System model validation is a priority of MVWG
System model validation is a deliverable under the Western Interconnection Synchro-phasor Program
Goal: Start conducting system model validation studies in 2012
System model validation is part of the NERC Model Validation Task Force efforts
Major impediment:
Validation base case development
Solution:
Automate the process of base case development
Leverage West-wide System Model (WSM) 15

16. System Model Validation Studies
WECC Powerflow Case:
Bus-branch
Bus number, ID
WSM Powerflow Case:
Node-breaker-element
Element Code 2
WECC Dynamic Database:
Bus number, ID
WSM Dynamic Database:
Element code, node 1 16

17. System Model Validation Studies
Option 1:
Convert WECC dynamic data base to “element code” definition consistent with WSM (one time effort)
Validation studies are done using WSM powerflow case and the new dynamic data file
Option 2:
Map generation, loads and equipment status from WSM to WECC powerflow case
Validation studies are done using WECC powerflow case and existing dynamic database 17

18. System Model Validation Studies
MVWG prepared RFP:
Procurement team identified the preferred proposal and created a “short list”. WECC is working on the contract with the top proposal.
RFP will focus on Option 1.
MVWG resources will develop Option 2 as the short term solution. 18

19. System Model Validation Statement of Work
See Statement of Work for more information
Develop and deploy analytic tools for system model validation
Apply tools for power plant model calibration, composite load model calibration, sub-system model calibration, small signal model validation, and model validation using large disturbance data
Presentation: TSS - Model Validation in WECC.ppt
Document: WECC MVWG SOW System Model Validation DGD.doc

20. Load Modeling 20

21. Composite Load Model Data
Presentation: TSS - WECC Compoite Load Model.ppt
Implementation Plan: Composite Load Model Implementation Plan doc
Motion: Approve the Implementation Plan for the Phase 1 Composite Load Model.

22. Wind Generation Modeling22

23. Status of Wind Modeling Effort
Version 1 of wind generic models implemented as library models in PSSE/PSLF & other platforms
Current focus is on
Refinement of models
Default data sets
Model validation
PSLF/17
PSSE/32

24. Phase 2 of wind model development – Model structure improvements
Type 1 and 2 improvements include:
Redesign aero/pitch model to better represent pitch strategy during low voltage conditions
Use LVRT flag to bypass rotor resistance control if LVRT situation occurs
Type 3 improvements to develop a non-GE specific model include:
Add option to bypass local volt/var controls
Review representation of the response during low voltage performance
Possibly add defensive pitch strategy similar to Type 1 and 2
Add frequency droop for high frequency conditions
Type 4 improvements include:
Add representation of mechanical side (shaft model) and option for direct torque control (current model is power control)
The specifications will be finalized at the next MVWG meeting

25. Wind Modeling - Implementation Plan
July/11 – REMTF memo requesting industry input
September/11 – Manufacturers reply
November/11 – MVWG to finalize specs for Phase 2
January/12 – Phase 2 model development complete
March/12 – MVWG Approval
April/12 – TSS approval & transition plan
Possibly allow 6 to 12 month grace period to provide data
May/12 – Additional model testing

26. Real Example of MVAR Flows

27. Powerflow Modeling (Lesson Learned)
Collector system equivalent must include shunts to properly model for voltage stability studies
Optimistic assessment of reactive requirements
Wrong
230-kV
34.5-kV W
Internal PF caps and external caps impacted by voltage squared (V^2/X)
Right
230-kV
34.5-kV
0.6-kV W 27

28. PV Generation Modeling28

29. Large PV Power Plant Modeling
Current versions of PSLF and PSS®E have models that can be used for representation of large PV generation
PSLF Version 18 includes a WECC generic version of a PV system model, PV1, which has additional adjustable options to cover a wider range of inverter types.
PV1 model consists of two modules - PV1E and PV1G. It is a full featured model based on the WECC Type 4 wind generation model.
Refinements to the models are in progress.
Add active power control (up-ramp rate limit and high frequency droop)
Add voltage dip logic function
Add option to bypass local volt/var control
Consistent with the WECC PV Modeling Guide, the feeder or collector system equivalent should be included in the power flow model for large PV plants.

30. Distributed PV Modeling
Distributed PV modeling can be separated into:
large commercial (usually warehouse rooftop) installation
residential rooftop panels
PVD1 is a more basic model than PV1 and is intended to represent large distribution-connected PV that are represented in power flow as stand-alone generators.
Large commercial installations are modeled explicitly in powerflow base case. An EPCL has been developed by Dmitry Kosterev to add the commercial PV generation in powerflow cases.
A similar version of PVD1 will eventually be made part of the WECC Composite load dynamic model to residential or smaller-scale distributed PV that is load-netted in power flow. Specifications are not yet complete, as further discussion is needed.

31. PV Modeling – Path Forward
Initial model specification
Model specification document
Model prototyping, testing
Implementation in PSSE/PSLF/PW, other
Validation and parameter sets
PV Dynamic Modeling Guide
Council approval
Deployment/dissemination in WECC
Model improvement/refinement cycle

32. Synchronous Generation32

33. Synchronous Generator, Excitation and Turbine Control Models
GENTPJ model – approved by TSS in January 2011
More accurate representation of over-excitation condition, particularly for salient pole machines
Power Plant Model Data Task Force created – first meeting November 2011
Excitation model conversion to IEEE models RFP (2011)
OEL, UEL and generator protection models ( )
Kaplan hydro turbine models ( )
Power Plant Model Validation 33

34. Update to gentpj model
Gensal models have been converted to gentpj in the MDF, with 17 exceptions that need additional investigation.
A note has been placed in the MDF zip file to document this change.
How to determine Kis factor for gentpj model:
If the V curve is not available, set Kis equal to zero.
If the V curve (no load curve and full load curve) is available, tune the Kis factor after the other parameters have been determined by matching the actual V curve and the model output.
An addendum to the baseline testing document to record the V curve data and a guideline on how to fit the curve using the Kis factor will be proposed at the next MVWG meeting in November.

35. Power Plant Model Data Task Force (PPMDTF)
The current process for generating unit model validation is described in the WECC Generator Unit Model Validation Policy. To summarize,
GO performs generator testing, validates generator model data and sends data/report to TP,
TP reviews and sends data/report to WECC,
WECC reviews (performs no disturbance test, etc.) and approves the generator testing and model validation reports, updates the Master Dynamics File (MDF), and issues certifications.
Gap in the process - TP does not review or does not have the expertise to adequately review the data and catch errors. There is currently only one WECC staff person who typically reviews and approves the changes.
PPMDTF will be an additional group that will help review and validate the data and assist the GO and TP to follow the Policy.

36. Power Plant Model Data Task Force - Purpose
Maintain accurate models of generators and associated controls for realistic simulations of the electric power system of the western interconnection. Minimize the number of errors in the generator model data in the Master Dynamics File (MDF).
Assist GOs and TPs to follow the WECC Generator Unit Model Validation Policy as per NERC Standard MOD-012-0, R1 and R2.
Assist GOs to follow applicable NERC Standards:
MOD-25 - verification of generator reactive capabilities
MOD-26 - verification of generator excitation system models
MOD-27 - verification of generator turbine control models
Provide education and expertise in the review of the model data and performing simulation verification.

37. Power Plant Model Data Task Force – Scope of Work
Coordinate review and validation of generator test results, and their proposed models and parameters with GOs and TPs.
Provide and develop the expertise in the review of additions and changes to power plant model data.
Perform a more in depth review, including additional simulation verification studies.
Review existing generator model data in MDF and create a dynamics data error list to address errors.
Provide an opportunity for training members of the Task Force by jointly reviewing, testing, and discussing power plant model data for accuracy. Develop technical expertise within the membership.
Develop additional tools for data checking.

38. Power Plant Model Data Task Force – Kick-off Meeting
1st Meeting - Nov 2011 in conjunction with MVWG meeting
Proposed Agenda:
Review purpose/scope of work, develop a task force charter
Review the Generator Unit Model Validation Policy and discuss if any updates are helpful
Review recently submitted power plant models
Review existing power plant models and start a process to create a Dynamics Data Error List
Intended participants:
Experts and those interested in becoming experts in power plant testing and modeling.
Transmission Planners, Generator Owners, and others that submit and/or review modeling data.
Members that perform simulations that use the power plant models (includes both operations and planning).

39. Exciter Conversion
MVWG issued RFP to convert legacy excitation models to IEEE-approved excitation models
IEEE models are available in PSLF and PSS®E
IEEE models are identical to the legacy models with the exception that IEEE models have interface points for OELs and UELs
OEL and UEL modeling is essential for FIDVR risk analysis
Contract awarded to John Undril
Update provided at July MVWG meeting
Independent model translation program created with the ability to convert any model to any other model
Some models do not have a one-to-one equivalent, work is in progress
To be completed by November MVWG meeting
Deliverables include conversion map, rule file, manual, executable mcon program, mcon program source code, model validation report, epcl code for validation of individual model conversion 39

40. Power Plant Model Validation
Power Plant Model Validation is one of the deliverable under WISP
Power Plant Model Validation application is developed using PSLF play-in function
Version 1A is available on the WECC website and was presented at the June Modeling Workshop
An application is being developed for checking the “reasonableness” of the power plant response:
Compare the actual response to “best practices” 40

41. Power Plant Model Validation
Disturbance play-in function in GE PSLF
Inject PMU recordings of:
POI bus voltage
POI bus frequency
Compare actual and simulated
power plant MWs and MVARs
Rest of WECC ~
Power Plant
Developed under BPA Technology Innovation program

42. Power Plant Model Validation
Successful model validation for 550 MW combined cycle plant
Voltage and frequency are inputs
Active and reactive power are “measures of success”
Blue line = actual recording
Red line = model 42

43. Power Plant Model Validation
What a bad model looks like (800 MW steam-turbine unit)
Voltage and frequency are inputs
Active and reactive power are “measures of success”
Blue line = actual recording
Red line = model 43

44. Resources NASPI Planning and Implementation Task team: Contacts:
Power plant disturbance monitoring document
Technical session at the upcoming NASPI meeting on June 8-9 in Toronto, ON
Presentation at NERC PC meeting on December 7, 2010
Contacts:
Dmitry Kosterev,
Alison Silverstein,
Donald Davies,

45. HVDC Modeling

46. HVDC Task Force Kickoff meeting held on July 12, 2011
Mission statement: To develop basic building block models and documentation to facilitate the analysis of conventional and voltage-source converter (VSC) based High-Voltage Direct-Current (HVDC) systems in power system powerflow and stability studies for planning studies, when investigating alternative means of transmission.

47. HVDC Task Force (cont.) Priorities:
VSC-HVDC; point-to-point
Conventional; point-to-point
Back-to-back Conventional
Multi-terminal Conventional
Multi-terminal VSC (no actual installations)
CCC is not presently of high priority (Rapid City back-to-back is CCC)
The task force will start with the VSC and Conventional HVDC models.

48. HVDC Task Force (cont.) Action Plan:
GE to look into issues reported:
The dynamic models (dcbtb1, dc2t)
The load flow mode 4 & 5
ABB to look into shared code developed several years ago to be a starting point for the planning conventional HVDC model (with review input from all of course)
VSC – vendors to discuss and get back to group on what they can share as a starting point
EPRI to start a skeleton document for the TF
Report on progress by September 16th

49. Modeling Workshop

50. Modeling Workshop 2-day workshop: June 21-22, 2011
Held at WECC offices in Salt Lake City
Over 100 participants (~60 in person, ~40 on phone/webex)
Topics:
Load modeling – composite load model structure and data tools
Load modeling studies – FIDVR, model validation and system impact studies
Generation modeling and validation
Wind generation modeling
Solar generation modeling