essential reliability services highlights and...• determine policy maker needs and develop...

Essential Reliability ServicesERSWG

NERC Planning and Operating Committee MeetingsMarch 7-8, 2017

RELIABILITY | ACCOUNTABILITY2

ERSWG 2016 Follow up

2016 Deliverables:• ERS Sufficiency White Paper completed &

posted.• DER Report approved at February Board meeting

& posted.• PC needs to formally disband the DERTF,

scheduled for March 2017


ERSWG 2017 Focus

Revised ERSWG Scope Document• Continue the development and refinement of ERS Sufficiency

Assessments (no longer to be called Sufficiency Guidelines). This includes:

• Ongoing analysis of current trends. Observations and results to be included in the annual State of Reliability (SOR)

Report.

• Development of forward looking (predictive) analyses of selected ERS Measures. Observations and results to be included in the NERC Long Term Reliability

Assessment (LTRA).

• Development of historical analyses of select ERS Measures. These will be illustrated in the SOR reports going forward.


ERSWG 2017 Focus

ERSWG Activities• Monitor activities of the subcommittees and working groups related to

ERS Measures.• Evaluate other tools and/or processes for assessing the sufficiency of ERS

Measures for both current and future states.• Develop recommendations for practices and requirements, including

reliability standards, as necessary, that cover the planning, operations planning, and real-time operating procedures associated with ERS.

• Identify and recommend subgroups (existing or new) of the Operating and Planning Committees to ensure ongoing both historical and forward looking trending/analysis of ERS Measures.


ERSWG 2017 Focus

ERSWG Activities – DER Related• Lead the implementation of recommendations from the February 2017 DER

Report (accepted February 2017) as directed by the NERC Board of Trustees. • Assess incorporation of DER data into the ERS Sufficiency Assessments and

Measures.


ERSWG 2017 Focus

ERSWG Deliverables• Develop technical reference documents or assessment briefs, as

necessary, on recommended ERS Sufficiency Assessments and Measures.• Develop briefings for use with policy makers, as necessary, on various

ERS issues.• Support historical and forward looking ERS assessments for the State of

Reliability and the Long Term Reliability Assessment Reports. Propose, develop and implement new data collection and analytical processes, as needed.

• Develop various DER related technical reference documents and/or data collection guidelines.


ERSWG 2017 Schedule

Date ActionJanuary – December 2017 ERSWG Leadership Conference Calls – Starting and reoccurring every 2 weeksJanuary – July 31, 2017 • Monitoring RS, RAS, PAS, ERS committee/group meetings

• Phone calls to set work efforts, guidelines, goals, and reviewing results for EOY reportFebruary 8 - 9 NERC Board Meeting (DER Reported approved)February 22 – 23 (Atlanta) ½ day each day

ERSWG Leadership Face to Face Meeting • Establishing ERSWG work plan DER subgroup creation and possible DER guidelines/paper

March 7 – 8, 8 (Atlanta) Q1: OC and PC Meeting

March 8 (Atlanta) ½ day onlyERSWG Face to Face Meeting (1/2 day Wed only)• Review current state of ERS measures, technical presentations, DER update

May 17-18 (Atlanta) ½ day each day ERSWG Face to Face Meeting• Progress meeting to update on ERS work efforts and DER work

June 6-7 (TBD) Q2: OC and PC Meeting

June 7-8 (TBD) ½ day each dayERSWG Face to Face Meeting• Review current state of ERS measures, technical presentations, DER update

August 1-2 (TBD) – if needed Progress meeting or conference call if needed to update on ERS work efforts and DER workAugust 9 NERC BOT Meeting, status update (as necessary)September 12 – 13 Q3: OC and PC Meeting

September 13-14 (TBD)½ day each day

ERSWG Face to Face Meeting (End of Year Deliverables)• Review current state of ERS measures, technical presentations, DER update• Finalization of ERS assessment briefs and any DER guideline/paper for the 2017 year

Early Nov (TBD) – if needed Progress meeting or conference call if needed to update on ERS work efforts and DER workNovember NERC BOT Meeting, status update (as necessary)December 12-13 Q4: OC and PC Meeting

December 13-14 (TBD) ½ day each ERSWG Face to Face Meeting• Review work of 2017 ERS measures and DER subgroup, Set work plan for 2018

Late January (TBD) 2018 – if needed Progress meeting or conference call if needed to update on ERS work efforts and DER work


ERSWG 2017 Summary & Request

Key items for 2017• Test/Validate current measures/assessment methods• Further develop forward looking methods of assessment• Determine policy maker needs and develop necessary briefing

documents • Prioritize and develop DER related reference documents/reliability

guidelines• Provide status updates and technical briefs, as appropriate.• Request OC/PC approval of revised ERSWG Work Scope.

Ryan D. Quint, NERCNERC Planning Committee MeetingMarch 7-8, 2017

Reliability Guideline: Forced Oscillation Monitoring & MitigationInitial Approval – Industry Comment Period


Overview

• Provides industry with understanding of fundamental behavior of forced oscillations and how they differ from system (natural) oscillations.

• Highlights use of PMU data for oscillation monitoring and analysis.

• Provides framework for identifying, characterizing, and determining the source of forced oscillations

• Recommends practices and mitigation strategies for system operators and operations engineers

• Appendices of operational tools and actual forced oscillation events


Guideline Overview


Characteristics of Oscillations


Considerations

• Sources of forced oscillations Generation Load Controls

• Monitoring devices for forced oscillations Reporting rates Filtering Electrical quantities

• Interactions between system and forced oscillations Resonance effects Widespread impacts of localized forced oscillations


Recommended Practices & Mitigation Measures

• Step 1: Identify occurrence of forced oscillation• Step 2: Determine oscillation frequency and magnitude• Step 3: Determine “containment” of oscillation• Step 4: Determine location or general proximity of oscillation• Step 5: Determine specific system component oscillating


Operational Tool Examples


Event Examples


Development Timeline

• April ‘16-Jan ‘17 Development of draft guideline• March PC PC initial approval for posting for comment• Mar 15-May 3 Industry comment period• May 3-21 Response to comments• June 6 PC Final Approval


Approval

• SMS is seeking PC approval to post the Reliability Guideline on Forced Oscillation Monitoring & Mitigation for a 45-day industry comment period.

Ryan D. Quint, NERC NERC Planning Committee Meeting March 7-8, 2017

Reliability Guideline: Developing Load Model Composition DataFinal Approval


Final Approval

• Purpose: provide TPs and TOs with insights into end-use load behaviors and how to capture that in the composition of dynamic load models

• Comment Period: No comments received• Updates: Editorial changes from Publications review• Action: Seeking final approval of guideline


Development Timeline

• Dec ‘15-Oct ‘16 Development of draft guideline• Oct 25 Detailed walkthrough of guideline to SAMS• Nov 3 LMTF approval of guideline• Nov 7 SAMS approval of guideline• Dec 13 PC initial approval for posting for comment• Jan 4-Feb 24 Industry comment period• Feb 24-28 Response to comments• March PC PC Final Approval

Review of Data Change Management Processes for RTCA and Planning Models (Recommendation 16)

Amir Najafzadeh, Senior Engineer, System AnalysisPlanning Committee Meetings March 7-8, 2017


Overview

The Charge• Standards Review• Regional Requirements Review• Gaps• Best Practices and Recommendations• Asking for Report Approval


The Charge

SW Outage Recommendation 16 - Discrepancies between RTCA and Planning Models

“… WECC should ensure consistencies in model parameters between its planning model and its RTCA model and should review all model parameters on a consistent basis to make sure discrepancies do not occur.”


Standards &Regional Requirements Review

Applicable Standards Review:• FAC-001-2 R1• IRO-010-1a R3• MOD-032-1

Existing Regional Requirements:• EI• WECC• Texas-RE


Gaps & and Recommendations

• Case Benchmark• Periodic Databank Update• Single Point of Entry• Data Tracking


PC Approval & Timeline

• MWG Drafted v1 August 2014• SAMS Approved v1 October 2014• Version 1 was not presented to the PC• MOD-032-1 became effective and required document rewrite • MWG Drafted v2 October 2016• SAMS Approved v2 November 2016• Presented to PC at December 2016 meeting• Posted for Industry Comment January 2017

Phil Fedora, RAS ChairPlanning Committee MeetingMarch 7-8, 2017

Reliability Assessment SubcommitteeStatus Report


Reliability Assessment SubcommitteeOutline

• 2017 Summer Reliability Assessment • 2017 Long Term Reliability Assessment• 2016 Probabilistic Assessment• Probabilistic Assessment Working Group• April Meeting Overview


Reliability Assessment Subcommittee2017 Summer Reliability Assessment


Reliability Assessment Subcommittee2017 Long-Term Reliability Assessment

Date DeliverableWednesday, January 25 2017 LTRA Materials Posted; Request Letter Sent to Regional Executives

Tuesday, April 11 –Wednesday, April 12

RAS Meeting: ERS, methods and assumptions presentations; resolve any issues with data collection and narrative responses; NERC to discuss process to transfer narrative responses to consistent assessment area section structures (template will be presented)

Friday, June 9 Data and Narratives Due to NERC

Friday, June 16 – Friday, June 30 RAS Peer Review

Friday, July 21 Data correction and final narrative responses due to NERC

Monday, August 14 – Friday, August 25

RAS Review of Draft Report

Friday, September 22 – Friday, October 6

PC/MRC/ERO Review of Draft Report

Tuesday, October 10 – Friday, October 13

NERC responds to PC/MRC/ERO Feedback

Monday, October 16 NERC sends updated report to the PC and hosts Webinar to present updates made

Monday, October 16 – Friday, October 20

PC Electronic Vote for report approval

Thursday, December 14 Target Release


Reliability Assessment Subcommittee2016 Probabilistic Assessment

• Addendum to the 2016 LTRA• Third NERC Probabilistic Assessment• Key Findings and Recommendations• Link to Regions and Assessment Areas’

Assessment Reports


Reliability Assessment SubcommitteeProbabilistic Assessment Working Group

• Continue the efforts of the PAITF Focus on Resource Adequacy Assessment

• Reports to the Reliability Assessment Subcommittee• Kickoff Meeting February 9th • Next Meeting - March 21st -22nd Finalize Workplan


Reliability Assessment SubcommitteeApril Meeting Overview

Summary• 2017 Long-Term Reliability Assessment (LTRA) Data Definition

and Collection

LTRA Informational Webinars

• Review 2017 Summer Reliability Assessment• Review Single Point of Disruption Short-Term Special

Assessment


Reliability Assessment SubcommitteeApril Meeting Overview

Summary (continued)• Reliability Assessment Guidebook Update• Approve Probabilistic Assessment Working Group Work Plan• Special Assessment Topics Identification of emerging reliability issues

Probabilistic Assessment Working Group (PAWG) –Updates

Noha Abdel-Karim, PhD., Senior Engineer, Reliability AssessmentNERCPlanning Committee MeetingMarch 7-8, 2017


Introduction & Background

• Purpose: Advance the work initiated by the GTRPMTF and

the PAITF. Evaluate more probabilistic approaches that will

provide further insights into resource adequacy assessment.

• Objectives: Conduct biennial NERC Core ProbA. Support NERC coordinated Special ProbA reports. Coordinate and promote alignment of

assessments. conducted by NERC, the Regions, and the industry at large.

• PAWG Scope of Work document approved by PC in December, 2016 meeting.

Visit link to access approved PAWG’s SOW document.

http://www.nerc.com/comm/PC/PAWG%20DL/Probabilistic_Assessment_Working_Group_Scope.pdf


• Membership and Leadership Positions Chair and Vice Chair nominated - awaiting PC

approval PAWG members (including alternates) cover

the entire North American footprint. More spots are open for subject matter

experts in the area of probabilistic analysis.

Updates –Members


Updates –Draft Work Plan

• Five key work plan items: Technical Reference on reliability measures for resource adequacy assessment. Probabilistic sections of the LTRA. 2016 Core ProbA. Natural gas availability and pipeline outages special assessment. Data collection approaches and recommendation report.

• Additional items and assessment topics: Support ramping and frequency capability studies – Coordination with ERSWG as

needed. External coordination with related groups like IEEE-LOLEWG for information sharing

and exchanging knowledge.

Visit link to access PAWG’s draft work plan document.

http://www.nerc.com/comm/PC/PAWG%20DL/PAWG_Work_Plan_-Draft.pdf


• Approve leadership nominations ( provided that names are available for the March meeting, else put action item on hold)

• Provide support to work plan draft –comments are encouraged but not mandatory at this time.

Request Actions by the PC


Noha Abdel-Karim, PhD.Senior Engineer, Reliability Assessment202-644-8081 office | 202-480-6261 [email protected]

mailto:[email protected]

2016 Probabilistic Assessment

Noha Abdel-Karim, PhD., NERC Senior Engineer, Reliability Assessment NERC Planning Committee MeetingMarch 7-8, 2017


Background

• Probabilistic Assessments 2011 Pilot Assessmento Complement 2010 LTRAo Study years: 2011 & 2014

2012 ProbA –First Reporto Complement 2011 LTRAo Study years: 2014 & 2016

2014 ProbAo Complement 2013 LTRAo Study years: 2016 & 2018

2016 ProbAo Complement 2015 LTRAo Study years: 2018 & 2020


2016 ProbA –Introduction

• Purpose: Offers a different approach for examining the complexity of the changing

BPS.

• Main Objectives: Calculate a complete and non-overlapping set of monthly and annual

probabilistic reliability metrics. Perform a resource adequacy assessment covering all hours (compared to

only the peak demand hour of each season in the LTRA). Provide LOLH and EUE measures, and convey a clear understanding of the

reserve margin implications. Compare results over time and between studies. Calculate probabilistic reliability metrics under a sensitivity case with

increased in load growth.


2016 ProbA –Implementation

• Monthly Reporting of Reliability Statistics Monthly LOLH and EUE reliability statistics were added to further

emphasize the objective of looking at reliability at all times of the year and not only seasonal peaks.

• Sensitivity Case A 2% increase of energy in both 2018 and 2020. Peak demand was increased by 2% in 2018 and by 4% in 2020. This sensitivity is generally interpreted as the effect of an increase in load

growth but could also provide insight related to additional resource retirements.


Area Summary Graphic Example

MRO-Manitoba HydroBase Case Reserve Margins (Left) and Probabilistic Measures (Right)

LOLH Results (Left) and EUE Results (Right)


Area Summary Graphic Example

MRO-Manitoba Hydro

Month

2018 Base 2020 Base 2018 Sensitivity 2020 Sensitivity

LOLH (hrs./month) EUE (MWh/month) LOLH (hrs./month)EUE

(MWh/month)LOLH (hrs./month) EUE (MWh/month) LOLH (hrs./month) EUE (MWh/month)

Jan0.008 19 0.000 0 0.017 44 0.000 0

Feb0.004 8 0.000 0 0.014 29 0.000 1

Mar0.024 20 0.000 0 0.041 42 0.028 42

Apr0.000 0 0.000 0 0.001 1 0.000 0

May0.000 0 0.000 0 0.000 0 0.000 0

Jun0.000 0 0.000 0 0.000 0 0.000 0

Jul0.000 0 0.000 0 0.000 0 0.000 0

Aug0.000 0 0.000 0 0.000 0 0.000 0

Sep0.000 0 0.000 0 0.000 0 0.000 0

Oct0.000 0 0.000 0 0.000 0 0.000 0

Nov0.027 44 0.000 0 0.157 218 0.002 4

Dec0.016 27 0.000 0 0.031 55 0.000 0

Annual0.078 117 0.000 0 0.261 390 0.030 47


Main Key Findings

• High reserve margins in most areas resulted in no loss of load probability in either the base or sensitivity case.

• Assessment Areas’ boundary changes can cause challenges in measuring changes from year to year and study to study.

• Monthly LOLH and EUE statistics were reported for the first time this year. Recommendation –Determining the precise reasons for monthly patterns is useful

for resource planning and future probabilistic resource adequacy analysis. • Modeling variable energy resources continue to become enhanced as they

become a larger portion of the generating mix. Recommendation –Probabilistic approaches should be used to represent the

stochastic behavior of wind and solar as these resources increase penetration. • Peer review for the probabilistic assessment analysis is largely methodology-

based. Recommendation –Critical methodology review is needed as probabilistic

approaches introduce increased complexity and relatively new assumptions.


Approve 2016 Probabilistic Assessment

Request Actions by the PC


Noha Abdel-Karim, PhD.Senior Engineer, Reliability Assessment202-644-8081 office | 202-480-6261 [email protected]


PAS Update

Paul Kure, Chair, NERC Performance Analysis Subcommittee NERC Planning Committee MeetingMarch 7-8, 2017


PAS update• PAS and working group scope documents – for approval• M-10 Transmission Constraints – approval for retirement

PAS Update


• PAS, GADSWG, TADSWG, AND DADSWG scope documents approved in 2011, 2011, 2009, & 2013, respectively

• Changes were clean up or consistency changes Removed phased-in activities Some activities were combined Membership changes to eliminate duplicates; reflect current status TADSWG to operate by consensus

• Removed changes inconsistent with PC charter as noted at December PC meeting

Scope changes today are for approval by the PC

Updated Scope Documents


Metrics Review

Reliability Metric M-10: Transmission Constraints

• Thought was that transmission constraints are a relative indicator of transmission robustness and a lack of transmission reinforcement would increase the number of mitigation plans for constraints

• Used the number of mitigation plans (SPS/RAS; operating procedures) as indicator of robustness (lack of constraints) on the transmission system

• PAS began a discussion during 2016 SoR on whether there was a correlation with the number of mitigation plans and transmission robustness


Metrics Review

Reliability Metric M-10:Transmission Constraints

• Data correlating mitigation plans to transmission system has been inconclusive

• There will be no gaps in metrics measuring transmission reliability. Six of the remaining metrics address transmission system

PAS recommends retiring M-10 (Transmission Constraints): requests PC approval

Open Distribution

NATF Update for NERC PC MeetingKen Keels

NATF Director, Practices and [email protected]; 704-945-1950

Open DistributionCopyright © 2017 North American Transmission Forum. Not for sale or commercial use. All rights reserved.

March 2017


Open Distribution

Topics

• Modeling and planning activities underway at NATF• NATF Publications Available for Open Distribution• Preview of June 2017 joint NATF-NERC Modeling Workshop• System protection activities underway at NATF

2

Open Distribution

Modeling and Planning Activities Underway at NATF

• EMS External Model Reference Document – Public: Spring 2017

• MOD-033 Reference Document– Public: Spring 2017 – File with NERC for Compliance Implementation Guidance approval

• CIP-014-2 Reference Document– Updating CIP-014-1 Reference document– Public: Spring 2017 – File with NERC for Compliance Implementation Guidance approval

• Actively following work of NERC Distributed Energy Resources Task Force

3

Open Distribution

NATF Publications Available for Open Distribution

Available on www.natf.net

NERC-endorsed Compliance Implementation Guidance

Submitted for endorsement as Compliance Implementation Guidance

4

http://www.natf.net/

Open Distribution

MOD-033 Reference Document

TABLE OF CONTENTSPurposeTopic 1: IntroductionTopic 2: Scope of MOD-033-1 Data ValidationsTopic 3: Approaches to R1.1 Steady State Model Validation Topic 4: Approach to the R1.2 Dynamic Model Validation Process Topic 5: R1.3: Guidelines to determine unacceptable differences Topic 6: R1.4: Guidelines to resolve unacceptable differences Appendix

Open Distribution 6

• When: June 20-21• Where: Exelon/ComEd in Oak Brook, Illinois (Chicago)• Planned topics

– Dynamic Load Modeling– Power Plant Modeling – Model validation and MOD-033 – Integrating Renewables at the Transmission Level – Modeling DER (renewables at the distribution level)– Catch all session: NERC/FERC update, NERC modeling updates,

Emerging modeling issues

Joint NATF-NERC Modeling Workshop

Open Distribution

System Protection Activities Underway at NATF

7

• Development of Forum Practices and Superior Practices– Short Circuit Modeling Practices– Protection System Maintenance Program (PSMP)

Template– System Protection Coordination Practices– Power Line Carrier Application and Maintenance

Practices– Protection Systems - Automated Testing Practices– DC Trip Circuit Design & Testing Practices

Open Distribution

System Protection Activities Underway at NATF

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• System Protection Performance and Misoperations Analysis– Measure Definition File – Dependability vs Security– Identify practices and training for development to address key risk areas

• Training Webinars– Directional elements settings practices– Directional comparison blocking setting practices– Breaker failure design and settings (coming soon)– Source impedance ratio effects on protection (coming soon)

Open Distribution

Questions?

9

FERC Order No. 830 Progress UpdateGeomagnetic Disturbance Mitigation and Research Plan

Ken Donohoo, GMDTF ChairNERC Planning Committee Meeting March 7-8, 2017


• Federal Energy Regulatory Commission (FERC) Order initiates further actions to address geomagnetic disturbances (GMD) Implementation of GMD Vulnerability Assessments (TPL-007-1) Revisions to TPL-007-1 Additional research Data collection

• GMD research work plan due to FERC by May 29, 2017

Order No. 830


• Order No. 830 directs NERC to revise TPL-007 to address Commission concerns Modify the benchmark GMD event definition used for GMD assessments Require entities to collect GMD data Establish deadlines for Corrective Action Plans (CAPs) and mitigating

actions to address identified GMD impacts

• Revisions must be filed by May 2018

Revisions to TPL-007


• NERC is seeking input on the research plan through: GMD Task Force Technical committees Research organizations

• GMDTF meeting held on February 21 – 22, 2017 Received input to research plan from task force

• EPRI and NERC will have the final plan ready mid of March 2017• Will need an off-cycle webinar to review the final plan with PC• Task 6 of research plan (Section 1600 data request goals) PC to approve data request for 45 day industry comment at June 2017 PC

meeting, approve at September 2017 PC meeting PC to submit data request to NERC Board of Trustees in Q4 2017 for final

approval (depending on comments received)

Next Steps


Preliminary Research Plan Proposal

File research plan with FERC

May 29, 2017

Task 1:Spatial

Averaging

Task 2,3:Latitude Scaling /Improve Earth

Conductivity Models

Task 8:Improve

Harmonics Analysis

Research Plan Begins:

Planning and Project

Management

Task 7:Geoelectric Field Calculation Tool

Task 4,5:Transformer

Thermal Impact

December 2017

December 2019

December2020

December 2018

June2017

System Analysis and Modeling Subcommittee (SAMS) UpdateMichael R. LombardiChair, System Analysis and Modeling SubcommitteeNERC Planning Committee MeetingMarch 7-8, 2017


SAMS Update March 2017 PC Meeting

SAMS Informational Items:• NERC-NATF Modeling Workshop• Approved Model List


NERC-NATF Modeling Workshop

NERC-NATF Technical Conference on Power System Modeling• Industry Experts• NERC Technical Committees• NATF Modeling Practices Group

Focus on Modeling and System Analysis Topics, including:• Dynamic load modeling• Power plant modeling• Power plant and system model verification• Integration of renewable energy resources at the transmission level• Modeling distributed energy resources at the distribution level• Efforts to improve interconnection-wide models


NERC-NATF Modeling Workshop

Workshop Date and Times:• June 20, 2017 -- 8:00 a.m. – 5:00 p.m. Central Time• June 21, 2017 -- 8:00 a.m. – 12:00 p.m. Central Time

Location:Exelon/ComEd – Commercial Center1919 Swift RoadOak Brook, IL 60523

Conference Registration:• https://www.eventbrite.com/e/technical-conference-power-system-

modeling-registration-32330299797

https://www.eventbrite.com/e/technical-conference-power-system-modeling-registration-32330299797


Development and Issuance of an Approved Model List

NERC Standardized Component Model Manual• Library of component models vetted by the industry for use in

Interconnection-wide models• Some Models Annotated:

deprecated model; use of this model is not recommended interim model; replacement recommended

• Modeling Working Group (MWG) posted 3/2/16


Development and Issuance of an Approved Model List

Next Steps:• Update and refine NERC Standardized Component Model Manual• NERC Approved Power Flow and Dynamics Model List• Maintain and document for industry list of ‘approved models’ for power

flow and dynamics Align with Model Notifications Capture Industry Advancements

• Coordination with the MOD-032 Designees to enforce the approved model list in their case creation development, as applicable

PCPMTF REPORT

Mohamed Osman, P.E., Senior Engineer of System AnalysisNERC – Planning Committee MeetingMarch 7-8, 2017


PCPMTF Background

PCPMTF: Plant-Level Controls and Protection Modeling Task Force:• Studying effects of plant-level, turbine, and boiler control and protection

systems• Comprehensive look at the short- and mid-term post-disturbance behavior of

plant control and protection systems• Outlining impacts plant control and protection systems have on unit reliability

and system stability during grid disturbances

PCPMTF Stakeholders:• Turbine Manufacturers; Generators Owners/Operators; North American

Generator Forum (NAGF); experts in power system dynamics and control; stability simulation software vendors


Events Investigated to Quantify Effects of Boiler and Turbine Controllers


What is the issue?

If we look at the generator tripping events that the TF haslooked at and could not be duplicated by models, most occurredbecause of either:

• Equipment failure

• Expected protection action (correct action)

• Protection action that was not properly coordinated

• Complex dynamics of combustion/boiler systems


Generator Protection

• Loss of field• Overexcitation protection• Overvoltage protection• Undervoltage protection• V/Hz protection• Over/Under-Frequency protection• Power/Load Unbalance (for STs)• Reverse Power relays• Many others (e.g. Neg. Sequence, Phase Differential Current, etc.) which

cannot be modeled in positive sequence simulation tools


Considerations for Quantities

• It is not practical or necessary to model the entire set of turbine or boiler controls

• Task Force focused on defining the functions and behaviors that should be modeled for transient and mid-term dynamics

• Variables to be monitored in simulation tools:

• Protection systems and Limiters:


Models with Representation of Plant-level DCS Controls

Turbine Load Controllers:• GGOV1• GGOV3• LCFB1

Turbine Control Modes: ability to represent boiler dynamics• ccbt1 & ccbt3 (PSLF)• TGOV4 & TGOV5 (PSS/E)

Power-Load Unbalance: ability to model fast valving scheme• TGOV3 and TGOV5 (PSS/E)


Generator Protection

• WECC has for years used simple models in GE PSLFTM called gp1/gp2 thatmodel many of these functions generically – WECC uses these only tomonitor the behavior in simulations, not to trip units

• This can be a good starting point, with the next steps being to: Update those models Double check to ensure they are applying reasonable default

settings/assumptions Add missing features (e.g. V/Hz, Power/Load unbalance, etc.)


Available Models

Existing turbine-governor models (see IEEE PES- TR1 report [1])allow for reasonable modeling of:

• Unit ramp rates in power

• Deadband

• Outer-loop MW controllers

• Baseload

• Temperature limit of GTs

The new IEEE Std 421.5 will have documented OEL, UEL andstator current limiter models


Task Force Recommendations

• Adopt a model similar to gp1 (and gp2) in GE PSLFTM that can monitor and provide warnings of potential unit tripping due to the generator encroaching on possible trip-zones of protection systems.

• Inclusion of Volt/Hz, over excitation limiter, under excitation limiter and reverse power dynamic models in future year planning cases.

• NERC SPCS should look closely at the reliability impacts of plant-level controls and protection on applicable NERC Reliability Standards.


References

[1] IEEE Task Force on Turbine-Governor Modeling, DynamicModels for Turbine-Governors in Power System Studies, IEEETechnical Report PES-TR1, January 2013.