NERC Event AnalysisNERC Event AnalysisUpdateUpdate

Member Representatives Committee Meeting

October 28, 2008

Robert W. CummingsNERC Director of Event Analysis & Information Exchange

2Active Event Analysis TeamsActive Event Analysis Teams

MRO System Separation – Sept. 18, 2007

Writing final report

FRCC South Florida Disturbance – Feb. 26, 2008

Writing final report

RFC PEPCO Disturbance – June 13, 2008

RFC Event Analysis Team – collecting data

SPP Southwestern Public Service Company Separation – June 17, 2008

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Ongoing & Emerging Trends

4Emerging & Ongoing TrendsEmerging & Ongoing Trends

Unexpected Generator Turbine Control Action (31)

Voltage sensitivity of generation auxiliary power systems (13)

Transmission equipment failures (11)

Human Error (8)

Protection system misoperation (8)

Near-term load forecasting error (6)

Wiring errors (6)

Inter-area oscillations (5)

Protection equipment failures (4)

System Integrity Protection Scheme Misoperations (SPS & RAS) (4)

Generation vs transmission protection miscoordination (3)

Lack of Redundancy (3)

5Emerging & Ongoing TrendsEmerging & Ongoing Trends

Loss of station observability (SCADA) (3)

Relay loadability (3) – 1 of these was in Europe

Relay settings (drifting) (3)

Relays / controls out-of-date with manufacturers’ tech. bulletins (3)

Uncoordinated load restoration (3)

Handling of missing/bad data by EMS systems (2)

Failed or run-away operation of substation automation (2)

Gas supply / gen. dispatch coordination (2)

Line hardware / conductor failures (2)

Protection system design errors / misapplications (2)

SCADA system misoperation (1)

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EA Trends – Top Two DisturbanceEA Trends – Top Two DisturbanceElementsElements

31 – Unexpected generator turbine control actions

• 28 in 7 events since August 2007 (and counting)

• 2 units CAUSAL in a system separation event

13 – Voltage sensitivity of generation auxiliary power systems (not included above)

Problem: THESE BEHAVIORS ARE NOT MODELED OR STUDIED

• Turbine controls (non-governor) are not modeled

• Typically only analyzing t = 0 to t = 20 seconds

7Generator – System Interface IssuesGenerator – System Interface Issues

Gen Protection

Gen Controls

Turbine / Boiler Controls

Trans Protection

System Controls

System Conditions

PRC-001 Coordination

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System Protection Performance Improvement Initiative

9Protection & Control Performance IssuesProtection & Control Performance Issues

Relay Loadability

• Standard PRC-023 – Relay Loadability passed by NERC Board, awaiting FERC approval

Protection System Redundancy

• SPCTF White Paper & SAR – December

PRC Standards Technical Support

• Protection misoperation analysis, maintenance, etc.

Protection System Coordination

• Trans & Gen Protection Coordination – IEEE collaboration

• Transmission Protection Coordination

System Performance & Protection Coordination with Turbine/Boiler Controls

10Protection & Control Performance IssuesProtection & Control Performance Issues

Elevate System Protection and ControlsTask Force to Subcommittee status

• Increased emphasis on the importance of system protection

Collaborative efforts with

• IEEE Power & Energy Society

• IEEE Power System Relay Committee

• Bridge between IEEE standards and NERC system performance requirements (in NERC standards)

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System ModelingImprovement Initiative

12Modeling IssuesModeling Issues

If something in not modeled, how can you predict system behavior or interaction????

Dynamics Modeling Issues

Missing models

Data errors

Models may not match field equipment and settings

Issue of “proprietary models”

No models for many wind farms

• No good indication of where wind farms are connected

• Registrations issues

13Need for New ModelingNeed for New Modeling

Turbine / boiler control models needed

• Units may remain stable, but ramp to zero and trip

Far more complex dynamic load models needed to analyze and predict FIDVR (Fault-Induced Delayed Voltage Recovery) behavior

• More load composition data needed to do this

Better governor models

Better SPS/RAS models

Models for new power electronic devices

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