Transcript Event Analysis and Protection

NERC Event Analysis
Update
Member Representatives Committee Meeting
October 28, 2008
Robert W. Cummings
NERC Director of Event Analysis
& Information Exchange
Active 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
Emerging & Ongoing Trends
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 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)
Emerging & Ongoing Trends
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 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 Relays / controls out-of-date with manufacturers’ tech.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)
EA Trends – Top Two Disturbance
Elements
 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
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Generator – System Interface Issues
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System
Conditions
Trans
Protection
Gen Protection
PRC-001 Coordination
Gen Controls
Turbine / Boiler
Controls
System
Controls
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System Protection Performance
Improvement Initiative
Protection & Control Performance Issues
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 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
Protection & Control Performance Issues
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 Elevate System Protection and Controls
Task 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 Modeling
Improvement Initiative
Modeling Issues
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 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
Need for New Modeling
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 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 (FaultInduced 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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