1. NERC Event Analysis Update Member Representatives Committee Meeting October 28, 2008 Robert W. Cummings NERC Director of Event Analysis & Information Exchange

2. 2 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

3. 3 Ongoing & Emerging Trends

4. 4 Emerging & 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)

5. 5 Emerging & 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(SCADA) (3)  Relay loadability (3) – 1 of these was in Europe  Relay settings (drifting) (3)  Relays / controls out-of-date with manufacturers’ tech.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)

6. 6 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

7. 7 Generator – System Interface Issues Gen Protection Gen Controls Turbine / Boiler Controls Trans Protection System Controls System Conditions PRC-001 Coordination

8. 8 System Protection Performance Improvement Initiative

9. 9 Protection & 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

10. 10 Protection & Control Performance Issues  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)

11. 11 System Modeling Improvement Initiative

12. 12 Modeling 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

13. 13 Need 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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