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Protection System Misoperations: Why Should a System Operator Give a Hoot?. April 17 & May 1, 2014 – Charlotte, NC September 11 & 25, 2014 – Nashville/Franklin, TN David Greene, P.E. Senior Reliability Engineer SERC Reliability Corporation. Learning Objectives.
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Protection System Misoperations:Why Should a System Operator Give a Hoot? April 17 & May 1, 2014 – Charlotte, NC September 11 & 25, 2014 – Nashville/Franklin, TN David Greene, P.E. Senior Reliability Engineer SERC Reliability Corporation
Learning Objectives At the conclusion of this training session, you should be able to: • Explain how Protection System Misoperations impact the Bulk Electric System (BES). • State the process for addressing Protection System Misoperations per the PRC-004 NERC Reliability Standard. • Listthe common categories of Protection System Misoperationsand name some common causes. • Identify ways in which Protection System Misoperations can impact System Operators (per PRC-001 requirements). • Recognize what is and is not a Protection System Misoperation from actual examples.
Outline of Topics • Explain Applicable PRC Standards PRC-001 & PRC-004 • Misoperation Reporting Process • Misoperation Categories • Misoperation Causes • Example 1 – Failure to Trip • Example 2 – Unnecessary Trip with Fault • Example 3 – Unnecessary Trip without Fault • Example 4 – Human error • Example 5 – Slow Trip • Example 6 – Special Protection System Fail to Operate • Example 7 – AZ/CA Blackout – SPS Coordination? • Examples 8-10 more Unnecessary Trip with Fault • Summary of Main Points
Understanding the Intent of PRC - 001 System Operator Can you handle the Truth??? We need you on that Wall Actually, you are on the wall whether or not you realize it
Understanding the Intent of PRC - 004 Protection System Misoperations will happen FIX THEM! And by the way, don’t dilly dally around getting it done!
Misoperation Reporting Process • Misoperation occurs • TO, GO, DP analyzes misoperation • TO, GO, DP develops Corrective Action Plan (CAP) • TO, GO, DP implements CAP • TO, GO, DP reports misoperations and CAP status quarterly • Region (SERC Protection and Controls Subcommittee PCS) reviews misoperations and operations reporting • Region provides misoperations and operations data to NERC after Region review • Region monitors timeliness of CAP implementation
Four Misoperation Categories • Presented in order of increasing occurrences: • Slow Trip • Failure to Trip • Unnecessary Trip without a Fault • Unnecessary Trip with a Fault
Ten Misoperation Causes AC system As-left personnel error Communication failures DC system Incorrect settings Logic error Design error Relay failures/malfunctions Unknown/unexplainable Other/explainable
Misoperation Example 1: Failure to Trip What the heck? Line Fault • Line Fault
Misoperation Example 2:Unnecessary Trip with Fault 04 03 01 02 X Line Fault Station A Station D Station B 05 06 Why trip? Station C
Misoperation Example 3: Unnecessary Trip without Fault Why separate from the grid? Generator trip
03 10 04 07 BUS 1 01 W 08 Misoperation Example 4: Human Error 02 NOT A Misoperation 12 06 09 BUS 2: Cleared to install capacitor
Misoperation Example 5: Slow Trip Station A G G 04 02 01 03 X Line Fault Why trip? W Station E Station B Station D Station C
Misoperation Example 6: Special Protection System (SPS) Failure to Operate L1 Line Overload, Instability 500kV W TX1 W TX 2 200kV X Line Fault and Lockout G1 L2 Out of Service G2 L3 L4 Line Overload Unit Supposed to Trip
Misoperation Example 7: AZ/CA Outage - SPS Lack of Coordination AZ/CA Blackout was initiated by a Switching Error, not a misoperation L3 L2 L4 Note: Drawing copied from the FERC, NERC AZ/CA Sept 8, 2011 Outage Report
Example 7 Cont’d: AZ/CA Outage - SPS Lack of Coordination • “S” Line Remedial Action Scheme (SPS) operated too soon • SONGS Separation Scheme (SPS) – Lack of Coordination • Protection Settings to close to Facility Emergency Ratings Note: Drawing copied from the FERC, NERC AZ/CA Sept 8, 2011 Outage Report
STA 3 01 03 BUS 1 Why trip? 31 32 02 10 07 04 W Why trip? Misoperation Example 8: Unnecessary Trip with Fault 08 06 Insulator failure 09 Open for Maint. 12 X 14 13 BUS 2 21 41 42 22 STA 4 STA 2
STA C 02 03 01 STA B BUS 1 X Line Fault 07 04 Why 01 and 07 trip? W Misoperation Example 9: Unnecessary Trip with Fault 05 06 09 BUS 2 X Line Fault STA D STA B
Misoperation Example 10: Unnecessary Trip with Fault Station A 03 04 G G Why 03,04,05 trip? 05 W Station E Station B Station D Station C 01 02 X Temporary Line Fault
Learning Objectives Met? Can you answer: How do Protection System Misoperations impact the Bulk Electric System (BES)? Which NERC Reliability Standard(s) address Protection System Misoperations? What are the four categories of Protection System Misoperations? Name three of the ten causes for Protection System Misoperations? How do Protection System Misoperations impact System Operators?
Summary • The main points of this training session are: • Protection System Misoperations happen – Fix them! • PRC-004 identifies requirements for analyzing, reporting and correcting misoperations – Comply! • System Operators get to deal with the results of Protection System Misoperations so: • YOU shall know the purpose and limitations of Protection Systems schemes applied in your area! (PRC-001, Requirement 1).
Now, Talk to MeDavid Greenedgreene@serc1.org704.414.5238 (W)704.488.0177 (M)