Addendum for Events with Failed Station Equipment

Background

In December of 2013, the NERC Planning and Operating Committees formed the AC Substation Equipment Task Force (ACSETF) to investigate substation equipment failures. The subsequent report from the ACSETF recommended that the NERC Event Analysis process collect information on station equipment failures going forward. The collection of this data will aid in future analysis of station equipment failures to identify trends that may be a threat to the reliability of the Bulk Electric System (BES) and potential ways to improve that reliability. As such, NERC Event Analysis is providing this addendum to aid in the gathering of that station equipment failure data.

This addendum is intended to be used as a checklist for information to include in the Brief Report for Events that contain failed station equipment. Please provide as much of the information as is available for each respective type of equipment failure.

This information is intended to be provided in addition to the identified contributing causes and root cause determined through the entities root cause analysis of the event.

Additional resources for entities to use in analysis of station equipment failures are IEEE C57.125 Guide for Failure Investigation, Documentation, Analysis and Reporting for Power Transformers and Shunt Reactors and IEEE C37.10 Guide for Diagnostics and Failure Investigation of Power Circuit Breakers.

Equipment Types

  1. Power Transformers
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  1. Instrument Transformers
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  1. Circuit Breakers
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  1. Relays
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Power Transformers

  1. Manufacturer

  1. Date of manufacture

  1. Transformer type

  1. Autotransformer

  1. 2 winding
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  1. 3 winding
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  1. Shell form
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  1. Core form
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  1. Other – please explain

  1. Winding configuration

  1. delta-wye
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  1. wye-wye
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  1. wye-delta
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  1. delta-delta
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  1. wye-wye-delta
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  1. Other – please explain

  1. Failure Mode

  1. Winding failure
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  1. Insulation failure
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  1. Tap changer failure
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  1. Bushing failure
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  1. Bushing manufacturer

  1. Date manufacture

  1. Bushing type

  1. Other – please explain

  1. Cause of failure

  1. Moisture
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  1. Partial Discharge
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  1. Voltage Transient
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  1. Through Fault
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  1. Other – please explain

  1. Station Bus configuration

  1. Straight bus
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  1. Ring bus
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  1. Breaker and a half
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  1. Double bus single breaker
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  1. Double bus double breaker
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  1. Other – please explain

Instrument Transformers

  1. Manufacturer

  1. Model

  1. Date of manufacture

  1. Type of instrument transformer

  1. Current transformer
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  1. Voltage transformer
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  1. CCVT
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  1. Wound
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  1. Failure Mode

  1. Winding failure
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  1. Insulation failure
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  1. Bushing failure
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  1. Bushing manufacturer

  1. Date manufacture

  1. Bushing type

  1. Other – please explain

  1. Cause of failure

  1. Moisture
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  1. High voltage capacitor degradation
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  1. Voltage transient
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  1. Loss of oil
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  1. Other – please explain

  1. Station Bus configuration

  1. Straight bus
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  1. Ring bus
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  1. Breaker and a half
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  1. Double bus single breaker
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  1. Double bus double breaker
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  1. Other – please explain

Circuit Breakers

  1. Manufacturer

  1. Model

  1. Date of manufacture

  1. Type of Circuit Breaker

  1. SF6 Single Pressure Puffer
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  1. SF6 Two Pressure
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  1. Oil Circuit Breaker
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  1. Air Blast Circuit Breaker
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  1. Vacuum
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  1. Other – please explain

  1. Failure mode

  1. Catastrophic type failure
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  1. i.e. – physical damage to high voltage and/or interrupter parts of the circuit breaker

  1. Bushing failure
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(1)Bushing manufacturer
(2)Date manufacture
(3)Bushing type
  1. Operational type failure
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  1. Fail to open
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  1. Fail to close
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  1. Slow to open
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  1. Slow to close
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  1. Fail to interrupt
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  1. Other – please explain

  1. Cause of failure

  1. Dielectric failure
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  1. Mechanism lubrication
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  1. Moisture
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  1. Contaminant
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  1. Other – please explain

  1. Station Bus configuration

  1. Straight bus
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  1. Ring bus
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  1. Breaker and a half
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  1. Double bus single breaker
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  1. Double bus double breaker
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  1. Other – please explain

Relays

  1. Manufacturer

  1. Model

  1. Date of manufacture

  1. Relay type

  1. Electromechanical
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  1. Solid state
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  1. Microprocessor
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  1. Type of failure

  1. Power supply
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  1. A/D
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  1. Failed contact
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  1. Failed directional element
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  1. High resistance contact
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  1. Other – please explain

  1. Cause of failure

  1. Heat
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  1. Age
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  1. Duty cycle
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  1. Mechanical binding
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  1. Other – please explain

Addendum for Events with Failed Station Equipment1