Summary of Revision, IEEE C37.119-2016, Guide for

Breaker Failure Protection of Power Circuit Breakers

Kevin Donahoe – GE Grid Solutions

2018 Texas A&M Protective Relaying Conference

• Introduction

• Breaker Failure Minimal Current Scheme

• Current Differential Breaker Failure Protection

• Column Ground Protection

• Breaker Failure Protection for Generator Applications

• Redundant Control Circuits

• Conclusions

• Questions

Agenda

Introduction • Replaced C37.119-2005 • PSRC Working Group followed up with the paper “Summary

of Revision, IEEE C37.119-2016, Guide for Breaker Failure Protection of Power Circuit Breakers

• Definition of breaker failure protection (BFP) • 2005: This protection is specifically relied upon to take

appropriate action to clear a fault when the breaker that is normally expected to clear the fault fails to do so for any reason.

• 2016: A form of protection that is designed to detect the failure of a circuit breaker to operate or to interrupt a fault. Upon detection of a breaker failure during a fault condition the scheme is designed to take appropriate action to clear the fault. Upon detection of a breaker failure during a non-fault condition, the scheme may take other appropriate action.

Introduction

• Covered in C37.102, IEEE Guide for AC Generator Protection • BFP can fall in overlap between generation and transmission • Added clause increase familiarity with the unique

requirements for generator BFP • IEEE-Standards Association asked to expand the scope of

the C37-119 • Now includes performance failures of breakers other than

fault clearing failures • Failure to close during synchronizing is now covered

BF Minimal Current Scheme

• Breaker failure applications associated with high-impedance power system apparatus, such as generators, transformers, static var compensators (SVC), and harmonic filters, may have such low currents associated with internal faults that current detectors are not reliable.

• BF logic can also be achieved using breaker auxiliary switches

BF Minimal Current Scheme

Considerations

BF Minimal Current Scheme

BF Minimal Current Scheme

BF Minimal Current Scheme

• False BFI – one cause, accidental battery ground • Measures to reduce possibility of false BFI

• BFI input that responds only above half of the maximum battery voltage

• Binary inputs are compliant with IEC 60255-26, Measuring relays and protection equipment – Electromagnetic compatibility requirements with specific reference to Clause 7.2.7, Power frequency immunity on DC binary inputs

• Minimize cable run length and capacitance • Data communication-based means for conveying the BFI

between buildings

Current Differential BFP

• Accurate fault diagnosis • Extra installation and maintenance cost • Logical condition of adjacent operation of protection zones

Column Ground Protection

• CT column changes BFP

• No overlap • Most likely:

column to ground flashover

• CTs around the base of each column

• Direct trip of 86 • IEEE Std.

C37.234: Buses

BFP for Generator Applications

• Mechanical Indication of Breaker Status • CT Locations • Open Generator Breaker Flashover Protection • Breaker Arrangement: High-Side Breakers • Breaker Arrangement: Low-Side Breaker • Generator Breaker Failure to Close Protection

Mechanical Indication of Breaker Status

• Consider, in a motoring event, failure to separate from the power system can damage the prime mover

• A steam turbine has a typical motoring power range .5-3% • CTs sized for 5A at generator rating – current in milliamps • CTs on dual breakers, CTR may be based on bus rating • Current measurement is not reliable for all conditions

requiring BFP

CT Locations

• Even after the breakers open, the generator will feed a in-zone fault until stored energy in the field dissapates

• Never use generator neutral CTs • For low-side breaker location, not appropriate to use

generator terminals • CTs that measure the current flowing directly into the

breaker

Open Generator Breaker Flashover Protection

• Flashover most likely to occur just prior to synchronizing or just after the generator separates

Open Generator Breaker Flashover Protection

Breaker Arrangement: High-Side Breakers

Breaker Arrangement: High-Side Breakers

Breaker Arrangement: High-Side Breakers

Breaker Arrangement: Low-Side Breaker

• For Faults • Trip the generator CB G • Open the generator field breaker • Isolate the energy source that drives the prime mover

Generator BF to Close Protection

• Synchronizing systems minimize: • Speed difference or slip rate • Voltage difference • Angle difference

• Main contacts make at the instant when the angle difference is as near to zero as possible

• If breaker mechanism is slow then the generator rotor angle will pass zero and start increasing

• BFP could isolate the synchronizing breaker so that the generator closes into a dead bus

Generator BF to Close Protection

BFP on Redundant Control Circuits

Conclusions

• “Summary of Revision, IEEE C37.119-2016, Guide for Breaker Failure Protection of Power Circuit Breakers” is available at http://www.pes-psrc.org/kb/published/reports/Paper_SummaryofRevC37-119.pdf

• Go to pes-psrc.org • Go to Knowledge Base • Go to Reports • D subcommittee or search for 119

Thank You

Questions?