Radiometric Timing of High-Voltage Circuit-Breaker Opening Operations

This paper demonstrates the feasibility of radiometric on-line circuit breaker timing. The timing test is crucial and can reveal a wide range of faults or defects. The work presented concentrates on the timing of gas-insulated substation (GIS) circuit breakers, which due to their enclosed nature pose a variety of challenges not encountered in air insulated substations (AIS). It is demonstrated how key events in the arcing process such as arc ignition and extinctions can be identified from the emitted electromagnetic pulses and how this information can be used to assess the integrity of the circuit breaker being monitored. The results are backed by site measurements of a high voltage reactor switching SF₆ double pole puffer breaker. The proposed technique can readily be extended to monitor closing operations as well as being adapted to monitor other types of circuit breakers.