Insulation Fault Diagnosis of Circuit Breakers Based on Waveform Characteristics of Radiated Electric Field Due to Switching Operation

In a gas-insulated substation(GIS), excessive switching operations of a circuit breaker (CB) could result in insulation fault. In order to detect the insulation fault of a CB, a novel monitoring method was proposed in this study. Taking a CB in the GIS as the research object, a synthetic test platform was established to measure the transient electric field pulses generated by the opening operations of the CB. Further, typical waveforms of the electric field pulses excited by switching operation of the same CB in healthy state were obtained. Experimental results show that CB insulation fault can be detected by analyzing waveform feature of the electric field pulses.