Mechanical Fault Diagnosis of Vacuum Circuit Breaker Based on Opening and Closing Current

The mechanical characteristic parameters of circuit breakers (CB) directly affect the operating performance and equipment life of CB, and play a crucial role in the regular operation of power systems. This paper proposes a vacuum circuit breakers (VCB) fault diagnosis method based on the Savitzky-Golay (S-G) filtering processing of coil current. First, S-G filtering processing is performed on the coil current data of a 12kV VCB. Then, the mechanical characteristic feature parameters of the processed data are extracted using the extreme point detection method of threshold condition and neighborhood comparison. Finally, through the comparative analysis of 200 times VCB opening and closing experimental data, the changes of parameters under several states of faults are summarized in the reference table of VCB fault diagnosis. On the basis of the instantiated parameters, it was introduced to quickly diagnose the fault types of different models of VCB. The results show that this method can accurately and quickly diagnose the overvoltage, undervoltage and turn-to-turn short circuit faults of VCB, and the fault diagnosis reference table obtained can reduce the pressure of operation and maintenance for the staff, which has high practical value.