Abstract：To explore the vibration characteristics of mechanical loosening faults in generator circuit breakers, this paper constructs a model using the three-dimensional finite element method. It simulates and analyzes the vibration responses under normal and typical mechanical loosening faults (threaded connections loosening, pin shafts disengagement), and verifies the results by comparing them with actual measurement data. The results show that under different operating conditions, the natural frequencies of the circuit breaker are densely distributed, with the first 100 orders all within 100 Hz; loose threaded connections and loose pin shafts, as local abnormalities, have no significant impact on the natural frequencies and mode shapes of most modes, but only change some orders (or local) modes or generate new modes; the acceleration response trend under abnormal conditions is basically consistent with that under normal conditions, however, the acceleration value at 590 Hz increases significantly under the condition of loose threaded connections, and some peaks shift under the condition of loose pin shafts. The results of this study can provide a theoretical basis and reference for vibration monitoring, fault diagnosis, operation and maintenance during the operation of the equipment.
2025, Vol. 26 
