Experimental study of the online monitoring of the mechanical characteristics of a hydraulic high-voltage circuit breaker

Online monitoring of primary equipment such as circuit breakers is widely used in smart substations. By analyzing the data acquired from online monitoring systems, the circuit-breaker status can be monitored, and the health of the breaker can be determined comprehensively. Using an online monitoring system, tests were carried out to measure the mechanical characteristics of a hydraulic high-voltage circuit breaker. Opening and closing coil current curves and distance curves were experimentally obtained by applying 0, 10, 20, and 50 kA of instantaneous load current. The main eigenvalues of the mechanical characteristics were calculated using the online monitoring system. Al though varying the load current does not impact the motor or circuit-breaker closing performance, the experimental results show that large load currents will impede breaker opening, a phenomenon that had not been reported prior to the online monitoring tests described here.