Experimental Investigation on Variations of Opening and Closing Operations of a Vacuum Circuit Breaker Driven by a Permanent Magnetic Actuator

Controlled switching of capacitive or inductive power loads, like capacitor banks, power transformers, shunt reactors, et al. could effecitively moderate the impact of switching transients on the power grid. However, the deviations of opening and closing operation of an electrical apparatus usually not only dependent on its inherent mechanical performance, but also on the ambient temperature, the idle time, and operating history. The objective of this study is to experimentally examine the deviations of a 40.5 kV vacuum circuit breaker (VCB) driven by a monostable permanent magnetic actuator (PMA). The opening time and closing time of the test VCB are recorded after each 1000 operations by 30 shots in a case of room temperature (293 K). The idle time, that is an interval between two adjacent operations, are set to examine its impact on the deviations of the test VCB. The idle time ranges from 1 min, 3 min, 5 min, 10 min, 30 min, 1 hour, 2 hours, to 3 hours. Moreover, the influence of the ambient temperature on the deviations of the opening and closing operations are investigated, which ranges from 253 K to 333 K and stepped by 10 K. Both the standard deivations and the maximum tolerances for the opening and closing operations are analyzed. The results contributes to the accurate controlled vacuum switching technologies.