Study on the comprehensive test technology of circuit breaker mechanical life and its accessories based on virtual instrument

Circuit breakers are widely used in power distribution systems. Accessories of circuit breaker expand and complement its function. Mechanical life test, operational reliability test, leakage module operation test, under voltage and shunt releases test, auxiliary and alarm contacts test are very important in the circuit breaker test. In this paper, it is detailedly described that the data acquisition and signal processing system developed with LabVIEW and controlled by industrial computer for circuit breaker test. The mechanical life test and operational reliability test with 24V/1A DC resistive load can be accomplished. The reliability of circuit breaker making and breaking can be judged by real-time detecting and processing the voltage between the contacts when contacts close and open. In the accessories test, industrial computer impels relevant hardware to generate test current or voltage, and then imposes on the circuit breaker and its accessories. Using high-speed data acquisition card, it measures relational electrical signal before and after putting on the test current or voltage. Through processing and analyzing, it can accurately determine the reliability of circuit breaker accessories action or breaker status indication.