Experimental study on surge immunity of on-line monitoring device of high voltage circuit breaker

The selection of the electromagnetic compatibility (EMC) noise immunity experiment level requires all online monitoring devices operating in the power systems to pass the Level-3 anti-surge (impact) interference experiment. In this paper, the anti-surge (impact) interference experiment on the on-line monitoring device of high voltage circuit breaker was conducted while the experimental conditions were established according to the State EMC Standard. The structure of power supply of monitoring device was improved by adding EMC devices of metal oxide varistor (MOV) and transient voltage suppressor (TVS) to suppress the interference on the place which was easy to be interfered, and the effect of the place to adding TVS was analyzed, as the power supply was the main transmit way of the interference. In addition, the theoretical and simulating analyses were also conducted according to above method. The results show that, the improved online monitoring device could suppress the surge (impact) interference effectively and eventually pass the level-3 anti-surge-interference experiment.