Experimental investigation on the matching characteristics of vacuum circuit breaker with double-break

In the paper, the prototype of vacuum circuit breaker with double-breaker was set up. In order to find the matching characteristics of VCB with double-break by means of breaking test, the matching characteristics test includes different vacuum gaps, different type electrodes and different grading capacitors. The optimal combination of AMF and TMF type electrodes was gained by comparing with the breaking capacity and voltage distribution of the four combinations. The breaking capacity of double-break VCB with AMF and TMF type electrodes in series while the AMF interrupter is in lower side is largest because the voltage distribution is most even caused by the different equivalent capacitance of different interrupters. The optimal matching vacuum gaps of the best combination were got by matching characteristics test of different vacuum gaps. The combination of maximum breaking capacity was series AMF type electrodes with suitable grading capacitors. According to the voltage distribution and breaking capacity, the appropriate range of grading capacitors is from 500pF to 2000pF. Moreover, the influence of grading capacitors was discussed by detecting the current of grading capacitors. The research was useful to series VCBs witch replacing SF6 circuit breaker to apply in high voltage level.