Experimental Investigation Into the Synergy of Vacuum Circuit Breaker With Double-Break

In order to find the synergy of double-break vacuum circuit breakers (VCBs), we conducted a synthetic test including different vacuum gaps, different type electrodes, and different grading capacitors. The double-break VCBs are composed of Axial Magnetic Field (AMF) and Transverse Magnetic Field (TMF) contact VCBs, which can constitute four combinations. The optimal combination of AMF and TMF type electrodes was obtained 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 on the lower side is largest because the voltage distribution is the most even which is caused by the different equivalent capacitances of different interrupters. The optimal matching vacuum gaps of the best combination were obtained by a synthetic test of different vacuum gaps, which may make the grading capacitors of double-break VCBs small, even obsolete. The combination of maximum breaking capacity was series AMF type interrupters with suitable grading capacitors of 500-2000 pF. The experimental results provide the best combination and matching control mode for VCBs with double-break.