The influence of electrode material on delayed discharges in vacuum interrupters

In this paper, the influence of contact materials on late discharges in vac uum switching devices was investigated. Experimental results show that the HV withstand capability of contact materials has a strong influence on the frequency of late discharges in vacuum switching devices. The addition of a small amount of W and Co into the CuCr alloy increases the voltage withsta nd significantly, resulting in a reduction of the frequency of late dischar ges by as much as 50%. Therefore, an efficient approach to decrease the fre quency of late discharges is to increase the Hv withstand of the contact ma terials.