Dependence of Spark Conditioning on Breakdown Charge and Electrode Material under a Non-Uniform Electric Field in Vacuum

作者：Kojima H^*; Takahashi T; Hayakawa N; Hasegawa K; Saito H; Sakaki M

来源：IEEE Transactions on Dielectrics and Electrical Insulation, 2016, 23(5): 3224-3230.

DOI：10.1109/TDEI.2016.005989

• Vacuum discharge
• conditioning
• non-uniform electric field
• vacuum circuit breakers
• breakdown

Spark conditioning is an effective method for improving dielectric strength in vacuum. In this paper, we discuss the dependence of spark conditioning on breakdown (BD) charge and electrode material in vacuum under various non-uniform electric field and circuit parameters. We applied a negative impulse voltage to a rod-plane electrode configuration with a cathode made of stainless steel (SS), Cu-Cr, or OFHC Cu (Cu), and an anode made of SS or Cu. We changed the gap distance, the tip radius of the rod electrode and the circuit parameters. As a result, the conditioning effect, i.e. improving BD electric field strength by the conditioning, depended on the BD charge (Q(ED)) and reached its maximum value against Q(ED). The optimal Q(ED) required to achieve the maximum conditioning effect decreased with the cathode melting point. Moreover, when BD caused by cathode heating (CH-BD) occurred readily, with the SS anode, the BD electric field strength at the cathode surface after conditioning depended on Q(ED), regardless of the gap distance and the tip radius. Thus, for CH-BD, we estimated the withstand voltage that could be achieved by spark conditioning from the electrode configuration and Q(ED). However, when BD caused by anode heating (AH-BD) occurred easily with the Cu anode, the optimal Q(ED) was larger than that for CH-BD because the cathode temperature was lower for AH-BD than for CH-BD.

• 出版日期2016-10