Conditioning Characteristics of Vacuum Gaps under Different Breakdown Energy Adjusted by Parallel Capacitors

The objective of this paper is to investigate the conditioning characteristics of vacuum gaps under different breakdown energies in vacuum interrupters. This study proposes a method of controlling breakdown energy by combining a high-value current-limiting resistor and a parallel capacitor. The energy release in the discharge circuit during breakdown is simulated, and the impact of breakdown energy on the conditioning effect is experimentally investigated. The results indicate that, by connecting a high-value current-limiting resistor in series between the vacuum interrupter and the lightning impulse voltage generator (LIG), the energy released to the vacuum gap during breakdown is limited, with the breakdown energy primarily determined by the capacitor connected in parallel with the vacuum gap. Breakdown energy has a significant impact on the conditioning effect. In the experimental results of this study, smaller breakdown energy results in better conditioning effects. For a vacuum interrupter with a 1 mm gap distance, the maximum breakdown voltage at the conditioning saturation stage is about 80 kV under conventional lightning impulse voltage (LIV) conditioning. By using the energy controlled conditioning method proposed in this paper, this value can be increased to 110 kV.