18 / 2024-03-26 14:52:31

Investigation on Dispersion of Breakdown Voltage for Double Vacuum Gaps in Series under Lightning Impulse Voltage

Breakdown voltage,Dispersion,Sphere-plane electrodes,Lightning impulse voltage,Double vacuum gaps in series

With the development of high-voltage vacuum circuit breakers, the multiple floating shields are used in vacuum interrupters. The insulation performance of the shield gaps needs to be evaluated during insulation design in the vacuum interrupters. And the shield gaps can be regarded as multiple vacuum gaps in series. The objective of this paper is to investigate the dispersion of breakdown (BD) voltage for the multiple vacuum gaps in series under lightning impulse voltages. In the experiments, the double and triple vacuum gaps were achieved by series-connected pairs of sphere-plane electrodes vertically. The material of the electrodes was Cu. The total gap distance of multiple gaps ranged from 1.0 – 18.0 mm. Both positive and negative lightning impulse voltages were applied by an up-down method to test the BD voltage. The dispersions of BD voltage for single, double and triple vacuum gaps were determined and comparatively analyzed. The experimental researches can help to further understand the BD characteristics of multiple floating shields in vacuum interrupters.

The experimental results will be presented in the full paper.