Breakdown Voltage Fluctuation and Breakdown Path Dispersion in a Hybrid Gas-Solid Insulation System Under Alternating Voltages

Abstract

Breakdown voltage of hybrid gas-solid insulation system may greatly fluctuate due to the complex discharge processes, and the relationship between the breakdown voltage and the breakdown path is not clear. This paper studies the fluctuation of the breakdown voltage and the dispersion of the breakdown path. The results indicate that when the barrier is close to the high-voltage electrode, the breakdown voltage fluctuation is significant, and the significance rises with the increase of the barrier size. The breakdown paths are divided into two types, the probabilities of which are related to the barrier position, and the average breakdown voltages of the two path types are approximate. Under 50 Hz alternating voltage, residual charges have a significant effect on the direction of the breakdown path and have little effect on the breakdown voltage. The breakdown voltage fluctuates significantly when the breakdown path is long. It is found that the low atmospheric absolute humidity is another reason for the breakdown voltage fluctuation.