The Influence of Parallel Multigap Rod Electrodes on the Breakdown Probability Distribution

Increasing the capacity and operating voltage of an electrical equipment commonly also requires increasing its dimensions. The geometrical change of the electrical equipment parts will influence the distribution of the electric field and the probability distribution of the breakdown voltage. Based on Ohm's Law, increasing the dimensions between two line-conductors can reduce the insulation strength between the two conductors. In this paper, an observation is focused on the dimensional change of parallel rod-electrodes arrangement in the air dielectric. The dimensional change is realized through the variations of the rod-electrodes number. Variations of one pair up to five pairs of rod electrodes are studied with the air gap between the electrodes of 1.5 cm, the diameter of 1.5 cm and the distance between the parallel electrode-pairs of 1.25 cm. The result of the research show that increasing the number of pairs of rod electrodes in parallel shifts the graph of the distribution function or cumulative probability of breakdown voltage, indicating the importance of considering the geometrical enlargement aspect in designing electrical equipment.