Effect of partial discharges on impregnated polypropylene films

The effect of partial discharges in benzyltoluene upon impregnated polypropylene films has been studied in a sphere/plane electrode geometry. It is shown that discharges even with a small apparent charge (/spl sim/1 pC) cause a significant decrease of the breakdown strength of the film. The addition of an epoxy compound to the liquid notably reduces the film degradation characterized by the breakdown voltage, in spite of the increase of the repetition rate and apparent charge of the discharges.<
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