Influence of Voltage Frequency and Filler Content on Breakdown Characteristics of Epoxy Resin

Epoxy resins have great potential for insulation of power electronic transformers due to their high dielectric properties and strong corrosion resistance. In the long-term operation of power equipment, epoxy resin will undergo insulation aging, and electrical treeing is the main way of its insulation aging, and electrical trees will gradually develop to complete breakdown. In practice, epoxy resins with fillers are often used as insulating materials. In order to study the breakdown characteristics of epoxy resin/Al
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composites, a experimental platform for measuring the breakdown voltage of epoxy resin composites was established in this paper, and the effects of frequency and filler content on the breakdown properties of epoxy resin/ Al
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composites under 50-2000Hz AC voltage were investigated. The results show that with the increase of frequency, the breakdown voltage decreases gradually, and the breakdown voltage has a threshold value; the breakdown voltage of composites shows a trend of first increasing and then decreasing with the increase of filler content.