On the mechanism of electrical breakdown initiated by the treeing: measurement of the space charge field formed in an LDPE film

The authors investigated both the tree-initiation voltage and the length of the path generated in an LDPE (low-density polyethylene) specimen due to the electrical treeing under a needle-plane electrode system. They then measured both thermally stimulated current (TSC) and thermally stimulated surface potential (TSSP) generated in an LDPE specimen, which is biased by the application of either DC or AC voltage. The authors also investigated the mechanism of electrical breakdown initiated by the treeing by studying the relationship between the tree-initiation voltage determined by the experiment and the space charge field determined by the thermally stimulated electrical measurements. It was concluded that the distance between the centroid of the space charge formed in an LDPE film and the tip of the needle electrode was approximately the same as the length of the path generated by the electrical treeing.<
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