Correlation between partial discharges and electrical treeing in low density polyethylene blended with organic additives

It is well known that there is a close relationship between electrical treeing and internal partial discharge. The purpose of the study is to characterize electrical treeing of insulators by analyzing the partial discharge characteristics. We carried out measurements of the electrical treeing characteristics, such as shape, length, and area of tree with voltage application time, and of the partial discharge characteristics, such as discharge magnitudes and number of discharge pulses in the sample, simultaneously. From the experimental results, we confirmed the following; 1) the shapes of trees are quite different depending on PD characteristics, that is, bush type were grown in the samples in which the magnitude and repetition rate of discharge were observed to be larger than those of branch type treed samples. 2) the magnitude of PD shows a good linear relation with the area of tree rather than the length of tree in the case of bush-like tree