PD Detecting during the Growth of Electrical Trees in HV XLPE Cable

Online observing the growth of electrical trees in XLPE cable section and monitoring its PD characteristics have been conducted. With different voltage levels, the electrical trees had different characteristics of growth. Secondary voltage applied promoted the growth of bush-like electrical trees. The PD data during the growth of electrical trees had been analyzed and found that the trends of the magnitude and times of PD in a frequency cycle with time are similar to the growth of bush-like electrical trees, which can be used to evaluate the degree of development of electrical trees in XLPE insulation, especially for HV and EHV cables.