Partial discharge characteristics of electrical trees in XLPE power cables

This paper studies the initiation process and the PD characteristics of electrical trees, and proposes a new method to recognize the growth state of electrical trees. The experiment result show that the electrical trees PD energy mainly concentrated in the -40°~90° and 120°~250° of 5MHz~7.5MHz, -20°~90° and 150~250° of 7.5MHz~10MHz. With the dense increase of the electrical trees, the more PD energy will be found in the frequency 7.5MHz~10MHz. At the first development stage of electrical trees, the PD energy mainly located at the frequency 5MHz~7.5MHz, when electrical trees develop to the next stage, the more PD energy will be found at the frequency 7.5MHz~10MHz.