Partial discharge characteristics of electrical trees in XLPE power cables

Abstract

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.

Review of condition monitoring and defect inspection methods for composited cable terminals

“… Partial discharge monitoring for high‐voltage cable joints based on the ultra‐high frequency (UHF) method [31]. …”

“…Meanwhile, the local discharge detection method can detect degradation states, such as electric dendrites and thermal oxygen ageing. L. Zhou et al [31] investigated the local discharge characteristics and the growth of electrical dendrite when local air pressure acted on the electrical dendrite channel at different temperatures by considering the effect of local air pressure on the electrical dendrite initiation and growth characteristics of XLPE cables under different operating conditions. It was found that the electrical dendrite can easily penetrate the cable insulation under high temperatures and high abrasion conditions.…”