Partial discharge detection by using combined VHF and AE sensors in XLPE power cables

Abstract

The purpose of this article is to troubleshoot and detection a partial discharge in cross-linked polyethylene (XLPE) cable by combining two very-high-frequency (VHF) and acoustic emission (AE) sensors, which is a novel approach to troubleshooting. The small size of these signals is the main problem in partial discharge (PD) measurements, which might cause the signal mix completely with noise and make troubleshooting difficult. Hence, attention has been paid to high bandwidth to eliminate disturbing noise. In this paper, Rogowski's coil is designed as a kind of VHF sensor for troubleshooting purposes. Then, it simulates and examines the characteristics of the partial discharge in the power cables that have been occurred due to the existence of a cavity. In the end, in order to prove the efficiency of the intended method, the actual partial discharge test was performed using the VHF and AE sensors. The combination of two VHF and AE sensors is capable of eliminating electrical interference and electromagnetic noise in the test site, as well as identifying different types of discharge, and providing a model for troubleshooting partial discharges in online and offline tests. In addition, due to the simple design and installation of the sensor in the equipment and have not to need to cut off equipment from the network, this method is economically very cost effective.