Detection and Localization of Partial Dsicharge in Air-Insulated Substations Using UHF Antenna Array

VHF-based partial discharge (PD) early warning technique has been tried to monitor and localize PD activities in the whole Air-Insulated Substation (AIS). This paper presents a PD detection and localization system based on this method. This system is composed of four-antenna array (double-cone strncture), signal conditioning unit (wide band filter, low-noise amplifier and band-stop filter) and high-speed acquisition unit. The main sources of background noise are analyzed and corresponding rejection methods are developed to reduce their effect. The probability-based localization algorithm which comprehensively consider the time differences of multiple signals are proposed to estimate the position of PD source. The developed system is applied to PD detection and location in substations, and the on-site results prove the effectiveness of the system.