Partial discharge detection approach for a medium voltage switchgear system

Abstract

Partial Discharge detection techniques strive to ensure a safe and reliable power network by preventing power failure. In this work, electromagnetic sensing of partial discharge, in air-insulated medium voltage switchgear (Type D24-121114 of Driescher) is considered. The partial discharges are approximated by Gaussian sources. A versatile broadband sensor for detecting two major types of partial discharge was designed and optimized. The antenna has low return loss and high gain over the frequency band of corona discharge, 0.75-0.9 GHz and dry band arcing, 1.25-1.4 GHz. The horn antenna is incorporated into the medium voltage switchgear for detecting partial discharges. The analysis of the electromagnetic field distributions generated by partial discharges in switchgear is coupled with the sensing e±ciency of the horn antenna. The results indicate a good correlation between the intensity, location and frequency band of partial discharge and their sensing. This study provides the foundation for a dual band detection system of partial discharge in switchgear systems.