Propagation characteristics of partial discharge and noise for distribution-grade gas insulated switches

In this paper, the propagation characteristics of partial discharge (PD) pulse, including noises for the on-site diagnosis of distribution-grade gas-insulated ground switches, were analyzed. The types of pulse signals were PD generated inside the switchgear, external PD, and noise from the loads. Four switches connected with 22.9kV CNCV cables were prepared to find out the propagation characteristics of partial discharges. Internal and external partial discharge, including noise, were measured using HFCT and TEV sensors. Throughout this study, it is possible to realize on-site environment of partial discharge diagnosis for the switches and to analyze propagation characteristics of PD pulse and noise in gas-insulated switches with cables. These propagation characteristics were implemented in the PD Diagnostic Verification Center construction in KEPCO.