High-Voltage on-Site Commissioning Tests for Gas-Insulated Substations Using UHF Partial Discharge Detection

This paper describes the practical application of the UHF Partial Discharge Detection method that VA TECH Reyrolle has routinely applied to high-voltage on-site commissioning tests on gas-insulated substations (GIS) for over 10 years. The location of the partial discharge (PD) sensors has a significant effect on the sensitivity of the UHF method. Research has been undertaken to quantify the parameters that affect this, i.e., attenuation, GIS geometry, etc. Verifying the correct operation of the detection system and its sensitivity is a crucial step in preparing for an HV test. In order to do this, special test equipment has been developed to ensure that all of the cabling, connections, etc. attached to the detection equipment are correct and the detection level of the couplers confirmed. The paper discusses IEC 60517 (general guidelines for GIS HV testing), its most usual interpretation, and how the application of the UHF technique can transform this interpretation.