A Practical Approach to Benchmark the Relationships between On-Line Measurement Versus Off-Line IEC60270 Measurement for Singapore Distribution Network Switchgear

Non-intrusive partial discharge (PD) measurements are critical for power utilities to detect asset anomaly without interrupting the supply grid network security. In SP Group (SP) medium voltage network, three core XLPE insulated power cables are connecting the gas-insulated switchgears (GIS) between different substations. Each phase of cable core of the GIS is accessible from cable basement. It provides condition monitoring engineers the means to clamp high frequency current transformer (HFCT), for investigation and confirmation of PD defects. HFCT with ultra-wide band measurement is of non-conventional PD detection in high frequency (HF) range as per IEC62478 Standards. It does not directly quantify the apparent charge of PD current pulses, i.e. not possible to be calibrated in pico Coulombs (pC) [1] .