691 / 2022-03-31 15:34:34

A novel PD location technique for MV switchgears based on time of flight method

partial discharge, MV switchgear, time of flight, localization

Insulation faults on medium voltage (MV) switchgears can lead to power outages, disrupting daily domestic activities and economies. An acknowledged solution is to conduct partial discharge (PD) evaluation of MV switchgears. However, the existed PD measurement instruments difficultly identify the exact PD-affected switchgear in a row of switchgears, causing their PD evaluation laborious and time-consuming. Therefore, this paper develops a novel PD location technique for MV switchgears. The technique is based on the time of flight (TOF) method, which detects the orientation of PD source by identifying the difference of time of arrival (DTOA) between the PD signals arriving at the two enabled sensors. A time-sharing mechanism is proposed to ensure the TOF method to be available for multiple sensors and simultaneously minimize the number of expensive high-speed acquisition chips. Wiener filter is used to calculate the DTOA from time domain waveforms of the detected PD pulses. The efficiency of the proposed technique was validated in three 10 kV metal-clad switchgears in laboratory.