Low Cost Transient Earth Voltage Probe for Partial Discharge Detection

Partial discharge (PD) that occurs in enclosed metal equipment such as air-insulated switchgear is unpredictable and causes the failure of an insulation system. This PD emits electromagnetic field and hence can be detected through a capacitive sensor mounted on the wall. Thus, it is suitable to detect and monitor internal PD activity in an enclosed metal equipment using Transient Earth Voltage (TEV) probe. Therefore, this study aims to implementing TEV probe which has been developed at a low cost to detect the partial discharge occurs in enclosed metal equipment. It involved the characterization of the parameter of the probe and also the measurement of TEV based on IEC TS 62478 standard. In addition, the spectral density and phase-resolved partial discharge pattern of the developed TEV probe were analyzed and compared with the commercial TEV. The time-resolved pattern of the partial discharge was also recorded to monitor the PD pulses in one full cycle. As a result, it was found the partial discharge was able to be detected through this developed TEV probe with acceptable PD patterns.