Application of On-Line Partial Discharge Detection Technology in Switchgear Based on Bushing Sensors

Medium Voltage (MV) switchgear is widely used in power transmission and distribution as an important component of the power system. Partial Discharge (PD) detection is an effective means of diagnosing insulation faults within switchgear to ensure its stable operation. In this paper, the SGPD-01 handheld device is developed based on the intrinsic bushing sensors in switchgear. It can non-invasively couple PD signals on the high-voltage side through the live indicator, overcoming the shielding effect of the multi-layer metal structure of the cabinet on the signal and greatly improving the accuracy of PD detection. In addition, the device can also support the construction of accurate three-phase PhaseResolved Partial Discharge (PRPD) and the clustering analysis of pulses, achieving phase determination of insulation defects and noise identification. A large number of field cases show that compared with traditional detection methods, the on-line PD detection technology based on bushing sensors can achieve accurate evaluation of internal insulation faults in switchgear.