Partial Discharge Monitoring Method in Switchgear with Bushing High-Voltage Sensor

10 kV and 35 kV switchgear are the key equipment in the power grid, and the safety of their insulation is related to the stability of the entire power grid. But the accuracy of the traditional partial discharge detection method is difficult to meet the detection requirements of the new SF6 insulated switchgear. This work analyzes the feasibility of using the high-voltage sensor in the bushing to detect partial discharge, and the analysis shows that the synchronous signal and the partial discharge signal can be obtained from the bushing sensor. Detection experiments were carried out using three typical partial discharge models, with both HFCT and a bushing sensor. The measurement results show that the bushing sensor can effectively detect the partial discharge in the switchgear and obtain a PRPD plot similar to HFCT. It is also found that adjusting the sampling resistance can change the partial discharge detection range of the bushing sensor.