Current Detection Methods of Partial Discharge for Distribution Network Switchgear

Abstract

There are many factors that can lead to partial discharge in the internal of switchgear. High-frequency current will be generated on the inner wall of switchgear when the electromagnetic wave generated by partial discharge reaches the enclosure of switchgear. In the same way, more complex current signal will be produced on the outer wall of the switchgear because of the electromagnetic radiation outside the enclosure. These two currents will flow to earth through the switchgear ground wire. We can determine whether the switchgear exist partial discharge and the severity of the partial discharge by comparing the current flowing through the outer wall and the total current flowing through the ground line.