Detection and Analysis of Arrest Partial Discharge in Switchgear Based on Transient Earth Voltage Detection Technology

In order to improve the safe and reliable operation of arrester inside the switchgear, the full current and resistive current of arrester is used as the judgment method for the evaluation of operation status, but this method exist the one sidedness. In addition, there exist many reasons for the partial discharge in arrester such as the insulation defect, insulation aging, lack of insulation gap and so on, so the partial discharge live testing is important for the evaluation of arrester operation status. The generation and principle of transient earth voltage are analyzed, give out the location method, selection of testing points and judgment method. The partial discharge source are judged though the comparison method, curve analysis method, reference experience criterion and trend analysis method based on the partial discharge defect cases of arrester. Through the site disintegration inspection of arrester, the partial discharge in switchgear is a hole discharge, which it is caused by the loose valve plate. So it can provide a important application basis for condition-based maintenance.