The Application of Threshold Value of the Phase Angle in Surge Arester Online Test

By paying attention to the threshold value of the phase angle, an insulation defect of a 110kV Surge Arester has been detected by conducting online test. Based on the results of several kinds of tests and experiments, the cause of this insulation defect has been discovered and the preventive methods has been provided, which have a practical significance to the safe operation of surge arresters.The threshold value of the phase angle has been dramatically addressed.