Research and Application of the Threshold Judgment Method for 110kV Metal-oxide Surge Arresters

This paper provides an overview of the domestic and international development of energized test technology for Metal-oxide Surge Arresters (MOSAs) while highlighting the existing problems. To address these issues, the authors propose a threshold judgment method based on phase angle and resistive current analysis of live-testing results, especially for 110kV MOSAs. The proposed method has been validated through the analysis of a large amount of live detection data collected over the past decade. This paper thoroughly introduces a moisture defect of 110kV MOSA discovered through the use of the threshold judgment method. The conclusions drawn from the study are presented, along with proposed effective measures for the short-comings in the MOSA live detection technology and subsequent improvement approaches of the threshold judgment method.