An optimal online monitoring scheme for lightening arresters based on the three-phase imbalance of leakage current

The online monitoring data of lightning arresters are susceptible to environmental temperature， humidity， and surface contaminants. However， conventional alarm threshold setting approaches for leakage current may result in false alarms. To address this issue， this paper proposes an online monitoring alarm algorithm for arresters based on the trend comparison of three-phase data. This algorithm utilizes a temperature and humidity suppression algorithm to mitigate their influence on the resistive current. It calculates the imbalance coefficients of the three-phase resistive current based on the corrected resistive current data and formulates alarm rules by combining them with the alarm thresholds of the resistive current. The algorithm is validated using lightning arresters in a 220 kV substation. Compared to the original single alarm rule， this alarm strategy effectively reduces the false alarm rate and improves the accuracy and practicality of online monitoring alarms.