Description of on-line detection technique on MOA leakage current

It is obvious that the state of Metal Oxide Arresters (MOA) on line have to be detected in order to prevent them from abnormal work, especially the resistive component of the continuous leakage current to be detected, which is a good indicator of the MOA condition. Several ways of monitoring the state of a MOA in service have caused some measurement error unexpected. The problem has been highlighted by worldwide researchers in the field because of its great value on both academic theory study and practical application. In this paper, some research results coming from the last documents in the field have been collected.