A newly developed leakage current monitoring system for the assessment of insulator pollution severity

Surface pollution is one of the contributing factors of insulator flashovers at rated voltage. Therefore in order to prevent transmission line insulators from experiencing flashover, it is very important to investigate the leakage current monitoring system to assess the pollution severity of insulators. In this paper, a newly developed leakage current monitoring system with a microcomputer-controlled device for voltage application duration control and data acquisition recording is presented. By using this new monitoring system, the conductivity of the pollution layer and the leakage current on the insulator surface can be monitored continually, hence the pollution severity can be displayed, and when pollution severity is in excess of predetermined criterion a warning signal will be released. The design consideration for the new system and the criteria of assessing pollution severity are discussed, and some on-site test results are also given in this paper.