PROJECT TITLE :

Measurement of leakage current for monitoring the performance of outdoor insulators in polluted environments

ABSTRACT :

The measurement of leakage current is employed for monitoring the performance of insulators to minimize system outages owing to pollution [1]. The technique is applied to transmission lines exposed to severe and varying conditions of pollution [2]. According to the current technique, preventative maintenance is initiated when a critical level of current is reached on polluted insulators. However, the technique requires continuous supervision to analyze the condition of the monitored insulators. Vital variations in the severity of pollution between sites will be detected by measuring the leakage current. In some sites, the severity of pollution will cause high leakage current activity in a very short time, whereas in others, a extended time is required and monitoring at completely different sites is important to determine the best insulator profile for each web site. With the selection of the best insulator profile for every site, maintenance will be scheduled accordingly, thereby minimizing pollution flashover outages. Since 1995, the Mexican Electrical Analysis Institute (Instituto de Investigaciones El??ctricas), along with the Mexican electrical utility (Comision Federal de Electricidad), has had many comes for on-line measurement of leakage current that are applied to numerous designs of insulators in an try to minimize pollution flashovers on transmission lines [3]. To date, the Comision Federal de Electricidad has had 44 leakage current monitoring systems put in on several transmission lines [four].