Programs at MERALCO to Improve Reliability by Assessing Performance of Different Insulator and Arrester Technologies

摘要

Insulator contamination and arrester failures are two of MERALCO's major causes of interruptions in its distribution system. With the impending deregulation of the electric industry and thrust on power quality, MERALCO have been investigating and searching for solutions to these two reliability problems. In looking for a countermeasure(s) against insulator contamination, different types of insulators were installed at various locations to evaluate which type of insulator can be used in heavily contaminated areas. Another project was initiated wherein pin insulators were installed at various locations to measure the contamination level within the franchise area. The objective of this project is to develop a pollution index map of the franchise area. With the pollution index map, the designer will be aided in deciding when to use construction standard for regular installation and the other standard for heavily contaminated areas. The main concern on failures of porcelain-housed arresters is its violent failure. To address this problem, a new type of arrester with polymer housing has been developed. Since polymer materials are flexible and elastic, the violent explosions which are common to porcelain can be prevented. Aside from having a safe mode-of-failure, the use of polymer-housed arresters has the potential of minimizing arrester failures due to two major causes: moisture ingress and contamination. In spite of the potential advantages of polymer-housed arresters, polymers are subjected to ageing due to environmental factors. In order to verify the performance of polymer-housed arresters in our environment, MERALCO conducted a trial installation starting in 1993 on these type of arresters.