Defect Analysis and Process Improvement of Metal-Oxide Arrester

Abstract

Metal-Oxide Arresters are important equipment to ensure the reliable operation of power systems. An experimental protocol for judging the nature of MOA defects accurately is introduced in this paper and applied to engineering practice. Through diagnostic tests and dismantling inspections, it is determined that a certain batch of 110kV line MOA has a familial defect of poor sealing. Then, the reasons for dampness are analyzed, and other defects except the dampness of the varistor are discovered. Besides, the improvement of manufacturing process is proposed from aspects of terminal structure and the coating material on the side of varistor;the actual data proves that adding fillers such as quartz sand or silica gel inside the MOA can reduce the failure rate effectively. This article provides a certain technical reference for the manufacture and defect disposal of MOAs.