On line monitoring of bushings on large power transformers

Abstract

Industry statistics suggest that 80% of all plant and equipment failures occur on a random basis and only 20% of the failures are age related. This means that 80% of failures have not been detected with common test and maintenance practices and therefore these failures have not been prevented. Based on different sources up to 30-35% of large power transformer failures are attributed to bushing insulation failures. About half of these bushing failures result in an explosion and fire. In today's competitive environment, increasing demands are being placed on the management of physical assets. Advances in technology are allowing new approaches to maintenance. These include reliability-centered maintenance, predictive maintenance, condition monitoring, and expert systems. Trend setting organizations are increasingly taking advantage of the convergence of these new technologies to implement proactive maintenance programs