Abstract
Development of decision support tools for maintenance strategy of electric power equipment based on the asset management technique becomes very intensive in order to reduce maintenance cost due to the liberalization of power business. In these years many theses have been presented about asset management in this area, but there are not yet so many concrete researches. This article introduces two approaches of decision support tool development for power equipment in CRIEPI. One is to support evaluation of dissolved gas analysis for oil-immersed transformers. It provides comparison to data obtained from the same kind of transformers, and criteria among them. The other is to evaluate average annual maintenance cost by considering an overhaul effect and failure risk. It provides an optimum overhaul strategy with suitable parameters.