Recent progress and future perspective on condition monitoring and diagnostic techniques for power equipment in Japan

In this paper, recent progress in condition-monitoring and diagnostic techniques for power equipment in Japan is reviewed and discussed with a future technical perspective. In particular, the dissolved gas-in-oil analysis (DGA) technique for power transformers and the UHF partial discharge detection technique for gas insulated systems are introduced in order to both enhance measurement reliability and optimize total cost, as effective methods for maintaining the equipment. Moreover, the combined and systematized application techniques are explained and discussed, together with fundamental research on partial discharge mechanisms from the viewpoint of diagnosis evaluation criteria.