Digest report of the investigation committee on degradation diagnosis technology based on characteristics of insulation materials in electric power apparatus

30 to 40 years have passed since cables and electric power apparatus were installed in the high-growth period of the Japanese economy, a lot of them have reached their design lifetimes and the time replace. On the other hand, it is requested because of the cost reduction in the operation of the power equipment that the degradation of these electric power apparatus is understood and the loss due to the breakdown is prevented beforehand. Moreover, it is strongly requested to use the electric power apparatus for the life limit.