Study on inspection of high voltage cable in railway line

East Japan Railway Company supplies electricity to substations, distribution stations, and various types of equipment through high-voltage distribution lines and cables. Our company has 5,000 km of high-voltage cables, which account for 60% of the total high-voltage distribution network. If there is an accident to a high-voltage cable, this may cut off signal equipment and station equipment, which will affect train operation. Since many high-voltage cables supply electric power to important facilities required for railway operation, these cables need to be properly managed. In this research, we focused on the partial discharge generated in high voltage cables and examined the inspection method for high voltage cables.