In recent years, the breakdown accidents of Oil filled cables (OF cables) are occurring across the country. In TEPCO breakdown accidents occurred in a 275kV terminal joint and in a 154kV cable. OF cables have high reliability, so it has been thought that it is not deteriorated unless it is used in operation voltages and over atmospheric pressure. The cause of two breakdown accidents was estimated electric charging degradation with the copper compound by the findings of the breakdown removal product. We devised electric charging degradation mechanism under the operation electric field from these phenomena. By this mechanism, copper of the conductor is eluted into insulating oil as a compound and is deposited in the specific place. Then the copper compound occurs a partial electric discharge and wakes up destruction before long. Even if OF cables are used under the operation electric field, there is a possibility that degradation is progressed by this mechanism.
J-STAGEがリニューアルされました！https://www.jstage.jst.go.jp/browse/-char/ja/
