Gas-insulated electric apparatus and method of detecting partial discharge therein

摘要

In a gas-insulated electric apparatus, such as a gas-insulated switchgear and a gas-insulated bus, having an insulating-gas-filled metallic container or sheath within which an electric conductor carrying a high-voltage current is supported by an insulating supporter, a potential detected by a first potential detector through at least a portion of the insulating supporter and another potential detected as a reference value by a second potential detector through an electro-static capacity disposed between the metallic container and the second potential detector are fed to the inputs of a differential amplifier of a partial discharge detecting device to thereby detect possible partial discharges along the insulating supporter with high sensitivity.