Development of Loop Current Interrupting Disconnecting Switch for Gas Insulated Switchgear

A magnetic driving type disconnecting switch has been developed which is capable of interrupting loop current in gas insulated switchgear (GIS). The disconnecting switch (DS) consists of a coil installed in the vicinity of electrode which produces a magnetic field of about 0.02 T/kA during interruption. The magnetic field rotates arcs, resulting in the enhancement of interruption. Thus, less dust is produced due to the melting of electrode materials, and consequently a withstand voltage after many loop current interruptions was improved compared with that of a conventional free burning type disconnecting switch.