Development of the automatic multiple-circuit switch

The Tokyo Electric Power Company (TEPCO) is now introducing a distribution automation system that uses a distribution line carrier system (the ground return system) with the intention of improving power supply reliability. To reduce equipment size in this system, the authors worked specifically on minimizing the mechanism of a switch and a remote control device, cutting down power transformer capacity and effectively using the space inside the substation door. These efforts have been led to the development of an automatic multiple-circuit switch that is small and that can be controlled at a remote location. A remote control device, a power transformer for the remote control device, a source voltage sensor, a coupling capacitor, and a five-circuit air-break switch are built into this automatic multiple-circuit switch. Its outer dimensions, however, are remarkably small; 1.100 mm (width)×1,450 mm (height)×450 mm (depth). Another feature of this switch is that its movable electrodes are detachable in an open state. This allows grounding or testing devices to be mounted easily, and it also contributes to easy and efficient maintenance operations