Development of SF₆ Gas‐Insulated Disconnecting Switch with Spiral Electrodes Using Motor Operating Mechanism

Abstract

Gas-insulated switchgear (GIS) requires reliability and economic efficiency. Circuit breakers, disconnecting switches (DS), and earthing switches have been designed to be more compact. DS requires performance in terms of insulation and current interruption. The bus-transfer current is the highest among all current interruption requirements for the DS. To develop an alternating current DS driven at a lower speed, it is necessary to reduce the electrode damage. This paper describes the fundamental characteristics of current interruption in a magnetically driven arc using a spiral electrode. Since the arc is rotated by magnetically driven force, the arcing time in the spiral electrode is shortened to about one-third compared with that of a plain breaker electrode. The DS using a magnetically driven arc was confirmed to comply with the bus-transfer current switching requirements in the JEC standard. Moreover, a physical model of the magnetic driven arc was constructed, and the behavior of the arc was evaluated quantitatively. As a result, performance of current interruption could be predicted.