Abstract
Gas insulated switchgear (GIS) have been demanded reliability and economical efficiency. Circuit breaker (CB), disconnecting switch (DS), and earthing switch (ES) have been designed toward compactness. DS is required the performance 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 with the low speed driven, it is necessary to reduce the electrode damage. This paper describes the fundamental characteristics of current interruption in the magnetically driven arc using spiral electrode. Since the arc is rotated by magnetically force, the arcing time with spiral electrode is shortened to about 1/3 compared with that of plain break electrode. The DS by magnetically driven arc was confirmed to comply with bus-transfer current switching requirements on JEC standard. Moreover, the physical model of the magnetic driven arc was constructed, and the behavior of the arc could be evaluated quantitatively. As a result, performance of current interruption became to be predictable.
