Study of High Current Interruption by Disconnector and by Earthing Switch in GIS

Abstract

After the study of phenomena and condition on both loop current interruption by disconnector (DS) and magnetic induced current interruption by earthing switch (ES), the optimum interruption methods were researched. The conclusions are summarized.
(1) Since the arc is rotated at the high speed in magnetic driving type interrupting chamber, loop current in GIS is interrupted by this type chamber with approximately 1/3 shorter arcing time comparing with that by free burning type interrupting chamber. Therefore, even after 200 time loop current interruption, insulation performance on insulator was not deteriorated. Magnetic driving type interrupting chamber is most appropriate for DS with loop current interrupting duty due to the small driving energy required.
(2) The most effective configuration, including the number of coil turn, was found for the magnetic driving type chamber of full scale disconnector.
(3) The suction type interrupting chamber which can produce gas flow with small-sized chamber and low driving energy is most suitable for magnetic induced current interruption of ES. The interruption performance of magnetic induced current in 550 kV 12, 000 A transmission line was confirmed on practical opening speed.