Abstract
Shunt reactors installed at GIS-substations are switched relatively frequently by large capacity gas circuit breakers (GCB's). Surge voltages appear at such switching operations through various mechanisms. Among them, high frequency current interruption and subsequent multiple reignition might cause highest overvoltage and may be harmful to the insulation of the components of the substation.
In this paper, shunt reactor current interrupting tests are conducted in high power laboratory. Existence of critical arcing time above which reignitions never occur is shown through these tests. From this fact, phase-angle-controlled-interruption system is proposed. With this system, arcing time is artificially set so that reignitions should be prevented. Reliability of this system is confirmed through reactor current interrupting test in the laboratory as well. After that, phase-angle-controlled-interruption system is applied to the shunt reactor switching at actual 275kV substation. Switching performance of this system is measured over three months. Reignition-free interruption is shown to be attained with this system.
