Evaluation of Electrical Insulation Properties of High Temperature Gas Heated by Inductively Coupled Thermal Plasma

The success or failure of interruption in a gas circuit breaker (GCB) is determined by a dielectric strength of high-temperature gas remaining between electrodes against a transient recovery voltage (TRV). To contribute for a high reliable interruption performance of SF6 gas alternative circuit breakers being developed, we have developed a unique method to evaluate the insulation characteristics of high temperature gas. This article presents a concept of a method for increasing the temperature of insulation gas using inductively coupled thermal plasma (ICTP). Then, the results of temperature estimation of high-temperature CO2 gas by a spectroscopy and dielectric breakdown test results are presented. Finally, by the electromagnetic thermofluid simulation, the gas temperature in the electrode space calculated is shown, and we suggest the applicability of the unique method for the reliable dielectric test of high temperature insulation gas.