Electrical insulation performance under thermal and electrical combined stress for resistive fault current limiters

This paper discusses the electrical insulation performance of resistive superconducting fault current limiters (SFCL) under quench condition exposed to thermal and electrical combined stress. Electrical stress of 50 Hz ac was applied to parallel ring electrodes molded with epoxy resin. Thermal stress simulating the quench of the resistive SFCL was, simultaneously applied to the ring electrode by an electromagnetic induction current. Experimental results revealed that breakdown (BD) or precursory partial discharge (PD) could be induced under such combined stress. A criterion for determining electrical insulation design of the resistive SFCL was proposed as a function of temperature of the ring electrode.