Experimental Study on the Electrical Degradation Characteristics of 2G HTS Conductors according to Amplitude of Applied Voltage

2G High temperature superconducting (HTS) GdBCO conductors are usually considered as proper superconductors to develop a superconducting fault current limiter and a superconducting cable which are operated in a high voltage condition. 2G HTS GdBCO conductors manufactured by SuNAM Co., Ltd. can be classified by a metal stabilizer: silver, copper, brass, and stainless steel. In previous study, the electrical performance of 2G HTS GdBCO conductors with copper stabilizer according to electrical breakdown voltage is reported. In this study, dielectric experiments are performed in saturated liquid nitrogen (LN₂) at 77K temperature to analyze the characteristics of electrical degradation such as critical current and index number of 2G HTS GdBCO conductors with copper and brass stabilizer according to amplitude of applied voltage. All dielectric experiments are performed with AC and lightning impulse voltages by using a sphere-to-plane electrode system. It is found that the electrical performance of 2G HTS GdBCO conductors is degraded according to the amplitude of applied voltage.