Study on the E-t Characteristics of GFRP for a High-Voltage Superconducting Apparatus

Power consumption has been increasing in industrial society [1]. The application of a superconducting apparatus is considered one of the most promising countermeasures against the increased power consumption. Additionally, the rated voltage of the superconducting apparatus has been being uprated to minimize the power loss. In order to ensure the electrical safety of a high-voltage superconducting apparatus, the dielectric design of solid insulation materials used in the high-voltage superconducting apparatus should be performed considering the aging characteristics. In this study, we examine the E-t characteristics of glass fiber reinforced plastic (GFRP), known to be one of the best solid insulation materials for cryogenic conditions [2]. Specifically, the E-t characteristics of GFRP according to its electric field uniformity are tested and analyzed to ensure the reliability of long-term operation. All the experiments are conducted in liquid nitrogen (LN2) to suppress the occurrence of creepage discharge and to promote the occurrence of electrical breakdown [3]. The experiments on the E-t characteristics of GFRP are performed with four kinds of sphere-plane electrode systems manufactured using stainless steel. The electric field uniformity and its relationship with electrical breakdown are analyzed using a finite element method, and the experimental results are analyzed using the Weibull distribution.