A Study on the Body Insulators for the Bushing for HTS Devices at Cryogenic Temperature

A bushing for high temperature superconducting devices (HTS bushing) is important because of applying high voltage to the cable or the winding of the transformer. It is cooled with liquid nitrogen (LN2) and is insulated with various insulators. For the development of the HTS bushing, it is necessary to know the fundamental characteristics of various insulators at cryogenic temperature.The electrical characteristics of the breakdown were studied under AC and impulse voltages. Also, the mechanical characteristics such as tensile strength in air and LN2 were studied. It was confirmed that GFRP is excellent not only electrical characteristics but also mechanical characteristics in LN2.