High voltage insulation performance of cryogenic liquids for superconducting power apparatus

This paper describes high voltage insulation technology of cryogenic liquids for superconducting power apparatus. The insulation of a superconducting transformer is classified into several insulation components. Moreover, we investigate fundamental insulation characteristics peculiar to the superconducting and cryogenic circumstances: area and volume effects on breakdown strength, V-t characteristics, quench-induced dynamic breakdown characteristics and so on. Finally, we systematize the electrical insulation of cryogenic liquids, and propose the flow chart for the practical insulation design of superconducting power apparatus.