抄録
The design of electric insulation is important for designing High-Tc superconducting DC cable (HTS DC cable). In HTS AC cable, it is known that liquid-nitrogen-impregnated laminated-paper-insulation is a promising insulation for superconducting cables. We thought that this insulation would be effective for the insulation of HTS DC cable. Therefore, DC breakdown tests, impulse breakdown tests and DC polarity reversal tests were carried out to obtain the fundamental properties of laminated-paper-insulation. The insulation of a 500kV HTS DC cable was designed by using design stresses decided from test results. Furthermore, a 100km HTS DC submarine cable suitable for 500kV-4, 000MVA was designed.