Electrical Insulation Design and Experimental Results of a High-Temperature Superconducting Cable

A 22.9 kV/50 MVA class high-temperature superconducting (HTS) power cable system was developed in Korea. For the optimization of electrical insulation design for HTS cable, it is necessary to investigate the ac and impulse breakdown and partial discharge inception stress of the liquid nitrogen (LN₂)/ laminated polypropylene paper (LPP) composite insulation system. These results were used to insulation design of the model cable for a 22.9 kV class HTS power cable and the model cable was manufactured. The insulation test of the manufactured model cable was evaluated in various conditions and was satisfied standard technical specification in Korea. Based on these experimental data, the single-phase and three-phase HTS cable of a prototype were manufactured and verified.