A 275 kV 3 kA high temperature superconducting cable (HTS cable), which could be used as a backbone power line in the future, was developed in the NEDO project called M-PACC. One of the most important developments of a high voltage HTS cable was the high voltage insulation technology. A design guideline and a test specification that was necessary to design, product and demonstrate of a 275 kV, 3 kA HTS cable have been studied by obtaining the various experimental data such as AC withstand voltage, impulse withstand voltage, partial discharge inception stress, and the V-t characteristics of the insulation, on the basis of the Japan Electrical Standards (JEC) and the International Electrotechnical Commission (IEC). Moreover, the 275 kV, 3 kA HTS cable with a length of 30 m was demonstrated under a long-term voltage and current loading test.
Mukoyama, S., Yagi, M., Okuma, T., Maruyama, O., Shiohara, Y., Hayakawa, N., & Mizutani, T. (2014). Status of 275 kV REBCO HTS Cable Development in the NEDO Project. In Physics Procedia (Vol. 58, pp. 310–313). Elsevier B.V. https://doi.org/10.1016/j.phpro.2014.09.077