AC Loss Analysis of 35-kV Superconducting Cables Operating at Full Load

The Shanghai superconducting cable project, operating at 35 kV with a rated current of 2200 A and spanning 1.2 km, commenced in December 2021 and has since been consistently operational, including full-load operation. Accurately estimating the ac loss of superconducting cables is crucial for assessing their current carrying capability, yet theoretical estimations often fall short. This article presents an analysis of the various losses of the superconducting cable at full load and proposes a comprehensive loss analysis method that integrates electrical and thermal measurement techniques. Data on dielectric loss, dc resistance, and ac resistance were obtained through a blackout test. In addition, during full-load operation, measurements were taken for parameters, such as cable inlet and outlet temperatures, liquid nitrogen flow rate, and pressure. Comprehensively leveraging these test data, this article deduces the leakage heat loss of the superconducting cable and its ac loss at full load.