Parameter Analysis of HTS DC Cable Core in LNG Temperature Considering AC Harmonic

With the continuous improvement of the performance of High temperature superconducting(HTS) materials and cryogenic technology, HTS power cable has been developed rapidly. Many HTS cable projects in liquid nitrogen(LN2) temperature region have been carried out all over the world. Our current research is that HTS cable transmits high-power electric energy in the HTS energy pipeline based on the cooling sharing. The DC current transmitted by the superconducting DC cable is from the output of the converter station rectifier. In the actual working condition, different rectifier topological structure correspond to specific AC harmonics. Therefore, the influence of specific AC harmonics and joint resistance on the parameters of HTS cable should be considered in the design stage in order to realize the current homogenization transmission in each layer of the cable core. The current homogenization design is more important for the safety of HTS cable in energy pipeline. In this paper, the influence of specific AC harmonics on the inductance and mutual inductance of each layer of superconducting cable is analyzed, and the corresponding current distribution of each layer of AC harmonics is obtained. The critical current characteristics of Bi-2223 HTS tape at different magnetic field angles in the temperature range of 85-90 K are experimentally studied. The electromagnetic and structural parameters of 1 kA HTS DC cable in the temperature range of 85-90 K are optimized by ant colony algorithm with considering AC harmonics are obtained.