Analysis of AC Loss and Current Distribution Characteristics of Multi-Layer Triaxial HTS Cable for 3-Phase AC Power Transmission

This paper presented numerical studies on layer-to-layer current distributions and AC losses in triaxial multi-layer three-phase cable conductors. The simulations were performed for triaxial cables of 2-layer/phase configurations with several combinations of twist pitch to investigate the influence of the cable twist configuration on the layer-to-layer current distribution and the AC loss under 3-phase AC operation. From the numerical results, it was shown that the twist pitch combinations for uniform layer-to-layer current distributions could be found. The numerical results also showed, however, that the AC loss can not be reduced by equalizing the layer-to-layer current distribution. The reason is clarified from the numerical data of the current density profiles across the superconducting layers. For the cable design, it is necessary to select proper twist configuration considering not only the equalization of current distribution but also the minimization of AC loss.