Calculation of self-field losses in a superconducting cable considering the twist of strands

AC superconducting cables are usually to be bundled by many strands to make large current capacity for AC power applications. Superconducting strands composing multistage cables have twisted structure in each stage for lower AC loss and higher stability. So, when transport currents flow in a cable, each strand is exposed to longitudinal and azimuthal magnetic fields produced by transport current flowing in the strand itself and longitudinal and transverse magnetic fields by transport current flowing in the twisted cable. In this paper, we calculate the self field loss generated in a second stage superconducting cable considering twist of strands in cables and filaments in strands. Also, we describe the influence on self field loss by twist direction of filaments and strands.