Influence of Harmonic Current on Magnetization Loss of a Tri-axial CORC REBCO Cable for Hybrid Electric Aircraft

High-temperature superconducting (HTS) triaxial conductor on round core (CORC) cable is a potential candidate for use in the transmission line of hybrid-electric aircraft because of its advantages in compactness, high power density, and reduced usage of HTS tapes. The harmonic currents generated by ac/dc converters, generators, and motors in the aircraft affect the ac loss of the transmission cable, thus influencing the efficiency of the cable. This paper analyzes the influence of harmonic current on the magnetization loss of a triaxial CORC HTS cable (10 MW, 3 kV/2 kA), which is designed for hybrid-electric aircraft. A finite element method model based on the T-A formulation has been developed for the HTS triaxial CORC cable, which calculates the losses induced both with and without applied harmonic currents. The results show that the magnetization loss has a significant nonuniform distribution among three phases even under a three-phase balanced rated load. The results also show that a small harmonic current (less than 10% of the rated load current) can lead to a considerable increase in the magnetization loss of the cable (up to 40%). In the triaxial CORC cable, harmonic currents lead to the highest increasing rate of magnetization loss with respect to frequency in the innermost phase.