Comparison of Double-Stator Superconducting Electrical Machine with Two Typical Superconducting Excitation Stator Topologies

This paper comprehensively compares the dual-stator superconducting excitation (DS-SCE) machines with two superconducting (SC) excitation stator topologies: the radial-type and the newly proposed quasi-spoke-type. Firstly, key dimension equations for the excitation stator are derived based on the concept of modular SC magnets. Then, a comparison is made between the radial-type and the quasi-spoke-types I and II machines in terms of the excitation stator dimensions, magnetic circuits, output torque, power factor, dc-winding-induced voltage, and magnetic field distribution around the SC coils. Finally, prototype experiments are conducted to validate the analyses. The results indicate that the quasi-spoke-type excitation stator and machine offer potential advantages of high-power density, low alternating current (AC) losses, and enhanced operational reliability.