Torque Ripple Reduction in an Axial Flux High Temperature Superconducting Motor

The design, construction, and operation of superconducting rotatory machines in an axial flux configuration are strongly dependent on the ability to reduce torque ripple. A new concept is presented in order to maximize the output power optimizing the magnetic flux density within the air gap of a three-phase fully superconducting induction motor. The machine is designed on a basis of bilateral stators distributed around a central rotor. The optimal distribution of magnetic flux and the minimization of torque ripple are resulting from an adequate distribution of motor phases, number of rotor bars, and choice of air-gap thickness. The magnitude of magnetic flux in the air gap is obtained by means of finite-element analysis, and some derived parameters are compared to experimental results. Then, the impact of the design on torque magnitude and torque ripple is discussed.