3-D Semi-Analytical Model of a Superconducting Axial Flux Modulation Machine

This article presents a 3-D semi-analytical model of a partially superconducting axial flux modulation machine for the computation of the flux density distribution, the torque, and the eddy-current losses in the armature. The modulation of the superconducting coil magnetic field by the superconducting bulks is calculated by solving the Maxwell’s equations in scalar potential with the variable separation method. Using Fourier series analysis and the convolution theorem, the bulk region is modeled by a domain with a spatially variable magnetic permeability. This variable permeability enables considering a diamagnetic bulk as well as a more complex magnetic behavior using the Bean model. The results of the proposed model are compared with 3-D finite-element models and good agreement is obtained for a significantly reduced computation time. The proposed model appears to be a suitable tool for optimization and sizing processes.