Conformal mapping: Schwarz-Christoffel method for flux-switching PM machines

Purpose: Flux-switching permanent magnet (FSPM) machines are double salient machines with a high energy density suitable for e-mobility. For a fast design process, machine specialists need easy-to-use motor models. For the FSPM model, analytical methods cost high efforts to create and to improve them. Numerical methods such as the finite element method (FEM) have been extensively studied in the literature with little emphasis given to their alternatives. Methods: This research shows the implementation of the Schwarz-Christoffel (SC) mapping for the FSPM. With this numerical method, the double salient motor geometry is transformed into a simpler geometry to reduce the model complexity. For the electromagnetic analysis, SC mapping is implemented both as a stand-alone method and as an integrated method with the tooth contour method and the orthogonal field diagram method. Results: Findings are presented in a comparative analysis for all created models including the finite element method. Results show a very good agreement among the presented models. Conclusions: The results obtained in this paper show that SC mapping is a good alternative to the FEM. With the provided step-by-step explanation on how to implement SC mapping, the method can be expanded to other electrical machine classes. © 2012, Ilhan et al.; licensee Springer.