Air-gaps 1 DCEFSM 1 Direct current excited flux switching machine Direct-current 1 Electric motor prototype 1 Electric motors 1 FEM 2D calculations 1 FEM 2d calculation 1 Finite element method 1 Flux-switching 1 Geometry 1 Minimisation 1 Minimization of the cogging torque 1 Rotor teeth 1 Stators 1 Torque 1 electric motor prototype 1 minimization of the cogging torque 1