Static Electromagnetic Field Computation by Conformal Mapping in Permanent Magnet Synchronous Machines

In modern servo drives or electrical drives for positioning, torque pulsation, tangential forces and ripple torque are undesirable effects. These parasitic effects are due to the presence of higher time and space harmonics in the air gap flux density. This paper presents a time-effective method to compute the radial and tangential field components under load and no-load condition by conformal mapping in the frequency domain. The proposed method is applied to a surface mounted permanent magnet synchronous machine, and compared to numeric results obtained by nonlinear FEA. The analytical results obtained by the conformal mapping are shown to be in good agreement to the finite element simulations.