Decoupling Force and Torque Generation in Bearingless Motors with Toroidal Windings

This work describes a finite element simulation method to properly evaluate the characteristics of a bearingless motor with toroidal windings. In this kind of motors, it is problematic to allow zero-sequence current, as the resulting zero-sequence flux is short-circuited by the stator back yoke, what immeadiately leads to saturation effects. Hence, a simulation method is introduced that does not demand for zero-sequence current. Finite element simulation results of a bearingless prototoype drive are compared and first measurement results of a commissioned prototoye are presented.