System to improve the torque smoothness of an electric machine

摘要

A stator for an induction machine comprises a cylindrical core that has a plurality of inner and outer slots and a plurality of toroidal coils wound about the core and laid in the inner and outer slots. Each toroidal coil occupies a single inner slot and is laid in the adjacent associated outer slot to minimize the distance the coils extend from the end faces of the core thereby minimizing the length of the induction machine. The coils are encapsulated in a material that fills any voids to provide a thermal path for uniform heat dissipation. In operation, a controller is coupled to three current sensors and detects the current of only three phases. These phases are then used to calculate the current of the adjacent six phases, thereby, allowing for better control of the electric machine.