Refinement of the Parameters of an Induction Motor by Changing the Design from an Internal Rotor to an External Rotor

To varying degrees, optimization is a widely accepted procedure in the design of electrical machines, especially induction machines. This is associated with stringent requirements stemming from international regulations. The use of induction machines in new solutions, including low-speed vehicle drives, introduces challenges because they require high electromagnetic torque at low speeds. These requirements, including dimensional constraints, mean that despite sophisticated optimization, the classic design does not achieve the desired results. In such a case, a general redesign of the motor is necessary, replacing the classic internal rotor motor with an external rotor motor. This paper presents an example of such a design change as part of the parameter refinement process for two selected high-power, high-pole induction motors. Both the FEM method and a suitably adapted analytical method were used to investigate the impact of the design change. This enabled verification of the analytical method’s accuracy and rapid modeling of phenomena and parameters in external rotor motors. The proposed approach can be used to design novel structures and select motor controls for various applications.