Permeability Harmonic Analysis and Core Loss Suppression of a Flux Modulation PM Hub Motor

In this article, a permeability directional modulation method for analysis and efficient suppression of core loss is proposed for the flux-modulated permanent magnet hub motors, where targeted decoupling design between the output torque and core loss is realized to achieve the research purpose of effective core loss suppression while maintaining relatively high output torque. The harmonic order and frequency characteristics related to the core loss and output torque are systematically studied to construct the characteristic harmonic group of core loss and output torque. On this basis, the key permeability harmonics are spatially located in stator and rotor structures, and the topological design form of permeability directional modulation is researched to achieve efficient suppression of motor core loss. Subsequently, the relevant performances of the motor before and after the directional modulation design are compared and analyzed. Theoretical analysis and simulation results verify the effectiveness of the proposed permeability directional modulation method.