Comparative analysis of hybrid dual permanent magnet machines with different asymmetric stator-pole topologies

This paper presents a hybrid dual permanent magnet (HDPM) machine that combines stator-mounted NdFeB magnets with rotor-embedded ferrites in a consequent-pole configuration, enhancing permanent magnet utilization while reducing rare-earth material consumption. The proposed design leverages a bidirectional modulation effect and an asymmetric stator-pole (ASP) topology to generate high-torque working harmonics. Four HDPM variants with Halbach-array ferrite rotors and distinct ASP structures are optimized using a multi-objective non-dominated sorting genetic algorithm II (NSGA-II), and their electromagnetic performance is comparatively analyzed. The results reveal superior torque density and efficiency in the proposed machine. Additionally, a 3D finite element analysis investigates the torque-enhancement mechanism of the rotor-ferrite overhang structure. Finally, experimental validation via a fabricated split stator-pole HDPM-ASP prototype confirms the machine’s effectiveness.