Multi-Objective Optimization Design of Halbach Consequent-Pole PM Machine for Rim-Driven Thruster

In order to balance the torque density and utilization of permanent magnet (PM) material in large air gap rim-driven thruster (RDT), a three-segment Halbach array consequent-pole PM rim driven machine (HCPM-RDM) with unequal pole arc is proposed in this paper. In this design, the proposed HCPM-RDM can significantly reduce the PM volume, while taking advantage of the flux focusing effects of the Halbach structure, and improve the torque density. To satisfy the operating requirements of the RDT, a multi-objective stratified optimization design is conducted, in which the response surface (RS) coupled genetic algorithm (GA) and particle swarm optimization (PSO) algorithm are purposely utilized. Then, the electromagnetic performance of the HCPM, CPM, SPM machines is extensively compared, which include the cogging torque, electromagnetic torque, torque ripple, loss and efficiency. Finally, the RDM prototype is tested to verify the effectiveness of corresponding optimization design and finite element analysis (FEA).