Multiobjective Design Optimization of High-Power Circular Winding Brushless DC Motor

This paper proposes a novel circular winding brushless dc (CWBLDC) motor, which offers high torque density as BLDC motors and low-torque ripple as permanent-magnet synchronous machines (PMSMs). The novelty of the proposed machine is the circularly connected windings and its way of commutation, which make it suitable for high-power high-performance marine propulsion applications. First, the structure and the operation principle of CWBLDC are described. The method for calculating phase current of CWBLDC is subsequently introduced and validated by prototype experiment. Then, the multiobjective optimization problem for designing a high-power low-speed CWBLDC is formulated. Through large-scale design parameter sweeping, the best type of slot-pole combination and the best design scheme is selected and validated by finite element method (FEM) simulation. Finally, a multifactor regression analysis is performed to establish the relationship between performance objectives and design variables.