Design Framework Incorporating Topology Optimization for Halbach Array In-Wheel Motors

This study presents a design framework incorporating topology optimization developed for Halbach array in-wheel motors. The proposed topology optimization method simultaneously optimizes the complicated features of the Halbach array, including the shape, arrangement, and magnetization directions of permanent magnet (PM) segments, as well as the back-iron shape. The design objective for topology optimization is set as to maximize the average torque, with constraints applied to torque ripple, base speed, and the volumes of PMs and iron materials. Unlike conventional parametric optimization methods, topology optimization enables the exploration of diverse configurations of iron and PM segments without relying on predetermined design settings. Thus, it is employed as a conceptual design tool to identify preliminary configurations and material distributions. This is followed by a detailed design process that refines the conceptual design, ensuring manufacturability and meeting additional performance requirements, ultimately producing CAD models ready for fabrication. The final design is then validated through prototype fabrication and experimental testing. The effectiveness of the proposed design framework integrating topology optimization is demonstrated through its application to Halbach array in-wheel motors.