Design and Comparison of Vernier Permanent-Magnet Machines With Different Winding Types Based on Fractional-Slot Windings

Vernier permanent-magnet (VPM) machines which have high torque density and high efficiency have been extensively used in direct drive. This article attempts to propose a new winding form and compare it with a traditional winding form as a part of fractional slot winding in the VPM machines to provide a design guideline in the aspect. Different winding forms are compared with the same copper loss and the same design. The design guideline of winding forms is provided by multiobjective generation algorithm (GA) optimization. Maximum torque value and minimum torque ripple are the optimization objectives in the GA optimization process. In addition, several models of the modularized motor with the new winding form based on the fractional-slot windings are compared, and the suitable application range of these models are discussed.