Design Optimization and Comparative Analysis of Permanent-Magnet Vernier Machines with Single-Winding Design

This paper conducts a comparative study among four permanent-magnet (PM) vernier (PMV) machines with single-winding design, including the surface-mounted PMV (SPMV) machine, the spoke-array PMV (SAPMV) machine, the U-shape consequent-pole PMV (UCPMV) machine, and the dual-stator PMV (DSPMV) machine. The machine topologies and design principles of four PMV machines are introduced, and the underlying reason for the design of the half-slot pitch displacement between two stators in the DSPMV machine is revealed analytically. Then, the multi-objective optimization using the non-dominated sorting genetic algorithm (NSGA-II) is carried out among four types of PMV machines, aiming to deliver high performances such as high output torque, high efficiency, high power factor, low PM consumption, and low torque ripple for practical industrial applications. The electromagnetic performances of the optimal designs are comprehensively evaluated using finite-element analysis (FEA). The advantages and disadvantages of each type of PMV machine are summarized, offering valuable insights to researchers in machine type selection.