Design and Analysis of T-shape Consequent Pole Dual PM Vernier Machines with Differential Magnetic Network Method

This paper has proposed a novel design of dual PM vernier machine with T-shape consequent pole rotor. The analytical model of T-shape magnet rotor based on differential magnetic network method are firstly derived. Given the additional optimizing parameter, edge arc difference, T-shape consequent pole (TCP) rotor has the potential to produce 6% higher fundamental airgap flux density or 30% higher PM utilization ratio than regular fan-shape consequent pole rotor. The influence of magnet size parameters including magnet thickness, pole pitch ratio and arc difference angle on airgap flux density of TCP rotor is then analyzed. The torque performance of TCP in regular consequent pole and dual PM consequent pole vernier machines are also studied. The comparison shows that T-shape consequent pole can produce higher torque than fan-shape magnet in vernier machines. At last, a prototype of dual-PM vernier machine with TCP rotor is built and tested, which has achieved 28 Nm/L measured torque density.