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

This article has proposed a novel design of dual permanent magnet (PM) vernier machine (DPVM) with T-shaped consequent pole (TCP) rotor. The analytical model of T-shaped magnet rotor based on differential magnetic network method is first derived. Given the additional optimizing parameter, edge arc difference, TCP rotor has the potential to produce 6% higher fundamental airgap flux density or 30% higher PM utilization ratio than regular fan-shaped consequent pole (FCP) 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 TCP can produce higher torque than fan-shaped magnet in vernier machines. At last, a prototype of DPVM with TCP rotor is built and tested, which has achieved 28-N·m/L measured torque density.