Reduction of Saturation and Unipolar Leakage Flux in Consequent-Pole PMV Machine

This article proposes some effective approaches to address the inherent issues of consequent-pole (CP) permanent magnet (PM) machines, such as saturation of the salient rotor core and unipolar PM leakage flux of the end region caused by asymmetric field. The effect of CP-Halbach PM array with different magnetization directions and parameters that affect the saturation has been investigated for the CP PM machine with short pole pitch. By employing the CP-Halbach array, the saturation issue can be solved and superior performance can be obtained without reducing the PM pole arc. In addition, unequal and multistep staggered rotors with magnetic barriers have been proposed to reduce the unipolar leakage flux in the end region. Compared with regular staggered rotors, not only better electromagnetic performance can be achieved, but also the end unipolar leakage flux can be reduced. Finally, a prototype is manufactured and the predictions have been validated by measurements.