Comparison of Dual 3-phase Modular Permanent Magnet Machines with Overlapping/Non-overlapping Windings and Redundancy

Abstract

Two dual 3-phase modular permanent magnet (PM) machines with non-overlapping and overlapping windings are analyzed and compared in this paper. One has 42 slots/32 poles (42S/32P) and the other one possesses 96S/32P combination, while two sets of windings have 0 degree phase shift for both machines. The structure specialties of two machines are described together with some constraints. Since two sets of windings are fed by independent inverters, operations with both sets of windings and only one set of winding are analyzed and compared, especially in terms of torque performance. It is found that the 42S/32P modular machine shows better torque performance than the 96S/32P machine in both operation conditions. The differences in both average torque and peak-to-peak torque ripple become larger with the increase of current, which is mainly due to the difference in saturation levels of two machines under high electric loading condition.