Investigation of Flux Weakening Capability of an Unconventional 9-Phase PM Motor with Different Winding Configurations

In this paper, two different winding configurations and phase angle displacements of an unconventional nine-phase permanent magnet (PM) motor have been investigated in terms of flux weakening capabilities. The focus has been on a 117-slot 36-pole unbalanced and asymmetric winding motor since these motors have certain benefits. In addition, it is not possible to create a balanced winding structure for this motor due to the selected slot-pole combination. Performance of the designed motors have been verified experimentally and flux weakening capabilities have been investigated using 2 Dimensional finite element analysis (2D FEA) and test results. It is shown that the flux weakening capabilities of the proposed 9-phase PM motors with two winding options yield similar results compared to a conventional balanced multi-phase PM motors.