Analysis of the Power Quality in Six-phase Induction Motor Drives with Arbitrary Winding Spatial Shifting

Abstract

Multiphase machines are becoming an alternative to the three-phase standard in high power applications with high reliability requirements. Due to the capability to inherit off-the-shelf three-phase technology, the most popular choice at industry is the use of multiple three phase windings. The disposition of the different sets of three phase winding is however varied. In the specific case of six phase machine, a spatial shifting among the three-phase windings of 0º, 30º and 60º has been used in dual-three-phase, asymmetrical and symmetrical machines, respectively. This spatial displacement has an impact on the power quality of the currents that supply the machine since the same magnetomotive force (MMF) in the airgap can be generated with different harmonic cancellation between phases. This work considers an arbitrary spatial shifting of the three phase windings in order to explore its impact on the power quality from the machine-side. Extensive simulation results compared the different types of six-phase machine and some conclusions are extracted about the advantages of each choice.