A Review of Multi-Phase Permanent Magnet Synchronous Motors

High efficiency, high power levels, reliability are demands that have led many researchers to dive into the field of multiphase motors. Especially the world of the electric car, a growing trend, is pushing for increasingly high-performance solutions that will facilitate their widespread use. The purpose of this work is to provide an overview of the multi-phase permanent magnet synchronous motor and to show what steps are needed to calculate the basic parameters to highlight some of the benefits. In order to understand how a permanent-magnet motor works, a review of three-phase motors is presented, specifying transformations that allow simplified modeling to control them. Emphasis is placed on five-phase, six-phase and nine-phase motors, then proceeding to highlight what are the topologies of multiphase drives based on the structure and number of levels of their respective output voltage. To obtain a more complete review, multiphase induction and reluctance motors are mentioned. Lastly, the covered topologies based on the number and arrangement of the phases are summarized and not only the benefits of the multi-phase machine are highlighted but also the advantages and disadvantages in using different multiphase drive.