Analytical Modelling of a Six-Phase Surface Mounted Permanent Magnet Synchronous Motor

A multi-phase permanent magnet synchronous motors (PMSM) has applied popularly in the field of industry (e.g. trucks, ship propulsion, mining, etc) due to its high torque, efficiency and reliable operation. So far, many researchers have studied the multi-phase PMSM (e.g, a three-phase PMSM, a six-phase PMSM) for electric vehicle applications. But, there are still significant limitations in the quantity of research on the six-phase PMSMs. Particularly, when researching this type of motor, authors mainly have provided specifications of the six-phase PMSMs and then conducted experiments on these machines without giving the detailed formulations to analytically compute and design dimensions and electromagnetic parameters. In this research, an analytic model is first developed to determine the main parameters of a six-phase surface-mounted PMSM (SPMSM). The finite element method (FEM) is then introduced to simulate and compute electromagnetic parameters, such as the current waveform, back electromotive force (EMF), flux density distribution, output torque, cogging torque, torque ripple and harmonic components. The development of proposed methods is applied on a practical problem of a six-phase SPMSM of 7.5kW.