Study of multiphase modular stator SPM based on phase variable model

Abstract

Multiphase modular stator surface-mounted permanent magnet machine(MSPM) features non-sinusoidal back electromotive force. As a result, the d-q model of MSPM is not accurate enough due to the ignorance of space harmonics. Phase variable model is able to be used to perform simulation of electric machine with same accuracy level as the full finite element(FE) model with much less simulation time. This paper aims to figure out the difference between the MSPM with conventional permanent magnet(PM) and shaped PM, and the phase variable model is adopted. Rotor-position-dependent variables including inductance, back electromotive force and cogging torque are obtained from FE model. Apparent inductance and incremental inductance are respectively applied to take the saturation effect of the ferromagnetic materials into account. Simulation with phase variable model of MSPM is performed using SIMULINK, and the results show that the MSPM with shaped PM has a better torque characteristic.