Research on Vector Control and PWM Technique of Six-phase PMSM

The mathematic model that based on decoupling vector space for six-phase permanent magnet synchronous motor (PMSM) is established. The six-phase PMSM is designed with two sets of Y-connected windings phase shifted by 30 electrical degrees. In the model, the variables of the motor are mapped to the alpha-beta subspace associated with the electromechanical energy conversion and z1-z2 o1-o2 subspace that has nothing to do with the energy conversion subspace in the model. The model implies that different current harmonics have different effects on electromechanical energy conversion. The vector control scheme for six-phase PMSM is presented, in which the currents in the subspace alpha-beta and z1-z2 are controlled in closed loop. A space vector pulse width modulation (SVPWM) algorithm of six-phase voltage-source inverter based on adjacent four largest voltage vectors is discussed. The voltage in alpha-beta and z1-z2 can be modulated simultaneously. Through the simulation and experiment analysis, the vector control method and PWM technique for six-phase PMSM are proved to be feasible and effective.