Research on field-weakening control of multiphase permanent magnet synchronous motor

Field-weakening control is also an important issue for multiphase motors when used in electric vehicles which require wide speed range. Since the multiphase motor is a multidimensional system, therefore field-weakening control must be operated on both the fundamental subspace and other harmonic subspaces simultaneously. In this paper, firstly the reference voltage vector limit of the five-phase permanent magnet synchronous motors (PMSM) fed by the five-phase voltage source inverter (VSI) is analyzed and determined, then the field-weakening control strategy and the determination method of reference current commands based on the multidimensional-orthogonal-decomposition vector control and the multiphase carrier-based PWM is presented. Finally, Simulation results verify the correctness and feasibility of the proposed field-weakening control strategy.