A vector control strategy for five-phase PMSM with third harmonic injection

Based on the viewpoint of vector space decoupling, a mathematical model of the five-phase permanent magnet synchronous motor (PMSM) with third harmonic injection is established under the rotating coordinate system. It is clear that different harmonic currents have different effects on electromechanical energy conversion. Calculation results prove that by injecting third harmonic currents, not only the motor output torque is enhanced, but also the magnetic saturation of the stator core is reduced. According to the principle that power capacity remains unchanged before and after harmonic injection, the changed trend between the motor output torque and the third harmonic injection rate is obtained through theoretical derivation and simulation analysis, which provides the theoretical foundation for optimization design of five-phase PMSM. The vector control system of five-phase PMSM based on the rotor field oriented was designed to realize the decoupling control of fundamental and third harmonic currents. Simulation and experimental results verify the effectiveness and feasibility of the proposed method.