Research on harmonic compensation for flux and current of permanent magnet synchronous motor

High order harmonic flux and current of permanent magnet synchronous motor (PMSM) are generated by the distortion of air-gap magnetic field and the nonlinear characteristics of inverter, resulting in the ripple of electromagnetic torque. In this paper, a novel harmonic compensation algorithm was proposed to solve this problem. Based on the harmonic model of the PMSM, harmonic voltage is injected to reduce harmonic components of the motor flux and current. By extraction of harmonic flux/current and injection of harmonic voltage in real-time, high-order harmonics of flux generated by the distortion of air-gap magnetic field and the nonlinear characteristics of inverter is counteracted. Thereby, distortion of motor current is reduced. The effectiveness of the algorithm is validated by simulation and experimentation.