Compensation for harmonic flux and current of permanent magnet synchronous motor by harmonic voltage

Resulting in the ripple of electromagnetic torque, high order harmonic flux and current of permanent magnet synchronous motor (PMSM) are generated by the nonlinear characteristics of inverter and the distortion of air-gap magnetic field. In this paper, a novel harmonic compensation algorithm was presented to reduce the harmonic components of flux and current. Based on the harmonic model of the PMSM, harmonic voltage is injected to compensate the 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 nonlinear characteristics of inverter and the distortion of air-gap magnetic field is counteracted. Thereby, distortion of motor current is reduced. The effectiveness of the algorithm is validated by simulation and experimentation.