The Current Harmonics Elimination Control Strategy for Six-Leg Three-Phase Permanent Magnet Synchronous Motor Drives

This paper focuses on the analysis and development of low-current harmonics for a six-leg, three-phase inverter for permanent-magnet synchronous motor (PMSM) drives. Each phase of the PMSM is operating independently, the low-order harmonics appear in the back electromotive forces (EMFs) and currents. In this case, the standard vector control cannot handle the current harmonics. This harmonic enhances the current and causes the torque ripple. This paper presents a zero-axis current estimator auxiliary vector control method to compensate for three multiples of the voltage harmonic. This method can eliminate the zero-axis current. A prototype PMSM system was built using the TMS302F28335 digital signal processor. And the computer simulation and control method were completed. When the system operated at half load, the total harmonic distortion of current decreased from 20.89% to 4.42%. At full load, the total harmonic distortion of current decreased from 8.43% to 1.71%.