Model predictive pulse pattern control of permanent magnet synchronous motors for medium- and low-speed optimization

Taking the permanent magnet synchronous motor (PMSM) as the research object, the model prediction pulse pattern control (MP3C) of a PMSM running in the medium–low-speed zone is adopted to further reduce the torque ripple and phase current total harmonic distortion (THD) of a motor running in the medium–low-speed zone. First, the objective function of the predictive pulse control method is optimized. The objective function is intended to be the difference between the switching voltage vector and the equivalent reference voltage vector. At the same time, the integral of the difference between the d-axis current reference value and the actual value is compensated into the voltage reference vector. Thus, the pulse pattern control selected by the objective function is optimal when the motor is running in the medium–low-speed region. In addition, the PMSM can run stably and reliably. Simulation results show that the torque ripple is reduced by 1.3 Nm and 1.2 Nm, and that the phase current total harmonic distortion is reduced by 0.10% and 0.03% when the motor is running at 5 Nm and 10 Nm and at a speed of 100 rpm, respectively. When the rotation speed is 1000 rpm, the torque ripple is reduced by 0.74 Nm and 0.78 Nm respectively. In addition, the phase current total harmonic distortion is decreased by 0.44% and 0.54%, respectively.