Model Predictive Control Method of Torque Ripple Reduction for BLDC Motor

The commutation torque ripple of a brushless dc motor (BLDCM) in a six-step driving mode generates vibration noise. To minimize the commutation torque ripple of the BLDCM, this article analyzes the cause of torque ripple and establishes the model of torque ripple suppression by using the phase current predictive method based on the trapezoidal back electromotive force (EMF). In addition, based on the prediction model of the non-commutation phase current, the pulsewidth modulation model predictive control (PWM-MPC) algorithm is proposed. By changing the duty cycle with prior evaluation, the predictive control avoids commutation current hopping, thereby reducing torque ripple during commutation. This control approach is more accessible to be implemented, because it does not require changing the topology of the motor driving circuit. Simulation models of the proposed control scheme constructed in the MATLAB/Simulink environment are given, compared with the conventional square-wave driving method. Moreover, experiments are performed to verify the feasibility. The output torque during experiments is transmitted to the computer software through the torque transducer. Compared with the traditional driving methods, the simulation and experimental results show that the proposed novel algorithm in this article could suppress the torque ripple efficiently.