Control Strategy for Reducing Torque Ripple of Brushless Direct Current Motor Based on Finite Set Predictive Control

Aiming at the problem that the brushless DC motor will produce large torque ripple during commutation, a torque ripple suppression strategy based on finite set model predictive control (FS-MPC) is proposed in this paper. According to the current waveform conditions at different speeds, an appropriate alternative switching tube conduction state is inserted during commutation. By bringing the conduction state of the alternative switching tube into the prediction model, the current magnitude of the motor at the next moment is predicted. The value function is used to select the appropriate switching tube state, so that the current fluctuation can be minimized during commutation, thereby reducing the torque ripple. And on this basis, a new method for determining the commutation time is proposed. By taking the moment when the Hall signal changes as the commutation start time, the motor parameters are calculated using the formula to obtain the commutation time length, and then the commutation time length is delayed to finally determine the commutation interval. After simulation analysis and verification, it is shown that this method can achieve a good torque ripple suppression effect in both high-speed and low-speed stages.