A Low-Power PWM Modulation Method for Suppressing Torque Ripple in Brushless DC Motors

Torque ripple stands as a prominent issue in brushless DC motors, significantly impacting systems requiring high precision and stability. A detailed analysis is conducted on the torque ripple during commutation periods using H_OFF-L-PWM modulation and an improved H_OFF-L_PWM modulation method, verifying the significant reduction of torque ripple achievable with the enhanced H_OFF-L_PWM modulation. Building upon this principle, an OFF-PWM-OFF modulation method is proposed, capable of entirely replacing the improved H_OFF-L_PWM modulation. This new method achieves equivalent suppression of torque ripple during commutation while reducing the number of switchings, thereby decreasing losses. Finally, a brushless DC motor wind power generation control system is developed on the PLECS simulation platform. Simulation results demonstrate a correlation between theoretical analysis and simulation outcomes, indicating that the OFF-PWM-OFF modulation method reduces current fluctuations and effectively suppresses torque ripple in brushless DC motors.