Torque ripple reduction in brushless DC motor drives

This paper proposed a novel dual closed loop control of speed and torque method in brushless DC motor (BLDCM) drivers based on genetic algorithm. By defining speed error and torque error as optimum objective functions, using genetic algorithm, the PID parameters can be optimized. In addition, the torque ripple during commutation has been analyzed, and a variable switch conduction mode has been introduced to reduce torque ripple during commutation. The simulation results show that the torque ripple of BLDCM can be eliminated effectively during the commutation period and non-commutation period.