Commutation Control for the Low-Commutation Torque Ripple in the Position Sensorless Drive of the Low-Voltage Brushless DC Motor

This paper discusses a commutation control method aimed at reducing the commutation torque ripple in sensorless drive of brushless direct current motors. These motors are generally used for low-cost applications because of relatively high efficiency and low manufacturing cost. On the other hand, they show a high torque ripple characteristic caused by nonideal commutation currents. This limits their application area, especially for low-voltage applications. In order to minimize torque ripple for the entire speed range, a comprehensive analysis of commutation torque ripple was made according to three commutation control methods whereupon an optimal current vector trajectory for low torque ripple was devised. The effectiveness of the proposed method was verified through simulation and experimental results.