A simple current control algorithm for torque ripple reduction of brushless DC motor using four-switch three-phase inverter

In this paper, a new current control algorithm is proposed for four-switch three-phase brushless DC (BLDC) motor drives, which are suitable for low cost applications. A current reference generation scheme is developed and implemented to obtain high performance characteristics in the four-switch system, such as small torque ripple and fast dynamic speed/torque response. Moreover, the proposed scheme can successfully eliminate the torque ripple during commutations, so that it can be expected that the four-switch system can be much more practically applied for the industrial application areas. The proposed current control scheme is theoretically explained in detail and the validity is verified by simulation results, along with the comparison with the conventional six-switch system.