Direct torque control of brushless DC drives with reduced torque ripple

The application of direct torque control (DTC) to brushless AC drives (BLAC) has been investigated extensively. This work describes its application to brushless DC drives (BLDC), and highlights the essential differences in its implementation, in relation to the torque estimation and the representation of the inverter voltage space vectors. Simulated and experimental results are presented, and it is shown that, compared with conventional current control, instantaneous torque control results in reduced torque ripple and a faster torque response.