Performance improvement of brushless DC motor drive controlled by a predictive algorithm

A novel modulation technique suitable for the current control of brushless DC drives under commutation is presented in the paper. The pulse width of the chain voltages are determined by means of a predictive algorithm under the constraints of minimum Joule losses and torque ripple free commutation. At maximum speed the torque ripple appears but is lower than that of six step operation. The proposed technique leads also to higher mean torque than that of traditional six step operation. Simulation results highlight the better performance of the drive controlled by the propose algorithm with respect to that of the traditionally controlled drive.