A SIMPLE SPEED CONTROL TECHNIQUE AND PULSATING TORQUE ELIMINATION METHOD IN A BRUSHLESS DC MOTOR

This paper presents a theoretical derivation and computer simulation of an optimal speed controller for a brushless dc motor using feedback from a linear model running in parallel with the inverter-fed model. The intent of the feedback from the linear model is to eliminate torque ripples from the inverter drive. A nonlinear model of such a motor, transformed into a linear model by a local dipheomorphism (defined in section 2) and a new model is introduced in order to eliminate the undesirable effects of the inverter harmonics.