Current control strategy for dynamic winding reconfiguration of a brushless DC motor

The modification of the torque-speed characteristic can be achieved by changing the connection between the coils from star to delta. During the reconfiguration process, depending on the strategy used, a torque interruption or jolts can occur. In this paper, we propose a novel strategy that suppresses these torque variations. The proposed approach is based on a fine control of the phase currents through the on and off sequence succession of the power stage and the control on the commutation angle. Numerical simulations are performed to substantiate the model.