Disturbance observer based robust finite control set predictive torque control for induction motor systems

Abstract

A disturbance observer (DOB) based finite control set predictive torque control (PTC) scheme for induction motors subject to lumped disturbances is proposed in this paper. To control an induction motor using the inverter switching character directly, the finite control set predictive torque control (PTC) method is studied which evaluates the electromagnetic torque and stator fiux in the object function. The optimized switching vector is choosed to control the insulated gate bipolar transistors (IGBTs), it also can minimize the error between reference signals and predicted values. Similar to direct torque control (DTC), PTC method does not need a modulator and an internal current PI controller, but the speed loop also adopts the PI controller. For improving the disturbance reject ability and simplifying the PTC control structure, this work introduces a novel PTC method based on DOB technique which does not need the PI speed controller.