Finite time current observer based adaptive backstepping control of buck converters

A finite time current observer based adaptive backstepping control strategy is proposed for the output voltage regulation of buck type DC-DC converters. The proposed current observer is designed by utilizing only the output voltage information to reconstruct the inductor current profile while achieving an adaptive control by means of backstepping procedure. This method eliminates the usage of extra sensor involved in sensing the inductor current, thereby reducing the cost of control besides overcoming the problems of measurement noise encountered while sensing. Simulations have been performed on a buck converter using Matlab software under both continuous and discontinuous conduction modes. Further, the usefulness of proposed scheme is also examined by subjecting the buck converter system to sudden changes in load resistance. The results obtained reveal that the proposed observer is successful in not only estimating the nominal inductor current but also estimates the perturbed level of inductor current under load disturbances in finite time. Satisfactorily transient and steady state response in the output voltage are ensured by using the proposed method.