Discrete controller with state and disturbance estimation for robust performance of DC/DC Buck converter

This paper presents discrete robust control of DC/DC buck converter. Regulating the output voltage of the DC/DC converter digitally, irrespective of line voltage and load variation has been driving motivation for investigation of discrete sliding mode control. Average model is used to design discrete sliding mode controller. Extended state observer is designed to estimate state and disturbance of the discrete model. Switch-free controller is designed, estimated value of disturbance is used in controller to compensate its effect. The significant contribution of this paper includes assurance of robust performance by compensating disturbance contributed by load, parameter and supply variations. Proof of existence of sliding modes and stability also has been contribution. It is shown that the proposed method provides robust voltage regulation both in simulation and experiment.