Functional observer based higher order sliding mode control for DC-DC Buck converter

The study in this article focuses on the design of functional observer based higher order sliding mode controller for DC-DC Buck Convertor. Functional Observer is used for linear estimation of unmeasurable state variables which are required for the closed loop stability of a dynamic system without unnecessarily estimating all the individual states. The proposed method thus reduces the overall complexity, cost of the system and minimizes the number of individual sensors which are required to measure each state variable of the system. Functional Observer based higher order sliding mode controller is used to obtain chattering free control signal which assures easy practical implementation of the controller when compared to the functional observer based conventional sliding mode controller. The robustness of the proposed observer based controller is tested under input parameter variation and unknown input disturbance.