A robust composite control for basic DC-DC converters

The aim of this work is to build a unified model for basic DC-DC converters that are subject to disturbances and parametric uncertainties on which a robust composite control is designed. Toward this end, three basic DC-DC converters, buck, boost, and buck-boost, operating in the continuous conduction mode are formulated by a unified model that control strategy is devised accordingly. A robust composite control strategy comprising an integral sliding-mode control and a robust linear control is implemented to the system. The advantage of integral sliding-mode control not only eliminates the so-called matched disturbances but maintains the system, namely equivalent system, on the designed sliding surface. While, in the mean time, the equivalent system asymptotically approaching the equilibrium by robust linear control with consideration of parametric uncertainties, such as inductance, capacitance, and load resistance; in this work, however, we treat also the input voltage as one of the parameters that subject to large variations. It is noted that although the control design are divided into two parts, the control, however, acts simultaneously to the system such that the design goals are reached.