Nonlinear H∞ controller design for a DC-to-DC power converter

We present a state feedback controller for the Cuk converter. It is shown that a special type of DC-DC switched mode power supply can be handled by the theory of affine-input systems. The controller design is based on the H_∞-theory of nonlinear systems. Using an appropriate exogenous system, the stationary control error can be made arbitrarily small. Furthermore, this design method leads to a simple controller and the stability of the closed loop can be guaranteed in the sense of Lyapunov. The implementation for a laboratory model shows a good tracking and disturbance behavior, which proves the feasibility of the proposed procedure