Application of Nonlinear and Optimal Control Techniques to High Gain DC–DC Converter

In this paper, a power converter is designed to give up an output power of 50 W. The design method is based upon two boost converter connected in cascade that gives an output of 460 V, and a high gain is needed. For controlling the voltage output of power converter, various control approaches like sliding mode controller and linear quadratic Gaussian regulator are described. The proposed small-signal averaged models for boost converter are derived mathematically. Then, it is used for designing of two different feedback controllers, which accomplish the additional understanding in the converter dynamics. First, a nonlinear sliding mode (SM) controller is designed; the design method depends on the selection of the sliding surface and switching function. And second, the design of linear quadratic Gaussian (LQG) state-feedback controller, by calculating the state-feedback gain matrix and Kalman estimator gain, is presented for the same converter topology. Here, the output voltage regulation and an excellent dynamic performance are compared between two different types of controllers. All the simulations are done in MATLAB/Simulink environment.