Robust Optimal Controller for Buck Converter Under Parametric Uncertainty: An LQR Approach

Abstract

A major problem to design the controller of power electronic converters is to maintain robust stability and performance criteria against changing parameters. The conventional methods to design robust controllers lead to a high-order controller that may not feasible to implement in real-time. In this paper, a robust linear quadratic regulator is proposed that can cope with the variation of parameters of the converter. This approach is based on state feedback which involves inductor current and capacitor voltage. These state variables should be measured and sent to the controller unit. To simplify implementation, an extended kalman bucy filter is proposed for buck converter to estimate the states of the converter. To more study, the performance of the proposed controller is compared with a conventional high order H∞ controller.