Discrete State-Feedback Control Design with D-Stability and Genetic Algorithm for LED Driver Using a Buck Converter

Abstract

In this paper, a discrete state-feedback controller is applied to control the current in power LEDs by using a buck converter. Sufficient conditions for the existence of the controller are given in terms of linear matrix inequalities (LMIs) with D-stability theory. In order to consider the specific closed-loop dynamics of the closed-loop LED driver, the genetic algorithm (GA) technique is applied, as a complement of the D-stability theory. Therefore, the proposed GA technique is used to search offline the optimal closed-loop eigenvalues to have a desired response of the closed-loop system, subject to a proposed cost function equation. The main contribution of this work is the design and the experimental validation of both the state-feedback controller and the GA to achieve the desired closed-loop dynamics of the LED-driver system. Finally, simulations and experimental results are done in order to illustrate the effectiveness of the proposed methodology.