Controle robusto baseado em desigualdades matriciais lineares aplicado a um conversor integrado Buck-boost Flyback para o acionamento de led com entrada universal

Abstract

This work proposes a high power factor universal LED driver operating with input voltage variation from 90 to 264 V rms and dimming. The driver was designed to comply with the standard IEC 61000-3-2. Therefore, as the system's operating point is dynamic, the linearized converter's model changes according to the input voltage and dimming level. To ensure stability and good dynamic response for all operating points, a robust state feedback is used. The feedback gains are obtained by using linear matrix inequalities. The parametric uncertainties are modeled and considered in the design in this method. In order to attenuate the undesired output current low-frequency ripple, a H1 optimization via LMIs is employed. Therefore, a set of LMIs is used to ensure robust stability and disturbance minimization, as well as robust performance. The inequalities are solved by using a Matlab Toolbox. A prototype was build, composed of a integrated buck-boost yback converter of 34,21 W, to evaluate the proposed control performance.