Investigação experimental de estratégias de controle robusto aplicadas à melhoria de desempenho de um conversor de potência CC/CC do tipo buck com estrutura Single Inductor Multiple Output

Abstract

Recently, DC/DC power converters have gained wide attention, especially in industry,telecommunications, and the control of renewable energy sources. The increase in the use of this technology can be explained by the growing demand for high-quality DC voltage regulation in various applications. Additionally, recent advances in power electronics along with control engineering have accelerated the development of DC/DC power converters. Therefore, they looked to optimize these converters in several ways, such as improving conversion efficiency and reducing their weight and cost. In the proposed work, control strategies for voltage regulation in a single-inductor, dualoutput Buck DC-DC converter system (SIDO) are investigated. Based on a nominal multiple-input, multiple-output plant model and performance requirements, both a Linear Quadratic Regulator (LQR) and a Decoupled PI control strategy are designed to control the power converter system under parametric uncertainties such as variation of the voltage source, variations of constant power loads (CPLs) and variations of load resistances. A prototype of a single inductor dual output DC-DC Buck converter was developed for experimental testing. The results indicate that the proposed LQR strategy approach is reasonable and provides adequate performance improvements in SIDO converter controllers under conditions of varying voltage source and varying load resistances, offering robust performance and system stability; however, more research is needed to address variations in constant power loads and in the design of a PI controller for its application in this kind of system.