Técnicas de Controle Multivariável para um Conversor CC-CC de Três Portas

Abstract

Three-port DC-DC converters are essential in off-grid photovoltaic power generation systems that have an energy storage module with batteries. The converters must deliver regulated voltages to the loads, reducing the effects of oscillations in both the source and the batteries. For this, controllers are needed, which must be multivariable. This work evaluates multivariable control techniques applied to a specific three-port DC-DC converter topology. The adopted control techniques are decentralized PI control, LQR control (Linear Quadratic Regulator), LQG control (Linear Quadratic Gaussian), and H∞ control. For the evaluation of the techniques, computational simulations are carried out in the MATLAB software. All controllers are capable of attenuating the effect of disturbances represented by changes in source and battery voltages, ensuring zero error in steady state and transients with low percentage overshoot and fast accommodation. From this, it is concluded that the implementation complexity of each controller and the robustness requirements must be the main criteria for choosing the adequate control technique.