Robust Control Applied to a Photovoltaic Array Emulator Using Buck Converter

Abstract

Considering the increasing use of photovoltaic energy in the actual scenario of electrical power generation, this paper presents the design of an electronic emulator which is able to emulate the characteristics of a PV array. The proposed photovoltaic array emulator is implemented using a mathematical model that represents the equivalent electrical circuit of a photovoltaic cell. The reference signal is obtained from the mathematical model obtained for controlling the dc-dc buck converter, which is used to reproduce the characteristic PV curve (current-voltage). The controller is designed by means of linear matrix inequalities (D-stability criteria in conjunction with H∞ constraints), considering uncertain parameters in the converter model. Finally, from computer simulations, the proposed work can emulate the PV behavior considering atmospheric variations, such as solar radiation and temperature, in order to evaluate the performance of the system and to validate the proposal of the work.