Controle LQG/LTR de um Conversor CC-CC de Três Portas Aplicado a um Dessalinizador

Abstract

This work proposes to use a centralized multivariable control strategy for an isolated three-port DC-DC converter that will gure as the integrating element between a photovoltaic system, a battery bank and the DC bus of a desalination system. The converter is represented by a multivariable state space model with 3 MOSFET switches as control inputs; the output voltage and the magnetizing current as controlled outputs; and the voltages of the photovoltaic panel and the battery as external disturbances. The control strategy is formulated using the LQG approach with recovery of the transfer loop gain (LTR) to guarantee stability to a state feedback controller with integral action. The main contributions of the work are: (i) the application, in power electronics, of a robust centralized control structure of state feedback, (ii) consideration of the input disturbances into the photovoltaic system and battery and (iii) use of the state estimator for the magnetization current loop. Finally, simulation results are presented and discussed to validate the performance of the proposed approach.