Modelagem e controle do conversor Dual Active Bridge (DAB) aplicado ao gerenciamento da entrega de energia de um banco de baterias

Abstract

This work aims to design and analyze a system capable of draining the energy stored in battery bank, or ESS (Energy Store System), supplying the demand for a bus that emulates the electric power system, from of the Dual Active Bridge (DAB) DC-DC converter. To motivate the of the case study a survey of the energy matrix for power generation is carried out, with emphasis on electric energy from the insertion of renewable energy sources, electric vehicles, smart grids connecting them to the existing system, with the use of DC-DC converters to manage the energy between them and the ESS. In the study the DAB converter the main characteristics in the backward flow process are analyzed, such as the direction of the circulating current in the circuit during the operation stages. From the average model for small signals that represents the converter, considering the addition of an inductive filter, will analyze the frequency domain responses of the open-loop transfer functions functions to assign in each plan the compensators according to project specifications. Two distinct controls are applied, one to maintain the constant voltage on the DC bus and other to keep the batteries discharge current constant, being attributed to the compensators slow response to any disturbance since the dynamics of energy delivery by the batteries is considered slow. For experimental results, initially a DC voltage source capable of emulating the same energy levels as the battery pack is connected provides, then a resistive load arrangement of 320 is connected to the DAB converter, which imposes 500W of power on the DC bus. The results are obtained in open loop to validate the operation of the converter, soon after, the loops are closed and then applied disturbances in the reference and in the load. Finally, the battery bank is connected and the total discharge is made, first applying the control keeping the voltage constant in the DC bus and in the second keeping the discharge current constant. In view of these characteristics, all results are presented during the discharge process of the batteries.