Estudo e desenvolvimento de conversor Dual Active Bridge (DAB)

Abstract

This work presents the design of a Dual Active Bridge (DAB) converter for managing the charging and discharging of lithium-ion batteries. The goal is to define the operational stages of the bidirectional converter and size it for a power of approximately 1 kW, with nominal voltages of 250 V on the DC bus side (high voltage) and 53 V on the battery side (low voltage). The aim is to keep the voltage ripple variation within operational limits: 2% on the bus (during discharge) and 1% on the battery (during charging), as well as a 5% variation in the current ripple on the DC bus side and 2.5% current ripple on the battery side. In this work, the methodology includes an explanation of the operation and a description of the elements of the DAB converter. The control of the converter is carried out using the phase shift method. The equations obtained from circuit analysis in each of the four operational stages are demonstrated, both in charging and discharging modes of the battery. From the equations, the converter’s components are sized. Computer simulations performed in PSIM software showed that the current and voltage values of the DAB converter comply with the previously presented specifications. In charging mode, a 0.28% voltage ripple and a 1.39% current ripple flowing to the battery were obtained. In discharging mode, a current ripple of 1.78% and a voltage ripple of 0.00002% on the DC bus were observed, indicating that the design was properly dimensioned.