Design and analysis of isolated bidirectional dual active bridge DC-DC converter

Power control has been done with different methods from past to present. Although classical methods were used at first, with the development of semiconductor technology, it was replaced by power electronics schemes. The increase in the use of technological products in daily life, industrialization, population growth, the formation of new settlements increase the energy demand day by day. The existence of DC devices that consume some of this increasing energy increases the need for DC-DC converters. Basic unidirectional DC-DC converters, such as buck and boost converters, do not feature bidirectional power flow. This limitation is due to the presence of diodes in their structure, which prevent reverse current flow. Generally, the diodes of unidirectional DC-DC converters are replaced by a controllable switch, resulting in a bidirectional DC-DC converter. Bidirectional DC-DC Converters are divided into two classes as Non-isolated and Isolated, depending on whether they have galvanic isolation between input and output. In this study, firstly, the analysis and design of Basic Bidirectional Unisolated Buck and Boost Converter was carried out in Matlab/Simulink. Then, the power flow analysis and determination of the design parameters of isolated bidirectional dual active bridge (DAB) DC-DC converter were examined theoretically and a 48/28V, 2kW converter was designed and simulated in the MATLAB / Simulink. The converter was operated for different relative transmission times in the forward and reverse directions, and it was evaluated whether it remained within the switching limits at zero voltage. It has been observed that the output voltage level of the designed converter can be adjusted to the desired value with the PID controller for both operating conditions. Keywords: Bidirectional DC-DC converter, DAB converter, single phase shift, zero voltage switching