Analysis, design and performance characterisation of transistor clamped dual active bridge DC-DC converter in wide voltage range

In order to control dual active bridge conventionally, control scheme such as single phase shift is used which reduces the system efficiency particularly when voltage conversion ratio differs from unity. This causes more circulating power and high current stress in switches. Moreover, voltage obtained at primary side of high frequency transformer is of two-level only, which increases voltage stress across it. Furthermore, it has only one degree of freedom which confines its ability to regulate power flow. In this paper, a transistor clamped dual active bridge dc-dc converter is proposed with three degrees of freedom which improves its ability to regulate power flow, and because of incorporation of five-level voltage on primary side of high frequency transformer, current stress in switches and voltage stress across high frequency transformer reduces. Mathematical modelling for the proposed converter is done for obtaining power flow equation. In addition to the phase shift control, proposed converter has two more control parameter which enhances the power flow controllability of the converter. Comparative analysis with conventional dual active bridge shows that the proposed converter is having more efficiency. Performance of the proposed converter is verified via simulation and hardware implementation.