Transistor clamped dual active bridge DC‐DC converter to reduce voltage and current stress in low voltage distribution network

Bidirectional isolated dual active bridge is a vital component for low voltage distribution network. Conventionally dual active bridge is operated using single phase shift control technique. At unity voltage conversion ratio, it operates efficiently, but when voltage conversion ratio differs from unity, its efficiency decreases and current stress increases due to more reactive power. Moreover, voltage obtained at primary side of high frequency transformer is of 2‐level only, which increases voltage stress across switching devices. 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 5‐level voltage on primary side of high frequency transformer, current stress in switches decreases significantly. It also leads to reduction in voltage stress across switching devices. Modeling of the proposed converter has been carried out to obtain 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. It has higher efficiency as compared to conventional 2‐level DAB. Performance of the proposed converter is validated via simulation and experimentation on developed laboratory prototype. 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 5‐level voltage on primary side of high frequency transformer, current stress in switches decreases significantly. It also leads to reduction in voltage stress across switching devices. In addition to the phase shift control, proposed converter has two more control parameter which enhances the power flow controllability of the converter. It has higher efficiency as compared to conventional 2‐ level DAB.