A Feedforward Control Methodology Incorporating Input and Output Voltage Variations in Dual Active Bridge Converter

In a typical data centre application, utilization of DC distribution system by generating a HV-DC bus (800V) is becoming increasingly popular for improved distribution efficiency. For this, the Dual Active Bridge (DAB) converter is increasingly being considered for the isolated DC/DC converter stage. One important requirement of such an application is the tight regulation of output HV-DC bus <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(V_{o})$</tex> irrespective of load and input DC voltage changes. In this paper, a input and output voltage feed-forward based control scheme is proposed, considering the power flow analysis from both primary and secondary sides. The proposed feed-forward method is found to be inherent in a DAB converter operation. The proposed feed-forward method is incorporated in the traditional two-loop control of DAB converter. Through analytical, simulation studies and experimental validation, the proposed scheme is compared against two loop control and is found to have improved the transient performance of the DAB converter.