Simplified Load-Feedforward Control Design for Dual-Active-Bridge Converters With Current-Mode Modulation

Many power electronic systems require dual-active-bridge (DAB) converters with ultrafast dynamic response. This paper presents a load-feedforward control design for DAB converters with current-mode modulation, which can enhance the dynamic response to fast load transients and current-reference step changes. A simplified nonlinear feedforward formula (NFF) and a linear feedforward formula (LFF) for the control design are proposed, which can be selected depending on the required feedforward accuracy (and acceptable computational complexity). The dynamic performance of a DAB converter operating in voltage regulation (VR) and current regulation (CR) modes is studied in frequency and time domains, with different feedforward formulas being used. This paper shows that the DAB converter with NFF has significantly faster transient response when operating in VR mode, whereas the improvement in transient response from using NFF is not much more significant than using LFF when the DAB converter is operating in CR mode.