A Current Proportional-Differential Feedforward-Based Bidirectional Seamless Fast Dynamic Response Control for Dual-Active-Bridge Converters

Fast load dynamic response is the main requirement for a high-performance dual-active-bridge (DAB) DC/DC converter. Conventional load current feedforward (LCFF) strategy or its improved variants have been shown to improve dynamic response significantly. However, in these strategies, the control delay existing in the DAB control loop is neglected, and the dynamic response is not truly optimal. To fill this gap, this paper establishes the mathematical model representing the relationship between the transient disturbance of load current and the output voltage to analyze the effects caused by the control delay, based on which a current proportional-differential feedforward-based (CPDF) strategy is proposed to compensate the control delay in the DAB converter. Faster output voltage recovery after sampling the CPDF strategy during load transients. In addition, the CPDF strategy does not need any hardware modification compared with LCFF-based strategies. Finally, both simulations and experiments have verified the practicality and effectiveness of the proposed strategy.