Average model of dual active bridge interfacing ultra-capacitor in electrical vehicle

In this paper a new bidirectional DC-DC converter is proposed to transfer energy between ultra-capacitor and DC bus in electric vehicle. We present the average model of this converter. This model is used to calculate the small signal and transient characteristics of the converter. The derived small signal model can be developed and the transfer function between the output voltage and the duty cycle is calculated. This function is used to design a PI controller to regulate the output voltage at desired voltage in the closed loop under load and input voltage variations with at short time response.