Current-Driven Bifrequency Resonant Dual Active Bridge Converter for Optimal Battery Charging

This article proposes a current-driven bifrequency resonant dual active bridge converter for efficiently charging a battery in constant current–constant voltage (CC-CV) mode. The novel converter gives the freedom to operate without complex control, while ensuring stable voltage and current regulation to achieve CC-CV charging. In the proposed configuration, the switching states causes the converter to form an equivalent parallel resonant tank which facilitates the proposed converter to behave as a current source and a voltage source using single step change in frequency and thus, offering dual source property at its output. This results in reduction of control complexity and the associated cost. In addition, the problem of input current ripple is eliminated and converter reliability is improved due to replacement of electrolytic capacitor by a resonant film capacitor. The behavior of converter is analyzed through state-plane analysis and trajectory of each interval with the closed form solution is presented. To verify the behavior of the proposed converter a scaled-down 500 W experimental prototype is developed and the results are presented for both CC and CV charging mode.