An Extendable Quadratic Bidirectional DC-DC Converter for V2G and G2V Applications

This paper proposes an extendable quadratic bidirectional DC-DC converter that has an improved voltage transfer ratio (VTR) with capability of redundancy and modularity for electric vehicle applications. As n modules are embedded, its VTR becomes n times higher for both directions of currents. Furthermore, the common electrical ground between input and output is preserved. This is a simple structure with the lowest rating of semiconductors in the family of quadratic bidirectional converters leading to ease of control ability. The proposed converter performance is evaluated in both power flow direction using the dead-beat controller which is smooth, accurate and fast response. Finally, the process of charging/discharging of a lithium-ion battery is controlled through the proposed converter. A 500 W experimental results are provided in both power flow directions in closed-loop system in the presence of the proposed controller. The obtained results verify the applicability of this structure.