Efficacy of Interleaved Two-leg Buck-boost Converter in EV Charger Design

The feasibility of using an interleaved two-leg buck-boost converter (ITBBC) in the design of an electric vehicle (EV) charger must be thoroughly studied to ensure its reliable operation. This paper analyzes the efficacy of using ITBBC at the battery-end point of each EV charger due to some advantages as follows: 1- hindering dc-bus voltage ripples from circulating into the current controller of the grid-side converter, 2- regulating the dc-bus voltage against variable battery voltage which can improve the efficiency of the whole system, and 3- reducing the ripple of the battery current to increase the battery lifetime. The small-signal transfer-function derivation of the studied converter is derived and investigated. An EV charger including ITBBC is designed and implemented. The mentioned advantages of the proposed system are verified by both simulation in MATLAB Simulink and experimental results.