A Bi-directional battery charger for electric vehicles using photovoltaic PCS systems

In this paper, a new concept of bi-directional battery charger for PHEV/EV with photovoltaic generation system and operation algorithm of battery charger system is proposed. A novel battery charger system with photovoltaic generation is designed to have function of photovoltaic power conversion and battery charging/discharging. Also, considering sensitive photovoltaic source according to in the environment conditions, grid and battery characteristic, operation algorithms of the system is proposed and these algorithms are analyzed by four cases according to load conditions in detail. Moreover, it is applied to battery charging algorithm of hybrid constant current constant voltage control combined merits of constant current control and constant voltage control. Informative simulation using PSIM and experimental result using 3.3kW lab-prototype set are presented for performance verification.