An Efficient G2V and V2G Converter Systems for EV Application

EVs are becoming a major contributor to smart grid development by bidirectional power flow in the connected distribution grid. In this paper the battery charging scheme for EV has been proposed by using bidirectional AC/DC converter and a bidirectional DC/DC resonant converter. Here bidirectional power flows from Grid to Vehicle and Vehicle to Grid. The proposed scheme operates in two modes: Charging and Discharging of the storage battery where each mode has two stages. The charging mode converts 230V, 50Hz grid supply into 410 V DC with a bidirectional AC/DC converter. At the second stage rectified voltage steps down to 120V with the help of a bidirectional resonant DC-DC converter to charge an onboard 120 V, 10AH battery. The direction of power flow reverse during discharge. The battery voltage boosts up to 410V by a bidirectional resonant DC-DC converter and then this output voltage is fed back to the grid with a help of the bidirectional DC/DC converter. The resonant converter operates with 40kHz switching. The soft switching technique ZCS/ZVS help to minimise the switching losses and reduce the size of the components. The AC/DC converter has been simulated with SPWM technique. The overall concept has been simulated in Simulink/MATLAB.