Abstract: The importance of Electric vehicles are increasing as they will form major sustainable transportation system in near future with less environmental pollution, fuel economy and energy efficiency. Bi-directional chargers adds the benefit of EVs by enabling energy transfer from vehicle to grid (V2G) or vehicle to home (V2H) in addition to charging from grid to vehicle(G2V). Typically, Bidirectional chargers consists of a AC-DC stage followed by DC-DC stage. This paper presents a non-isolated integrated bi-directional DC-DC converter for interfacing the vehicle battery to the DC link in both charging modes and discharging modes. The DC-DC converter is formed by integrating buck and boost converters and thus it is able to operate in buck as well as boost modes in both direction (charging and discharging). During charging (G2V) the dc link voltage is stepped down by the DC-DC converter to battery voltage and provides required charging current by current control. This is buck operation during charging. During V2G or V2H operation the function of the DC-DC converter is to boost the battery voltage to provide the dc link voltage. As it can also operate in boost mode in charging direction, the converter can charge the battery from a low voltage DC source such as photovoltaic panels by providing it directly to dc stage of the charger.
Keywords: Bidirectional dc-dc converter, Electric vehicle charger, Vehicle to Grid (V2G), Vehicle to Home (V2H).