Control strategy of a multi-port, grid connected, direct-DC PV charging station for plug-in electric vehicles

Photovoltaic modules have become a viable renewable energy source for energy systems in communications, commercial, and residential applications. Plug-in electric or hybrid vehicles appear in the market as an emerging technology to reduce carbon emissions and improve energy efficiency. PV modules and plug-in hybrid vehicles interact with the power grid as energy source and energy storage elements, respectively, however little was reported on energy conversion systems featuring three-way energy flow among the power grid, PV modules, and plug-in hybrid vehicles. This paper proposes a plug-in hybrid electric vehicle (PHEV) solar carport charging station concept featuring a multi-port power electronic interface among photovoltaic modules, PHEVs, and the power grid. A unique control strategy is implemented, allowing efficient energy transfer while reducing the conversion stages between the source and load. The system is designed to be modular to improve flexibility and allow for ease of expansion. In the proposed system, a single modular system will provide charging for two parking spaces.