A PV/Battery Multi-port V2X EV charger suitable for off-grid applications
Project description
The demand for electric vehicles (EV) are increasing as efforts continue to meet decreasing CO2 emission goals. When more people are in possession of an EV, subsequently more charger installations will appear on all nodes of the electricity grid. This has the consequence of risking overload in one phase in distribution networks, as people plug in their EV at approximately the same time. Simultaneously, local generation such as photovoltaics (PV) are increasingly being installed, which provides local generation but not at the same time as loads are being used.
Using a benchmark DC-link connected multiport 10 kW system, including an interface for PV panels, a battery energy storage system, the EV charger converter and an inverter which connects either to the grid or acts as the local grid former in stand-alone mode, control strategies and hardware constraints will be investigated in order to improve the efficiency of the inverter over partial load operating ranges. This is motivated as PV panel generation reaches peak production during mid-day, and load usage is concentrated to mornings and evenings. If more of the electricity from PV can be used instead of converted to battery energy, this cycles the battery less and improves longevity and efficiency. While a storage battery will help re-distribute the load and generation peaks, without an inverter that can re-distribute power between phases, instability on the local distribution grid will continue to increase and the total stand-alone independent run-time will be limited.
The PhD candidate will investigate, both for grid-connected case and stand-alone operation, imbalanced operation of the inverter stage of the multi-module three-phase charger. By enabling unequal drawing on unevenly loaded phases in grid connected mode, the charger system itself could decrease instability on the local distribution grid. And by enabling unequal loads within the local load where the three-phase charger is installed as it operates in stand-alone mode, the total stand-alone independent run-time will be sought to match at least the time of the most frequently occurring black-out time in Europe.
PhD Candidate: Carina Engström; c.b.m.engstrom@tudelft.nl
Supervisor: Gautham Ram Chandra Mouli; g.r.chandramouli@tudelft.nl;
Promoter: Pavol Bauer; p.bauer@tudelft.nl
More about the DriVe2X project: https://drive2x.eu/