Dynamic load control at a bidirectional DC fast charging station for PEVs in weak AC grids

Widespread acceptance of Plug-in Electric Vehicles depends on the presence of charging infrastructures with filling times close to those of petrol stations. On the other hand, the roll out of fast charging stations which have significant power demand would cause several issues in the power grid such as overload, voltage drop and power loss. Therefore, to avoid costly upgrades in the existing power grids, it is necessary to have fast charging stations able to provide fast PEV charging while keeping the power grid intact. This paper proposes a bidirectional DC fast charging station with dynamic load control to address voltage drop and overload issue in weak distribution grids. By dynamic control of charging process, the proposed charging station maintains the voltage at the point of common coupling and prevents overloading in the incoming lines even when the charging power demand is more than the charging station capacity.