A Hierarchical Control Strategy for Electric Vehicle Coordinated Charging

The increase of Plug-in Electric Vehicle (PEV) load brought big impact on the power system, which threaten safety and reliability operation of distribute network. Therefore, a coordination PEV charging scheme is urgently needed in the grid dispatching system to make PEVs the smooth access to the grid at all levels, and decrease the difference between load peak and off-peak. The proposed two-level charging strategy is mainly based on sub-control centers at charging station level and main control centers at municipal level. The PEVs charging load guiding curves can be obtained at the main control centers by solving load-shifting optimization problem, which is allocated to sub-control centers to follow. In this way, control centers can achieve load-shifting and reduce charging cost according to actual situation. Simulations verify the effectiveness of proposed hierarchical control framework.