Hierarchical charging management strategy of plug-in Hybrid Electric Vehicles to provide regulation service

Plug-in Hybrid Electric Vehicles (PHEVs) can be treated as mobile distributed energy storage units in a power grid. This paper addresses the feasibility of achieving system ancillary services with large-scale PHEV integration. The charging model of single PHEV and the statistic power demand model for charging process of large-scale PHEV are presented. Based on these models, a hierarchical large-scale PHEV charging management strategy with demand response is proposed. The proposed strategy not only meets the requirement of system dispatching but also is customer satisfaction constrained. Several cases are studied to verify the influence of customer satisfaction degree and starting time of charging management control on the potential of PHEVs to provide the auxiliary service adjustment. Simulation results also show that the number of PHEVs involved in the charging management process, which is mostly influenced by the setting of customer satisfaction degrees and the moments when PHEVs plug in the grid, has a great influence on the performance of charging management strategy.