Hierarchical control for electric vehicles in smart grid with renewables

This paper presents a 3-level hierarchical control framework for optimizing the charging and discharging of plug-in electric vehicles (EVs) and supporting smart grids with renewable energy (RE) sources. Using linear control model, the level I control defines the economic power dispatch schedules for the main power plants, emergency ancillary services, RE sources and EV aggregators. The EV aggregators in level II control determine the power rates of its subordinate vehicles subject to physical constraints and customer requirements. The level III controllers in each EV execute the allocated rates with their own adjustments to support real-time frequency violations while meeting the charging requirements. The advantages of the proposed control framework come from its simple and fast algorithms, the ability of managing large number of EVs through aggregators as well as meeting the grid constraints and customer requirements.