Active and reactive power control strategies for electric vehicles in smart grids

Electric vehicles (EV) can be used as distributed energy storage devices to provide to the smart grid different regulation services. However, to have enough impact in the grid, the trend is to jointly manage a set of EV by means of a new stakeholder called aggregator. Knowing the availability, mobility habits, and the state of charge (SOC) of each EV battery, the aggregator performs the allocation of an active and/or reactive set-point to each EV within a time slot. This paper aims to propose reference charger currents for each EV from the individual set-point received by an aggregator. Control strategies for bidirectional active power control are compared under ideal and distorted source conditions. Besides, to contribute to reactive power support and voltage control in the bus where the set of EVs are connected, a reactive control strategy is proposed and validated by simulation. The proposed control strategies are applied to a Mode 2 single-phase EV battery charger connected to a single-phase grid. Simulation tests have been conducted using different control strategies and active/reactive set-points provided by the aggregator.