Automatic Generation Control-based Charging/Discharging Strategy for EV fleets to Enhance the Stability of a Vehicle-To-Weak Grid System

In this paper, an automatic generation control (AGC)-based charging/discharging strategy is proposed for EV fleets to augment the stability of a weak power grid (WPG). The Vehicle-to-Weak Grid (V2WG) system under study is indeed a two-area microgrid including WPG, two EVs stations, PV units and loads. Firstly, the balancing power relation for three operating modes including no change mode, load increment and PV increment are comprehensively investigated. In doing so, a power sharing algorithm for each active EV is proposed to contribute to the WPG frequency deviation compensation. Then, AGC is developed for each area to attain the related angular frequency errors which are aimed to provide the tie-line power error needed for the dynamical frequency variation compensation using the appropriate EVs action. Moreover, the proposed strategy coefficients are analyzed to understand how much they can impact the stability margin of the system angular frequency errors. The simulation results in MATLAB/SIMULINK environment validate the ability of the proposed strategy-based EV fleets at providing a stable WPG under the increment of both load and PV units.