Exploring flexibility of electric vehicle aggregators as energy reserve

Abstract

With rapid development of electric vehicles (EVs), the potential of EVs serving as the power reserve is increasing. EVs are designed as a transportation for people’s daily trip with mobile energy storage. With large integration of intermittent renewable energy sources (RES), the imbalance between supply and demand cannot be quickly and effectively addressed by the traditional reserve due to the high-penetration of uncertainty and stochastic nature from the RES. An EV aggregator (EVA) acts as a mediator between the system operator and vehicle owners, enabling mutually beneficial coordination for EV owners and the power system. This paper proposes a flexibility evaluation model for the EVA to minimize the power imbalance risk from dispatching the clustered EVs to act as the power reserve. The EV reserve flexibility area (EVRFA) is defined to characterize the EV reserve flexibility (EVRF). Furthermore, a dispatching strategy of EVA for balancing the load demand and user trip is proposed. The dispatching guidance is used to dynamically modify the trip chain, the EV’s spatial distribution and State of Charge (SOC) are re-determined after the EV’s participation in the flexibility response. Finally, a case is investigated to verify the effectiveness of the proposed method.