Real-time Charging Scheduling for Electric Vehicle Aggregators in the Ancillary Service Market

An electric vehicle (EV) aggregator can offer new streams of competitive service to power system operators by performing optimal scheduling of EV charging which ensures reliable grid operation and cost-effective charging for the EV owners. This paper proposes an optimal EV charging and discharging scheduling strategy for EV aggregators that will maximize its profit while minimizing EV owners’ charging costs by enabling the EVs to provide valuable ancillary service to the grid. The model was applied to the regulation, flexible ramping product and proxy demand response markets of California independent system operator (CAISO) under four case conditions with realistic data consisting of Ill EVs arriving and departing at a 22kW AC leve1-2 public charger located in Palo Alto, California. The results show optimally scheduled charging of the EVs yields significant increase in profit for the aggregator.