Multi-time Scale Optimal Bidding Strategy for an EV Aggregator in Energy and Regulation Markets

The increasing proportion of renewable energy sources into the power grid is calling for more regulation capacities. Electric Vehicle (EV) has a huge potential for regulation ancillary service due to its large amount in the electricity market. This paper proposes a multi-time scale bidding strategy for the EV aggregator, which considers the battery degradation cost of individual EVs. Firstly, with the piecewise linear cost function, a battery degradation cost model is established and incorporated into the optimal bidding strategy. Secondly, the degradation cost is calculated based on the change of state of charge (SOC) every 5 minutes, which is more realistically. This problem is studied in the context of the United States Pennsylvania-New Jersey-Maryland (PJM) market rules. The case study results demonstrate that the proposed model effectively incentivizes the demand resources to provide regulation ancillary service without reducing the operating profit of EV aggregator significantly.