Topic：Integrating EV Charging and Discharging into Power Grid Through Bilateral Negotiation
Time:10:00 AM – 12:00 AM, Wednesday, April 2, 2025
Location: Room A716, New Main Building
Guest: Prof. Lin Yunfeng, Lee Kong Chian School of Business, Singapore Management University
Abstract:
To deal with demand uncertainty on a power grid, a power plant with limited ramping capability can collaborate with an electric vehicle (EV) company. With proper charging and discharging prices, the EV company voluntarily withdraws electricity from or returns electricity to the power grid in suitable phases. We model the two parties’ interactions as a bargaining game on the prices, followed by the EV company's charging and discharging problem and the power plant's electricity generation problem. To solve this bargaining game, we propose a novel “Guess and Verify” approach. Specifically, we first find an optimal solution within a restricted price set in which the two parties' total cost is minimized, and then verify its global optimality. Under an equilibrium contract, we find that the power plant can reduce its expected cost from the collaboration. This is because the EV company fully charges in a low electricity demand phase, reducing the power plant's curtailment cost, and fully discharges to the power grid in a high electricity demand phase, lowering the power plant's electricity generation cost. Based on real data, our numerical experiments suggest that the EV company's charging and discharging can substantially harmonize the power flow within the grid and save significant cost, especially when the electricity demand gap across different phases increases or the power plant's ramping capability decreases. Surprisingly, the EV company's percentage cost saving can exceed 100%, implying that it can make a profit from the collaboration. For the power plant, the percentage cost saving is 2-7%.
