A Stackelberg game-based pricing strategy for integrated office building-electric vehicle system aggregators and charging management

The increasing penetration of electric vehicles (EVs) imposes significant stress on building power infrastructures, especially in existing buildings with high EV charging demand. This paper proposes a Stackelberg game-based pricing strategy for an integrated office building-EV system to coordinate the conflicting interests between EV aggregators and EV users. The upper-level model maximizes the aggregator’s profit by designing real-time retail electricity prices, while the lower-level model minimizes each EV user’s charging cost by deciding charging schedules and selecting between fast and slow charging modes based on a charging urgency index (CUI). The bi-level model is solved iteratively until it converges to a cyclic equilibrium, from which the Cyclic Best-Response Profit-Maximizing Solution (CBR-PMS), is selected. A case study is conducted using data from an office building in Suzhou, China, considering 50, 100, and 200 EVs across four representative months. Simulation results demonstrate that the proposed coordinated charging strategy effectively reduces EV users’ charging costs by up to 7.386% and increases aggregator profit by up to 4.259% compared to a fixed time-of-use (TOU) tariff. The strategy also shifts EV loads away from building peak hours, flattens the total grid power profile. Sensitivity analyses reveal that the equilibrium outcomes are influenced by pricing flexibility parameters, charging power levels, EV parking durations, and transformer capacity limits. The proposed method provides a practical and economically beneficial solution for existing office buildings to accommodate large-scale EV integration, offers actionable insights for policymakers and system operators, and promotes sustainable building-transportation integration in rapidly electrifying urban environments.