A Two-Stage Optimization Framework for Battery Swapping Stations Interacted with Electric Vehicles and Power Grids

This paper proposes a two-stage framework to optimize the operations of battery swapping stations (BSSs) interacted with electric vehicles (EVs) and power grids. In the first stage, a tiered pricing mechanism is introduced to maximize the EV owners' benefits. If the state of charge (SOC) of the BSS battery to be swapped to the EV owner is greater than a certain threshold, the tiered price of charging the battery decreases or increases with the SOC when the power grid state is valley or peak, respectively. Consequently, the BSS encourages or discourages the EV owner to select a battery with a relatively high SOC when the grid state is valley or peak, respectively. In the second stage, the BSS revenue from providing battery swapping services to the EV owners and from providing demand response services including peak shaving and valley filling to the power grid is maximized. In particular, the operation modes (i.e., being charged, being discharged, or idle) and the corresponding charging or discharging power of the BSS batteries in stock are optimized depending on the grid states of the present and next time slots. The effectiveness of the framework is validated in a case study with real-world battery swapping data.