Hierarchical transactive power exchange method on expressways for EV energy supplement

Electric vehicle (EV) users' driving requirement is restricted by the long charging period and high cost. In this paper, a hierarchical transactive power exchange method on expressways is proposed to eliminate range anxiety faced by EV users and further reduce their cost. When EVs are driven on expressways, battery swapping is considered the suitable power exchange mode due to high efficiency and adjustability. EVs are scheduled to supplement energy in battery swapping stations (BSSs) according to the remaining energy and battery swapping cost. Then, the power exchange among batteries and the power grid in BSSs is optimized for reducing the operation cost. In the optimization process, battery-to-battery and battery-to-grid modes are considered for reducing the power cost in the high electric price period. Some EVs release battery energy in designated BSSs and supplement energy in other BSSs. It reduces fast charging power of the battery and operation costs in designated BSSs. Several case studies are presented to validate the effectiveness and economy of the proposed method.