A graph theory-based optimal configuration method of energy hub considering the integration of electric vehicles

This paper proposes a novel optimal configuration method of energy hub (EH) considering the integration of electric vehicles (EVs), which can co-optimize the structure and capacity of EH as well as the charging and discharging schemes of EVs. First, a computerized modeling method for EH is proposed based on the graph theory. The EH is transferred into a hierarchical digraph automatically, and the compact matrix form of power balance and energy conversion equations is deduced. On this basis, the optimal configuration model of the EH integrated with EVs is constructed, which is extensible and can plan from scratch without any presupposition of EH structure. The objective function of the optimal configuration model is to minimize the total cost, and the constraints include power balance, inside topology, varying energy conversion efficiencies of energy devices, and operation characteristics of EVs. The piecewise linearization method is utilized to transfer the EH configuration problem into mixed-integer linear programming. Case studies based on a realistic integrated energy system verify the effectiveness of the proposed method. Results indicate that with the consideration of EVs participation, the proposed EH optimal configuration method can save the total cost of EH configuration by 2.97%. •A graph theory-based standardized matrix modeling method for EH.•Joint optimization of the structure and capacity of EH as well as the charging and discharging schemes of EVs.•Consideration of the varying energy conversion efficiencies of CHP and HP.