Charging and Discharging Schedule Optimization Method Considering Renewable Energy and Distribution System for Electric Buses

Electric buses are introduced toward achieving carbon neutrality by 2050, and there is a movement to utilize their storage batteries. On the other hand, the electric power system, where distributed energy resources are rapidly spreading, is becoming increasingly complex, and the impact of charging by electric buses on power system is an issue. In this study, we propose an optimization method for electric bus charge/discharge schedule that considers sector coupling between transportation system and power system. Then, we evaluate the effectiveness of the proposed method from the viewpoints of both the distribution system operator and the electric bus operator by performing power flow calculations using a distribution system model. The results show that the proposed method can contribute to power demand shifting and smoothing power flow in distribution network by charging and discharging, and that multiple evaluation indices, for example, peak-cutting of power flow, line occupation rate, distribution loss, reverse power flow utilization rate, renewable energy rate and CO₂ emissions, are improved compared to the conventional charging scheduling method.