Optimization of heterogeneous charging infrastructure and charging schedule of electric buses for city routes

The problem of optimizing the equipment of urban transport network nodes with charging stations of various types and the daily charging schedule for them for a fleet of battery electric buses is considered. Charging stations of depots should provide slow charging of electric bus batteries at night to the maximum level, charging stations of route terminals are intended for fast partial recharging of batteries, sufficient for electric buses to perform next trips of their daytime tasks within a representative period of the day. The criterion of optimality is the minimization of the total daily cost of charging stations, wear of electric bus batteries and consumed electricity. A mathematical model of the problem in the form of mixed integer linear programming has been developed. The means of increasing the efficiency of the model through additional constraints have been studied, and the most efficient subset of such constraints has been identified. A computer experiment with randomly generated problem instances has confirmed a good performance of the model for medium and large-scale problems.