Adjustment of Energy-Saving Train Operations Based on Synergies of All Trains in the Same Power Supply Area

As a major use of electricity, the energy efficiency of urban railways is of great concern. To reduce the operational energy consumption of a metro line, this paper proposes a two-stage optimization model for energy-efficient train operations based on three aspects: train operation strategies at inter-stations, running time allocation within an operating cycle, and utilization of regenerative braking energy of multiple collaborative trains in the same power supply area. The first stage is based on a multi-objective optimization algorithm, which optimizes the position-speed curves at each inter-station to obtain a series of energy-saving running curves and the corresponding Pareto fronts. In the second stage, a single-objective optimization algorithm and parallel computing method are used to solve the integrated optimization model for train operations with the minimum net energy consumption as the objective function, to reduce the net energy consumption in an operating cycle. Finally, numerical experiments are carried out with data on the Beijing Yizhuang line. The results show that the proposed bi-level programming model and solution methods have a good energy-saving effect.