Energy-efficient operation of multi-trains for metro systems with considering the regenerative energy

Utilization of the regenerative energy has a great potential to reduce the energy consumption in metro systems, which is related to the train timetable as well as the driving strategy. This paper proposes an energy-efficient train operation approach by integrating the train scheduling and the driving strategy. Firstly, the models of calculating the traction energy and the reused of the regenerative energy are introduced. Then, the optimization model of train operation is then formulated by taking the systematical energy (i.e., the difference between the traction energy and the reused regenerative energy) as the objective function. Based on the space-time-speed network methodology, the optimization model is transformed to be a discrete decision problem and the dynamic programming method is used to obtain the corresponding solution. Finally, a case study is conducted in the end to illustrate the effectiveness of the proposed approach.