Energy-Efficient Train Control by Multi-Train Dynamic Cooperation

Regenerative braking technology has been widely used by subway trains, where regenerative braking energy (RBE) will be generated during train braking processes. An RBE usage method is proposed for subway trains, where train braking processes are predicted based on the field data of the train control system, and the braking information will be obtained in advance. The RBE will be calculated, and then, part or all of it will be distributed to neighboring trains in the same or adjacent power supply sections. Several feasible schemes for the RBE distribution are given, where the speed profiles of the neighboring trains will be adjusted to absorb the distributed RBE. An optimal RBE distribution scheme with the most effective usage of RBE will be obtained based on calculation results of the given schemes. For each adjusted speed profile of the neighboring train, a power process will be normally introduced. Existence of the optimal solution for speed profile adjustment is analyzed under the precondition that the train runs in a long speed-holding journey, and then, the necessary condition of the optimal solution is found by perturbance analysis. A simulation case of Yizhuang Line in Beijing subway is studied, and the simulation results show that the proposed method can use the RBE efficiently.