Optimizing train trajectories for energy consumption using a traction- and speed-dependent engine efficiency

Kurzfassung

Speed profile optimizations of trains constitute an effective method for the reduction of the overall energy consumption within a railway system. The study aims to determine energy efficient driving strategies by taking the power losses of the propulsion system as well as time constraints and physical limitations imposed by the train and its operational environment into account. Due to the complexity of the underlying problem an analytical approach can only be applied in a limited way. Instead, the paper proposes a novel solution based on dynamic programming. Considering the propulsion system's efficiency as either constant or variable, this enables a thorough comparison of different energy-efficient trajectories. Based on characteristic scenarios the potential for energy savings is identified and suitable driving strategies are derived. The study concludes with a discussion of the practical applicability of the suggested solution and its results.