Scheduling method for minimum energy consumption considering constraints of time intervals between local and express trains

摘要

Recently, the railway sector is required to improve energy efficiency. Since no additional hardware investment is required, the authors are focused on the optimisation of the train timetable for less energy consumption. Train timetable contains the slack time for each interstation for robustness against delay. Although energy consumption can be reduced by the slack time, the slack time distribution was not always optimal in the viewpoint of energy saving. The authors already proposed to optimise the slack time distribution based on the “Law of Identical Incremental Energy Consumption”, however, it could be applied to the line only with local trains. The authors propose the extended train timetable optimisation technique considering minimum train intervals between local and express trains. In the formulation, the relation between the energy consumption and the running time for each interstation was investigated by means of a train simulator. The condition of the minimum interval was added to the model as a non-linear inequality constraint under the fixed total time between the origin and destination of each train. The proposed method was demonstrated by a case study of a typical Japanese commuter line. It was found that several percent of energy was reduced by the proposed method.