Optimization of neutral section location on high-speed railways with consideration of train operations

Neutral Section (NS), also referred to as the “phase separation section”, isan important component for electrified railways. NS leads to forced coasting operation and thus its location has an impact on energy consumptions of train operation for both running directions. This paper proposes a Mixed Integer Linear Programming (MILP) model to optimize the NS location and the train speed trajectory concurrently, so as to achieve a minimum energy consumption of train operation. A case study on a 21-km inter-station journey for high-speed railway is done, and the energy consumptions for the optimal NS location have been calculated and compared with the ones for other NS locations. The energy consumptions for scenarios with various NS locations are calculated by applying the optimal train trajectory with pre-determined NS locations. It is found that the minimum energy consumption based on the optimal NS location can achieve a 1.12% energy-saving rate in comparison to the mean value of energy consumptions for scenarios with other NS locations and can save 6.12% energy consumption comparing to the worst case. This is because the forced coasting resulted from NS contributes less to increase of energy consumption within some areas, where more operations of cruising and coasting are likely to be taken and less traction and braking can be replaced.