Train Timetable Optimization for Suppressing Traction Power Fluctuations, Especially on Mountainous Railway Lines with Long, Steep Grades

Abstract

Railways traversing steeply sloping plateaus in mountainous regions face severe environmental conditions. However, weak external power grids and severe fluctuations in traction power threaten the stability of the grids and pose risks to train operation. To date, little research has focused on train timetable optimization in such mountainous regions, while simultaneously considering their impact on the power grid. In the present work, we took a mountain the railway was under construction as an example to study train timetable optimization of mixed passenger and freight railways to reduce their impact on weak power grids. The 372.47-km mountain railway, on which the study was based, is an electrified railway running from Qamdo to Linzhi in western China. An optimization model of train uniformity and optimal passenger travel time was constructed, and a two-layer improved genetic algorithm proposed to obtain the optimal solution. This was shown to effectively save energy, reduce load fluctuations, and suppress voltage fluctuations to reduce railroad operational impact on the power grid.