Railway vertical alignment optimisation at stations to minimise energy

Abstract

As the energy prices and environmental concerns increasing, improving railway operation efficiency, which is an effective method to reduce energy consumption and operation expense, attracts people attention. In metro systems, the two traditional approaches to minimize energy consumption are optimizing the timetable and driving strategy, respectively. In this paper, a new approach is proposed to improve energy efficiency by optimizing the vertical alignment at stations along metro route. Firstly, the authors develop a simplified route with one station in the middle to analyze the relationship between energy consumption and the parameters of vertical alignment at the station. Secondly, they carry out an optimization simulation on vertical alignment at Beijing Subway Yizhuang Line No.5 station. The results show that the energy consumption could be reduced by 1.66%. Finally, the optimization simulations are extended to the entire Yizhuang Line. The results show that with adding optimal vertical alignments at all stations, the total energy consumption and journey time could be reduced by 5.6% and 0.53%, respectively. Above all, optimization of the vertical alignment at stations is an effective way to minimize energy consumption and improve energy efficiency.