Optimising Frequency-Based Railway Services with a Limited Fleet Endowment: An Energy-Efficient Perspective

Abstract

Energy-saving and energy-recovery strategies represent key factors to achieve operational cost reductions within rail systems’ management tasks. However, in altering service features, they also affect passenger satisfaction. This paper investigates the effect of implementing such measures in the case of rolling stock unavailability. Numerous operational scenarios were explored by analysing different planned headway and rolling stock configurations. The scenarios were simulated with and without the adoption of Energy-Saving Strategies (ESS), both in ordinary and in disruption conditions. Our results show that, in ordinary conditions, the optimal scenarios are those that minimise the planned headway. By contrast, in disrupted conditions, due to greater passenger inconvenience, the use of a time-optimal condition is preferable if a real-time adjustment of ESS is not feasible. However, if the ESS can be updated in real-time, use of ESS is preferable only if the adopted headway is the smallest of those associated with the rolling stock scheme considered.

Sustainable Mobility: A Review of Possible Actions and Policies

“…In recent years, research has been very focused on ecodriving applied to rail transport [78][79][80][81][82][83][84][85][86][87][88][89]. Although the rail transport system is more environmentally friendly, energy consumption and greenhouse gas emissions, where the energy consumed is not produced from renewable sources, are still high.…”

Quantification of the aerodynamic gain on two virtually coupled modular trains

“…Another advantage of VC consists in reducing the coupling realization time. As widely shown in the literature [8,9], the coupling/decoupling times have an influence on the cycle time of a railway service with direct repercussions on the maximum service frequency achievable on the line, therefore a real coupling could reduce the service frequency (and therefore of the line capacity) while a VC would make the frequency of service almost completely unchanged and thus maintain a good service performance. On the other hand, physical coupling only links trains with a same service type while VC provides the diversity of trains in the same railway platform by offering the possibility of connecting trains with different service types (people and goods).…”

Influence of Infrastructure and Operating Conditions on Energy Performance of DC Transit Systems

“…Overall, it is demonstrated in [7] using improved experimental data and modern vehicles can provide statistically relevant energy savings. On the other hand, a better exploitation of regenerative braking energy can be achieved by means of energy storage systems [2,3] and reversible traction power substations (TPSs) [8], controlling train operations and driving profiles [9], practically exploiting the scheduled service time reserve [10], and even including cases of timetable disruption [11]. The latter, in particular, represents a high-level solution that does not require major changes to the infrastructure and can be implemented in the automatic train operation (ATO) subsystem for metros and the supervision center or the operation and control center (OCC) for railways [12][13][14][15][16].…”

“…Improvement is also achievable by controlling train operations [11,44,45] in order to increase the probability of the presence of nearby powering vehicles when regenerative braking energy is available for regeneration. If the speed profile of each train is known, it is possible to increase the synchronization between absorbing and regenerating vehicles, adopting energy-efficient timetables by controlling train headway and dwell times at each station stop [9,46,47].…”