Improvements of energy efficiency of urban rapid rail systems

Abstract

Generally, there are 3 complementary means of energy reduction in urban rail systems operation, such as rapid rail or subway. First, the driving style and timetable of a single train run can be adjusted, so that traction energy consumption is minimal. To implement this strategy in manually operated systems an assistance system would be necessary. Secondly, use of energy regenerated during braking in the railway network contributes to a further reduction of overall energy consumption. To influence the amount of regenerative energy used by other trains, optimal choice of the synchronization time between the departures in the 2 directions is necessary as well as train running time control. The 3rd approach deals with strict adaptation of transport supply to demand by using small vehicles and flexible headway scheduling. The operational effort of the railway system can be reduced for a constant or even increasing traffic demand, so that the required traction energy is minimized. An estimation of the potential energy reduction is provided for each strategy by means of simulation and case studies.