Energy Impact of Different Intra-Platoon Spacing Policies for Virtually-Coupled Trains Sets (VCTS)

Abstract

Virtually-coupled train sets (VCTS) is a new railway operation concept that allows trains to drive together in a harmonized fashion without a physical connection, similar to a platoon of road vehicles. Since the distance between trains is not necessarily fixed (in contrast to mechanically connected trains), VCTS may get a small time advantage every time there is a change in the speed limit of the track. This paper analyses the time difference between mechanically coupled trains and VCTS using two different inter-vehicular distancing policy (namely constant gap (CDG) and constant headway (CTH)). The analysis is carried out analytically for a simple track for sake of visualization, and numerically on a virtual but representative regional track. The results show that the time advantage for CDG policy non-negligible, while the CTH performs worse than its mechanical counterpart. This report shows also that the time advantage can be converted into energy reduction in the range from 2-12% by allowing trains to drive slower while respecting the same timetable.