Minimal-Energy Driving Strategy for High-Speed Electric Train With Hybrid System Model

This paper studies a minimal-energy driving strategy for high-speed electric trains with a fixed travel time. A hybrid system model is proposed to describe the new characteristics of high-speed electric trains, including the extended speed range, energy efficiency, and regenerative braking. Based on this model, train driving is characterized by the gear sequence and the switching locations. An approximate gradient information is derived via the variational principle. To avoid a combinatorial explosion, the gear sequence is fixed by a priori knowledge. Then, a gradient-based exterior point method is proposed to calculate the optimal driving. In the case study, the minimal-energy driving with a fixed travel time for CRH-3 is investigated, and the result reveals some new understandings for high-speed electric train drive. Additionally, the tradeoff relationship between energy consumption and travel time is quantitatively studied, which is helpful in assigning an appropriate travel time for high-speed trains.