Cooperative train control for energy-saving

Energy efficiency is paid more and more attention in subway systems to reduce the operational cost as well as ensure an environmentally friendly transportation mode. Optimization on the driving strategy and efficient utilization of the regenerative energy are two effective methods to reduce the energy consumption in electric rail systems. This paper proposes a cooperative train control model to minimize the practical energy consumption, i.e., the difference between the traction energy of the successive train and the reused energy from regeneration. Firstly, we design a numerical algorithm to calculate the optimal driving strategy with a given trip time, in which the variable traction forces, speed limits, and gradients are considered. Then we formulate a cooperative train control model to adjust the trip time of the successive train for efficient use of the regenerative energy. Finally, the optimal driving strategy of the following trip is obtained for the successive train with the optimal departure time. Furthermore, some case studies based on the Beijing Yizhuang subway line are presented to illustrate the effectiveness of the proposed approach on energy-saving.