An Energy-efficient Train Control Algorithm Considering Third-rail Voltage

Abstract:With the rapid development of economy, the sustainable development of urban rail transit is confronted with enormous challenges, one is the increasing transport demand; the other is the urgency of energy conservation and emissions reduction. On the one hand, in order to meet the growing transport demand, headway of trains in urban rail transit is continuously compressed and traveling density of the railway is increasing, which will directly lead to the increase of energy consumption of rail transit. On the other hand, environmental pollution has attracted attention of the whole world. Researchers began to pay more attention to environmental protection problems.This paper mainly studies coordinated control of trains to improve the use of regenerative braking energy based on train operation strategy to save energy. An energy-efficient optimal algorithm to adjust train operation strategy in real time is proposed in this paper by considering third-rail voltage. The algorithm can realize the maximum use of regenerative braking energy.The specific research contents in this paper are as follows:1) Research of related theories and methods. Based on the research at home and abroad, this paper tries to analyze the energy-saving strategies and principles of regenerative braking, and the influence of third-rail voltage on regenerative braking. In order to lay the theoretic foundation for the energy-saving effect, this paper also tries to analyze advantages and disadvantages of energy consumption calculation methods and propose the calculation model of energy consumption in this paper.2) Study on energy-efficient train control algorithm. This paper analyzes constraints and load conditions during operation, and then establishes a train operation control model taking the length or train into account. Also, a numerical algorithm based on a given energy consumption value is proposed to meet the need to adjust train operation strategy.3) Study on adjustment of train operation strategy. This paper introduces a model integrating train operation control and traction power supply. And then analyzes scenarios of utilization of regenerative braking energy based on the integrated model. This paper also proposes adjustment algorithm of train operation strategy considering third-rail voltage, which can make full use of regenerative braking energy by adjusting train operation strategy in real time.4) This paper establishes a prediction model of transit arrival times based on cellular automata to evaluate the headway, one of the judging conditions of whether to adjust the train operation strategy or not, between adjacent trains at station.The feasibility and effectiveness of the proposed model are verified on the integrated simulation platform based on field test of Yizhuang line, Beijing Subway. At last, a scenario that10trains run through4stations is simulated, and the result shows that after using the proposed algorithm, it can save9.04%on total energy for train running.