A Timetable Optimization Model for the Istanbul, Turkey, Metro Network Considering a Novel Regenerative Braking Energy Model

Abstract

Optimization of train operation is crucial in rail transport networks where large amounts of energy are used. The energy-efficient operation of trains is seen to be a good approach to saving operating costs in metro systems. There are two main techniques for efficient train operation. These are decreasing traction energy and increasing the usage of regeneration energy. In order to make maximum use of the regenerative energy of trains, an integrated optimization method that calculates the optimum train speed trajectory and timetable is proposed in this study. The suggested model aimed to increase the overlapping time of braking and accelerating train groups by improving the timetable. In addition, it is intended that two trains in the same electric zone do not accelerate or brake simultaneously so that the catenary voltage does not rise and decrease too much. The Istanbul M3 subway system with its real operating data is modeled and simulated. The genetic algorithm and simulated annealing algorithm were employed in the optimization process. The outputs of the study show that the consumption of traction energy can be substantially decreased by employing the best train speed profile and timetable.