System energy optimisation of metro-transit system using Monte Carlo Algorithm

With rising concerns on energy and environment, the energy-efficient operation techniques in railway systems are paid more attention in recent years. The metro-transit system has some distinguishing features like short headway and a high number of stations with short interstation distance, which makes effectively using regenerative energy becoming more significant in the energy-saving study. This paper illustrates a system energy optimisation approach to reduce global substation energy consumption, using Monte Carlo Simulation. The conception of substation and regenerative energy estimation is proposed in the optimisation. A railway power network simulation is utilised to validate the energy-saving performance in Beijing Yizhuang Subway Line. After applying efficient-driving strategies remaining current timetable, the substation energy can be reduced by 29.9% compared with current operation. By slightly changing the journey time of each interstation, the substation energy consumption can be reduced by additional 13.8% due to an increasing usage of regenerative braking energy.