"Rising numbers of agglomeration residents cause increased need for people movement on daily basis. Because of congestion of local roads, air pollution and limited parking space, providing mass transit based on electric traction is reasonable. While the electric rail vehicles are considered highly efficient in themselves, they need to be analyzed as a part of a transport network, because energy consumption depends on operating conditions as well. Information about energy efficiency of whole system operating under realistic conditions could be helpful for modernization of traction power supply, timetable planning or while ordering new rolling stock.
This paper presents approach to analysis of energy efficiency of a suburban rail network, using specialized software developed on Matlab/Simulink basis. For the sake of analysis, simple transport network consisting of three lines was considered. Vehicles, assumed as uniform electric multiple units, operate according to the set schedule, taking into account varying electric drive efficiency and mass dependent on passengers’ number. Vehicles are supplied by four substations with nominal voltage of 3000 V DC, using overhead contact line. Developed model includes calculation of energy losses in power supply, therefore it is possible to determine efficiency of the whole network as a relation of mechanical energy of vehicles movement to electrical energy fed from public power system. Mean useful voltages for vehicles and substations are computed as well. Program structure allows for further expansion, e.g. with optimization algorithms."

electric traction;rail network efficiency;rail vehicle simulation