The effects of traction effort characteristics of vehicles on the performance and energy efficiency of DC supplied metro lines

This paper examines the effect of traction effort characteristics on system performance and energy efficiency for DC traction power systems. In particular, the effect of base speed drops and maximum traction effort reductions in case of low line voltage is investigated using a computer simulator, which can take many of the complex behaviours of a DC traction power system including the power regeneration properties of the vehicles into account. Two metro lines of Istanbul, namely Taksim-4 Levent and Kadiköy Kartal metro lines are considered as case studies to examine 750 V and 1500 V DC systems.