A novel urban rail transit system based on DC distribution and energy internet architecture

In this paper, a novel energy internet architecture of urban rail transit is treated based on DC distribution. Renewable sources, cool/heat sources, electrical vehicles, braking energy feedback are added to the system. Flexible electricity trading strategies are included because of storage devices. It builds a DC distribution at the voltage level of 550 V to achieve efficient power transmission referring to the proportion of different loads in actual rail transit system. The efficiency and loss of the traditional AC system and DC system are calculated and compared. It shows that new design decreases the losses of conversion and cables and releases a large number of converters and rectifiers, which can promote energy conservation and environmental protection. The cost of cables and conversions also has a drop. The proposed architecture is supported by analysis, calculation and simulation.