Simulation method and device for power supply system of urban rail Y-shaped line with main and branch lines operated independently

The invention discloses a simulation method and a device for a power supply system of an urban rail Y-shaped line with main and branch lines operated independently. The method comprises the steps: acquiring information required by simulation calculation of the power supply system of the urban rail transit Y-shaped line; exporting a power supply system model file from a power supply system main wiring diagram by using a graph-model integration technology; generating a simulation parameter file based on the information required by the power supply system simulation calculation; analyzing the simulation parameter file to generate a running diagram simulation file; and analyzing the running diagram simulation file and the power supply system model file, and then calculating the power supply system by applying an alternating current and direct current alternating iteration power flow algorithm to obtain a power flow change condition of the power supply system within a period of time. According to the method, the p