Modeling And Simulation Of Inverter Feedback Devices In Urban Rail Traction Power Supply System

System simulation of urban rail inverter feedback devices becomes the new issue of traction power supply system designing needed to be solved. Traction power supply system modeling and simulation containing feedback inverter is the base to accomplish relevant research of traction power supply calculation, the optimization of inverter feedback device location and capacity and energy feedback effect evaluation. This paper focuses on the research of AC-DC integrated calculation of city rail power supply system containing inverter feedback devices and provides technical support for the designing of the power supply system from the level of system modeling and simulation.This paper introduces modeling of the components of the urban rail supply system including the DC network, the AC grid, which contains AC load flow calculation equivalent network, DC system models of traction substation, trains and traction network to analyze the principles and solving algorithm implementation process.Two traction substation converter program can realize inverter-feedback function, which includes the one using the inverter SCR thyristor element and the one using the VSC full-controlled voltage source inverter switching device, by organizing their commutation circuit model and steady state power model and control mode.Using matlab as a programming tool, this paper achieves the iterative calculation algorithm of AC and DC power system by method of alternative integration. For feedback devices mounted inverter traction substation, state transition method is proposed based on the current flow criterion to achieve the three operating states converting between rectifier shutdown and inverter. VSC inverter circuit inverter feedback device as the main, in the capacity range selection constant DC voltage, AC voltage operation constant control strategy combination is confirmed. By AC-DC integrated power supply calculation the entire power supply system flow distribution can be solved, and how regenerative braking energy back into the AC network before allocated and utilized of the inverter can be analyzed.Finally the AC-DC inverter feedback device containing network-wide real-time dynamic simulation capabilities is realized, and based on Shanghai Metro Line 4 test vehicle energy consumption statistics, dynamic simulation is achieved on the basis of the actual load data and actual train power supply system structure and parameters. Through simulation of the inverter feedback device at different promoters and different operating voltages grid density, the feedback using effects of regenerative braking energy in each substation is evaluated and energy savings of the inverter feedback type of regenerative braking energy utilization project is analyzed.