Modeling And Simulation Of Urban Rail Traction Power Supply System With Inverter Feedback Device

In recent years,the development speed of urban rail transit construction in China has been gradually accelerated,and the medium voltage inverter feedback regenerative braking energy utilization device has been widely used.In order to make effective use of the inverter feedback device in the newly built subway line and improve the energy saving effect of the system,it is necessary to analyze the power flow at the beginning of the power supply system design.However,the existing power supply simulation is difficult to meet the needs of regenerative braking energy utilization scheme design.Therefore,thesis studies the modeling and simulation of urban rail DC traction power supply system with inverter feedback device,analyzes the influence of inverter feedback device on the system through the actual test of the system,and finally analyzes the factors that affect the energy saving effect of the system.Suggestions are put forward for the setting of parameters such as the starting voltage of the inverter feedback device and the no-load voltage of the rectifier unit.Based on the study of various operating state model,train model and traction network model of traction substation in DC traction power supply system of urban rail transit,the state determination method of traction substation based on hysteresis comparison strategy is studied,and an iterative calculation algorithm of alternating current of urban rail AC and DC is proposed.The power supply system with inverter feedback device is measured and the algorithm is verified.The operation performance and energy-saving effect of the inverter feedback device are analyzed,and it is obtained that the starting voltage of the inverter feedback device can not achieve the effect of energy saving and voltage stabilization at1770 V,and the inverter feedback device has no obvious effect on power quality.the response time of the inverter feedback device is less than 1s,which meets the requirements of the national standard.In order to improve the ability of inverter feedback device to alleviate the second stage action problem of OVPD,the strategy of providing fast response time of inverter feedback device and setting delay of OVPD second stage action is put forward.finally,the effectiveness of the simulation algorithm of traction power supply with inverter feedback device is verified by comparing the measured and simulation results of traction load process.The factors affecting the energy consumption of the operation system of the inverter feedback device are studied.The influence of the starting voltage of the inverter feedback device on the traction energy consumption under the condition of high no-load voltage of the rectifier unit is studied,and the change of the adjacent traction energy consumption under the no-load voltage fluctuation of the traction station is analyzed.it is suggested that the no-load voltage of the rectifier unit and the starting voltage of the inverter feedback device should be kept at a certain distance.The daily feedback energy of the inverter feedback device under different starting voltages is studied,and the influence of the starting voltage of the inverter feedback device on the energy consumption of vehicle braking resistance is analyzed.It is suggested that the starting voltage of the inverter feedback device should not be set above 1750 V when the no-load voltage is high.