Modeling And Simulation Of Traction Power Supply System With Integrated Grounding Wire

The simulation analysis of the high-speed railway traction power supply system depends on the accurate modeling of the traction power supply system and the algorithm of the power flow calculation.The research object of this paper is the high-speed railway traction power supply system with integrated grounding wire.With the general modeling of the traction power supply system impedance and electromagnetic induction,the algorithm of the power flow calculation,the ratio of the return current and the effects of the electromagnetic induction are studied gradually.Based on the parallel multi-conductor transmission line theory,this paper sets up a unified mathematical model of the traction network and realizes the impedance calculation for different forms of traction network.With the method of buried bare wires,the modeling of integrated grounding wire makes up for the shortcomings of grounding resistance equivalent method which cannot calculate wire current,and takes the coupling between the integrated grounding wire and other wire into account.With the method of voltage current transformation matrix,the establishment of a general traction substation equivalent circuit realized.Based on the chain network structure,the traction network,the train and the substation are unified to conduct the dynamic power flow calculation.The power supply simulation becomes closer to the real situation.With the introduction of integrated grounding wire in high-speed railway,the distribution of traction return current becomes very complicated.Modeling simulations based on the measured line containing integrated grounding wire are carried out.The distribution proportion of return current in different back wire is figured out and compared with the measured return ratio.In this way,the accuracy of the buried bare wires method and the chain network flow algorithm are verified.The return current test schemes are explored.Calculation of the return current ratio and its variation range provides reference for design and test of the return system.Where the high-speed railway and urban rail are closely parallelly built,the high-speed AC traction network may cause induction voltage in the neighboring DC traction network conductors through the electrostatic induction and the electromagnetic induction.In this paper,the electrostatic induction voltage and the longitudinal induction electromotive force in neighboring urban rail traction network on the Dashengguan Bridge are separately carried on the field test.The electrostatic induction voltage is calculated with the method of mirror image and capacitance network.The mutual inductance between the conductors is calculated with the theory of Carson.The shielding effect of reflux on electromagnetic induction is taken into consideration.The simulation modeling of the electrostatic induction and the electromagnetic induction is respectively compared with the measured results.The effects of the electrostatic induction,the electromagnetic induction and the steel truss shielding are quantitatively evaluated.The Suggestions of improving the electromagnetic induction effect are proposed.Research shows that high-speed rail had a bad influence on the neighboring urban rail.It's better to install the induced voltage suppressor on the urban rail.