Research On Rail Potential Dynamic Emulator Considering Regenerative Braking Energy Absorbing Device

DC traction power supply system is widely used in urban rail transit.The rail potential and stray current issues have become one of challenges,which seriously threaten the safe operation of urban rail transit and the life of buried metal pipelines.The reported rail potential and stray current studies focus on mathematical modeling and simulation analysis,which can not provide verification for the emerging mitigation measures.In view of the fact that the mitigation measures face high safety risks in field test,dynamic emulator has attracted much attention because of its advantages such as not limited by space and time,easy for simulating the dynamic movement of trains,etc.Therefore,both topology and and control strategy of the rail potential dynamic emulator are studied in this thesis.Firstly,this thesis analyzes the advantages and disadvantages of the current reflux parameter distribution theory,simulation software and rail potential dynamic emulator.Combined with the modeling of DC traction power supply system and equivalent circuit model,the reflux system is simplified,and the distribution-parameter reflux system is transformed into a centralized parameter.The distribution law of the reflux system parameters considering the finite boundary effect is deduced,which provides a theoretical basis for hardware dynamic emulator considering the regenerative energy absorbing device(READ).Secondly,the topology,working principle and control strategy of two kinds of variable resistance modules(LRM and HRM)are studied in detail.On this basis,rail potential dynamic emulator with considering regenerative braking energy absorbing device(CB-RPE)including train,traction power substation(TPS),traction network,braking resistor,LRM and HRM is constructed.The evolution law,parameter selection and control strategy of the system are studied.By measuring the voltage of HRM to ground,the dynamic distribution of rail potential between train and TPS can be obtained.Finally,the simulation and experimental verification of each component of the dynamic emulator are carried out,and the corresponding experimental platform is built to realize the rail potential simulation under multiple working conditions of train.The simulation and experimental results show that considering the READ rail potential dynamic emulator is correct and feasible.