Study On Characteristics Of Railway Continuous Power Lines' Induction Electricity Produced By Electrified Railway

The close distance between the 10 kV Railway Continuous Power Line along the electrified railway and the traction network is shorter,and the parallel distance is longer.And due to the asymmetry of the traction power supply system,a strong electromagnetic induction effect is generated on the Railway Continuous Power Line,threatening the personal safety of the workers,and affecting the normal operation of the railway power supply and distribution system.This paper studies the relevant mechanism of electromagnetic coupling between electrified railways and Railway Continuous Power Lines.The main influence factors and influence rules of electromagnetic induction between electrified railways and Railway Continuous Power Lines are deeply studied,which has laid the foundation for taking effective induction protection measures.First of all,based on the analysis of electromagnetic coupling mechanism of capacitive coupling,resistance coupling and inductive coupling between electrified railways and 10 kV Railway Continuous Power Lines,the calculation model of railway electric potential due to rail leakage current is derived.The calculation method of the traction reflux in lines when the Railway Continuous Power Line and the power cable metal shield are grounded at both ends is given.Considering the influence of the size of the cable core,a modified formula for calculating the induced voltage of the single core cable metal sheath is put forward.Second,the electromagnetic coupling simulation model between the traction power supply system and the Railway Continuous Power Line is built by using CDEGS software.The validity and correctness of the model are verified by comparing the theoretical calculation,field test and simulation results of the relevant electrical quantities.On the basis of this,the effects of proximity distance,parallel length,soil resistivity,and power supply methods on the induced voltages during overhead maintenance of Railway Continuous Power Lines are calculated.The influences of the core current,cable length,and traction load current on the induced voltage distribution of the metal sheath on the cable power line are quantitative studied.The distribution characteristics of induced voltage and sheath circulation under different grounding methods for the protective layer of non-directly grounded protective sheath of power cable metal sheath are given.Comparing to protective layer grounding method for shielding layer and armor layer,it is demonstrated that splitting the sheath protector ground can more effectively reduce the circulation in the shield and armor layers.Finally,combined with the relevant operation regulations of electric power safety,the possible electromagnetic induction damage to workers is analyzed.The safe distance between the grounding lines at both ends is simulated and calculated when the Railway Continuous Power Line is overhauled under different field conditions.The protective measures for the protective layer of the circumfluence at both ends of the three core cable are proposed.It provides an important basis for optimal design and safe operation of Railway Continuous Power Lines.