Study On Integrated Grounding System Of High Speed Electrified Railway

High running speed, high running density, strong traction load current, high rail leakage resistance lead to steep rail potential rise.Considering human and machine safety issues, rail potential, traction current feeding and earthing should be attached importance to.The concept and the technique of integrated grounding system is introduced.It emphasis on two points: one is the influence of return circuit to human, the other is the safety of various electrical equipment in system.So, it has a significant meaning to propose integrated grounding system of high-low voltage compatibility and strong-weak power unity fitted for civil safety standard.A brief condition of grounding technique and relevant standard used in foreign high-speed electrified railway is introduced.According to the basic theory of current feeding and earthing, rail potential distribution regularity and characteristic for different traction power supply system is deduced.By analyzing the influence of various parameters in integrated grounding system on rail potential, effective methods to reduce rail potential are proposed.Then the mathematical model is built and the simulation results indicate the correctness of these principles.With different integrated grounding systems designed for jing-jing railway, the traction network parameters are compared and analyzed under both normal and fault conditions by simulation.Integrated grounding system fitted for civil passenger railway line is presented according to safety standard.The development of software for integrated grounding system simulation not only has realistic meaning to the design and evaluation of grounding system, but also provides guarantee to human, machine safety and traction network reliability.