Study On Integrated Simulation Of Traction Current And Track Circuit In High-speed Railway

With the trend of railway speed-up and electrification,our nation has already put 400km/h High-Speed Railway(HSR)on the agenda.However,higher-speed electrified railway will lead to greater traction power and traction current,which means signalling equipment(represented by track circuit)have to face more severe electromagnetic environment and greater Electromagnetic Interference(EMI)due to the fact that traction current and signalling current use the rail as the common transmission channel.Therefore,it is of the essence to build a parameter-adjustable integrated simulation platform to predict traction current distribution in higher-speed condition and to obtain anti-traction-current-interference configuration of track circuit.Based on this background,this thesis focuses on the following aspects:Firstly,analysis on traction-current-elicited conductive interference is carried out from the facet of source,coupling path and susceptible equipment,according to three elements of Electromagnetic Compatibility(EMC)principle.Combined with the case study of on-site traction-current-harmonics-interfered track circuit,the harmonic influence on track circuit is verified and the relevant theoretical bases are laid for model-building.Then,continuous mathematical method and node voltage method are adopted to formulate the traction current module of the simulation platform in obedience to Carson theory.Comparison of two methods are made under the condition of single train and multi-train tracking,and simulation of traction current and rail potential of 400km/h HSR is performed in the double-line multi-train tracking situation.Comparative verification of traction current distribution is made between simulation and railway field data.Also,discussion on whether rail potential simulation data meets the related requirements of EN 50122 standard and evaluation of through-ground wire diameter in integrated grounding system are arranged under the premise of higher-speed HSR.Lastly,with the help of line setting of traction current module,interference-injectable models of track circuits in different carrier frequency are established,which enables the integrated simulation platform with track circuit module.In addition,the track circuit collaborative optimization strategy based on the transmitter-and-attenuator modification is proposed in conformity with on-site case for anti-transient-interference purpose.The central results are as follows.Rail potential of 400km/h HSR in the state of multi-train tracking simulation does not outnumber 120 V requirement of the standard,but it is pretty much close.Through-ground wire with larger diameter signifies greater current-carrying ability;TJ-70 type is suitable for the current-carrying demands of HSR in most situations,while TJ-95 type must be in service when the ambient temperature comes up to a certain degree.For track circuit,there will be a set or sets of parameters(transmission voltage levels and attenuation values)which allow the reliable operation under the influence of corresponding interference.Major work of this dissertation is of reference value involving engineering cost,human/equipment safety issues and signalling system anti-interference performance.