Pantograph Arcing Electromagnetic Radiation Model Of High-speed Train Passing Electric Phase Separation And Its Typical Application Analysis

In recent years,the development of railway industry in China is extremely rapid?In the traction power supply system,the 27.5kV contact wire is the only way for high-speed trains to obtain electrical energy.In order to balance the three-phase load,two-phase AC power supply is generally implemented,and the two-phase power supply arms are separated by an electrical phase separation device.With the increase of train speed and traction load,the pantograph-catenary arc will be produced when the train passes through the electric phase separation device,which may affect the operation of the peripheral radio equipment.Therefore,the research of pantograph-catenary arc in high-speed railway has become an important subject of electromagnetic compatibility in recent years.Based on the modeling and analysis of the high frequency current generated by the high-speed train passing through the electric phase separation,the electromagnetic radiation of the pantograph arc is taken as the main interference source.Based on transimission line theory and radio wave ropagation theory,the longitudinal propagation characteristics of electromagnetic radiation and the influence of electromagnetic interference on peripheral sensitive electronic equipment are studied.The main work of the thesis can be summarized as follows:(1)Firstly,the transmission line model of high-speed train passing through electric phase separation is established based on transmission line theory.Aiming at the electric phase separation structure and high-speed train,combining with Habedank arc model,the transmission line model of four transient processes of high-speed train passing through the electric phase separation process is established,and each transient equivalent model is further simplified into five lumped parameter circuits which have no direct connection on the topology by using transmission line theory,and calculated according to Kirchhoff's law.The time-frequency characteristics of high frequency current of pantograph arc are analyzed and compared with the traditional circuit model of lumped parameter.(2)Secondly,using the high frequency current obtained from four transient processes as the excitation source,a pantograph arc radiation model is established.According to the different frequencies,the research on pantograph arc radiation modeling is divided into two parts: the high-frequency current of 100kHz-30 MHz is used as the excitation source,the neutral line and the power supply arm are used as the carrier.According to the electromagnetic field theory,and the pantograph-arc radiation with the frequency of 100kHz-30 MHz is studied.Using the high frequency current above 30 MHz as the excitation source and the pantograph as the carrier,the frequency radiation in the pantograph arc of 30MHz-120 MHz is studied according to the high frequency current of the pantograph obtained from the theory of transmission line in the first part.Compare the test data with the theoretical analysis to verify the correctness of the theory.(3)Then,a transmission line theoretical model based on lossy earth and car body is constructed to study the longitudinal radiation characteristics along the high-speed railway.In IEC 62236-2,only the formula of transverse attenuation and propagation characteristics of electrified railway along the direction perpendicular to the railway is given.For the medium wave radiation represented by 0.5MHz,it is found that it has longitudinal propagation characteristics in the evaluation and test of the airport navigation facilities on the high-speed railway.Based on the field test and the theory of non-uniform transmission line,the model of longitudinal propagation radiation based on 0.5MHz is established,and the theoretical results are compared with the actual test to verify the correctness of the model.(4)Finally,the influence of pantograph-catenary arc on the electromagnetic interference of peripheral wireless communication navigation equipment is studied.Taking the extension line of parallel airport runway of high-speed electrified railway as an example,based on the theory of electric wave propagation and combining with the second part,the field intensity and field test data of pantograph arc with passing through electric phase separation are calculated.According to the requirements of the protection rate of ILS equipment in GB/T 6364,the influence of electromagnetic interference(EMI)on the arc radiation is analyzed,and the electromagnetic interference to the navigation system at different parallel distances between the high-speed electrified railway and the runway extension line is studied.