Research On Low Frequency Radiation Emi Characteristics And Suppression Technology Of Traction Power System Of High Speed Train

China's high-speed train has experienced a development process from foreign introduction and absorption to complete independent research and development.With the continuous improvement of the speed of high-speed train and the power of the vehicle,the electromagnetic environment in the train becomes more complex,which is often accompanied by the problem of excessive low frequency EMI radiation.Excessive electromagnetic interference causes voltage and current fluctuation and unstable operation in high-speed train,and even leads to abnormal communication and even shutdown failure in high-speed train when serious,potentially threatening passenger safety.Only by making clear the mechanism and characteristics of EMI can be suppressed from the root.To solve this problem,this paper,by means of theoretical analysis,modeling,simulation and experimental verification,focuses on the low-frequency radiation EMI characteristics and suppression technology of the traction power system of high-speed train.In this paper,the generation mechanism of low-frequency radiation EMI and the disturbance source characteristics of low-frequency radiation EMI are firstly explored.The conductive EMI loop model of traction power system is established on the basis of considering the parasitic effect,so as to realize the identification and clarity of the conduction path of the conductive current loop.The near-field coupling characteristics of the low-frequency radiation EMI are reflected through the conduction current loop,and the low-frequency radiation EMI model of traction power system is established.Based on the traction power system low frequency radiation EMI model,combined with the high speed train is difficult to change the original structure,active power supply cannot be achieved,such as present situation,put forward a kind of non-contact,can filter out certain frequency filtering scheme,the proposed filtering scheme for the modeling analysis,using the index of insertion loss is verified the feasibility of the scheme.Finally,a traction power system simulation model was built to simulate the conductive EMI characteristics of high-speed train,and an experimental prototype and test platform were built to simulate the low-frequency radiation EMI characteristics of the traction power system.Meanwhile,the suppression effect of the proposed filtering scheme was tested.To sum up,the low-frequency radiation EMI characteristic model of traction power system of high-speed train established in this paper can provide a theoretical basis for the study of low-frequency radiation EMI of high-speed train.