Research On Electromagnetic Compatibility Of Maglev Train With Carbon Fiber Composite Car Body

With the rapid development of rail transit,the requirements of safety performance,comfort,environmental protection,running speed and lightweight structure of train are higher and higher,which makes the shortcomings of traditional metal car body more and more obvious.Carbon fiber composites have low density,high specific strength and modulus,low thermal conductivity,good corrosion resistance,vibration reduction and impact resistance,and gradually become a new choice for rail transit car body materials.At the same time,compared with other rail transit vehicles,the maglev train is suspended by electromagnetic force,so the electromagnetic environment inside the maglev train body is more complex.However,the permeability and conductivity of carbon fiber composites are not high.Compared with traditional metal car body,the electromagnetic shielding effect of carbon fiber composites is greatly weakened,which easily leads to the magnetic induction intensity in maglev train exceeding the standard,thus affecting the safety of train operation and the comfort of passengers and drivers.Therefore,it is necessary to study the electromagnetic compatibility of the maglev train with carbon fiber composite body.Firstly,the electromagnetic interference source of maglev train is analyzed.The electromagnetic interference of maglev train mainly comes from the low frequency AC magnetic field produced by linear motor and the DC steady magnetic field produced by suspension system.The magnetic field generated by linear motor and suspension system is analyzed theoretically.Then,according to the three-dimensional structure parameters of linear motor,single electromagnet and suspension module,builds the threedimensional model in ANSYS Maxwell simulation software.By observing the lateral edge effect of linear motor and the distribution of air gap magnetic field of suspension system,obtains the distribution regular pattern of electromagnetic interference of linear motor and suspension system to the maglev train.Secondly,the sensitive equipment of maglev train is analyzed.The sensitive equipment of maglev train mainly includes signal communication system,braking system,passenger information system,passengers and drivers.Then,the composition of each equipment and the type and flow direction of transmission signal are analyzed.Refer to the standard of electromagnetic environment control limits(GB/T24338),explains the anti-interference standard of each equipment.At the same time,the electromagnetic radiation standards related to the control and limitation of public exposure to electromagnetic environment are analyzed.Combined with the electromagnetic field characteristics of electromagnetic interference sources,the electromagnetic standards are summarized,and the standards issued by the International Commission on non ionizing radiation protection in 2010 are selected as the electromagnetic standards analyzed in this thesis.Finally,the three-dimensional structure parameters including train and track are given,and the three-dimensional simulation model of maglev train is built in ANSYS Maxwell simulation software.Analyzing the electromagnetic environment inside the car when the car body is made of carbon steel,stainless steel,aluminum alloy and carbon fiber composite respectively.According to the analysis results of the magnetic field intensity distribution of carbon fiber carbody material,the electromagnetic compatibility of the train is designed from three aspects of shielding material,shape and thickness.Then,the shielding device is added to the vehicle model of ANSYS Maxwell simulation software.The simulation results show that the electromagnetic environment in the train meets the standard after the EMC design.