中低速磁浮交通电磁辐射原理研究

Research on the Principle of Electromagnetic Radiation in Low and Medium Speed Maglev Traffic

研究目的:中低速磁浮列车运行时,会对外产生电磁辐射。目前对中低速磁浮交通电磁辐射的研究主要采用现场测试的方式,基于测试值,分析中低速磁浮交通对临近铁路、机场等相关无线电子设施的电磁辐射影响。本文则从理论角度分析中低速磁浮交通电磁辐射的原理,通过Maxwell软件对悬浮电磁铁产生的直流稳态磁场和直线电机产生的低频交流磁场进行仿真分析;采用时域有限差分方法对电弧放电引起的高频电磁场进行理论计算,最后基于理论结果分析中低速磁浮交通对临近铁路和机场无线设施的电磁辐射影响情况。研究结论:(1)中低速磁浮交通产生的对外电磁辐射主要包括三个方面:悬浮电磁铁产生的磁场为直流稳态磁场,主要分布于磁浮气隙附近;直线电机产生的磁场为低频交流磁场,由于频率很低,无法形成有效的辐射,故主要分布在列车附近;电刷与供电轨产生的电火花能辐射出MHz级别的电磁波,能够有效地在空间中进行传播,故干扰距离较远;(2)中低速磁浮交通产生的电磁辐射场是一个复合空间电磁场,在近距离空间场不仅包括电弧放电引起的高频电磁场,还包括悬浮电磁铁、直线电机产生的低频磁场,在远距离空间场主要包括电弧放电引起的高频电磁场;(3)本研究成果可用于了解中低速磁浮交通的电磁辐射原理和对外的电磁辐射影响,可为中低速磁浮交通的工程建设提供参考。

Research purposes: When the medium and low speed maglev train runs,it will generate electromagnetic radiation. At present,the research on electromagnetic radiation of medium and low speed maglev traffic mainly adopts the method of test. Based on the test data,the influence of low and medium speed maglev traffic on the electromagnetic radiation of relevant wireless electronic facilities of nearby railways,airports and so on is analyzed. In this paper,the principle of electromagnetic radiation from low-speed maglev traffic is analyzed theoretically. Through Maxwell software,the DC steady-state magnetic field produced by suspended electromagnet and the low-frequency AC magnetic field produced by linear motor are simulated and analyzed. The finite difference time domain method is used to calculate the high frequency electromagnetic field caused by arc discharge. At last,based on the theoretical results,the influence of the medium and low speed maglev traffic on the electromagnetic radiation of the nearby railway and airport wireless facilities is analyzed.Research conclusions:( 1) The external electromagnetic radiation produced by medium and low speed maglev traffic mainly includes three aspects: The magnetic field produced by the suspended electromagnet is DC steady-state magnetic field,which mainly distributes near the air gap of the magnetic levitation;The magnetic field produced by linear motor is low frequency AC magnetic field,which can not form effective radiation because of the low frequency,and is mainly distributed near the train;The sparks generated by brushes and power supply rails can radiate MHz electromagnetic waves,which can effectively propagate in space,so the interference distance is far away.( 2) The electromagnetic radiation field generated by medium and low speed maglev traffic is a complex space electromagnetic field. In the near space field,it includes not only the high frequency electromagnetic field caused by arc discharge,but also the low frequency magnetic field produced by suspended electromagnet and linear motor. In the long-distance space field,it mainly includes the high frequency electromagnetic field caused by arc discharge.( 3) The research results can be used to understand the electromagnetic radiation principle and external electromagnetic radiation effect of medium and low speed maglev traffic,and provide reference for the engineering construction of medium and low speed maglev traffic.