矿井电快速瞬变脉冲辐射特性研究
Radiation Characteristics of Electrical Fast Transient/Burst in Coal Mines
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摘要: 为了研究井下电快速瞬变脉冲群引起的辐射骚扰,分析了EFT/B单脉冲波形的频谱,得出其幅值频谱达到1 GHz,运用时变电流源电磁辐射理论,建立了电快速瞬变脉冲电流激励下电偶极子辐射电磁场的时域解析模型,并进行了仿真计算. 仿真结果表明,辐射电磁场与峰值电流成正比,辐射电场较强,磁场较弱,场强随距离增加而迅速衰减,辐射场以近场为主. 通过井下开关投切试验,验证了投切感性负载会引起较为严重的瞬态电磁辐射骚扰.Abstract: To study the radiated disturbance caused by electrical fast transient/burst (EFT/B), the frequency spectrum of single EFT/B pulse waveform was analyzed by Laplace transformation. The analyzed amplitude spectrum of EFT/B was up to 1 GHz. Analytical expressions of electric dipole radiated electromagnetic fields excited by EFT/B were deduced by using the radiated theory of time-varying current source. The numerical simulation was implemented. Results in time domain show that the radiated electromagnetic fields are proportional to the peak current of EFT/B pulse; the radiated electric field is dominant; the radiated magnetic field is relatively weak and the field strength attenuates with the increase of distance rapidly. The radiation disturbance caused by EFT/B could be observed obviously from the experiments of switching on or off inductive load in a coal mine.
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