架空导线耦合雷电电磁波机理与实验分析
投稿时间: 2016-06-08  最后修改时间: 2016-06-08  点此下载全文
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作者单位E-mail
陈晓东 张家港市防雷中心 akingch@sina.com 
中文摘要:随着电力系统以及精密电子设备的不断增加,因雷电引起的损失也越来越严重,电力系统的运行状态直接关系人们的日常生活,研究雷击架空线感应电压变化情况是具有很大的实际意义。针对架空导线耦合雷电电磁波机理的问题,通过传输线模型的理论分析,利用理论推导与试验相结合的方法,采用架空导线耦合模拟雷电的试验。得出:当雷电回击通道中雷电流在5kA到29kA范围时,架空导线耦合雷电电磁波形成的过电压幅值随雷电流的增大呈线性增加;耦合的能量随雷电流的增大呈幂函数关系增加;并且随导线长度的增加,耦合到的过电压和能量均减小;随导线截面积的增大,耦合到的过电压和能量均增大。该结论在架空导线雷电防护中具有一定的参考价值。
中文关键词:架空导线  耦合  模型  雷电电磁波  传输线理论
 
Analysis of overhead conductors coupling lightning electromagnetic waves mechanism and experiment
Abstract:With the power system as well as the increasing sophisticated electronic equipment, because of the loss caused by lightning more and more serious, the power system operating state is directly related to people's daily lives, study lightning induced voltage overhead line changes is of great practical significance . Due to the low probability of being struck by lightning directly overhead lines, accounting for about 10% of all lightning, so lightning sensors are the main factors causing power transmission line fault .Based on the principle of overhead line lightning electromagnetic coupling, combined with experimental data. Through the establishment of the lightning return stroke channel, the earth and the overhead wires integrated model, the overhead line coupling simulation of lightning current tests and comparative analysis and simulation, based on the experiments made: By studying the overhead line is coupled to the lightning electromagnetic environment voltage amplitude and energy law, for different lengths of overhead lines, draw a lightning electromagnetic coupling voltage overhead lines and high energy lightning current correlation coefficient curve fitting, lightning protection of overhead wires provides a theoretical basis. Using transmission line theory, there are three different descriptions of external electromagnetic fields on the transmission line coupling method: You can think of the transmission line is linked the incident flux two conductors and termination of excitation to the incident electric flux two conductors, so that the transmission line induction voltage is generated source and induced current source. Test using simulated lightning current impulse current generator, the height of 1.2m, 20mm diameter metal rods at both ends of the metal rod in here and play a simulated lightning channel transmit electromagnetic effects of lightning 8 / 20μs wave is applied in the simulation of lightning, because the electromagnetic field theory held that complex radiator can be approximated by a number of electric dipole and a magnetic dipole combination. Thus, the general radiation field can be electric dipole and a magnetic dipole to be approximated, and electric dipole is sufficiently short current-carrying conductor. It is applied at both ends of the metal bar from lightning impulse 5kA to 29kA current step size 2kA.When the over-voltage amplitude of the lightning return stroke channel lightning current when 5kA to 29kA range of overhead conductors lightning electromagnetic coupling with the formation of lightning current increases linearly increased; energy overhead conductors lightning electromagnetic coupling with lightning current size with good power function, the impact of current from the time 5kA to 29kA, the voltage range at 5v to 40v, the energy range 0J to 0.05J;overhead conductors lightning electromagnetic coupling is formed not only over-voltage amplitude and magnitude of lightning current, but also to the overhead wire length and cross-sectional area related, that the longer the overhead wires, coupled lightning electromagnetic wave is formed over-voltage and energy the smaller, the greater the cross-sectional area of the lightning electromagnetic coupling is formed over-voltage and the greater the energy.
keywords:Overhead conductor  Coupling  Model  Lightning electromagnetic waves  the theory of transmission lines
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