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以Agrawal耦合模型为基础,利用二维时域有限差分方法,研究了城市建筑物对理想地面架空线附近的雷电电磁环境和架空线上感应出的耦合电压的影响,并分析了建筑物位置、建筑物高度以及回击电流参数等因素对电磁环境及耦合电压的影响差异。结果表明:建筑物的存在削弱了架空线附近的垂直电场,当建筑物分别位于架空线两侧时,水平电场方向相反;建筑物高度的增加对架空线附近的水平电场波形影响不大,当建筑物高度或者建筑物与闪电通道距离增大时,垂直电场均减小;对于15 m高的建筑物,当它与闪电通道分别位于架空线路同侧及异侧时,在继后回击下相比建筑物不存在时的耦合电压之比分别为46.1%和61.3%,在首次回击下的比值分别为47.0%和56.1%,建筑物对架空线路上的耦合电压产生较大的衰减;无论建筑物位于架空线的哪一侧,建筑物高度越高,距离架空线越近,衰减作用越明显。
Based on the Agrawal coupling model and the two-dimensional finite difference time domain method, the influences of urban buildings on the lightning electromagnetic environment near the ideal ground overhead line and the coupling voltage induced on overhead lines are studied. The location, Building height and backwash current parameters and other factors on the electromagnetic environment and the coupling voltage difference. The results show that the existence of buildings weakens the vertical electric field near the overhead lines. When the buildings are located on both sides of the overhead lines respectively, the horizontal electric fields have opposite directions. The increase of the building height has little effect on the horizontal electric field waveform near the overhead lines. When the height of a building or the distance between a building and a lightning channel increases, the vertical electric field decreases. For a building of 15 m height, when it is located on the same side and on the opposite side of the overhead line with the lightning channel, The ratio of coupling voltage to the building’s absence was 46.1% and 61.3%, respectively, and the ratios at first strike were 47.0% and 56.1%, respectively, and buildings significantly attenuated the coupling voltage on overhead lines. Which side of the overhead line is located, the higher the height of the building, the closer the overhead line, the more obvious the attenuation effect.