| On the basis of research for power transmission line's lightning-proof property, this paper calculates the lightning-withstand level when lightning strikes to the tower and discusses the factor that effect the lightning-withstand level. This paper establishes the model of lightning striking to the tower by ATP-EMTP on power transmission line. The model considers peak value of lightning current, tower footing resistance, tower style, line surge impedance, power frequency voltage and distance between towers. The results indicate:· According to the research of induced voltage wave, it is pointed out that when the tower is struck by lightning, the peak values of induced voltage across the insulator strings and the injected current do not appear at the same time, and the effect of induced value is limited and should not be magnified· reducing the footing resistance is one of the most efficiency method to reduce the back stroking rate of power transmission line· The back stroking rate will fall by couple ground wire and enhancing insulation· The line-surge arrester can improve the lightning-proof property of transmission line on mountainous area and enhance the lightning-withstand level· The new arrest can improve lightning-withstand level greatly...
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