平原地区500kV输电线路雷电屏蔽性能的模型试验研究

Small-Scale Model Experimental Study on Lightning Shielding Performance of 500 kV Transmission Lines in Plain Area

雷害是输电线路故障的主要原因,在我国南方多雷地区,超高压输电线路频繁发生雷电屏蔽失效引起的跳闸,有必要更深入地研究超高压输电线路的雷电屏蔽性能。采用1:40线路模型,通过大量的冲击放电试验,研究了500kV输电线路的雷电屏蔽性能,得到了500kV输电线路绕击概率的空间分布规律,近似为抛物线,并分析了影响绕击的各种因素,如保护角、导线电压、导线对地电阻、非垂直落雷等。试验研究结果对提高500kV输电线路的雷电屏蔽性能有一定的借鉴意义。

Lightning damage is the principal cause of the faults in transmission line. In South China where lightning is rather active, the tripouts of UHV transmission lines, which are caused by the failure of lightning shielding, frequently occur, so it is necessary to research the lightning shielding performance of UHV transmission line in depth. Using the model of 500kV transmission line in proportion at 1：40 and by means of a large amount of impulse discharging tests, the performance of lightning shielding for 500kV transmission line is researched, the spatial distribution regularity of probability of shielding failure occurred in 500kV transmission line, whose shape approximates to parabola, is obtained. The factors influencing shielding failure, such as protection angle, conductor potential, conductor＇s resistance to ground, non-vertical fallen lightning and so on, are analyzed. The results of experimental investigation are available for reference in improving the performance of lightning shielding for 500kV transmission lines .