架空输电线路雷击感应过电压耦合机理及计算方法分析

目前国内雷击杆塔时的电感模型计算方法与国外通用的波阻抗计算方法有很大不同，计算结果出入较大。文章探讨了雷击架空线路附近地面(感应雷)与雷击杆塔时架空线上产生的感应过电压的异同点，认为二者，一个主要是电磁场的耦合，一个主要是线路的耦合；但雷电对架空线的影响都体现在雷电通道中电流和电荷对架空线的影响。场路耦合是统一的，实际应用中不能重复计算这两种影响。此外电感模型的计算误差是由电感对电流的微分响应造成电压损失产生的。并用工程实例计算结果证明了上述结论的正确性。

ANALYSIS ON COUPLING MECHANISM AND CALCULATION METHOD OF LIGHTNING INDUCED SURGE ON OVERHEAD TRANSMISSION LINES

At present the inductance model calculation method of transmission towers adopted in China for the towers being struck is remarkably different from the versatile wave impedance method calculation adopted in other countries, and there are obvious differences between the calculation results of the two methods. The similarities and differences of the induced surge on overhead line when lightning strokes the ground near overhead line (indirect lightning) and lightning strokes tower (direct lightning) are researched. On this basis it is summarized that coupling mechanisms of induced surge on overhead line for two kinds above-mentioned light stroke are different, one is the coupling through electromagnetic field and another is the coupling through electric circuit. But the impact of lightning on overhead line reflects the influence of charge and current in the lightning channel on overhead line, so these two mechanisms are unified under certain specification and in practice the influence of the two coupling mechanisms should not be repetitively considered. Besides, it is pointed out that in the lightning performance computation the calculation error of inductance model is caused by the voltage loss that is brought about by the differential response of inductance to current. Finally, case calculation is performed and the conclusion of above-mentioned analysis is further verified.