中文摘要：

开展负极性雷电地闪过程中地面物体正极性上行先导特性的模拟试验研究是完善雷电屏蔽分析模型的基础，选择正确的模拟试验方法十分必要。分析了采用棒-棒、棒-板及板-棒等典型放电间隙结构的模拟试验方法的电场特征，研究了各种方法获得的正极性先导特性，并通过与自然雷电下的电场特征及上行先导特性进行对比，评价了各模拟试验方法的等价性。结果表明：采用棒-棒间隙和棒-板间隙无法模拟自然雷电下地面物体附近的电场空间分布特性；采用板-棒间隙可以模拟自然雷电下地面物体附近的电场空间分布特性，但传统的冲击电压发生器无法产生与自然雷电下行先导趋近地面过程中电场时变规律相同的冲击电压。因此，提出了研发一种基于电力电子技术、能够模拟自然雷电下电场时变规律的高压任意波形发生器，并结合板-棒问隙结构，形成正确有效的正极性上行先导特性模拟试验方法。

英文摘要：

Studies on the positive upward leader under negative ground flash using simulation tests provide a base for improving the lightning shielding analysis model. So selection of simulation test methods is meaningful. In this paper, the electric field distributions in rod to rod gap, rod to plane gap and inverted rod to plane gap were analyzed and compared with those under natural lightning to evaluate the equivalence properties of simulation test methods with the aforementioned gap constructions. The characteristics of positive upward leaders obtained using the simulation test methods were analyzed, and the problems of the simulation test methods were indicated. Using the rod to rod gap or the rod to plane gap is impossible to keep the similarity of the electric field distribution near the tip of the rod. On the contrary, using the inverted rod to plane gap can approach the electric field distribution in natural lightning. However, the traditional impulse voltage generator is incapable of simulating the trend of electric field＇s changing with time as the development of downward leader in lightning, and it causes inequivalence. A scheme for effectively simulating the positive upward leader was proposed, including design of a novel impulse voltage generator to simulate the time-change law of the electric field under nature lightning, and application of the inverted rod to plane gap construction to simulate the electric field distribution under nature lightning.