佛山地区雷电流幅值概率分布研究

Research on the Probability Distribution of Lightning Current Amplitude in Foshan Area

规程DL/T620—1997经验公式lgPI=-I/88与佛山地区实际的雷电流幅值概率分布存在较大差异,小电流发生概率偏低,而大电流发生概率偏高。经过拟合分析,结合IEEE推荐,公式PI=1/(1+(I/37)3)能正确表达佛山地区雷电流幅值概率分布,其分布曲线与实际吻合,是指导防雷工作的重要基础。结果表明,处在绕击区段的小电流雷电发生概率高出规程要求20%～30%,这可能是导致绕击事故较多的原因之一。

There is a big difference between DL/T620-1997 empirical formula lgP1=-I/88 and the actual probability distribution of lightning current amplitude in Foshan area. Through fitting analysis, combined with IEEE recommendation, the lightning current amplitude probability distribution of Foshan can be correctly expressed by the formula P1=1 /（1＋（I/ 37）^3 ）, and the curve is match with the actual, will be the important foundation of lightning protection. The results showed that the probability of small-current is higher than the regulation 20% to 30% in shielding failure section, which might be a reason of more shielding failure.