云南省雷电流幅值时空变化特征及累积概率分布OA北大核心CSTPCD

Based on the data of VLF/LF lightning location system in Yunnan Province from 2017 to 2022,the spatiotemporal variation law and cumulative probability distribution characteristics of lightning current amplitude are analyzed.The results show that the spatial distribution difference of positive lightning stroke current amplitudes is more significant than that of negative lightning stroke.The high-value areas are distributed in northwest Yunnan,Honghe in southeast Yunnan,Pu′er and Xishuangbanna in southwest Yunnan.In the central and eastern regions of Yunnan with high lightning return stroke density,but the amplitude of lightning current is relatively small.The aver-age current amplitudes of positive and negative return stroke in the province are 42.6 kA and 27.3 kA.The amplitude range of positive return stroke current is wide,while the amplitude distribution of negative return stroke current is concentrated.The probability of large amplitude current occurring in positive return stroke is higher than that in nega-tive return stroke,and the cumulative probability of current amplitude greater than 60 kA in positive and negative re-turn stroke is 27.6%and 4.4%.Cloud to Ground flash activity with strong current amplitude mainly occurs at night and in the morning from August to October,while weaker lightning current amplitude occurs in spring.Based on the IEEE recommended formula and combined with the Levenberg Marquardt algorithm,a cumulative probability formu-la for lightning current amplitude applicable to different regions of Yunnan Province is obtained through iterative fit-ting.The relative error between the fitted value and the measured value is small.This study can provide technical basis and reference for lightning disaster prevention design and transmission line lightning resistance evaluation.