云南高海拔地区雷电活动分布规律的研究

Study on the Distribution Regularities of Lightning Activity in Yunnan High Altitude Area

为获取云南省的雷电活动规律,结合雷电定位系统2005年—2008年的雷电监测数据,对整个云南省的落雷次数、雷暴日、落雷密度等雷电参数进行统计分析,并对雷电流幅值分布进行拟合。结果表明,采用IEEE推荐的表达式比雷电定位系统测量的雷电流幅值累积概率曲线和概率密度曲线拟合效果比采用我国现行规程中推荐公式要好,规程推荐的雷电流幅值累积概率在大于29 kA时比实际值大,而规程推荐的典型杆塔反击耐雷水平大于41 kA,这使得反击耐雷水平的设计趋于保守。根据电气几何模型的基本原理,对输电线路的绕击跳闸率进行计算,结果表明实际雷电流幅值概率密度计算得到的绕击跳闸率将比规程推荐公式计算值大,当最大绕击雷电流达到80kA时,所有电压等级的绕击跳闸率将是规程计算绕击跳闸率的4倍以上,这与目前高压输电线路雷击跳闸率比设计值偏高的事实基本相符。

In order to get the lightning distribution regularities in Yunnan province,based on lightning-monitoring data during ten years （2005-2010） of lightning location system, statistics and analysis of lightning parameters of the region such as ground lightning number, thunderstorm day, ground lightning density,are carried out,the lightning current amplitude distribution is fitted. It turns out that the fitted curves of the cumulative probability and probability density of lightning current amplitude are better by the expressions in IEEE than by that in the Chinese current regulations. The lightning current amplitude cumulative probability recommended by regulations is higher than actual value at 29 kA or higher, however, the typical tower back flashover lightning withstand level is higher than 41 kA,which makes the design of back flashover lightning withstand level tend to be conservative. The shielding failure flashover rate is calculated according to the fundamental principles of electrical geometry mode,the results show that the shielding failure flashover rate calculated by the actual light- ning current amplitude probability density is larger than that the calculated value by regulations recom- mended formula. If the maximum shielding failure lightning current is 80 kA,the shielding failure flashover rate of all voltage level is more than four times of which calculated by the regulations, and this is in agree with the fact that the rate of lightning trip on high-voltage transmission lines is higher than the designed value.