基于皮尔逊Ⅲ型概率分布的湖南电网覆冰重现期计算

Calculation of Hunan Power Grid Icing Recurrence Interval Based on Pearson Ⅲ Type Probability Distribution

电网覆冰重现期表征了特定覆冰出现的频率,掌握准确的电网覆冰重现期对于电网抗冰工作具有重要作用。利用湖南气象台97个观测站57年的覆冰观测数据,提出了基于皮尔逊Ⅲ型分布的电网覆冰计算方法,计算了湖南地区97个观测站15年一遇、30年一遇、50年一遇和100年一遇冰灾的覆冰日数。结合采用插值法,绘制了全省覆冰日数重现期分布图,该分布图为电网抗冰工作提供了重要技术指导。利用全省的平均覆冰日数,以覆冰日数大于11天为特别严重覆冰的划分方法,开展了特别严重覆冰重现期计算。计算结果表明,湖南地区类似2008年的特别严重覆冰重现期为12.4年,这与过去57年上曾经出现了四次类似特别严重覆冰情况吻合。特别严重覆冰重现期的计算,提升了对电网抵御冰灾重要性的认识。

Icing recurrence interval is a token of specifically ice-cover frequency.It is very important to master exact icing recurrence interval for power grid anti icing.Using the 57 years icing observation data of 97 weather observation stations,calculation method of power grid icing recurrence interval based on Pearson Ⅲ Type Distribution is presented,and icing days for recurrence period of 15 years,30 years,50 years and 100 years are calculated.Icing day distributing maps of Hunan province are painted with interpolation arithmetic,which provide direction for anti icing of power grid.According to the rule that extra serious icing is more than 11 icing days,recurrence period of extra serious icing is calculated.The result shows that recurrence period of extra serious icing similarly 2008 year is 12.4 years.This is accordant with that there are four times extra serious ice-cover in past 57 years.Knowledge of importance for resisting ice disaster is improved by this paper.