探空资料在输电线路覆冰事故评估中的应用

为了分析2008年初浙江省电网大面积覆冰事故发生的原因,在缺乏有代表性电线结冰观测的条件下,利用气象探空观测资料统计分析低空各个海拔高度上气温、湿度条件,发现低温与高湿度的配置条件出现状况与输电线路覆冰事故调查结果有较好的对应,可将这样的配置条件视作覆冰气象基本条件,并可通过对比历史上严重冰雪天气灾害发生期间的低空覆冰气象条件,分析评估电网覆冰事故。分析指出:2008年1月中旬至2月初,浙江内陆海拔100 m以上高度出现持续性较严重的覆冰气象条件,是有系统气象记录以来最严重的时段,覆冰条件随着海拔高度的增高而加强,其主要原因是大气层低空低温与高湿配置条件较好,持续时间长。

Application of Upper Air Sounding Data to the Evaluation of Power Transmission Line Ice-Coating Accidents

Large-area power transmission line ice coating accidents occurred in Zhejiang Province early 2008. And the upper air sounding data are used due to the lack of representative ice coating observations. The configuration of temperature and humidity factors at various altitudes in the lower atmosphere is also obtained. It reveals that combination of continuously low temperature and corresponding high humidity fits the investigation of transmission line incidents so well that it can be regarded as a basic criterion for ice coating prediction and early diagnosis. The evaluation indicates that, from middle January to early February in 2008, the continuous occurrence of low temperature accompanied by high humidity was the main factor of power transmission line ice coating accidents. In such severe air conditions, the correlation between intensity of ice coating and altitude is proved to be positive in the lower boundary layer. Comparisons with the similar historic weather records point out that, the unprecedented severe meteorological conditions resulted in the extremely severe ice-coating accidents in early 2008.