The principle and function of adding extra-large shed to the top shed of composite insulators to prevent the flashover caused by guano are presented.

• 介绍了复合绝缘子加装超大伞裙防止鸟粪闪络的作用和原理,对其在设计使用中出现的问题进行了分析,并提出了相应的防范措施。