A new concept of rain contamination flashover(RCF) is proposed based on the analysis of the RCF of bushing and CT at Gezhouba power station.The causes leading to these incidences are investigated.To study measures against the RCF of bushing and CT
tests are performed on a porcelain housing for 500 kV MOA with and without aided sheds.The factors affecting the performance of aided sheds such as the shape
the number
the applied location and the fixing method are discussed.