Theoretical Research And Application Of 110kV To 500KV Composite Insulator

Composite suspension insulators may prevent flashover due to the deposit of moisture and dirt, and is widely used in modern power grids. As the usage grows and the experience of how they operate accumulates, users and customers start asking for higher demand for long term stability, but there lacks a mature analytical study of how such insulators may be used and operate where lightning density is high.This article bases on the statistics of the uses, trips and damages of such insulators in the last few years in Dongguan, with help of a theoretical model simulating lightning impulse test to give a calculated result and analysis. The lightning endurance test and other parameters were examined on the largely used insulator model made by CYG insulator Co., Ltd. to compare with the simulated results. Meanwhile this article also introduces the production technique, and investigates how such technique affect the lightning endurance based on real tripping cases. Combining three aspects from theory, testing and operation, this article studies the probable improvements on the composite suspension insulators used in 110-500 kV power grids, and proposes a way to increase the endurance of lightning strike for such insulators in lightning-dense area, therefor reduce the tripping probability and maintain a more reliable and safer operation in transmission.