DC Icing Flashover Performance of Composite Insulators with a Parallel Air Gap Used for Overhead Ground Wire Insulation

作者：Guo Yujun; Jiang Xingliang; Meng Zhigao; Li Zhenyu; Hu Yuyao

来源：Transactions of China Electrotechnical Society, 2017, 32(14): 252-258.

DOI：10.19595/j.cnki.1000-6753.tces.151954

• 50% flashover voltages
• Air-gaps
• Composite insulators
• Flashover performance
• Icing
• Over head ground wires
• Power-law functions
• Suspension insulators

The de-icing method of overhead ground wire has become an urgent problem. An insulator with a parallel air gap is generally installed for overhead ground wire insulation, whose de-icing voltage is related with the flashover voltage of insulator and breakdown voltage of air gap. Thus the air gap affects the de-icing length of the ground wire. Quantitative contrast experiments were carried out to study the relationship between the icing flashover voltages of the insulators and their air gaps. The test results show that, for clean (non-iced) strain and suspension insulators, the relationship between the 50% flashover voltage U50%and the air gap length d can be described as a power-law function. That is, U50%increases with the increase of d, but the growth rate decreases. Under icing condition, the air gap length of strain insulators can be chosen based on the ice thickness di, as (10+2di) mm. In heavy icing areas, the parallel air gap length of suspension insulators can be 80~100 mm. During the de-icing period, the air gap length should be chosen as small as possible to improve its lighting protection performance, under the guarantee of good insulation between the ground wire and the tower.

• 出版日期2017