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Investigation of Flashover Voltage and Non uniform Pollution Correction Coefficient of Short Samples of Composite Insulator Intended for ±800kV UHVDC.
- Source :
-
IEEE Transactions on Dielectrics & Electrical Insulation . Feb2010, Vol. 17 Issue 1, p71-80. 10p. - Publication Year :
- 2010
-
Abstract
- Differences in the amount of pollution on the top and bottom surfaces of an insulator have a great influence on the dc pollution flashover voltage. Up to now, many investigations have been carried out on non-uniform pollution flashover performance of porcelain and glass insulators, but very few on composite insulators. In this paper the influence of non-uniform pollution distribution on dc composite insulators on their flashover performance was analyzed, and a correction formula for the non-uniform pollution flashover voltage was proposed, based on artificial pollution tests carried out on short samples of a composite insulator intended for ±800kV UHVDC. The test results showed that, when the ratio (T/B) of the salt deposit density (SDD) on the top surface to that on the bottom surface is between 1/1 and 1/10, the value of the characteristic exponent a indicating the effect of SDD on the flashover voltage ranges from 0.22 to 0.255. The value of a is nearly independent of T/B. However, the flashover voltage U50 decreases with the increase in T/B. The correction formula indicating the influence of non-uniform pollution distribution on the flashover voltage could be expressed as K=1 - b×log(T/B). For the tested composite insulators, the factor b was 0.141 to 0.156, which is smaller than that of porcelain or glass insulator. That is to say, the influence of T/B on the flashover voltage of the composite insulator is weaker than those on the porcelain and glass insulators. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10709878
- Volume :
- 17
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- IEEE Transactions on Dielectrics & Electrical Insulation
- Publication Type :
- Academic Journal
- Accession number :
- 48612734
- Full Text :
- https://doi.org/10.1109/TDEI.2010.5412004