POLLUTION PERFORMANCE OF 110 KV METAL-OXIDE ARRESTERS

Pollution test results of single unit 110 kV metal oxide surge arreste rs with porcelain housing according to the solid layer and salt Ibg me thods are presented. During 6 hours of testing, the internal and exter nal charge and maximum temperature along the varistor column were meas ured. The formation of single stable dry bands on the housing was ofte n observed, especially during salt fog tests, In such cases, the varis tor temperature can reach about 70 degrees C. The simple electrical mo del of the arrester enabling calculations of voltages and currents as a function of arrester and pollution parameters is shown.