CaSO4 Content in Contamination Influence on AC Pollution Flashover Characteristics of XWP2-160 Porcelain Insulator String

A large amount of CaSO
₄
is contained in the transmission line insulator contamination under natural conditions, and the CaSO
₄
in the contamination has an influence on the pollution flashover characteristics and leakage current of the insulator. The tests were carried out in a fog chamber using XWP2-160 double-shed suspended porcelain insulators and the influence laws of CaSO
₄
content in the contamination on polluted insulator string's pollution withstand voltage and leakage current were studied. The results indicate that with the increase of CaSO
₄
content, the pollution withstand voltage will increase in the way of power function, and the leakage current peak value will decrease. With the effect of CaSO
₄
, the influence degree of Soluble Contaminant Density(SCD) on the pollution withstand voltage is 1.5 to 1.8 times of that of Non-Soluble Deposit Density (NSDD), the influence degree of SCD on the leakage current peak value is 3 to 4 times of that of NSDD. With the increase of pollution degree, the influence of the change of CaSO
₄
content on the pollution withstand voltage will increase. With the increase of the CaSO
₄
content, the influences of the change of SCD and NSDD on the pollution withstand voltage and leakage current peak value will decrease. The research results can give a reference for the design and operation of insulators.