Effects of semi-conducting glaze coating on the electrical performanceof a H.V. station post insulator covered with ice

摘要

The main objective of the present paper isto study the effects of semi-conducting glaze coatingon potential distributions along a standard postinsulator under icing conditions. Thin semiconductingglaze requires very large number ofelements for finite element analysis because of openboundary around ice covered insulators. To reduce thenumber of elements and hence computation time, theregion between the domain of interest and infinity ismodeled simply by adding a circular boundary, asecond mesh of the same size, and boundaryconstraints to force equivalent boundary potentials tobe identical. Infinity lies at the center of the secondmesh. In effect, second mesh represents the conformaltransformation of all the space exterior to the firstmesh into a circle. Results are compared with anormal glazed standard porcelain post insulator undericing conditions. It is found that semi-conductingglaze coating makes potential distributions more linearalong a station post insulator under icing conditionsand hence improves the withstand performanceconsiderably as confirmed by the laboratoryexperiments.