A Research On The Subarea BEM Of 3-D Electric Field Of Composite Insulator

At present, with more and more composite insulators used in service, there emerged many problems. The partial discharge and premature aging resulting from too high electric field in insulators are familiar problems. So it is necessary to have an electric analysis for studying and improving the performance of composite insulators.Having summarized the calculation methods of electric field, this paper develops the subarea FEM, which is not only able to keep the prevenient advantage of analyzing easily open domain field, but also overcome its' disadvantage of unfitting to analyze subarea uniform field.Singularity integral is one of the most serious problems in FEM , and this paper adopts gauss integral to deal with it. But an error of gauss integral appears at the same time, which will influence the reliability of FEM, so we go deeply into studying the integral precision of two dimensional and three dimensional electrostatic field. Having analyzed many factors, such as distance, angle, element size, the number of gauss integral, etc., which have great effect on the gauss integral precision. Then we present a series data of integral criterion for the differ precision grade, and develop the methods to improve integral precision within the criterion. In the end, we calculate the precision of the gauss integral in dealing with singularity integral, which reflecting the reliability of this method.Based on the FEM formulae, We compile the two-dimensional and three-dimensional electrostatic field analysis software. Then we analyze random two-dimensional interconnected field and disconnected field by using this two-dimensional software, we confirme the veracity and feasibility of the three-dimensional electrostatic field analysis software by resolving two three-dimension calculation example of 35KV and 110KV composite insulator.