Electric Field Simulation Study Of Composite Insulators With Internal Defects And Under Pollution Conditions Respectively

This article outlines the development and application of composite insulators both athome and abroad, also introduces the operating experience in China, pointing out thatcomposite insulators are gradually recognized by the power industry though with a shorterdevelopment history and will become the main choice for super UHV transmission project.However, with the extensive use of composite insulators, problems are gradually exposed inrunning. According to the research hot spots of composite insulators in recent years, themechanism of mandrel fracture and sheds parameters the present are studied from the electricfield perspective in this paper.With the rapid development of computer technology, the engineering calculation ofelectromagnetic field levels has also been greatly improved, and its calculation accuracy hasbeen able to meet project needs. This article describes the mainstream calculation method ofelectromagnetic field, that is, numerical finite element method (FEM), and ANSYS, a large-scale electromagnetic field analysis tool which based on FEM, then, the electric fieldsimulation principle applies to research object in this paper is described in detail.Analysis the electric field of EHV AC composite insulators with internal defects, thispaper presents the equivalent circuit and the discharge mechanism, establishing three-dimensional model with air-gap simulating the adhesive surface defects between rod andumbrella covers. Then, respectively analyze the effect of four different situation of adhesivesurface, that is, without defects and three different size air gap existence within the adhesivesurface, to electric field distribution. Finally, the accident insulator and related product aredissected, and the experiment results have verified conclusions of the electric field simulation.Simulating electric field of UHV DC pillar composite insulators with alternate big andsmall umbrellas covered with filthy conditions, fixing mandrel diameter, analyzing theelectric field under the single umbrella (distance between adjacent umbrellas and umbrellalength) and the three interactional umbrella parameters respectively. The results reveals thatthere is the optimum range of parameters, and will provide guidance for the follow-upsystematic test of umbrella parameters.