Research On Composite Insulator's Electric Field Distribution And Grading Ring's Parameter Design

With the development of the power system,voltage level grows higher and higher.In the modern high-voltage transmission system,the application of composite insulators become more and more used.During the power system normal operation,the corona phenomenon occurs usually because of the uneven distribution of the potential,thereby affecting the electromagnetic environment,operating characteristics of the insulate material,causing a serious threat to the safe of power grid operation.The way to solve this problem is that installing the grading rings at both ends of the insulator.However,the size and the position of grading rings cannot be set arbitrarily,otherwise it will make the potential of the surface of grading ring too high,and thus lead to a corona discharge to air.Therefore the parameters of grading rings need to be optimal designed.This article includes the following tasks:The physical model of insulators firstly introduced at before,and then discussing the numerical computing of insulator model,particularly analyzed how to ignore secondary factors to simplify the model,as well as how to deal with open field problem.And based on the finite element software ANSYS,creating the material property,loading boundary conditions,applying load,and post-processing operations to solve.Then calculate the potential distribution in each case of the insulator,and the analysis of the comparison results obtained.The potential distribution on insulator is very uneven.Nearthe conductive terminal,the potential decline rapidly,and the electric field concentrate on it.So that it will be prone to causing corona,even seriously it will breakdown.Installing grading rings at both ends of insulator can solve this problem.After installing the grading ring,potential distribution factors have the following parameters:the length of the insulator,the radius of grading ring,the tube radius of grading rings,the height of the ring and the termal grounded or not.By analyzing the parameters to potential distribution,the paper obtain the actual needs of the grading rings's project in each parameter ranges and reference dimensions.It has important guiding significance to design the actual production.Finally,the paper computing and simulating the parameter of the optimized model in ANSYS and verify the results of the optimization of the design.Finally,the paper analyzed the insulator of transient electric field calculation and calculated the resistance value and equivalent capacitance value.By using ANSYS software to insulator transient electric field was simulated.