Study On Optimization Of Electric Field Of Pot Insulator For High Voltage Gas Insulated Equipment

High voltage gas insulation equipment is an important part of the global energy Internet and UHV transmission and transformation projects with the advantages of high reliability,small footprint and low failure rate,which is widely used in modern power networks.As an important part of the basin insulator,due to the high unevenness of the electric field distribution,the insulator flashover or breakdown accidents occur frequently,which has a serious impact on the power system.Aiming at the phenomenon of uneven distribution of electric field along the surface of basin insulator and high local field strength,through theoretical analysis and simulation,the principle of insulator electric field optimization is studied,and the insulation optimization design scheme is proposed.The effectiveness of the optimization scheme is verified by simulation,and the different factors affecting the electric field optimization effect of the insulation design scheme are analyzed.The main research contents are as follows:(1)Based on the classical electromagnetic field theory,the electric field distribution characteristics and optimization principles of different types of insulators are studied.The volume gradient insulator optimizes the electric field by changing the radial dielectric constant distribution of the basin dielectric.The high dielectric constant material is used in the high field strength area and the low dielectric constant material is used in the low field strength area.The surface gradient insulator constructs a high dielectric constant surface layer on the insulator surface,and optimizes the surface electric field distribution of the insulator with the surface dielectric constant distribution to improve the overall insulation performance.(2)In order to improve the electric field distribution of basin insulator,based on the optimization principle of insulator electric field distribution,the electric field optimization design scheme of basin insulator is proposed,and the effectiveness of the optimization scheme is verified by finite element simulation.The simulation model of basin insulator is established,and the Bernstein polynomial is used to fit and reconstruct the basin structure of insulator.The geometric structure optimization design scheme of basin based on Levenberg-Marquardt algorithm is proposed.By using the iterative formula of dielectric constant,the design parameters such as reference electric field strength,upper and lower limits of dielectric constant are adjusted,and the optimal design scheme of gradient material dielectric constant distribution based on iterative algorithm is proposed.At the same time,based on the optimal dielectric constant distribution of insulators,a gradient discrete optimization design scheme is proposed to discretize the dielectric constant distribution of basin insulators.(3)Considering the mechanical properties of basin insulators,combined with the geometric structure and gradient material optimization design ideas,a comprehensive optimization design scheme,electric field of basin insulators based on finite element iterative calculation is proposed,and the effectiveness of the optimization scheme is verified by simulation.The electric field homogenization effect of various insulation design schemes is analyzed,and the electric field distribution characteristics and field strength optimization differences of different insulation design schemes are studied.(4)According to the electric field optimization scheme of volume gradient and surface gradient insulators,different factors affecting the electric field optimization effect are studied.Based on the principle of electric field optimization and the gradient insulation design scheme,different factors affecting the electric field optimization effect are obtained.The effects of the number of layers,the upper limit of dielectric constant and the thickness of the surface layer on the electric field optimization effect are analyzed.The variation trend of the maximum field strength along the surface of the gradient insulator after optimization is studied.