The Research Of Stress Characteristics And Insulation Performance Influence On GIS Composite Bushing

With the constant increase of the power system voltage level, so a higher requirements ofthe mechanical reliability and insulation performance are came up with the high voltageelectrical equipment. Good mechanical reliability and insulation performance directly makethe electrical equipment security and stability. In the paper, natural vibration characteristics ofGIS overall structure is calculated and analyzed; the mechanical reliability of GIS compositebushing is calculated, including the static calculation and dynamic response calculation ofdifferent earthquake intensity; electric field under the four ways of GIS composite bushingwhat has occurred in the structure deformation under different earthquake intensity or not areanalyzed and compared.Firstly, three dimensional finite element model of GIS is established, using modalanalysis method to calculate and analyze the natural vibration characteristics. According to thestructure characteristics of the product, choosing the definition size of grid unit, adopting themethod of intelligent classification combined with local refinement to get a reasonablesolution. Through the analysis of the inherent vibration frequency and vibration model of GIS,it is concluded that the frequency range of values and deformation of the parts of GIS. It hasthe vital significance to avoid the resonance and improve the mechanical reliability of GIS,and provides theoretical basis for calculation the earthquake response of GIS compositebushing.Secondly,800kV GIS composite bushing as the research object, a finite element model isestablished, the static and dynamic response of different earthquake intensity is calculated, thedynamic response calculation of composite bushing using the response spectrum analysismethod, to get the deformation and stress distribution of composite bushing, it providestheoretical reference for the mechanical reliability of800kV GIS composite bushing.Finally, using the finite element analysis method to calculate the electric field of800kVGIS composite bushing, electric field under the four ways of GIS composite bushing what hasoccurred in the structure deformation under different earthquake intensity or not are analyzedand compared, the electric field distribution of composite bushing is obtained, including thefield intensity biggest position and the value of maximum field. According to the result of insulation breakdown criterion formula for judging the insulation performance, reference thecorresponding breakdown voltage value which SF6gas pressure is0.5MPa, to examineinsulation reliability of800kV GIS composite bushing, to analyze the effects of structuredistortion analysis under earthquake to the insulation performance of composite bushing.