| SF6Gas Insulated Metal-enclosed Switchgear（GIS）is an important combined electrical equipment in power system,and the dynamic and static insulation performance of the whole equipment is determined by the joint action of insulation performance among various components and electrical connection assemblies in the unified system,as well as the interaction of electricity,magnetism,temperature,force,environment and other factors during service.The operation process involves complicated physical and chemical changes,which inevitably leads to the degradation and deterioration of insulation performance of GIS system.It is difficult for traditional static insulation analysis method to characterize and describe the dynamic process of insulation degradation of GIS system and its internal influence mechanism.Based on the general system theory proposed by Bertalanffy,this dissertation establishes a multiple model on GIS to study the influence mechanism of insulation performance between the complete machine and the components in GIS insulation system.For the complex network dynamics behavior of electric field distribution,this dissertation proposes the electric field influence domain network construction method,and establishes the GIS electric field influence domain network topological model,in order to explore the field coupling relationship and influence mechanism among the electrical components in the GIS insulation system.In terms of the nonlinear relationship between design variables and objective functions in GIS insulation system,the optimization method based on computational electromagnetic integral equation and the transient insulation analysis method are proposed to analyze the transient insulation performance of GIS under extreme operating conditions.The main research covers:Modeling and analysis of GIS insulation system field coupling model based on general system theory.By analyzing the nonlinear relationship among operating conditions,system topology,state parameters and system behavior under different operating conditions,the field coupling relationship between components and the influencing factors of transient insulation performance are analyzed,when the input of insulation system changes due to the influence of operating conditions at any time.Moreover,based on the relationship chain of insulation system,the memory,inheritance,automaticity,environmental path sensitivity and discontinuity of the system are studied,the field coupling insulation model considering the influence of working conditions and state variables is established.GIS insulation system performance analysis based on the response surface methodology-geometric feature charge simulation method（RSM-GFCSM）.Taking the simulated charge coordinates and electric quantity as the design variables,the maximum electric field intensity in the field as the target response,and the contour point potential as the constraint response variable,an optimized simulation charge method is proposed.By optimizing the spatial optimal response variable and design variable,the distribution of electric field in the solution field is described.In order to verify the feasibility and effectiveness,the electric field values of typical components in GIS have been solved and compared.Considering that metal particles in the field of GIS insulation system are difficult to be detected and prone to cause insulation flashover,the RSM-GFCSM is used to calculate and analyze the electric field distribution when metal particles exist in GIS.In addition,the quantitative method is used to analyze the relationship between the position and size of metal particles and the discharge fault,which is of reference value for the reasonable design and safe operation of GIS insulation systems.Research on construction methods of electric field influence domain network and dynamic behaviors of electric field network in GIS insulation system based on network science methods.By analyzing the field coupling relationship of the GIS insulation system,the electric field network construction method is proposed based on the influence domain from the perspective of electric field distribution characteristics and evolution law.In addition,an electric field network topology model of the GIS insulation system is constructed,which explores the network characteristics and insulation failure mechanism of GIS whole-field electric field from the perspective of system topology and field parameter coupling.It turns out that the nature of the field network of the GIS insulation system based on influence domain field is a degree-degree positively correlated network,which corresponds to scale-free and small-world network characteristics.With the evolution of field network distribution,the average degree and between of each part gradually decline.It indicates that the influence of some parts of the GIS field network decreases with the development of opening pocess for the SF6circuit breaker.Therefore,reducing the betweenness of nodes of GIS field network to reduce network transitivity is crucial to improving the insulation of GIS.Analysis of instantaneous insulation and GIS instantaneous insulation performance based on RSM-GFCSM.As the state variable of each part element of the insulation system is only the function of the external environment and the state of the parts it have coupling relationship with,in order to study the coupling relationship between state variable of each part element of the insulation system under extreme environment and parts element.According to the research results,there is a dependency relationship among the component structure topology,the field strength change rate and the field distortion rate in the GIS insulation system,which has a direct impact on the insulation breakdown probability and the degradation rate of GIS insulation system.Through GIS lightning impulse withstand voltage experiment,instantaneous insulation simulation experiment,and comparative analysis of the two experimental results,it can be concluded that,it is necessary to suppress the change rate of field strength amplitude,reduce the insulation breakdown rate and delay the degradation of the system in the design of GIS insulation system,which can provide insulation guarantee for the safety and reliability of equipment for long-term operation.According to the general system theory,the nonlinear relationship between environmental parameters,structural topological parameters,state parameters and insulation behavior characterization parameters of GIS insulation system is constructed.An optimization method based on electromagnetic integral equation and the electric field influence domain network construction method based on network science are proposed.A novel scheme is provided for the evolution behavior of dynamic and static insulation performance of switching devices and insulation calculation analysis. |
