The Research Of Electric Field And Insulation Characteristic For Ultra High Voltage Disconnector

At present,the first 1000 kV Ultra high voltage AC experiment demonstration project has been entered the debugging and commissioning stage.The insulation of the ultra high voltage apparatus is put forward higher request duo to the development of the ultra high voltage(UHV) transmission network.Numerical calculation of the electric field for high voltage apparatus play an important part to the internal structure optimization design and improve its insulating properties.The electric field distribution of the electric apparatus can be improved and local maximum electric field value can be reduced due to the rational design of the internal structure,and it is the core problem to improve the insulation performance.In order to solve the distribution of the electric field intensity in chamber of disconnector in UHV GIS,the two typical mathematical models of three-dimensional electrostatic field for 1100 kV GIS disconnector chamber are established in this paper. Based on the numerical analysis of electric field,the electric field intensity in chamber of disconnector is calculated by using the finite element method,rebuilding the regions of complex structure for amplifying dangerous regions and checking the quality of mesh.The calculation results show that the focus region of electric field intensity is the earthing switch contact gap,and the distribution of the electric field intensity can be effectively improved by increasing the insulation gap or changing the figure of the contact shielding case.The distribution of electric field on the surface of electrode shield covers can be improved by the reasonable size of the structure design of basin-insulator.By comparing the distribution of electric field intensity in two types of disconnector chamber,which obtained the corresponding region in two types,the maximum electric field intensity and the distribution of electric field are slightly different,and they both have some certain insulation margin.The insulating stand is optimized by changing the height of shielding case and checking the distribution of the electric field intensity of insulating stand surface with various structures. Last,according to the related connection structures of UHV GIS,three-dimensional electrostatic field are analyzed for T-type structure,connect-conductor and inner-conductor which shapes are complex.The accurate calculation of the three dimensional electric field for large practical engineering problem and the results of the electric field analysis provides a theoretical for ultra high voltage electrical equipment and the internal structure to further optimize the design.