Electric Field Analysis And The Research Of Insulation Structure Improvement Of The Large Converter Transformers

Converter transformer is important equipment in HVDC. Its function is to the mutualtransmission of electrical energy in the AC and DC systems and the working reliability ofconverter transformer has an important effect of HVDC. It is very troublesome when afault occurs on the power system. In respect of insulation design, converter transformerexposed to different types of voltage system. It makes the insulation design of convertertransformer is more complicated. Therefore, it is necessary to analysis of convertertransformers electric field distribution under different voltageConverter transformer two-dimensional electric field calculation model is establishedbased on500kV converter transformer product structure. Converter transformer valvewinding end of the electric field in three different voltages is calculated. The electric fielddistribution of converter transformer winding end in different incentives through thecalculation of the electric field is obtained. In order to further study the insulating materialimpact of the electric field of the converter transformer and the resistivity or dielectricconstant of insulating material is not the same electric field is calculated and convertertransformer internal electric field distribution is calculated. According to the electric fielddistribution law, and converter transformer valve winding end insulation weak part islocated and analysis field strength of weak links.Converter transformer valve winding end of the electric field in three differentvoltages is calculated. The insulating structure of the converter transformer winding endhas been improved according to electric field distribution of converter transformer windingend. Electric field strength of electrostatic ring and molding angle ring of convertertransformer valve winding end is relatively large by calculating. Therefore, it can get to aconclusion that by changing the electrostatic ring radius of curvature and the radius ofcurvature of the molded corners ring. That is converter transformer electric fielddistribution is affected by electrostatic ring radius of curvature and the radius of curvatureof the molded corners ring, and found the minimum value of the electric field of the end of winding when the radius of curvature of electrostatic ring or molding angle ring thechanges in a certain range by the electric field. Studies converter transformer electric fieldanalysis and application, insulation structure design of converter transformer and the endof converter transformer valve winding insulation structural improvements have referencevalue.