Calculation And Analysis Of Converter Transformer End Electric Field

With the develop of living standards and rapid economic growth in China, people arebecoming dependent on energyr.The secondary energy consumption are increasing occupy theproportion of all the energy consumption.Therefore,how to get the high quality, reliableelectricity to consumers has become the important issues for the national power department.Power for our country, there has been an issue for reasonable distribution, long distancetransmission is indispensable, to grasp the long-distance transmission technology also isimminent, high-voltage direct current transmission arises at the historic moment at this time, itcan better for long distance transmission of electric energy, compared with other ways to saveenergy, the capacity is big, these advantages make up its rapid development, the convertertransformer is one of the key equipment of transmission system, is also a weak link in theinsulation system, so it is necessary to conduct in-depth research.In this paper, according to an actual converter transformer product structure, reasonableconverter transformer was established after proper simplification calculation model of thetransient and steady state electric field, calculating the steady dc voltage, power frequency acvoltage and ac/dc superposition voltage and polarity reversal voltage under the action of anelectric field respectively, through the calculation of electric field, it is concluded that theconverter transformer valve side winding end electric field distribution under differentincentive effect, and its influence factors are analyzed. In converter transformer under polarityreversal voltage, analyzes the inversion of the length of time influence on the maximum fieldstrength, medium is given in the inversion process line distribution characteristics, and find outthe weak electric insulation.Electric field intensity and temperature areinfluence the dielectric nonlinearity convertertransformer,when given the influence of temperature distribution of the maximum fieldstrength and electric field intensity and the equipotential line. Comeparing with the divverencebetween anisotropy and gay of insulating medium, then to analyze the different reasons, theresistivity is given the influence of the initial value of the electric field characteristics.Converter transformer was calculated under polarity reversal of anisotropic nonlinearelectric field, distribution of equipotential line before and after the first polarity reversal isgiven, considering the nonlinear dielectric case, on the side of the valve electric field numerical calculation, and analyzing and comparing the linear, isotropic anisotropic linear,isotropic nonlinear, anisotropic nonlinear electric field distribution characteristics before andafter the first polarity reversal, the change rule of converter transformer value side electricfield and the factors affecting the distribution of electric field, exchange converter transformerinsulation design provides a theoretical basis and reference.