Research On Basic Characteristic Of ±800kV Direct Current Ground Electrode

The current injecting to earth of the±800 kV high voltage direct current transmission system ground electrode is 4000 A, the ground electrode radius will reach several hundred meters , the earth potential induced by earth current are higher than that of±500 kV, the effect to the environment will more severe, therefore the problem of design, operation and maintenance about ultra high voltage direct current ground electrode need study. This paper studies the basic characteristics of ground electrode, exampled by Jin Sha river one issue project. Main content is included: Theory and application fields of magnetotelluric method(MT) are discussed; Make use of image method and equivalent method,the calculation formulas about earth resistance and potential distribution are deduced; Step voltage calculation formula is given; Design project of Dongyang electrode Jin Sha river one issue are analyzed; Emulating with the ANSYS software, the conclusions about UHVDC ground electrode are reliable.