A method for calculating the optimal inner and outer ring ratio of an extra-high voltage direct current transmission double-ring grounding electrode

The invention discloses a method for calculating the optimal inner and outer ring ratio of an extra-high voltage direct current transmission double-ring grounding electrode, relates to the extra-highvoltage direct current transmission double-ring grounding electrode, and finds the optimal inner and outer ring ratio of the double-ring grounding electrode by calculating the surface potential distribution of different inner and outer rings. The outer ring radius, the embedding depth, the ground current, the electrode material and other variables are fixed, only the inner ring radius is changed to calculate the surface potential; the different inner ring radiuses, namely the surface potential maximum values under different inner and outer ring ratios, are recorded, and a curve that the surface potential maximum changes along with the inner ring radius is obtained. And the minimum value of the maximum value of the surface potential along with the change of the inner ring radius is obtained, the corresponding inner