Abstract:For the demand of transmission of bulk power through UHVDC, based on the faultiness of the equally divided current guiding system of traditional electrode design, this paper proposes a new outer-6 and inner-3 non-equally divided scheme to optimize the current guiding system design of the electrode for the UHVDC transmission system with 6 250 A rated dc current or higher. Based on the two N-1 faults which stipulated in grid code and other three N-2 faults which occur during real operation, the threshold value of current guiding capability of current guiding system of UHVDC electrode is calculated. Besides, the current loading capacity calculation of guiding system under both normal operation and fault condition with the proposed outer-6 and inner-3 scheme is analyzed. A simulation model is established in the ETTG to discuss the selection of section of current guiding cable. Moreover, an economic comparison between the non-equally divided scheme proposed in this paper and traditional equally divided scheme is conducted. The general conclusion of the electrode current guiding system design with non-equally divided scheme is summarized in the end.