| The ions generated by corona phenomenon of UHVDC (Ultra High Voltage DirectCurrent) transmission lines exist in the whole interelectrode space, than it produces totalelectric field and ion current density. The total electric field and ion current density isimportant parameters for the estimate of UHVDC transmission lines design scheme,electromagnetic environment, and something problems related. So it is very necessaryto calculate them accurately and effectively.Firstly, for the calculation of the electric field and ion current density of UHVDCtransmission lines on the ground, a finite element–integral method is applied to solvebipolar ionized field control equations. In this paper, the initial charge density of t spaceis improved on the basis of analytical solution in the solving process, and it accord withthe actual conditions of the space charge distribution.Secondly, the author compiled the corresponding simulation program based onfinite integral method.By using the method on coaxial cylindrical model and±400kVDC transmission lines, it verified the effectiveness of the algorithm. In addition, theactual500kV DC transmission lines are calculated by the method in this paper, andcompared with the results based on the assumption of Deutesch, it showed the methodin this paper has preferable accuracy.Thirdly, the method is applied to the actual UHVDC transmission lines, to simulateand calculate total electric field and ion current density on the ground, and than, tocomprehensive analysis the influence on them when the transmission lines havedifferent the wire to height, the pole distance, split number and corona is differentbetween positive and negative poles and lightning wires whether exist or not.Finally, this paper used the method to discuss distribution synthesis of total electricfield when the UHVDC transmission lines near building. And the paper use themethod to calculate the total electric field in the experimental models of existingbuilding,and the results is compared with the Upstream Finite element method， Thecomparison results show that the method is effective when we calculate the total electricfield near the buildings around DC transmission lines. Secondly,Analyzes thedifferent building width, height, buildings and different distance between building andtransmission lines how to influence the distribution of total electric field whenUHVDC transmission lines close to building, it has the certain instructive significances in the future construction and design of DC transmission lines... |
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