Analysis Of Electric Field Under Wires And Corona Loss About UHVDC Power Transmission Lines

Due to the vast territory，the economic development is not balanced with theresource distribution of China. Developing the UHVDC (Ultra-High Voltage Direct)transmission is helpful to optimize resource allocation and energy supply. In recentyears, the improvement of people’s environmental is awareness. So UHVDC powertransmission is developed at the same time to let lines’ electromagnetic environmentmeet the requirements of environmental protection.The factors affecting electromagnetic environment are total electric field and ioncurrent density the key factors. Besides, the distributions of the surface electric fieldof lines are also closely related to the electromagnetic environment of UHVDCtransmission lines. The charge simulation method as the theoretical basis, at first,UHVDC split conductor surface electric field distribution has to be analysis. Thetraditional method based on Deutsch hypothesis calculating DC ion flow field isimproved, and then put forward a more accurate calculation of bipolar UHVDCtransmission line ion flow field and corona loss method.At the same time, draw lessons from emitting charged thoughts, a simplemethod is presented to compute ground electric field and corona loss of single-stageDC transmission line.The method was proved correct and then this paper has discussed the relationshipbetween±800kV line parameters and the total electric field at ground level, thedensity of the ion flow, corona loss.The paper finally discusses±800kV double-circuit transmission line structureparameters and researches the their affections on ground electric field, ground particlecurrent density. From an electromagnetic environmental perspective, throughscientific analysis, reference value of the double-circuit transmission line structureparameter design is given. Analysis shows that,±800kV double-circuit transmissionline’s electromagnetic environment is significantly better than the same voltage levelsingle circuit line. What’s more, the line corridor is smaller, which not only improveline transmission capacity, reduce investment and improve the electromagneticenvironment, at the same time, save land resources.This paper’s research and work have some guiding significance to UHVDCtransmission line construction.