Research On Conductor Selection Of High Voltage Direct Current Transmission Line

Conductor selection is an important work for transmission line project planning; it directly affects the safety, reliability and economy of transmission line. It has realistic meaning to study conductor selection for transmission line under the circumstance of guarantee the system’s safety.The systematicor standardized theory and method for conductor selection are still vacancy for the projects or stduies in China or abroad.This essay introduces the procedure of conductor selection for HVDC transmission line, which starts from system planning, based on the actual conditions and system requirement, length of transmission line, the area climatic and topographical conditions that line crosses to decide the factors and defined condictions for the transmission line. Proper economical current density will be decided through fee calculation of whole life cycle, and the section shall be confirmed in accordance with system transmission capacity, as well as the price, manufacturing and construction craftmenship, and site geological and climatic conditions will be factors for finalize a certain type of conductor; then, based on the studies of project in China and abroad and the manufacturing and conscturction workmanship to determine the quantity and distance of the bundle. This essay adopts analysis of current-carrying capacity calculation method and comparison of transmission capacity and efficiency; it also applies Pick Formular to calculate the strength of conductor’s onset corona under DC transmission circumstance, and the electric charge of bundle conductor is calculated through Markt-Mengele method; the maximum average surface electric field and rated electric field will be calcualated through EPRI Formular; the compound field strength and ion current density will be calculated by semiempirical formula; the radio interference level will be calculated by formular recommended by CISPR; the audible noise level of line will be calculated by formulars suggested by BPA and EPRI, then, through the above methods to judge whether the counductor meets the electrical requirement or not. It is suggeted to analysis the mechanical properties according to the conductor’s manufacturing factors, and the sag feature is supposed to judged by pull/weight ratio method, the over-loading capacity can be compared by certain stress with ice covering, to the anti-fatigue performance is ascertained through comparison of aluminum part’s stress, as well as comparison the actual loading capacity and tensile force of different kinds of conductors, then the economical feature will be compared withfee calculation of whole life cycle at the final step. This paper takes an example of construction a HVDC over head transmission line, with formulars’ calculation and MATLAB programming to verfy each indicator, which makes the selection meet the design requirement and get the optimal proposal.This essay-the study of conductor selection provides procedural and standardized theory guidance for transmission line project planning and design. In accordance with methods propoed in the article, the selected conductor can meet the techincal specification and actual utilization, which has stability, safety, economy and rationality features. The methods in this essay are proved in real project and will be a useful experince for application and promotion, and it has good economic and social benefit.