Optimum Design Of Ultra High Strength Aluminum Alloy Core Aluminum Conductor Structure

At present,China’s transmission lines generally use steel-cored aluminum stranded wire(ACSR)as the overhead transmission line.However,ACSR can cause a large amount of power loss during power transmission.The high strength aluminum alloy core aluminum stranded wire is a new type of overhead wire made of carbon nanotube modified aluminum alloy core material and hard aluminum wire.The carbon nanotubes modified aluminum alloy cored aluminum conductor has the characteristics of light weight,low resistance,non-magnetic,small sag,and large current carrying capacity,potential for the application in transmission lines.At present,the design methods of the new wire structure are mostly improved on the basis of ACSR or traditional aluminum alloy core-aluminum stranded wire.The wire structure design method is slightly rough,thus it is difficult to obtain the best combination of material distribution ratio and the strand winding pattern.Due to the particularity of the carbon nanotube modified aluminum alloy core,it is urgent to optimize the structure of the new high-strength aluminum alloy core aluminum conductor,which will facilitate the large-scale application for the overhead transmission wire market in the near future.The research strategy of this paper is to study the working principle of overhead conductors and the structural design principle of high-strength aluminum alloy core aluminum stranded wire.According to the physical properties of the core part and aluminum part of high-strength aluminum alloy core aluminum stranded wire,theoretical calculation and numerical optimization are adopted.The method is used to calculate the structural parameters of the electrical and mechanical properties of the conductor after optimization.The practicality and superiority of applying the new conductor under the condition of 110 k V typical transmission line are verified by multiple physical field simulation.Firstly,this paper analyzed the calculation methods of main electrical and mechanical properties of wires,and obtained the mathematical constraint relationships between wire performance and various structural parameters under standard working conditions,which were considered as the theoretical basis for optimal design of wire structure.It laid a solid foundation of numerical theory for the construction of subsequent optimization models.Secondly,combined with the triple demand of wire capacity increase,energy saving and economy,the optimization model of ultra-high strength aluminum alloy core aluminum stranded wire based on multi-objective optimization method was proposed.The objective function,design variables and constraints of the model were defined and designed.The two optimization schemes were designed which respectively regarded the specification number as the classification standard and the cross-sectional area as the classification standard,and the NSGA-II algorithms were used to solve models.Five effective solution sets were obtained,which fully demonstrated the feasibility of the optimization method in this paper.Finally,the mechanical simulation and electromagnetic simulation were used to verify the practical application effect of the new conductor under the condition of 110 k V typical transmission line,which further proved the feasibility of the optimized design.The research results have strong pertinence and operability,and can provide some references for transmission line designers and wire developers.