Analysis Of Mechanical Characteristics And Software Development Of Wires On Overhead Transmission Lines

The calculation of the mechanical properties of wires is an important part of the design in overhead transmission lines,as a connecting link between the preceding and the following,and is the main research content of this paper.In the previous calculations of overhead wire mechanics,we generally use the low accuracy combination calculation method of parabolic method and charpy type,both methods have certain assumptions that cause certain errors,it may not be able to meet the refined requirements of UHV transmission line design.In order to improve the design quality,according to the actual needs of engineering design,this article aims to develop the calculation software for wire mechanical property with precise calculation,perfect function,friendly interface and easy operation.In the calculations of overhead wire mechanics,the parabolic method assumes that the unit length of the overhead wire is uniformly distributed along the straight line connecting the two suspension points,and simply-supported beam method assumes that the tension insulator string is a straight rod,as for the transmission line with higher voltage,the tension insulator string on the tension tower is long and heavy,and the weight per unit length of tension insulator string is far greater than the weight per unit length of the overhead line.At this time,the above two assumptions will have a greater impact on the mechanical properties of overhead wires,and the error is also may become bigger.In view of the above situation,this thesis inferred the catenary control equation which can reflect the shape and gravity characteristics of the real overhead wire based on the catenary theory,and it is applied to the mechanical calculation of overhead line to calculate its length,stress and sag.For the mechanical calculation of the overhead transmission line wire with the tension insulator string,we can also regard it as a catenary according to the true shape of the anti-tensor insulator string,at this time,the difference between the tension insulator string and the overhead wire is only their weight per unit length,then we can use the continuity condition at the connection point of the overhead wire and the tension insulator string,that the tangent slope at the connection point of the overhead wire and the tension insulator string is the same,and the tension is the same,the overhead wire sag with the tension insulator string is solved.Finally,I carried out field measurement by measuring instruments and compared the measurement result to verify the reliability and accuracy of the theory.The software for calculating the mechanical properties of wires is based on AutoCAD,Excel and Microsoft Visual Studio,based on the VisualBasci.NET programming language,I developed a general-purpose calculation software for wire mechanics with complete functions and considering the influence of tension insulator string on the mechanical properties of overhead wires based on the theory of calculation in this paper.It can help to accurately calculate the mechanical properties of electric wires and greatly improve the engineering design efficiency,provide reference and basis for the study of the mechanical properties of overhead lines with tensile insulator strings,which has high engineering application value.