Design Of Seriation Fittings For Large Crossing

This paper reviews history and current situation of design and application ofthe large crossing fittings in our country. Being aimed at the actuality that most oflarge crossing fittings rely on import, we have developed the correspondingproducts independently, and have formed the seriation. The seriation productsfacilitates the designer's exertion, which leads to reduce the fabrication cost of theproject and shorten project cycle. On the basis of fully surveying and studying on large crossing projects, thispaper classifies and gathers the characteristic parameters, furthermore puts forwardthe seriation grouping parameters and design scheme for large crossing fittingsclearly. Three kinds of typical tension string ( 4 × 32t , 4 × 42t and 6 × 42t ) andthree kinds of typical suspension string ( 4 × 21t , 4 × 32t and 4 × 42t ) weredesigned. At the same time some means, such as material optimum seeking andoptimizing the computing technology, etc were be used. Relying on the project ofWuhu large crossing, the fittings were went on to trial-produce and test proving,and the tests showed that the mechanical and electrical performance of all thefittings attain the design target and meet the requirements of correspondingstandards. These products have been used to three large crossings in the ±500kVSANGUANG direct current transmission lines, and may also be used to the otherprojects. The 420kN suspension clamp, the 456kN dead-end clamp and the 1000kNtower-link fittings are initiate at home, which fills the domestic gaps and aresuperior to the same external products.