900 mm2大截面导线压接管优化设计研究

锦屏-苏南±800 kV特高压直流输电工程首次大量应用四层铝股结构900 mm^2大截面导线,由于铝钢比大,导线中铝线承担的拉力相对较大,按传统经验设计的压接管对导线的握力不满足标准的要求.为最大程度减小压接引起的铝线强度损失,提高金具对导线的握力,进行了金具的优化设计研究.在分析握力影响因素的基础上,设计了基于不同内径和拔梢长度的铝管的正交试验方案,金具与同一导线压接后进行握力试验,对试验结果进行二元回归分析,得到内径和拔梢长度对金具握力的影响规律.对于900/40导线配套的压接管,在一定范围内增加铝管内径和拔梢长度有利于提高金具握力.推荐了优化的压接管尺寸用于金具制造,工程抽检结果表明优化后金具的性能达到了预期效果.

Optimal Design of Hydraulic Tube for 900 mm2 Large Cross-Section Conductors

The large cross-section conductor with a sec- tional area of 900 mm2 and four-layer aluminum wires is widely used in the ＋800 kV Jinping-Sunan UHVDC power transmission project for the first time. The aluminum conductor withstands relatively high tension for the large ratio of aluminum to steel, so the grip strength of the hydraulic tube designed according to traditional experiences cannot meet the requirements of the standard. The optimal design of the hydraulic tube has to be made to minimize the strength loss of aluminum conductors caused by crimping and improve the grip strength. Orthogonal test schemes based on combinations of different inner diameters and taper lengths of the tube are designed after analyzing the factors affecting the grip strength. Different tubes are fitted with the same conductor by crimping and then the grip strength test is carried out. The influencing law of the inner diameter and taper lengths on the grip strength is obtained by binary regression analysis. For the hydraulic tube matching 900/40 conductor, the increase of inner diameter and taper length in a certain range helps to improve the grip strength. Optimal sizes of the hydraulic tube are recommended for manufacture, and results of the sampling test indicate that optimal fittings achieve the expected effect.