双分裂导线连接金具异常发热原因分析与研究

Analysis on the Abnormal Heating of the Link Fittings for Double-Bundled Conductors

针对一起双分裂导线连接金具异常发热的缺陷进行了深入分析,发现耐张引流线夹接触不良是导致连接金具发热的主要原因。通过进一步的建模与仿真计算发现,随着双分裂导线某子导线耐张引流线夹接触电阻的逐步增大,该线夹处的发热功率呈现逐步增大的趋势,当接触电阻增大到一定程度后,由于子导线的分流作用,该线夹处的发热现象会逐步转移至连接金具,而接触电阻的拐点电阻的大小与连接金具本身的电阻值密切相关。通过这一特征规律的研究,为红外有效检测输电线路连接金具和耐张引流线夹的发热缺陷提供了参考依据。

The abnormal beating of strain clamp is one of the most common defects of the overhead transmission lines. The abnormal heating of the link fittings is, however, very rare because the link fittings generally carry mechanical load instead of current. In this paper, an in-depth analysis is made on one abnormal heating defect of the link fittings for double-bundled conductor, and the result indicates that the main causes for the abnormal heating of the link fittings are the poor contact of the strain clamp. Further modeling and simulation analysis shows that the beating power of the strain clamp of a sub-conductor rises with the increase of the corresponding contact resistance. When the contact resistance increases to a certain extent, the beating of the clamp will gradually transfer to the link fittings because of the shunting effect of the sub-conductor, and the value of the contact resistance at the turning point is closely related to the resistance value of the llnk fittings. This research can provide a valuable reference for infrared detection of the abnormal heating of the strain clamps or link fittings for overhead transmission lines.