中文摘要：

架空输电线路的导线弧垂是反映线路安全运行的重要参数．也是输电线路在线监测和动态增容需要重点关注的状态量之一。为了实时掌握输电线路的运行状态，国内外非常重视导线弧垂的在线监测，也形成了几种比较成熟的监测方法。笔者立足于国内外实际应用情况，重点对导线温度、张力以及倾角传感器监测弧垂的测量精度在理论上和应用上进行了分析和比较研究。在传感器精度足够高的前提下，研究结果表明3种方法监测弧垂的误差都在4％以内，其中张力传感器法误差最小达1％，3种方法都能满足工程要求。

英文摘要：

Conductor sag of a transmission line is an important parameter for evaluating the safety of the transmission line, and it is also one of the key parameters in on-line monitoring and dynamic expansion of capacity of the transmission line. For real-time control of transmission line＇s operation, on-line monitoring of conductor sag has attracted great attention in the world, consequently, several mature monitoring methods have been presented. According to the applications, the authors analyze and compare three on-line monitoring methods of conductor sag in terms of their monitoring accuracy. Three methods use conductor temperature sensor, tension sensor, and tilt angle sensor, respectively, to monitor the conductor sag. The results show that if the accuracy of the sensors is high enough, three methods can all meet the requirement of engineering with the errors below 4%, of which the monitoring method with tension sensor gets the smallest error of 1%.