利用光纤的应变与Bragg波长的对应关系，分别得出了架空输电线悬点等高以及不等高条件下的输电线弧垂计算方法；提出了一种基于光纤布拉格光栅（fiber Bragg grating，FBG）应变传感器的架空输电线弧垂实时监测方案，通过监测线路的应变值，可以获得线路的实时弧垂值。仿真计算结果表明，本方案可实时监测10 m以上的弧垂变化，且能够支持16 mm的弧垂测量精度，具有较高的工程应用价值。

According to the relationship between fiber strain and Bragg wavelength, the calculation methods of sags are obtained under the conditions of isoheight and non-isoheight suspension center of overhead transmission line. A real-time monitoring scheme of sags on power transmission lines based on fiber Bragg grating (FBG) strain sensors is proposed. As a result, the real-time sag values can be determined by the strain of the monitoring lines. It is shown from the simulation that the scheme is applicable to the real-time monitoring of sag variation more than 10m, and the accuracy of measurement reaches to 16 mm, which has excellent feasibility in the project application.