Research on the Accuracy of Online Sag Monitoring of Overhead Transmission Line

The line sag of a transmission line is an important parameter that reflects the operating status of the line, and it is also one of the state variables that need to be paid attention to in the online monitoring and dynamic capacity increase of the transmission line. In order to grasp the operating status of transmission lines in real time, researchers attach great importance to online monitoring of sag, and several mature monitoring methods have been formed. Based on the actual application situation in the world, this paper conducts analysis and comparative research on the measurement accuracy of sag monitoring by temperature, tension and inclination sensor from the aspects of theory and application. On the premise that the sensor accuracy is high enough, the research results show that the errors of the three methods in monitoring sag are all within 5%, all meeting the engineering requirements. Especially, the error of the tension sensor method can be as small as 1%.