An attempt to OHL dynamic line rating by strain-vibration detection of tower

Abstract

There are many on-line overhead line (OHL) thermal monitoring systems, which are commonly known as dynamic line rating (DLR) systems using different sensors and approaches. Interaction between sag, tension and conductor temperature of OHL enables different approaches using sensors for detecting needed parameters for line ratings. The ambition of this project was to consider deformation and vibration behaviour or structural critical components of tower as a source of information for conductor tension parameters. Vibration behaviour or structural critical components is an important source of information for deciding on the mode of exploitation by a rapid adaptation to existing conditions currently encountered. The concept of monitoring is based on stress-strain analysis, vibration and deflection behavior of structural component. Correlation between tower deflections and conductor tensions are well-defined in case of large angle of tower. In tested polygon of 220 kV OHL there was section with large tower angle and situation of right-of-way in forest, which played barrier for wind. So, condition for hot spot section of line was likely fulfilled. The monitoring system based on algorithm which incorporates the geometric characteristics via calibration function. Dynamic line rating (DLR) systems is supported by numerical analysis of the structural components of the model enables simulation of mechanical behaviour and deflection of conductor and tower.