Design And Application Of Transmission Line Tension Sensor Based On Fiber Bragg Grating

The safe operation of transmission lines is related to national economic and social stability.The health monitoring of transmission lines is of great significance to economic development and people’s life.In order to realize the health monitoring of transmission lines,based on the stress device test project of fittings health of important crossing lines of State Grid Henan Electric Power Company,a transmission line tension sensor based on fiber Bragg grating is designed and applied to real transmission lines.On this basis,the transmission line tension and transmission line galloping are analyzed.Firstly,taking the standard fitting as the basic structure,based on the fiber Bragg grating sensing principle and three-dimensional force measurement principle,a transmission line tension sensor is designed.Using the method of finite element analysis,the selection of measuring points of the sensor is analyzed,the feasibility of the sensor design scheme is verified,and the measuring range,sensitivity,relative measurement error,the effects of eccentric load on the calculated load of the sensor are analyzed.Secondly,according to the design scheme,the fiber Bragg grating is bonded to the fitting to complete the encapsulation and preparation of the transmission line tension sensor.The temperature and tension sensing characteristic test systems are built respectively.The temperature and tension sensing characteristic test experiments are carried out on the sensor,and the sensing characteristics such as range and sensitivity of the transmission line tension sensor are evaluated.The experimental results show that the performance of the sensor meets the engineering requirements.Finally,the transmission line tension sensor is applied to the real transmission line to monitor the small span tower line system for a long time.According to the long-term monitoring data,the tension and galloping signals are analyzed.In the aspect of tension monitoring,the thermal stress is analyzed according to the characteristics of tension signal.Reliability analysis is carried out on transmission lines according to the national standards,and the transmission line tension safety early warning mechanism is established with the transmission line tension as the reference index.In the aspect of galloping monitoring,combined with the time-domain and frequency-domain signals of tension,the galloping is judged qualitatively.The frequency components of galloping and the reasons for its change are analyzed.The galloping angle is calculated according to the galloping frequency and verified by video monitoring method.The phase to phase distance of the transmission line is transformed into the galloping angle,which is used as a reference index to establish a galloping early warning mechanism.