Development Of FBG Tension And Tilt Sensors Applied To Ice Monitoring Of Overhead Transmission Lines

Compared with the traditional resistance strain gauge, Fiber Bragg Grating (FBG) has a better insulation property and is electromagnetically immune. Besides, by the help of Optical Fiber Composite Overhead Ground Wire (OPGW), it can work without field power sources. Thus, FBG has a broad application prospect in the transmission line condition monitoring.In order to monitor the icing of the transmission lines better and enhance the performances of the developed FBG sensors of the laboratory, an FBG tension sensor and an FBG tilt sensor have been developed in this paper. The tension sensor was S-shaped and the tilt sensor was based on the principle of the cantilever. Both of them were temperature compensated mechanically. To design the structure parameters of the sensors, they have been mechanical analyzed and simulated in the laboratory, also, prototypes have been developed.To verify their working performances, temperature compensation test, static performances test and icing test have been performed in the laboratory. Results of the experiments showed that the temperature compensation effects of the two sensors were quite good, which could reach 99.72% and 99.24% respectively. The static performances of the developed FBG tension sensor were as follows:nonlinear error 0.78%, sensitivity 20.4N/pm, hysteresis 1.47%, repeatability 0.46% and accuracy 1.18%. The static performances of the FBG tilt sensor:nonlinear error 1.16%, sensitivity 44.7pm/°, hysteresis 1.57%, repeatability 0.47% and accuracy 1.61%. To simulate the field icing situation, an icing test was performed too. It was shown that the temperature compensation effect was quite good and the tension sensor could work properly in the icing environment.