Application Of FBG Sensing Technology In Substation Structural Safety Monitoring

Be subject to the complex topography, landform and geological conditions of the plateau in Yunnan, many new substation tends to through a lot of excavation fill form addressing resides in the mountains. The serious geological disasters like landslide which cause great threat to the structure of the substation security in the rainy season, affect the safe and stable operation of power grid seriously. Building anti-slide pile and retaining wall in the upstream and downstream of the slope is the main way of processing the substation’s slope landslide. But as a result of the action of slope sliding, the safe hidden trouble of the substation structure is more apparent, such as the fissure in the upstream and downstream anti-slide pile and retaining wall, the ground subsidence of the inside and outside of the substation, the faulting of slab ends in the retaining wall. Nowadays, most of the substation structure’s safety monitoring is mainly depended on artificial periodic observation. It’s difficult to respond to sudden events and extreme weather conditions for the continuous monitoring needs. The research of real-time online monitoring of the substation structure safety is important. The traditional monitoring method of the slope landslide deformation have some drawbacks when the substation structure safety monitoring due to the limit of the technologies themselves and the special electrical environment of the strong current, the high voltage, and the strong electromagnetic field.Based on the current real-time online monitoring of the mountainous area substation structural safety requirements and the FBG material’s special physical properties of corrosion resisting, non-electricity sensing transmission, Integrating sensing and transmission, absolute measurement, wavelength division multiplexing, time division multiplexing, high-precision, high sensitivity, electric insulation, anti-electromagnetic interference, low cost, great stability and long service life, we use FBG (fiber Bragg grating) sensor technology to develop a FBG sensing network system for the substation structure safety monitoring. We realize the real-time online monitoring and early warning substation of the mountainous area structure parameters such as stress and displacement. It provides the aided decision and technical support for the substation structure’safety maintenance.Based on the soil pressure of the upstream and downstream anti-slide pile, retaining wall and tower column foot, and displacement of the downstream retaining wall’s faulting of slab ends of the substation, we have carried out the application research of the FBG sensing technology in the substation structure safety online monitoring with the laboratory analysis theory and the design, construction and testing of sensor network system in a typical substation. In this paper, the following research work has been done:(1) Adapt to the special need of the mountain substation structure safety monitoring, we introduction of FBG sensing technology into the internal foundation of the anti-slide pile, retaining wall and tower column foot, and the retaining wall’s faulting of slab ends. We have respectively to carry out the research of the FBG distributed measurement for the substation structure stress and displacement parameters.(2) For the different monitoring characteristics of substation structure stress, displacement parameters and the measuring points, we have researched and used the special designing FBG soil pressure sensors and FBG displacement sensor. And designing and carrying out the blue print of FBG sensing network system.(3) Carried out the analysis research of relevance of the sensing network system monitoring data and the local precipitation monitoring data. Referencing to relevant data statistics model to analysis and set the monitoring alarm limit threshold value of the substation structure stress and displacement parameters.In this paper, the research has been successfully applied in the real-time online monitoring of some typical220kV mountains substation structure safety for a long time in Yunnan. The FBG sensing network system Built with new type fiber Bragg grating sensors as the core has been running steadily. Monitoring results is associated with environmental factors and has a good reference. It has achieved the goal expected monitoring and will have a good prospect of popularization and application in power system.