Insulation Protection Type Optical Fiber Bragg Grating Temperature Sensing Technology Research

The insulator is exposured in the polluted nature condition. The rain, snow or other bad weather make the insulator surface dirty and cause the power system pollution flashover accident. The pollution flashover on the insulator surface is an important factor of the power grid security threat. It serious related to the power supply system reliability and safety. With the rapid development of economy, the gradually expand the scale of power grid, the safety and accurate detection of insulator becomes a problem of power grid transmission line safety to solve.The advantages of Fiber Bragg Grating (FBG) sensor are anti-electromagnetic, interference, corrosion resistance, electrical insulation, low dielectric loss and small volume. Therefore, the FBG was used in the photoelectric measuring technical area, especially, in the insulation temperature monitoring.In this thesis, FBG is used as a sensing element to measure the heat sections of silicone insulator and porcelain insulator and the related theoretical analysis and experimental study were also been done. According to the structure and application environment, a kind of FBG contact sensor with insulator protected used in high voltage was designed. The sensor is unitary structure with silicone rubber material. It includes: some insulate units, fiber, fiber connection and FBG sensor. The FBG sensor is pasted on the heat sections of silicone insulator and porcelain insulator with epoxy resin. The heat sections of silicone insulator are two sides of the metal bar, isolation and sheathing of insulator. The heat sections of porcelain insulator are the surfaces of cap and porcelain disk.With working in the high voltage, heat sections of insulator have the temperature changes. And the temperature changes cause the asynchrony between change of the grating refractive index and optical thermal expansion. Optical fiber Bragg grating finally made reflection center changes wavelength.The research content includes:(1) Based on the structure and application environment, the design of a kind of FBG contact sensor with insulator protected used in high voltage. Temperature sensor model is established in this paper. With the require of the insulator voltage level, the sensor is processed.(2) The sensor takes the withstanding15kV AC voltage experiments in non-pollution, rainy, polluted conditions. The experiments indicated that the sensor can be used in15kV electrical equipment.(3)5sensors are calibrated in this paper, the non-linear errors of5sensors are1.03%FS,0.85%FS,0.96%FS,0.83%FS,0.99%FS and the sensitivities are9.9pm/℃,10.0pm/℃,10.4pm/℃,10.2pm/℃,10.0pm/℃.(4) The FBG contact sensor with insulator protected is used in heat field distribution experiments of porcelain insulator. The experiments of silicone insulator are measured in the different conditions.(4) The FBG contact sensor with insulator protected is used in heat field distribution experiments of silicone insulator. The experiments of silicone insulator are measured in the different conditions.