FBG Electric Equipments Temperature Sensing System Based On The Technology Of Internet Of Things

Fiber Bragg grating (FBG) is a kind of good temperature linear optical device, its central wavelength changes as the surrounding temperature’s drift and they have linear relationship. FBG sensors have many advantages the same as ordinary optical fiber sensors have, besides this, because of their wavelength modulation to signals, FBG sensors have special advantage that reflected light intensity affects demodulation accuracy barely when it is weak. FBG sensors are so easy to be embedded into electrical equipments, used with high resolution and in large scale as temperature and strain sensors they are thought be the perfect device to realize "optical flexible structure". Besides this, FBG sensors have many other advantages, such as strong ability to avoid electromagnetic interference, high solution precision and low production cost. The application of power cable is becoming popular as power industry’s development in our country. FBG sensing system is able to find the hidden trouble inner electric power equipment and reduce the chance of safety misadventure.Some researches about theory and project practice of FBG sensing system based on the technology of IoT are done. Effective measures to improve the performance of system are proposed in this paper. The innovations are as follows.1. A new design of ASE source using optical fiber ring as reflection device is proposed in project in order to save Erbium doped fiber and improve the property of ASE light.2. Experiments about the influence that high temperature (50-200degree) has on the reflectivity and linearity of FBG are made. The result indicates that general industrialized FBG can be used to measure high temperature with physical protection.3. Analysis about the attenuation of pumping LD in ASE source is made from point of view of fiber core matching. The method to improve the utilization ratio of LD is also proposed in this paper.4. The cause of ORL in fiber-optic elements (such as jumper cables connector and fiber end) is presented. In addition, suggestions to optimize the fiber optical sensing network in order to improve the SNR are presented. Methods to suppress noises caused by the fiber end interfaces of FBGs, including using index-matching fluid, bending fiber pigtails in the way mentioned in this paper and cleaving the slant angle of the fiber interfaces to be8°all contributed to the optimized SNR.5. The preliminary PC software of the FBG sensing system is presented in this paper. The local server part of PC software gets the original data of sensors and shows it on interface continuously and automatically and the remote client part gets the worked data and shows it according to local server continuously.