Research Of Distributed Electric Power Optical Fiber Sensing System In Temperature And Strain Monitoring

Electric power optical fiber, the mileage of which is over one million kilometers in China, acts as an information channel for electric power grid communication, scheduling, and protection in the electric power system. In consideration of this, distributed electric power optical fiber sensing research is instrumental both in monitoring electric power optical fiber itself and in environmental monitoring along the optical fiber corridors.Any variation in electric power optical fiber is the most prominently and directly reflected by change in temperature and strain and, because of this, temperature monitoring and strain monitoring are two major and important approaches in monitoring electric power optical fiber. As Brillouin scattering is intimately related to temperature and strain in the case of optical fiber, distributed optical fiber sensing based on Brillouin scattering has been widely studied and applied.This system, featuring Brillouin optical time domain reflectometry (BOTDR) and intended for electric power optical cable monitoring applications, is capable of long-range and distributed monitoring of electric power optical cable temperature and strain. This system was in large part designed and developed on Labview virtual instrument platform and the design and development process involved parameter configuration, data acquisition, data processing, design of frequency sweeping, image display, data storage, interface design, and system test. The hardware framework was built in accordance with BOTDR technology and software design was then made on the Labview platform. Software design primarily dealt with data acquisition control in the data acquisition card, frequency sweeping control in the frequency synthesizer, and noise reduction of scattered signal as well as employing different data fitting algorithms so as to get accurate Brillouin frequency shift. This system was in the end proved feasible in an experiment, which demonstrated that this system had achieved real-time monitoring of optical fiber temperature and strain and may thus be used in monitoring electric power optical fiber fault events in the electric power system such as fire, ice coverage, lightning, and galloping.