The Study Of FPGA-Based Cable's Temperature Monitoring System Using Distributed Fiber Bragg Grating

Cable is an important part of power system, due to the cable in underground, Potential aging and defects will not be discovered. As time increases, possible overheating or short may case fire, if measure temperature before the accident and take measures quickly, the accident can avoid effectively. Due to the high voltage, high current, great magnetic field, the traditional electric temperature does not apply, we can measure local position temperature only,do not monitor hole line. Fiber Bragg grating sensor has short polyure, bending loss, connecting loss, detectors, current magnetic factors do not influent measure information, we can realize the goal of quickly and accurately measuring temperature. it has lowcostmaintenance suitable for online monitoring.Firstly, based on equation of heat conduction, finite-element method is used to analyse temperature field of cable and provides witness for monitor temperature. Analyzing the basic theory of characteristics of fiber grating, spectrum characteristis of even cycle fiber Bragg grating,and sensing mechanism on temperature and strain.Secondly, study the demodulation technology of distributed fiber Bragg grating,after compare advantages and disadvantages of demodulation plan,propose a cable's temperature monitoring system using distributed fiber Bragg grating based on FFP-TF, it can monitoring multiple points. Do more experiments on design plan, collect a large number of experimental data.Finally, design sensor signal processing system based on XILINX XCS250E FPGA. The system contains functional modules such as photoelectric conversion and amplifying circuit,voltage signal circuit,data collection and LCD display. Simulation and experimental results verify that the system is effective.