Research Of Fiber Bragg Grating Current Sensor

Optical fiber Bragg grating has the advantages of good stability, wide dynamic range, anti-electromagnetism interference, large measurement range and many other advantages, which has been widely used in many fields of research and application in recent years. One of them is the study of fiber Bragg grating current sensor. Fiber Bragg grating (FBG) sensor has many advantages such as small size, electric insulation and anti-electromagnetic interference. It has a broad application prospect in high voltage power system and current measurement and now it has become a hot spot.Based on the review of the research status for fiber Bragg grating current sensor and the characteristics of the fiber Bragg grating, then the principle of sensing device is presented and the sensing device structure is demonstrated. In addition, the signal processing system with the core of DSP (TMS320VC5402) and the auxiliary chip of MCU has been designed in this article. The schamtic circuit and PCB board have been designed and made in this article, and the software of the system is also introduced in detail. The hardware circuit includes amplifying circuit, AD transformation circuit, LCD display circuit, circuit of DSP and the related circuit of MCU. DSP is responsible for data acquisition and processing, MCU is responsible for controlling the stepping motor of the demodulation circuit so as to demodulate the wavelength signal of FBG well enough. Software includes the data acquisition, HPI communication, SPI communication, display programs and stepping motor driver programs to achieve signal processing. The experiments has been finished as follows: the strain characteristics experiment of sensor grating, the matching experiment of matching grating with stepping motor and demodulation experiment of sensor grating. The experiment platform has been built for signal processing system of fiber Bragg grating current sensor. Experimental results indicate that this system can operate stable and accurate. Finally, after summarizing the work which has been done and then the further research work is put forwarded on how to improve the precision of the experimental data.