An Optical Fiber Current Sensor Utilizing Twin Fiber Bragg Grating Fabry-Perot Interferometer

As very important equipments in electric power industry, current transducers(CT) play a primary role for working well and calculating precisely in power supplying system. With the development of electric power industry, higher voltage level emerges continuously, and higher accuracy of measurement and protection are demanded increasingly. The traditional electromagnetic current transformer was not seasoned with requirement of development. It is an absolute trend that novel photoelectric CT substitute the old CT. Optical fiber current transducers(OCT) base on modern electronic technology and optics technology which have many excellent characters. OCT have already been accepted by electric power engineering because of attractive characteristics of avoid electromagnetism interfere, small volume, high sensitive, high accuracy, high reliability and wide bandwidth.The main research work of this thesis is design a new OCT system based on study the internal and overseas OCT at present particularly. Sense organ which utilizes twin fiber bragg grating Fabry-Perot interferometer in a single-mode fiber. The OCT systems not only possess of the good qualities of all-optical fiber structure, but also adopt frequency measurement technology of light intensity. This technique effectively eliminates fluctuations of ambient changes and internal birefringence of optical fiber and also makes the sensor entirely-fiber, stability, brief, economical and anti-jam ability of the sensor significantly.At the field of photoelectric signal process, the thesis designed the electron-circuitry. Gave the principles of component selection, pre-amplify, band-pass filter circuit, signal process, and software arithmetic deeply. Adopt digital signal process technology and make the electrocircuit hardware performance and proficiency.The primary experiment was made base on a OCT system of laboratory. From analyze measurement result and the error of experiment, the data of experiment coincident to the theory perfectly. Correctness of all principles and design of the OCT system was proved. This OCT system had simple structure, high sensitive, low cost and easy use. Possess of considerable reference value to a practicable product develop and design. In the end of the thesis put forward betterment measure of the OCT system. The research in this thesis is expected to provide theoretical basis to development of Fabry-Perot optical fiber current transducers and to help for practice product design.