Study Of Fiber Bragg Grating High DC Sensor Based On Magnetic Coupling

Electric power industry, as the basic industry of the national economy, plays an irreplaceable role in our country's economic. With the power transmission system capacity increasing and the running voltage levels rising, we found that traditional high electric current detection technology can't match it, which causes peoples to pay more attention to the development of new current transformers. Optical fiber current sensor is considered to be the ideal alternative products of the traditional electromagnetic type current transformers, for its intrinsic safety anti-electromagnetic interference and many other advantages.At present, Optical fiber grating with its unique advantages becomes the research focus gradually. More and more people do the research of current sensor using FBG as the main current sensitive components. There are many optical fiber grating current sensing solutions such as magnetostrictive material, current heating, piezoelectric ceramic, magnetic coupling and so on. But almost all are in the laboratory study phase, which have a long distance to the ideal current sensor. In this paper we analyzed the advantages and disadvantages of all kinds of FBG current sensors and give a new FBG high-current sensor based on magnetic coupling with magnetic collecting pieces and high sensitivity elastic components. We make the prototype, set up the test system, did many tests and analyzed the performance of the sensor. The result shows that the sensor is feasible.Major research work includes the following sections:(1) Analysis of the based theory of FBG.(2) A detailed analysis on the principle of magnetic coupling, deduced the sensor theory, and did a finite element analysis to the key components of the sensor.(3) Designed a high sensitivity elastic component and the sensor prototype according to the analysis.(4)Built the relevant test systems, did many experimental tests to the sensor, did a detailed analysis of the measured data and analyzed the performance of the sensor.In this paper, we gave a new idea to measure high-current by FBG and verified it by principle analysis, designing prototype, experiments and data analysis. Hopes to give some help to the future research about high-current sensors.