The Development Of Fiber Bragg Grating Hydrogen Sensor Using In Transformer Oil

The performance of weakly partial discharge or low overheating is one of the early failure of transformer, hydrogen is the main failure gas, detecting the content of hydrogen in oil is an important way to monitor transformer. At present it is necceraly of on-line monitoring system to separate transformer oil and failure gas, which will bring pollution to transformer, use long time to equilibrate or have complicate structure. Electronic components will always be involved in testing process, which are susceptible to the influence of the electromagnetic interference.Put forward and developed a Fiber Bragg Grating(FBG) hydrogen sensor,which is based on the theory of palladium volume expansion when palladium absorb hydrogen and the FBG sensitive to strain, on the surface of FBG coated a palladium as the hydrogen sensing membrane. Used magnetron sputtering can solve the hysteresis of tranditional sensor; coated polyimide beforehand can solve the problem of palladium abscission of tranditional sensor. The developed sensor has good linearity, high sensitivity, without delay and strong reliability, the sensitivity of FBG hydrogen sensor is62.73pm/%H2, the related coefficient is0.992, norlinearity error is1.612%.On the platform of dissolving hydrogen in transformer oil, a measurement of hydrogen in transformer oil has been done by using FBG hydrogen sensor, and the result indicate the sensor response quickly. On the platform of partial discharge in laboratory, the experiment of partial discharge of several models have been done, and the result turns out the wavelength of FBG hydrogen sensor is linearly dependent with the measuring value of gas chromatography, has nothing to do with test model and discharge capacity, and response quickly, the sensitivity of FBG hydrogen sensor is0.043pm/ppm, the related coefficient is0.974, norlinearity error is14.65%.