The Research Of Current Sensing Based On Gmm And Fbg

The current measurement is quite important in the power industry, its’precision andreliability related the safety and economy of operation in electric power system closely.With the development of power, conventional current transducer can’t meet requirements.Now the optical current transformer(OCT) have potential application cost because ofits’unique advantages will be used to replace conventional current transducers in thefuture.In this paper, on the present situations in the field of OCT, a novel electrical currentsensing configuration is constructed based on fiber bragg grating and giantmagnetostrictive material. The content of this research includes:In the depth analysis of fiber grating sensing principle, the correspondingmathematical model are derived based on the axial strain characteristic, temperaturecharacteristic and cross-sensitivity characteristic; then the sensing properties of giantmagnetostrictive material is analyzed. Then the sensor is designed based on the giantmagnetostrictive material and the fiber bragg grating. Theoretically complete thecalculation of the sensor detection on the high voltage bus current.With the advantages and disadvantages of various demodulation methods areanalyzed, and the appropriate demodulation is designed: tunable F-P filter demodulationsystem. For the core components of the demodulation system are selected.On this foundation of theoretical design, the experiment system is built up. And itstudies prestressing force effects, offset magnetic field effects and temperature effects onthe experiment system. The diameter and size of the drive coil and the bias coil aredesigned. Completion of the DC and AC testing experiments, and the experiment resultare analyzed.