The Research Of Based On Fiber F-P Sensors To Monitor Vibration Signal Of The Transformer Core

Transformer fault is a great threat for the power system security, reliability, quality,economic operation, a serious failure of the transformer even will generate the entiregrid system collapse and does great harm to the grid system. With the rapiddevelopment of China’s power grid, it is very necessary to improve the operationalreliability of electrical equipment, especially the large-scale transformer and monitortheir operating status. The transformer body is an important part of the transformer,andthe transformer core is the core component of the transformer body, therefore, theoperational status of the transformer core is an important criterion to judge transformersafe operation or not and we need to on-line monitor of transformer core in order toensure the grid’s safe operation. Combination of domestic and international researchstatus of on-line monitoring of transformer vibration the online monitoring, this paperhas presented a on-line monitoring system of transformer core based on fiberFabry-Perot sensors and realized the whole design and building,which is used to onlinemonitor and analysis of transformer core vibration signal.This thesis analysed the vibration reasons through the transformer vibrationtransmission routes, and conclude that the magnetostriction of silicon steel is the mainreason to cause the core vibration. Then it detailed that the core silicon steelmagnetostrictive effect and principle, got the vibration model of the ferromagneticmaterial through theoretical analysis, including the relationship of core magnetostrictiveexcitation voltage, current, core vibration acceleration core magnetostrictive. This thesisconcluded the superiority of the optical fiber Fabry-Perot sensors for strainmeasurement of transformer core by comparing several sensors and measurementmethods which can be used for core vibration measurement.According to the basic principles of the transformer, the transformer wasequivalent to ideal circuit model. Through build the Multisim circuit simulation circuit,analysis of the simulated current waveform by matlab fft, which can obtain frequencyspectrogram and analyze the associated transformer core vibration spectrum and loadchanges. to. With the measured transformer for the experiment, a1/2simple andeffective transformer model was builded, which used Ansys software to do the analysisof electromagnetic coupling and simulated and calculated output parameters of thetransformer under load, such as the secondary voltage, magnetic field distribution. And then did structural analysis by Ansys software to calculate the resonant frequency of thetransformer core silicon steel, which can provide an effective simulation data forreference for subsequent measurement of vibration experimentsThis thesis completed the overall design of the online monitoring of transformercore system based on fiber Fabry-Perot sensor, on the basis of which builded systemplatform and get the transformer core vibration signal, analysis and verify that the corevibration signal fundamental frequency should be twice the fundamental frequency ofthe AC excitation voltage (or current); higher harmonic components in the corevibration signal is mainly distributed around the inherent frequency of the core whichwill change as the load changes.The experiments shows that it is a stable and online monitoring system which notonly can extract the core vibration signal, but also be easy to optimize and upgrade. Thisdesign provides an important reference for the platform design of other systems basedon fiber Fabry-Perot sensors of similar design and transformer vibration measurementsin related fields.