Research On A Novel Fiber Fabry-perot Sensor For Partial Discharge Detection

Partial discharge is one of the important reasons for the insulation damage of power equipment.In order to detect latent faults in power equipment,it is necessary to monitor the power equipment on-line.The on-line monitoring of partial discharge of electric power equipment can effectively prevent sudden failure and avoid unnecessary economic losses to the society.Because of its ability to avoid electromagnetic interference and real-time on-line monitoring,acoustic partial discharge has become the focus of attention.However,because of its low sensitivity,the built-in installation of the sensor is inconvenient and easy to be damaged,which brings problems to the measurement.Taking the liquid solid composite medium of transformer as the research object,aiming at the above problems,this paper put forward a structural design for fastening the traditional F-P sensor quartz diaphragm end face with the steel structure,then made it to external high coupling efficiency F-P sensor.By using the finite element simulation software COMSOL to the transformer tank internal partial discharge acoustic emission simulation in liquid-solid composite medium calculation of acoustic waves in liquid-solid composite media transmission,the attenuation and the liquid-solid composite interface coupling rules,and proved that the external high coupling efficiency F-P sensor can effectively capture the sound signal.Through the analysis of ideal characteristics of external F-P sensor parameters.In the traditional F-P sensor fiber pigtail,quartz tube and quartz diaphragm on the basis of the increase of fixed structure and steel structure with vibration coupling gap notch,with fixed constraint material filling fixed support external high coupling efficiency of F-P sensor sample.Construction of external F-P sensor frequency response test system,using a tunable distributed feedback laser as light source,frequency modulation signal generator for external incentive of high coupling efficiency of F-P sensor response parameters.Build a plate-plate high voltage discharge experimental system,simulation of transformer internal liquid-solid composite insulation medium,through the external pressure by external high coupling efficiency of F-P sensor and piezoelectric ceramics for simultaneous detection of partial discharge acoustic emission signal.Finally,compare and analyze the F-P sensor and the PZT captured acoustic signal,and determine the output spectrum based on Fourier fast transformation.After further improving the sensor structure,we can improve its detection sensitivity.