Research On Trackside Equipment Monitoring System Of Pantograph-catenary Dynamic Contact Force

The cable terminal will produce partial discharge phenomenon in the work,which will cause equipment damage and then failure.Therefore,online monitoring and inspection of partial discharge of cable terminal can effectively avoid the extension of failure and prevent the cable from major damage,so as to reduce the impact of failure on people’s social life and economy.Since the 21 st century,the progress of acoustic emission detection method is very obvious,which has aroused wide attention of researchers.The advantages of acoustic emission measurement method are obvious,the most important is that its working environment is not affected by the electromagnetic field,and it can carry out real-time monitoring,sound source positioning,etc.,but there are also some problems of acoustic measurement method,that is,its sensitivity is low,it can not be measured quantitatively.In this project,the cable terminal is taken as the research object,and the fiber Bragg grating sensor is embedded in the terminal to design a partial discharge(PD)on-line monitoring system with good detection and strong sensitivity.Using the simulation software COMSOL,this paper studies the transmission of acoustic emission signal inside the cable terminal,uses the acoustic solid coupling model,sets the sound source point inside the cable terminal for simulation,studies the attenuation of acoustic emission signal in different frequencies inside the cable terminal,and uses these characteristics to find the best embedding position of the optical fiber sensor.In this project,the fiber Bragg grating is used to match the narrow-band laser source,and the change of signal is obtained through the change of light intensity.At the same time,the difficulty that the initial wavelength of narrow-band laser source can not match is solved.Based on the actual background,this paper studies a set of cable terminal partial discharge monitoring system based on Fiber Bragg grating acoustic emission sensor,including the selection of fiber Bragg grating sensing scheme,the selection of fiber sensor location,the composition of hardware and the design of various hardware circuits,the design of software and parameter configuration.The hardware part includes the selection of laser source,connector,circulator and other equipment,as well as the design of minimum system circuit,acquisition circuit,drive circuit and power supply circuit.The software part is based on Lab VIEW platform to design the program of the sensor system,write subroutines and configure parameters.