The Railway Runthrough Earth Cable Theft Deterrent Research Based On M-Z Interferometer

With the rapid development of high-speed railway in China and the whole world,how to ensure a proper functioning of the train system has been a crucial issue.The railway runthrough earth cable which makes the railway system electrical equipment ground can eliminate the disturbance of lighting current,so as to guarantee the reliable work of railway equipment.Since runthrough earth cable contains a large amount of copper,the criminals often steals it.Therefore,how to find the theft incident and find the position in time is an urgent problem.This paper designs a railway runthrough earth cable theft deterrent system based on dual Mach-Zehnder interferometer optical fiber sensing technology and completes the simulation and experiment.The specific research contents and achievements are as follows:(1)This paper analyzes several common interferometric fiber optic sensor and introduces the principle,and analyzes the Mach-Zehnder interferometric fiber optic sensor in detail.Then this paper introduces a description of the key devices.(2)This paper studies the dual Mach-Zehnder optical fiber sensing technology positioning principle by searching and reading the literature.Then apply it to the railway runthrough earth cable theft deterrent system.The cross-correlation algorithm is studied.(3)This paper presents a monitoring mechanism for event occurrence.Firstly,the noise is filtered by noise threshold and secondly the DFT energy proportioning algorithm is used to distinguish train vibration signal from incision vibration signal.(4)Firstly,the dual Mach-Zehnder interferometric fiber sensor location algorithm is simulated by LabVIEW platform.Secondly,the paper uses MATLAB to simulate the positioning algorithm and wavelet denoising technology.At the same time,the vibration waveform of the train vibration and the incision event is simulated.And the paper uses the event monitoring mechanism to distinguish the two kinds of vibration signals.(5)This paper sets up the railway runthrough earth cable theft deterrent system.The false alarm rate of 6.7%and the positioning accuracy of 20.89m were achieved on the 5km optical fiber cable.This achieves the expected results.