Research On The Mine Anti-grade Tripping Optical Fiber Differential Technology

Over recent years,there have been frequent override trippings led by the short circuit in the power supply system of mines,which has seriously threatened to the life and security of workers and the stable operation of the power supply system of mines.Therefore,considering the features of domestic mines power supply system of multiple levels,short transmission circuit,interfering signal in mine and strong corrosion,the paper purposes an optical fiber differential protection devices on the basis of designed by S3C2440AL-40 ARM9 clip so as to improve the security and liability of such devices from anti-grade tripping protection.In terms of the design,the study is mainly focused on the working principle,protection signal model,methods to ensure time synchronization,protection sampling algorithm,software and hardware of circuit design.To begin with,according to the actual situation of mine power supply system,the dissertation discussed the basic principle of optical fiber differential,compared and select the differential protection criterion,made an analysis of different optical fiber communication modes and designed a special fiber channel suitable for mine power grid.Then,corresponding improvement has been made to the problem that timely adjustment is largely influenced by the change of channel.As for the problems of too much signal interfere in the mines and unable extract real information accurately by single-use the Fourier transform,combined with Fourier transform and wavelet transform,wavelet entropy and other techniques to improve the protection algorithm,used MATLAB to set model construction and algorithm simulation of mine power supply network.Simulation results show that the protection algorithm in this dissertation has high accuracy and anti-jamming ability.After that,software and hardware of optical fiber differential protection devices against anti-grade tripping have been designed based on ARM 9 clips and embedded ?C/OS-II Operation system.The hardware of the protection system covers minimum system and the design of function modules,and the software covers main program,data acquisition program,communication program,fault handling program and human-Computer Interaction Program.Based on the ARM9 S3C2440AL-40 clip,the project has completed the design of the protection device against mine anti-grade tripping,designed a mining type optical fiber communication model and made improvement to the traditional time synchronization approach and sampling algorithm.As the result of stimulation experiment and function testing indicates,the mine anti-grade tripping optical fiber differential protection devices of this dissertation can fulfill the protective action correctly and has high reliability and application value.Figure [51] table [5] reference [55]...