Research On Leakage Fault Detecting And Locating Device For Rural Indoor Cable

Electric energy is a kind of energy which is convenient for transmission and convenient to use,and modern life can not be separated from it.As the rapid development of China's rural economy,the types and quantities of electrical appliances for individual users have increased significantly.Rural electricity environment has become complicated.In order to reduce the occurrence of rural electric shock accidents,RCD is re-install in the rural areas.This paper combines the advantages of existing detection and positioning methods and the fault simulation model is established based on the characteristics of rural indoor leakage fault.The method of leakage fault detection is put forward,and the factors affecting the detection are analyzed,and the experimental research of leakage fault detection and localization is carried out.Firstly,study on types of equivalent load on ground of leakage fault,and linear load and nonlinear load simulation model are established based on the actual data,and related parameters are obtained.Compared with the actual current waveform,the feasibility of the model is obtained.The principle of leakage fault in low voltage distribution network is expounded.And the mathematical model is used to establish the simulation model.And the current characteristics of the equivalent load of the leakage fault are analyzed.At the same time,the Fourier transform is used to analyze the waveform characteristics of nonlinear load leakage faults.Then the method of leakage fault detection is put forward-inspection tour method.The principle of the detection method used in this paper is explained.Based on the analysis of the magnetic field model of the current-carrying straight wire and its joint in a certain space,the magnetic field characteristics are calculated by ANSOFT software.And it is analyzed that the material in the actual situation may have an impact on the magnetic field.The results show that the direction of the magnetic field at the joint is not perpendicular to the conductor.In building materials,theoretically only some of the metal material will cause interference to the detection.Considering the actual use environment of the equipment,this paper designs the magneto resistive sensor as the core of the leakage detection and positioning equipment,as well as signal transmission system and data display processing software program.The hardware of data acquisition and transmission system mainly include: data acquisition unit,signal transmission and reception unit,data display and processing unit.It is designed that the main program and subroutine based on the IAR Embedded Workbench Evaluation and Labview software development environment.Then the acquisition signal is applied on wavelet packet denoising and other follow-up processing by MATLAB.An experimental platform for leakage fault detection is established to carry out the sensor characteristics experiment,anti-interference experiment of detection device and experiment of simulating leakage fault.Based on the experimental results,it is verified that the signal communication circuit and the display part of the host computer are good,flexible and stable in the range of 5m;through the simulation of leakage test,the specific range of the circuit and the leakage points are detected,and the error ranges from 1 to 3 cm.The error is within acceptable limits.The results show that the design of the device has a certain practicality.