Research On Coal Mine High-voltage Power Cable Fault Location Based On Low Voltage Pulse Method

High voltage power cables have made great contributions to the economic development for coal mining enterprise. It often broken because of the insulation aging or some external role often, and this will lead to some economic losses. In order to recover the cable running as soon as possible, the fault need to be located analysis and ruled out. Low voltage pulse method has some advantages for coal mine high-voltage power cable fault location, such as operation simple and practical, etc.., therefore the low voltage pulse method for coal mine high voltage electric power cable fault location have large research value and significance.Firstly, this paper describes the application status cable fault type, location technology development status and the application status of low voltage pulse method in positioning. The wavelet transform is used to extract the pulse signal singularity calculated reflection time and fix the fault point. At the same time, the low voltage pulse method noise problem is analyzed, and the selection of the modulus maxima points of the pulse signal coefficients is effected by the noise. In order to solve this difficulty, a new de-noising algorithm based on the wavelet entropy optimized spatial correlation filtering is proposed. The maximum range of wavelet entropy is selected to optimize the noise energy threshold. The details of the pulse signal can be better kept by this method. This method can improve the precision of fault location, and has high signal-to-noise ratio and mean square error at the same time.On this basis, single type cable fault, with connector cable faults and old and new hybrid cable fault location are studied. First, single type cable fault location are studied, at the same time with connector cable fault reflection waveform characteristics were studied. The fault location is achieved based on the reflected waveform characteristic impedance rule. For the old and new hybrid cable characteristic impedance discontinuities due to inconsistencies resulting in velocity were analyzed to study the pulse signal propagation characteristics, the way of the signal traveling wave velocity section analysis is put forward. The transmission characteristics are researched, and the wavelet modulus maxima way is used to search the singularity of the pulse to locate the cable fault, and achieved good results.Finally, the coal mine high voltage power cable fault location system based on LabVIEW is designed according to the content of this paper. The fault precise positioning of the high voltage cable is achieved based on the Advantech PCI-1714 data acquisition card and LabVIEW advanced Signal Processing Toolkit, and then the purpose of combining the theory and practice is achieved.