| As developing as our Country's economic, the range of power cable'sapplication is larger and larger. But, because of the cable's bad makingtechnology level, poor quality, installation and the operation circumstance, thepower cable could sometimes fault. It takes large loss to the user. So, detect thefault accurately and quickly has a momentous importance for the powersystem's stability and the user's power using quality.The paper chooses fault analysis and distance measurement of the powercable as the main content. Nowadays, the common method of power cabledistance measurement is the moving pulse method. The fault waves usually aregot at the broken spot. It is usually hard to analysis. In the past, the analysismethod has a problem that the accurate time of the beginning of the pulse is hardto be detected, it take a very serious consequence. The shortage of the method isthat the collection signals are different from each other every time.The paper combines wavelet theory with signal mutuality, raises a newmethod to detect the beginning time of the pulse, realized the distance calculatedby program. The result is tested by simulation analysis. At first, the paper hasput wavelet on the original signal, obtains the high frequency decomposedsignal and low frequency decomposed signal. Second, the signal mutualitytheory is applied on the low frequency reconstruction signal, therefore gets theapproximate fault time singularity. Third, use the method of searching modulusmaximum line to find out the precise singularity in the high frequencyreconstruction signal. At last, the precise time of the pulse is got in the highestfrequency decomposed signal level. The time is used to calculate the faultdistance of the power cable.The paper, using MATLAB platform based on theory analysis, draw up thedistance calculation flowchart of the fault power cable. Furthermore, for a realfault signal, the paper gives the detail calculation course. By simulation, thepaper gets a good result.
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