Investigation On On-line Fault Location System Of Power Cable

Because of the demands of power continues to increase, it is necessary to add new transmission lines. However, due to limited land available, overhead lines can not be unlimited. Undergrounding cable was largely laying because of the occupancyless of the land. But, the probability of failure of the power cable increasing every year. So it is very important to find and locate the fault to power cable. The common way now was injecting travelling wave to identify the reflected wave, but this led a long period of powercut, in addation,this is may be damage to the cable itself. In recent years, based on the developing techniques on the inherent travelling wave from transmission cables,on-line fault location has also made great progress.Since the 1980 s, wavelet appear in engineering applications highlights the tremendous advantages to theengineering apply,it is widely used and studied by scientists and engineers. Because of the ability in non-stationary signal processing and mutational point identifing, so it is have the incomparable advantage of wavelet based on-line fault location.The feature of fault cable was studied in this paper,and a fault simulating platform was also built for the cable through MATLAB-SIMULINK to extracted the fault travelling wave. Processed the travelling wave used Dmey wavelet,found the maximum of wavelet coefficients,and calculated the fault distance using two-terminated ranging formula. Basing on it, designed a simple and friendly GUI used MATLAB, made easier for the engineers and technicians.