| High-voltage transmission lines are high-capacity, long-distance power delivery major way, therefore, in case of failure for accurate positioning, fast troubleshooting of major importance for the safe operation of the power system. Currently, the traveling wave method has good stability, high precision positioning and highly favored by the majority of electricity workers. Traveling wave method is divided into single-ended and double-side method. Although the single-ended method relies only fault signal acquisition end fault distance can be calculated, but the accuracy of the traditional single-ended method is mainly reflected in the identification of the first wave traveling wave, and accuracy can not be guaranteed always. Although the double-ended method avoids this problem, but must ensure that both ends of the detection device synchronization, high hardware requirements, cost will surge. Based on the above deficiencies of traditional methods, we use a method based on traveling wave fault location natural frequency, the biggest advantage is to avoid the wave head identification difficult. However, this method has the primary natural frequency values determined in the application relies on a single frequency peak is not reliable, accurate extraction of the natural frequency of the main components is not enough and so on.Taking into account the natural frequency extraction single main problem is not taken by this paper based on the original basis of the natural frequency of the traveling wave positioning theory to improve, taken out a comprehensive new approach to consider the fundamental and multiple harmonics: main natural computing globally frequency. Through a series of derivation global primary natural frequency of the main natural frequencies and the weighted average number of times the reciprocal of the natural frequency component. With this global primary natural frequency, more accurate positioning. Simulation results considering the principles described herein with only a single primary natural frequency positioning methods were compared, the results show this method high accuracy, good reliability, error is within an acceptable range.Key-based single-ended transmission line traveling wave fault location method in natural frequency, the accuracy of the primary natural frequency of the extraction is carried out in a precise positioning point of failure. Currently the main extraction methods are mostly used natural frequency wavelet transform, MUSIC method, wavelet analysis by selected wavelets greater impact, select MUSIC spectral estimation parameters greater impact, they have failed to solve this problem. In this paper, the primary natural frequency of the orthogonal extraction method to ensure the accuracy of the traveling wave natural frequency acquisition. Firstly EEMD traveling wave signal decomposition and orthogonal ICA method of treatment to inhibit cross-term WVD's own problem, and then converting each component of WVD and superimposed to obtain orthogonal natural frequency spectrum, and then use primary natural frequency obtained for fault localization process. The simulation results show that under different fault types, fault distance and different transition resistance, the proposed method has higher accuracy than the MUSIC method, and the traveling wave contains high stability under different noise conditions.Overall, the paper positioning principle and the main natural frequency extraction method two improvements, the formation of a more perfect fault location based on the new method of traveling wave natural frequencies, the accuracy and reliability are improved, The method for locating faults in transmission network laid the practical application of a theoretical basis. |
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