Fault Location Of Transmission Line Through Traveling Wave Based On EEMD And Teager Energy Operator

With the rapid development of science and technology,the Zhilian Power Grid has been formed across the country,and the scale has been continuously expanded.The voltage level of transmission lines has also been continuously improved.The long-distance transmission line has a harsh living environment,and the geographical and climatic environment is complicated.Failure will have a major impact on social benefits,so it is necessary to quickly,reliably and accurately determine the location of the fault.Therefore,this paper proposes a method based on the combination of empirical mode decomposition(EEMD)and Teager energy to locate the faults in the transmission line.Use EEMD to decompose the wave head information after the fault and select the eigenmode component IMF that meets the condition,and then use the Teager operator to obtain the position of the highest point in the energy map,which is the sudden moment of the traveling wave head information in the fault,and finally use The double-ended ranging algorithm finds the fault distance.First of all,this paper outlines the existing fault location methods for transmission lines and summarizes the types of faults in transmission lines.Secondly,this thesis studies and analyzes the basic theory of traveling wave.For the uncertainty of wave velocity,in order to improve the accuracy of traveling wave ranging,a double-end ranging algorithm without wave velocity participation is adopted to avoid the wave velocity.Direct involvement,which eliminates the drawbacks.Thirdly,in order to extract the feature of the traveling wave current signal,the accuracy of the extracted feature quantity is improved,so that the frequency characteristic of the traveling wave current signal can be more accurately characterized,and the accuracy of the fault location is enhanced.Considering that the acquired signal has strong non-stationarity,the original signal is decomposed by the time-frequency decomposition method.The Ensemble Empirical Mode Decomposition(EEMD)used in this paper is the empirical mode decomposition(Empirical Mode Decomposition).On the basis of(EMD),the modal aliasing phenomenon and the end effect are weakened,so as to obtain a better decomposition effect.Obtain the spectrum of each component,and select the eigenmode component that matches the range of the traveling wave frequency.In order to obtain the sudden change of the signal,and consider that the Teager energy operator can detect the obvious energy change when the signal is abrupt,select The Teager energy operator detects the maximum mutation point of the signal.In the simulation analysis stage,in order to verify the feasibility and superiority of the proposed method,the EMD,EEMD and Teager energy operators are combined respectively to obtain the measured fault distance.The experimental results show that the time-frequency decomposition method and Teager The combination of energy operators can effectively calculate the fault distance,and the results obtained by the EEMD-based method are closer to the actual value.It can be concluded that compared with EMD,EEMD can more accurately decompose components of different frequencies,thereby improving the accuracy of ranging.