1.School of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha 410114, China;2.Foshan Electric Power Corporation, Foshan 528000, China;3.State Grid Jining Electric Power Corporation, Jining 272100, China;4.State Grid Xiangtan Electric Power Corporation, Xiangtan 411104, China

In order to promote the practicality of the transient protection principle based on waveform uniqueness, this paper proposes a transient protection method for transmission lines combining empirical mode decomposition-Wigner Ville distribution (EMD-WVD) and cuckoo search (CS) algorithm. This method uses EMD to process fault transient signals to obtain single-component signals in different frequency bands. Waveform correlation coefficients are used to calculate the similarity between each single-component signal and the original transient signal to screen the true transient signal components. Then, WVDs of the true components are obtained respectively. The WVDs of all the true components are linearly superimposed to obtain the energy spectral density map, which is then iteratively matched with the energy spectral density map in the fault sample database to calculate the similarity. Internal and external faults are identified based on similarity to achieve the fast and reliable protection from transmission line faults. Simulation results show that the EMD-WVD method can effectively improve the accuracy of fault transient waveform analysis, and the CS algorithm can effectively improve the waveform matching speed. The combination of the two is expected to promote the practical application of transient protection.