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Study on weak Feature Extraction of The complex PQ Disturbance based on Multi-level SVD

To extract the weak feature of complex power quality (PQ) disturbance effectively, a new method named mutli-level singular value decomposition (SVD) is proposed, whose idea is combing advantages of SVD and wavelet transform (WT). With recursive construction of the two row Hankel matrix and decomposition by SVD, the original signal is decomposed into a series of approximation signals and detail signals with different singular values. Applying the proposed method to the triple PQ disturbance with noise, the simulation results that the multi-level SVD method can clearly distinguish the weak oscillation and the 7th harmonic characteristics, and is more effective than SVD and WT.