Compression Of Transmission Line Insulator Leakage Current Data Based On Compressive Sensing Theory

Research finds that leakage current is closely related to flashover discharge, it can characterize external insulation status of insulator scientifically. Insulator leakage current especially in the flashover discharge process contains a lot of high-frequency pulse component,it requires the signal sampling rate and processing speed higher. So the huge data collection caused great burden on the data communication and storage.Found that leakage current is sparse under a certain transform domain, insulator leakage current was compressed in the subject based on compressed sensing theory. Sampling frequency that compressed sensing sampled high-frequency leakage current is far below the Nyquist sampling theorem,thus it reduces the burden of data communication and storage, making high-frequency signal acquisition possibly.In this paper,we analyse insulation leakage current sparsity between the wavelet and fourier transform.From these results, wavelet transform represents the leakage current signal more succinct than fourier transform.Relation has be made study of the measurement and the sparsity in a deep-going way. We have found the approximate relationship between measurement and sparity by combining experimental data.The simulation experiment encloses insulator leakage current in the transmission line based on compressed sensing, it first represents the non-stationary insulation leakage current sparse by wavelet transform, and then projects linear measurement by Gaussian measurement matrix, and finally adopts orthogonal matching pursuit algorithm to restore original signal.Experimental results show that the original signal can be recovered by a few of measurements with high precision.The algorithm not only reduces the required sampling frequency of the sensor, but also the data storage and transmission costs.To further improve the reconstruction speed, empirical mode decomposition method is induced to process insulation leakage current stably after the analysis of limitations from the wavelet and Fourier transform processing non-stationary signals . Compressed sensing was applied to compression simulation experiment. We can see that the optimized algorithm not only improved reconstruction computing speed but also reconstructed original signal precisely by contrasting experimental results of original algorithm.