Natural-gas pipeline leak location using variational mode decomposition analysis and cross-time-frequency spectrum

A novel method based on variational mode decomposition (VMD) and cross-time-frequency spectrum (CTFS) is proposed for leak location in natural-gas pipelines. Leakage signals are decomposed into mode components by VMD, and an adaptive selection method using mutual information is proposed to process these mode components and obtain the sensitive components closely related to the leak. CTFS is applied to analyze the time-frequency distribution of sensitive mode components. The delay and the corresponding frequency information are extracted when CTFS reaches the maximum. The corresponding frequency is used to calculate the group velocity of wave speed, in combination with the dispersive curve. Finally, the time-delay information and wave speed can be used to determine leakage source. The proposed scheme has been experimentally validated; the results demonstrate that the average relative location errors are reduced to one-third when compared with the CTFS location method based on empirical mode decomposition (EMD).