Leakage Signal Analysis of Urban Gas Pipeline Based on Improved Variational Mode Decomposition

摘要

Aiming at problems of multipoint leakage source detection and low positioning accuracy in urban gas pipelines, a multipoint leak location method base on improved variational mode decomposition (VMD) was proposed. By improving the VMD decomposition of the original leakage signal, the parameters of the VMD were optimized to reduce the influence of noise and weak correlation signals on the leak location. Then the multi-point leakage location model of pipeline was established, and the sensitive modal component Intrinsic mode function (IMF) with the most leakage information was selected by multiscale entropy. According to the characteristics of the blind source separation method, the relevant time delays of the simultaneous leakage of multiple points on the pipeline and the frequency of the signal are extracted. Finally, The location of the leak source is determined according to the principle of cross-correlation. The experimental results show that compared with the direct cross-correlation method and the VMD-based method, the proposed multipoint leak diagnosis method has less error, the minimum relative error is 1.61%, and the positioning accuracy is higher.