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Abstract

Due to the nonstationarity of the pressure fluctuation signal from a hydraulic turbine draft tube, this research proposes a pressure fluctuation signal analysis method based on variational mode decomposition (VMD). Firstly, the research was used to compare VMD with empirical mode decomposition (EMD) by using a simulation signal, which shows that the VMD method could effectively inhibit mode mixing, but EMD method could not. This could improve the accuracy of such analysis. Then, the VMD method was applied to analyze the real pressure fluctuation signal from a hydraulic turbine. The results showed that VMD produced clearer time–frequency spectra. This allowed accurate analysis of pressure fluctuation signals. This research provided a new method of pressure fluctuation signal analysis for hydraulic turbine draft tubes.

Keywords

Hydraulic turbine pressure fluctuation signal variational mode decomposition empirical mode decomposition mode mixing time–frequency spectrum

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Pressure fluctuation signal analysis of a hydraulic turbine based on variational mode decomposition

Abstract

Keywords

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References