Fluctuation Signal Analysis of Hydraulic Turbine Based on Hilbert-Huang Transform and Median Filter

Abstract

As a new time-frequency analysis technique, Hilbert-Huang Transform (HHT) behaves differently in signal decomposition and analysis method, but it is weak in noise resistance, even low noise may disturb the HHT result greatly. The paper launches an investigation on the application of HHT for fluctuation signal analysis of turbine draft tube. The analytic framework for HHT is introduced, median filter is adopted to reduce the frequency leakage of certain signal component. The experiment data from the turbine of hydropower station is analyzed by the method. The results shows that the proposed method can reveal time-frequency features of the signal effectively.