In order to study self-excited vibration mechanism of the main inlet valve of a pumped storage power station, its waterflowing system’sprecision numerical simulation model was established based on the transient flow theory to obtain the variation curve of water level of the upstream pressure measuring pipe with time by calculation.The empirical wavelet transform (EWT)method was used to do feature extraction and spectral analysisfor self-excited vibration signals and simulatedonesof the main inlet valve,and verify the correctness of the numerical model.The modified Morris method was introduced to find pipeline length, pipelinewater hammer wave velocity and valve clearance of main inlet valve being sensitive parameters invarious performance ones.Finally, aiming at sensitive parameters,3 schemes were set to do numerical simulation, respectively and study their specific effects on self-excited vibration process. The results showedthat main inlet valve clearance has a large influence on self-excited vibration amplitude and its growth rate, but has little effect on system’s period; pipeline water hammer wave velocity and pipeline length have great influence on self-excited vibration amplitude, its growth rate and system’s period.
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