Experimental Analysis Of Units' And Powerhouse's Vibration In A Large-scale Hydropower Station

The structural vibration problem of hydropower station has become a key problem in the design and operation of a power station. Due to the vibration, the benefit of power station system is affected. Long-term vibration may cause fatigue damage of the structure and insecurity in the operation of units.The structural vibration problem of hydropower station has been given a common emphasis more and more becourse of the giant various danger. To master the vibration characteristic of hydropower station structure well and resolve the vibration problem, the best method is the field test. Then start a feedback analysis to the experimental data, seeking after the relation between the vibration and operation condition, and so on. At the same time, according to much field experimental data and conclude the characteristic of powerhouse vibration. So, it will be much valuable to optimization operation of hydropower station, decrease the accident and improve the efficiency of units servicing. Link up the field experiments of Three Gorges and Lijiaxia hydropower station, this paper's primary studies such as:(1) The time-domain analysis, amplitude-domain analysis, frequency-spectrum analysis, vibration source analysis, correlation analysis and energy analysis on the measured data of units and powerhouse structure are made based on the result of the field test of variable speed, variable load, flow fluctuation and special condition operation to the hydrogenerator unit of Three Gorges.(2) Get the characteristic of structure's natural vibration and check the resonance vibration of structure according to calculating the three-dimensional finite element model of Three Gorges.(3) Base on the analytic result of vibration of the units and structure, link up the analysis result of experimental data, and characteristic curve of water turbine model, refer to request of units'running safely,compartmentalize the function course reasonably and forecast the vibration regions.(4) Apply wavelet to the analysis of vibration sources in the unsteady process signals of starting up and shutting down in Lijiaxia hydropower station.