Study On Vibration Characteristics Of Water Turbine Generator Set And Plant Of Hydropower Station

The operation characteristics of Water Turbine Generator Set mainly include energy (output and efficiency), cavitation and stability. Energy is related to extent of water-power utilization; cavitation is related to service life of turbine; the stability not only has great effect to turbine life, but also is directly related to the normal operation of power station. Meanwhile, the vibration of plant structure induced by water-power set has become key problem in designing and operation. Wavelet analysis and fractal geometry have been gradually presenting their advantages and extensive prospect in analysis of measured vibration signal. Basing on actual measurement data of Luosiwan power station, this paper study the operation characteristic of water-power set and the vibration of plant separately. Detailed content and main conclusion of this paper are listed below:In chapter 1, general Situation and existed conditions of vibration of water-power set and plant are introduced, the new method of signal analysis such as wavelet analysis, fractal geometry and the problem to be solved in this paper are summarized.In chapter 2, according to measured data, efficiency of water-power set is received, and corresponding characteristic curve is provided.In chapter 3, combining specific example, set vibration, axis swing, pressure pulsation and spectrum is analyzed, the stability of the water-power set is evaluated, unbalanced factors existed in the set is pointed out, possible excitation sources is obtained, hydraulic excitations as the most important factor is emphasized, measure aimed to improve set operation is provided and stable interval is divided.In chapter 4, wavelet analysis and fractal geometry is used to deal with signal analysis. Energy of frequency range of pressure pulsation and its contribution to vibration are determined by wavelet analysis, and then fractal characteristic of turbulence is illustrated, finally fractal geometry is applied to identification of Shaft central locus of water turbine generator set basing on wavelet purification. It is proved that fractal geometry is an effective method to computer image identification; fractal dimension can also be a way to abstract the symptom of the failures.In chapter 5, plant vibration induced by machine vibration is primary discussed, excitation sources of plant are revealed from view of actual measurement. Natural resonant frequency of main building is calculated by FEM and the resonant reaction is checked, dynamic structure response is analyzed under different application method of loads, and the significance of introducing vibration test of plant structure to field test in hydropower station in future is pointed out.