Stability Analysis Of Rotor System In Hydro-generate Unit

Presently, rotor system’s vibration in hydro-generate unit is an ubiquitous problemsexisting in the hydropower station, and it causes potential safety hazard to hydropowerstation. In history, there are too many accidents caused by excessive vibration in hydro-generate unit. Small vibration effects the electricity generating’s efficiency and quality.Big vibration can make spindle motor rupture. More seriously, it can make the wholehydropower station explode, which causes a serious consequence. Not only cause hugeeconomic loss, but also cause certain influence on production and people’s life. Thus, it isnecessary to study the hydro turbine’s vibration. Accoring to the vibration’s law, weresearch the vibration frequency and vibration model, the influence of physicalparameters and geometric parameter’s change to vibration.If the natural frequency and incentive frequency is close, there is resonancephenomenon, which can cause many times the normal vibration damage. To reduceresonance damage, we study the characteristics of resonance and the inhibition ofresonance method.The problem about hydro turbine’s vibration contains lots of aspects, including thevibration caused by the hydraulic problem, the vibration caused by mechanical problemsand electromagnetic problems. For large hydropower station, electromagnetic problem ismore important. Research for rotor system in hydro-generate unit’s vibration mainlyfocuses on the forced vibration excited by electromagnetic force.Taking the hydro-generate unit as background, using MATLAB, we separately writeprograms with matrix displacement method and finite element method, calculate mainshaft of hydropower units system’s transverse vibration, which contain naturalfrequencies and corresponding vibration model, and analyze the physical parameters’effect on transverse vibration.MATLAB and the finite element method are used to calculate the hydro turbinespindle system’s torsional vibration, which contain natural frequency and the zero naturalfrequency inspired by electromagnetic force.Energy method of electrical-mechanical coupling is used to analyze the spindlesystem of hydropower units’s torsional vibration, transverse combinated resonance andthe variation of amplitude-frequency characteristics when geometric parameters andelectromagnetic parameters are changed. The results of this study is a guidance for thestable operation of the hydropower station.