Dynamic Analysis On The Shaft System Of Water-turbine Generator Set Of Gezhouba Hydraulic Power Plant

Whether the hydraulic generator set runs safely affects the security of hydraulic power plant. Dynamic stability of shaft system of hydraulic generator set is particularly important to turbine operation.The phenomenon of extraordinary sway and noise have appeared in some of the running hydraulic generator set.Based on ANSYS rotor dynamic module, finite element model of the shaft system of Gezhouba hydraulic generator set is established. Bearing and imbalanced force are simulated with spring element. Mass and rotary inertia of generator rotor and turbine runner are imitated with mass element. The influence on critical speed by gyroscopic effect, stiffness of guide bearing, imbalanced electromagnetic force, mass and rotary inertia of generator rotor and turbine runner, position of guide bearing is analyzed. In addition, dynamic response under imbalanced force is considered. The law of dynamic response change when the phase and frequency of imbanlanced forces which impact on generator rotor and turbine runner is different is analyzed too.Through analyzing autooscillation and dynamic response, natural frequency and the law of dynamic response are obtained, which provides optical analysis and reference for the coupling affect with bracket and capping.