Abstract To study the lateral vibration characteristics of hydroturbine generating set shaft system, the rotor and runner of the hydroelectric generating set were taken as research object, then the first-order differential motion equation was established by defining the generalized coordinates and the generalized momentum first to construct energy function. Besides, the additional external force was used as the external input excitation to form the generalized Hamiltonian model. The nonlinear dynamic responses of rotor and runner with varying damping coefficient and speed under the combined action of unbalanced magnetic tensile force and hydraulic unbalanced force were analyzed by numerical analysis method, as well as the characteristics of the shaft center axis and time and frequency domain. The results show that damping coefficient is one of the important factors that affect the stability of the system. When the damping coefficient is small, the system motion has obvious double-cycle characteristics, and the lateral vibration amplitude is large; when the damping coefficient is increased, the axis amplitude decreases and the system is stabilized to periodic motion. The results provide a theoretical basis for the stable operation of hydroelectric generating set, and also provide new ideas for further research on the vibration control of the unit under different external input excitations.
WANG Pengfei,ZHANG Jingjing,CHEN Diyi*. Hamiltonian modeling and dynamic analysis of shafting system in hydroturbine generating set[J]. Journal of Drainage and Irrigation Machinery Engin, 2020, 38(8): 794-800.