Propagation of Structural Vibrations and Pressure Waves in the Hydropower Turbines

This article discusses two non-typical dynamic problems that occurred during the operation of a power unit located at the water power plant. The first one concerns the propagation of pressure waves in the turbine flow system, the frequency of which coincided with the excitation frequency resulting from the electric generator rotational speed. The second one is a natural mechanical vibration of the power unit (hydraulic turbine, gear and generator). It turned out that the structure that supports the generator is not rigid enough. These two dynamical problems led to the occurrence of the resonant vibrations. Apart from discussing the diagnostic methods used, the article also gives practical ways to minimize the adverse impacts of the dynamic problems described above on the machine’s performance. The effective solutions have been proposed and implemented, making it possible to achieve a significant reduction in the levels of vibration and noise.