Study on the dynamic response of the powerhouse under the vibration load of the Hydropower Station

Abstract

The vibration problem of hydro-turbine generator sets is very complicated. There are examples at home and abroad that the vibration of the generator sets causes the vibration of the plant structure, and even causes the structural damage to affect the normal operation of the power station. The Hydropower Station is a second-class (2) type project. In order to study the dynamic response of the plant under the vibration load of the unit, the finite element dynamic time history method is adopted, and the vibration loads are assumed to be simple harmonic loads. The dynamic response of the plant under the four working conditions are calculated, namely the rated operating conditions, two-phase short-circuit condition, half-magnet short-circuit condition and unit out-of-step condition. The calculation results show that under the four vibration response calculation conditions, the structural deformation is concentrated at the loading position of the machine pier. The dynamic displacements of the stator base section and the bottom section of the machine pier are relatively small and relatively evenly distributed. The stress concentration (or larger stress area) mainly occurs in the machine pier, and the dynamic stress in other parts of the plant is small. It is said that the stress concentration in the load application point and its nearby area is obvious. The displacement of the unit structure in all directions, the maximum root mean square velocity and the maximum root mean square acceleration value, and the vibration stress in each direction did not exceed the allowable value. The plant is safe under the vibration load of the unit.