The Modeling And Finite Element Analysis Of The Shaft System Of Water Turbine Generator Sets

Hydro generator units are working in a complex environment,so the operation stability of the units is always affected by vibration.At present,with the continuous development of productivity and the increasing demand for energy,the water head of hydropower generating units is generally higher,and the capacity of single unit is larger and larger,and the structure is becoming more and more complicated.The development trend makes the vibration problem of the hydraulic turbine more prominent,and the requirement of the design and operation monitoring of the unit increases.In order to ensure the safety and stability of hydraulic generator set,it is necessary to study the vibration characteristics of shaft system,and to understand the vibration law of shafting comprehensively.According to the actual data of the pumped storage unit,this paper established the model of shaft system vibration characteristics by using the method of lumped mass,considering the unbalanced magnetic pull and guide bearing stiffness on the vibration characteristics,simulation of the turbine shaft system is implemented using the ANSYS software in the line unit,calculated the first three orders of critical speed and modes of the shaft turbine generator by modal analysis method,accomplished a comparative analysis of the impact of unbalanced magnetic force on the vibration characteristics,obtained the stiffness of bearings for different shafting modal through modal analysis of critical speed of shafting stiffness under different combinations of guide bearings.These results provide some references for the design and parameter selection of turbine,and provide a basis for further research in the future.