Vibration Characteristic Analysis Of Pumped Storage Unit Based On ANSYS

With the rapid development of various construction and power industry in China,pumped storage power station has become an important part of modern power system.Pumped storage units have the characteristics of high head,fast speed and large capacity.Due to rapid starting and flexible operation,many tasks have been shouldered in the system,such as peak load regulation and valley filling,frequency regulation,phase modulation,accident standby,black start and so on.Compared with conventional hydropower units,pumped storage units have complex hydraulic transition process,frequent start-up,shutdown and working condition conversion,and are more likely to vibration.Severe vibration can damage the structure,reduce service life,greatly reduce the operation efficiency and output of the units,even endanger the safety of the power station structure and cause significant property and personal losses.Some problems of vibration of pumped storage units must be deeply analyzed and studied to ensure the stable operating of units.This paper analyzes the vibration characteristics of a pumped storage unit based on ANSYS software,main work accomplished was as follows:(1)According to different forms of excitation force,the vibration of pumped storage unit is divided into hydraulic vibration,mechanical vibration and electromagnetic vibration.The frequencies of various excitation forces are calculated to determine the components that may cause the vibration of the units.(2)Taking the components that may cause the vibration of the unit as the main components of vibration analysis,the finite element model of the main components is established by using solid works software and ANSYS software.(3)Modal Analysis is carried out for the frequency characteristics of the main components,natural frequencies are calculated,and resonance is predicted and analyzed.(4)The load-bearing components are selected as the typical components,the structural static analysis and harmonic response analysis of the structural characteristics of the typical components are carried out,and the analysis and calculation of the parameters such as stress,deformation,stiffness and strength of the typical components are completed.(5)Based on the transient dynamic analysis of the vibration data of the top cover during a pumping start-up,the stress variation range of the top cover is calculated.Through the above analysis,the possibility of resonance of the main components of the unit is determined,and the influence of the structural characteristics of typical components on the stable operation of the unit is studied,which provides a theoretical basis and reference for the vibration analysis and structural improvement of pumped storage units.