Dynamic Joint Simulation Analysis Of Large Wind Turbine Tower Blade Coupling Structure

With the development of large-scale wind turbines increasing,vibration is often accompanied in the process of its operation.Considering the nonlinear vibration,it is important application value to study the structural dynamic characteristics.The coupled vibration of large wind turbine tower blades is nonlinear coupled vibration,and the resulting displacement and stress changes will have an important impact on the stability of the system.As the main elastic body of the wind turbine,the coupling structure of the tower and blade directly affects the hierarchical coupling between the components of the wind turbine,thus affecting the stability of the whole system.By using the co simulation technology of multi parameter monitoring of large scale wind turbine tower blade coupling structure,with the response under different conditions analysis,it identified the need for improved structural parts,the changes of multiple parameters of the key components of monitoring tower blade coupling structure with the time.It studied on the influence of various parameters on the structure and put forward the improvement measures,structure site before and after the improvement of the dynamic can be comparative analyzed.Produced by the harmonic synthesis method of aerodynamic load,combining the displacement strain relationship of vibration and potential theory,modal analysis,wind vibration analysis of tower blade coupling structure,so that the tower blade coupling vibration and structure parameters on the wind turbine stability effect,and provide the reference value for the kinetic parameters of process of large-scale wind power the unit is running in the condition monitoring and control.In renewable energy is paid more and more attention to the moment,wind turbine is a complex multi-body system considering joint simulation of dynamics analysis has important practical significance for optimization design of large scale wind turbine.The main tasks of this project are as follows:(1)Aiming at the aerodynamic response of the flexible multi-body tower blade coupling structure of the large wind turbine,the analysis method under different yaw angle is put forward.According to the flow chart of the method,establish the model of wind turbine blade coupling of flexible multi-body dynamics for large tower structure,calculation of aerodynamic load distribution by harmonic superposition method,considering the influence of wind shear and tower shadow effect,combined with the modal analysis,the induced factor and aerodynamic response time.The results show that in the three forms of torsion,flapping and shimmy,with the increase of yaw angle,the amplitude of dynamic displacement decreases,the blade tip moment and the root shear mean value decrease,and the axial and tangential inducing factors change little,and the wake is stable.The aerodynamic response of the coupled structure in a large wind turbine tower is directly determined by the change of vibration displacement,which has an effect on the efficiency of the wind turbine.As a main component of aerodynamics,tower blade coupling structure plays an important role in the design and operation of large wind turbine blades,ensuring the safe and stable operation.(2)The vibration study on the stability of the flexible multi-body system of the wind turbine caused by the coupled vibration of the tower blade of a large wind turbine is carried out.Considering the influence of tower structure parameters on the stability of the system,the natural frequencies of the system and the components were calculated,and the vibration analysis of the wind turbine tower blade coupling structure was carried out.The aerodynamic load generated by harmonic synthesis method is applied to analyze the wind-induced vibration response of the tower blade coupling structure,and the influence of tower blade coupling vibration and structural parameters on the flexible multi-body system of wind turbine is obtained.The results show that the variation of tower structure parameters and the coupling vibration displacement of the tower blades have certain effects on the stability of the flexible multi-body system of wind turbine,so as to provide some reference value for the normal operation of large wind turbines.(3)Dynamic analysis is carried out for the dynamic response of the flexible tower section in a large wind turbine.Two way fluid solid coupling method is used to analyze the fluid and structure dynamics of the flange at the segmental flange of the tower.Combined with the flow chart,the typical modal diagram of the flange of the tower is obtained.Considering the analysis of hydrodynamic coupling structure in the blade tower,in the combined effect of wind shear and fluctuating wind,the tower flange speed,pressure,shear stress and vorticity distribution,while considering the comparison of stress and displacement should be coupled with not considering the coupling effect of tower flange.As a results,the shear stress of the tower flange shows a nonlinear trend.The wind speed of the bolt uniformly distributed is stable.Considering the coupling effect,the flange amplitude of the tower flange is smaller than that without considering the coupling effect.The results can be used as a reference for monitoring the dynamic parameters of the flange structure under the coupling effect of the tower frame blade of a large wind turbine.(4)Through the combined action of the whole vibration of a large wind turbine and the local vibration,the dynamic response of the tower blade coupling structure vibration is studied.Based on the displacement strain relationship and the theory of potential energy,the modal analysis is carried out,and the dynamic response of the vibration is analyzed in the light of the pulsating wind load.Through the analysis of dynamic parameter variation curve,the improvement measures of tower structure are put forward,and the dynamic response of the improved structure is compared.The superiority of the improved structure is explained,so as to provide a reference for engineering application.