源网激励下虚拟同步直驱风电机组结构载荷响应特性分析OA

[Objectives]Against the backdrop of energy transition and large-scale grid integration of wind power,and aiming at the increasingly complex electro-mechanical coupling characteristics of wind turbines with frequency-supported control,this study conducts theoretical and simulation analyses on the load characteristics of direct-driven permanent magnet synchronous generators(D-PMSG)under virtual synchronous generator(VSG)control.[Methods]Based on multi-body dynamics and small-signal analysis theory,a linearized electro-mechanical coupling model of VSG-PMSG is constructed to characterize the dynamic relationship between loads and source-grid excitation,followed by an analysis of the response mechanisms of VSG-PMSG under impact and fatigue loads.A nonlinear electro-mechanical coupling model of VSG-PMSG with multi-time-scale interactions and multi-dynamic link effects is established.Simulation analysis of load characteristics of VSG-PMSG is conducted under typical disturbance scenarios,such as turbulent wind and grid impacts.Indicators including maximum load increase and equivalent fatigue load are selected to evaluate the effects of VSG control on turbine impact and fatigue loads.[Results]Under turbulent wind excitation,VSG control can reduce the drivetrain fatigue load and the tower bottom side-to-side fatigue load.In addition,under grid-side frequency excitation,VSG control can induce drivetrain impact load and the tower bottom side-to-side impact load.However,these are significantly smaller than the transient impacts caused by three-phase short-circuit faults.[Conclusions]VSG control alters the electrical and load characteristics of wind turbines,particularly affecting the drivetrain mode and the tower bottom side-to-side mode.The research findings provide a theoretical basis for control strategies and mechanical structure design of frequency-supported wind turbines.