直驱风机机网侧变流器统一建模及其弱电网下稳定性研究

Unified modeling of generator-side and grid-side converter in direct-drive wind turbines and stability analysis under weak grid

随着电网中风电占比不断攀升,弱电网下风电并网的稳定性问题愈加受到关注。针对风电并网的稳定性问题,现有研究将机侧和网侧解耦,分别对两侧进行简化分析其稳定性,但从时间尺度的角度来看,机侧和网侧动态是存在耦合的,现有的建模忽略了这一耦合。文章针对弱电网下风电并网的稳定性问题,建立机侧和网侧变流器控制的统一模型,并给出了考虑机侧和网侧变流器控制的稳定性分析方法,对比传统的阻抗分析方法,文章采用的分析方法更加精确,最后利用Simulink仿真对分析结果进行了验证。

With the increasing proportion of wind power in the power grid,the stability of wind power grid connection under the weak grid has attracted more and more attention.In view of the stability of wind power grid connection,the existing research usually decouples the generator side and grid side to simplify and analyze the stability of both sides,but from the perspective of time scale,there is coupling between the generator-side and grid-side dynamics,which is ignored in the existing modeling.In this paper,a unified model of converter control for machine side and grid side is established in view of the stability of grid-connected wind turbines.The stability analysis method considering machine side and grid side converter control is given.Compared with the traditional impedance analysis method,the analysis method adopted in this paper is more accurate.Finally,Simulink simulation is used to verify the analysis results.