计及全风况小干扰稳定的双馈风机变换器控制参数设计

随着双馈风电并网容量增大,系统的稳定性与风机变换器控制参数的相关性也越来越大,风机变换器控制参数整定时必须计及电网小干扰稳定性。针对双馈风机单机无穷大系统,建立风机工作在全风况下的小信号模型,采用李雅普诺夫线性化方法并考虑风速分区,分别推导出风机在最大功率跟踪区、恒转速区、恒功率区电网小干扰稳定分析的状态方程。分析风机变换器控制参数与特征根之间的相关性,引入表征系统稳定性强弱的小干扰稳定裕度指标,提出使系统全风况小干扰稳定的风机变换器控制参数设计方案。实例仿真表明:所提方案可快速获取有效参数,并保证全风况下电网小干扰稳定性。

Control Parameters Design of DFIG Converter Considering theSmallSignal Stability of Power Grid Under All Possible Wind Speeds

With the increase of doublyfed induction generator (DFIG) wind capacity connected to power grid, the stability of power grid was much related to the parameters of wind converter controllers, and wind turbine converter parameter setting must consider smallsignal stability of grid. The smallsignal model of wind turbine and infinite power grid under all possible wind speeds was established. The smallsignal stable mathematical state equations were established respectively in maximum power tracking zone, constant speed zone and constant power zone by Lyapunov linearization method. Index of stability margin was introduced to evaluate the smallsignal stability of grid, and the parameters setting method was proposed with considering the relevance between wind turbine controller parameters and eigenvalues which could maintain the smallsignal stability of grid under different wind speeds. Simulation results showed that suitable parameters of wind converter could be obtained by the proposed method to maintain the stability of power grid under all of the possible wind speeds.