计及小信号稳定的DFIG变换器控制参数优化

Controller Parameter Optimal Design of DFIG Converter Considering the Small-signal Stability of Power Grid

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,据此提出一种计及电网小干扰稳定的双馈风机变换器控制参数优化方案。针对双馈风机单机无穷大系统,建立风机工作在低于额定风速的小信号模型,采用李雅普诺夫线性化方法,推导出电网小干扰稳定分析的13阶状态微分方程。分析风机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,并对每个特征值实部大小进行限制,提出使小干扰稳定裕度指标最大的风机变换器控制参数整定方案。实例仿真表明,所提方案可快速获取有效参数,并改善系统小干扰稳定性。

Following the increasing DFIG wind capacity connected to power grid, the stability of power grid is much related to the parameters of wind converter controllers, so a controller parameter optimal design of DFIG converter was proposed considering the small - signal stability of power grid. The small - signal model below rated wind speed of single wind turbine and infinite power grid was established, the stator flux-oriented vector control strategy was used in rotor side of converter, and the stator voltage-oriented vector control strategy was used in grid side of converter. The 13-order small-signal stable mathematical model was established with Lyapunov linearization method. Index of stability margin was introduced to evaluate strength small-signal stability of grid. And limiting the real part of each eigenvalue, the parameters setting method was proposed with considering maximum of stability margin and the relativity between wind turbine controller parameter with eigenvalue. Simulation results show that using the proposed method can obtain the suitable parameters of wind converter and improve the stability of power grid.