双馈风电机组抑制电力系统低频振荡的鲁棒控制策略

Robust Control Strategy of DFIG Suppressing Power System Low Frequency Oscillations

针对大规模风电场接入电力系统面临的低频振荡问题,提出了一种双馈风电机组(doubly-fed induction generator,DFIG)附加鲁棒控制策略,通过控制双馈风电机组的转子侧无功输出向系统注入无功功率以达到提升系统阻尼的目的。首先采用TLS-ESPRIT辨识算法辨识出系统模型,然后采用基于区域极点配置的鲁棒控制理论设计附加阻尼控制器。为对所提控制方法相比于传统控制方法的优势,设计了基于极点配置的阻尼控制器。最后在PSCAD软件中搭建含风电的两区域模型验证所提控制方法的有效性。仿真结果表明DFIG附加鲁棒控制器能有效抑制电力系统低频振荡,具有较好的鲁棒性。

For low frequency oscillations of power system caused by large-scale doubly-fed induction generator（ DFIG）based wind farm integration,this paper proposes a supplementary damping control strategy of DFIG to improve the system ＇s damping by controlling the reactive power of DIFG. Firstly,the system model is identified by using total least squaresestimation on signal parameters via rotational technique（ TLS-ESPRIT） algorithm,and then the supplementary damping controller is designed by using the robust control theory based on region poles assignment. In order to compare the advantages of proposed method against traditional method,the damping controller based on pole placement theory is designed. Lastly,a two area power system containing the wind power is constructed in the PSCAD to validate the proposed control strategy. The simulation result shows that DFIG supplementary robust damping controller can suppress low frequency oscillations efficiently and show good robustness.