基于舒茨—基布逊法的双馈风机直流侧电压抑制

Shultz-Gibson Method Based DC-link Voltage Suppression of DFIG-based Wind Turbines

针对双馈风机故障期间直流侧母线过压的问题,提出一种利用舒茨—基布逊法抑制直流电压的控制方法。首先,建立双馈感应发电机网侧变流器模型,利用小信号法探究了直流侧电压不稳定的机理。在建立网侧变流器状态空间模型的基础上,利用舒茨—基布逊法构建李雅普诺夫函数,得到了基于李雅普诺夫稳定判据的网侧变流器非线性状态反馈器。仿真结果表明所提方法可在电网电压故障期间抑制直流侧电压的振荡,提高双馈风机的故障穿越能力。

In view of the DC-link overvoltage of doubly-fed induction generator （DFIG） based wind turbines during the short- circuit fault, a DC-link voltage suppression method based on the Shultz-Gibson method is proposed. The grid-side converter model of DFIG is developed and the mechanism of the DC-link voltage instability is explored by small signal modeling. Based on the developed state-space model of grid-side converter, the Lyapunov function is formed by using the Shultz-Gibson method. Then the nonlinear state feedback controller of grid-side converter based on Lyapunov stability criterion is obtained. Finally, the simulation result shows the proposed method is able to suppress the DC-link voltage oscillation during a grid voltage fault, so as to improve the low voltage ride-through capability of DFIG-based wind turbines.