基于宽频带转子附加阻尼的双馈型风机次同步振荡抑制策略

A suppression strategy for DFIG subsynchronous oscillation based on broadband rotor additional damping

针对双馈型风电场并网引发的次同步振荡问题进行了研究,建立了双馈电机以及变流器的等效模型。基于动态等值阻抗解析式分析了并网阻抗特性的关键影响因素。结果表明控制器转子侧内环增益对次同步频带阻抗特性影响较大。在此基础上,提出了一种基于宽频带转子附加阻尼控制的次同步振荡抑制措施。该抑制措施实施于双馈型风机转子侧变流器控制中,无须附加装置,利于工程实现。最后,通过时域仿真验证了该抑制措施的有效性以及在暂态工况下的适用性。

This paper studies the problem of the synchronous oscillation caused by Doubly Fed Induction Generator（DFIG） grid connection, and sets up equivalent model of DFIG motor and converter. Based on dynamic equivalent impedance analytic expression, the key factors of grid-connected impedance characteristics are analyzed. The results show that the internal loop gain of the controller rotor side has a large effect on the impedance characteristics of subsynchronous frequency band. On this basis, the paper puts forward a subsynchronous oscillation suppression method based on broadband rotor additional damping control. The proposed method is implemented on converter control of DFIG rotor side, without additional device and good for engineering application. Finally, the validity and applicability under transient condition of the suppression strategy are verified by time-domain simulation.