基于转子侧附加阻尼控制的双馈风机并网次/超同步 振荡抑制方法

针对风电经串补输电线路并网发生的多起次/超同步振荡现象,首先推导了基于有功无功解耦控制的双馈风机阻抗模型。其次分析了电网参数、双馈风机控制参数以及电机参数对风电并网系统稳定性的影响。然后针对串联补偿输电线路参数以及风机控制参数引发的次/超同步振荡现象,提出了双馈风机转子侧控制环节附加阻尼控制器的抑制方法。并对比分析阻尼器放置于功率外环以及电流内环对系统稳定性的影响,得出阻尼器放置于电流内环对次/超同步振荡抑制效果更好的结论。最后,在PSCAD/EMTDC中搭建双馈风机并网模型,通过时域仿真验证了阻抗模型分析风机并网次/超同步振荡的正确性以及所提方法对次/超同步振荡抑制的有效性。

A sub/super-synchronous oscillation suppression method for a DFIG-connected grid based on additional damping control on the rotor side converter

There is a problem of multiple sub/super-synchronous oscillation events occurring in a system where the wind power transmission lines are connected to the grid through series compensators. To help tackle this, first, the impedance model of a DFIG based on active and reactive decoupling control is derived. Secondly, the influence of the power grid, DFIG control and motor parameters on the stability of the wind power integrated system is analyzed. Because of the phenomenon of sub/super-synchronous oscillation caused by the parameters of series compensation transmission line and DFIG control parameters, an additional damping controller, added to the rotor side converter control link of the DFIG, is proposed. Also the influence of the damper placed in the power outer loop and the current inner loop on the rotor side converter control link is compared and analyzed. It is concluded that when the damper is placed in the current inner loop, a better effect on the sub/super-synchronous oscillation suppression can be obtained. Finally, the DFIG model is built in PSCAD/EMTDC. The correctness of the impedance model and the effectiveness of the proposed method to suppress the sub/super-synchronous oscillation are verified via time-domain simulations. This work is supported by the Key Project of NSFC and High-Speed Rail Joint Foundation (No. U1434203).