基于改进型LADRC的STATCOM抑制双馈风电场次同步振荡策略

针对双馈风电场经串联补偿线路送出引发的次同步振荡问题，提出了一种基于改进型线性自抗扰控制(LADRC)的静止同步补偿器(STATCOM)，实现对系统次同步振荡的抑制。LADRC设计时考虑延时因素，在控制计算中消除由信号测量、传输等延时导致的输入量之间时间轴上的不匹配。基于改进型LADRC设计了STATCOM的附加阻尼控制器、电压外环、电流内环控制器以及锁相环，使STATCOM为系统提供正阻尼，同时增强控制系统的速动性和抗干扰能力，以适应次同步振荡工况，并从阻抗角度分析了STATCOM抑制次同步振荡的作用机理。在MATLAB/Simulink中搭建了系统的时域仿真模型，实验结果证实了所提出的抑制策略在动态性能和抗干扰方面的优越性。

Sub-synchronous oscillation suppression strategy of doubly-fed wind farms with STATCOM based on improved LADRC

A static synchronous compensator(STATCOM) based on improved linear active disturbance rejection control(LADRC) is proposed to suppress the sub-synchronous oscillation caused by the transmission of doubly-fed wind farms through series compensation lines. The time delay factor is considered in LADRC design, and the mismatch on time axis between inputs caused by the time delay of signal measurement, transmission and other reasons is eliminated in the control calculation. Based on the improved LADRC, the additional dam-ping controller, the voltage outer loop and current inner loop controllers of STATCOM are designed, so that STATCOM can provide positive damping for the system, while enhancing the speed and anti-interference ability of the control system to adapt to the sub-synchronous oscillation conditions. The mechanism of STATCOM suppressing sub-synchronous oscillation is analyzed from the perspective of impedance. The time domain simulation model of the system is built in MATLAB/Simulink, and the simulative results confirm the superiority of the proposed suppression strategy in dynamic performance and anti-interference.