基于模糊自抗扰的不平衡电压下DFIG的LVRT控制

Low Voltage Ride Through Control for the DFIG Based on Fuzzy Active-disturbance Rejection Controller

为防止电网电压跌落导致的风电机组脱网现象,实现双馈感应风力发电机(DFIG)的低电压穿越(LVRT)运行,提出电压不平衡条件下模糊自抗扰控制(Fuzzy-ADRC)策略。通过引入广义微分实现对系统输入信号的快速无超调跟踪,采用非线性函数进行模糊运算对参数在线修改,形成新的非线性状态误差反馈控制律(NLSEF),再通过扩张状态观测器(ESO)估计出系统总扰动并予以补偿。所提出方案能在电网故障时不依靠系统精确参数的前提下防止转子侧过流,抑制电流负序分量,减缓暂态电流的振荡。最后对所提出方法进行了仿真验证,结果证明了该方法的有效性和可行性。

In order to prevent the grid voltage drop which could cause the wind turbines to take off the net,and realize the doubly- fed induction wind generator(DFIG)of low voltage across(LVRT)operation,the fuzzy self immunity under the condition of unbalanced voltage contro(l fuzzy-ADRC)strategy was put forward. The system was achieved by introducing generalized differential input signal of fast tracking without overshoot,the fuzzy nonlinear function was used to modify parameters online,to form a new nonlinear error feedback law,and then the disturbance and the system total compensation were estimated and compensated through the extended state observe(r ESO). The proposed scheme could avoid the lateral flow of the rotor without relying on the precise parameters of the system,and the negative sequence component of the current could be suppressed and the oscillation of the transient current could be slowed down. Finally, the proposed method was simulated and verified,and the validity and feasibility of this method are proved.