基于线性自抗扰控制的双馈风机次同步振荡抑制研究

Research on Suppressing Sub-synchronous Oscillation of Doubly-fed Induction Generator Based on Linear Active Disturbance Rejection Control

双馈风力发电机(doubly-fed induction generator,DFIG)并网时的次同步振荡(sub-synchronous oscillation,SSO)问题,严重威胁系统的平稳运行。系统运行工况发生变化时,现有的传统控制策略可能效果不佳。为了解决这个问题,提出了基于线性自抗扰控制(linear active disturbance rejection control,LADRC)的SSO抑制策略,在转子侧传统双环PI控制的基础上,原有功内环的PI控制部分替换为线性ADRC,其中线性扩张状态观测器实时估计补偿次同步控制相互作用(sub-synchronous control interaction,SSCI)分量,该方法参数整定简单且鲁棒性较强。通过搭建DFIG并网模型,并与PI控制对比,验证该控制策略在稳态和暂态拥有良好的控制性能;通过与附加阻尼控制和非线性ADRC对比,得出线性ADRC可以在多工况下抑制次同步振荡,相比于现有控制,在参数整定更简单的情况下能更有效地使畸变电流收敛,进而稳定DFIG风机系统的输出功率,最后在RT-LAB实验平台进一步验证其有效性。

Sub-synchronous oscillation(SSO)in a grid-connected doubly fed induction generator(DFIG)threatens the stable operation of the system.Traditional control strategies may not be effective when the operating conditions of a system change.To solve this problem,a sub-synchronous suppression strategy based on linear active disturbance rejection control(ADRC)is proposed.On the basis of the traditional dual loop proportional-integral(PI)control on the rotor side,an improved auto disturbance rejection control is used to replace the PI part of the original inner loop,in which a linear extended state observer is used to estimate the part of compensation sub-synchronous control interaction(SSCI)in real time.The proposed method involves simple parameter tuning and is strongly robust.By building a DFIG grid connection model and comparing it with PI control,it is verified that the control strategy has good control performance in both steady-state and transient states.By comparing with additional damping control and nonlinear ADRC,it is concluded that improved active disturbance rejection control can suppress sub-synchronous oscillations under multiple operating conditions,converging the distorted current more effectively compared to the simple tuning of existing control parameters,thereby stabilizing the output power of the doubly fed fan system.Finally,the effectiveness of the proposed method is verified using an RT-LAB experimental platform.This work is supported by National Natural Science Foundation of China(No.61905139)and Shanghai Key Laboratory of Power Station Automation Technology(No.13Z2273800).