电网不平衡下基于内模观测器和无源控制器的DFIG网侧变换器控制方法研究

Research on DFIG Grid-side Converter Based on Internal Model Observer and Passivity-based Controller Under Unbalanced Grid Voltage Condition

为了解决电网电压不平衡对双馈异步发电机(DFIG)系统运行造成损害以及达到消除DFIG网侧有功与无功的2倍频谐波、网侧电流的负序分量3种不同控制目标,提出了一种基于内模观测器和无源控制的DFIG网侧变换器(GSC)控制方法。首先,基于端口受控的耗散哈密顿(PCHD)模型,采用互联和阻尼分配无源性控制(IDA-PBC)方法,设计出了GSC无源控制器。然后,针对控制器中电流环存在参数摄动、干扰等不确定因素,在无源控制基础上加入了基于内模控制(IMC)的状态观测器,而观测器参数由极点配置方法优化,实现了对电流的补偿控制,使得电流稳态波动变小。最后,Matlab/Simulink软件仿真和硬件实验的结果均表明,所提的内环采用无源和内模的协调控制、外环采用PI控制策略较传统的双闭环PI控制方法,具有参数易调节、动态响应速度快、鲁棒性强等优点。

In order to solve the problem of excessive damage to doubly fed induction generator（DFIG） system under unbalanced voltage,and to achieve the three different control objectives of eliminating the second harmonics of grid-side active,reactive power,and the negative sequence component of the grid-side current,we proposed a DFIG grid-side converter（GSC） control method based on internal model observer and passivity-based control.And then,according to the uncertain factors such as the parameter perturbation,interference of the current loop in the controller,a state observer based on internal model control（IMC） is combined with passivity-based control,to realize the control of current compensation is proposed,which can reduce the current steady state fluctuations,and observer parameters are optimized by pole placement method.Finally,the results of Matlab/Simulink software simulation and hardware experiment show that the proposed control method,of which coordinated controller of PBC and IMC is used in its inner loop,and PI controller is used in its outer loop,has the advantages of simple structure,fast response speed and strong robustness,compared to the double closed PI controll method.