基于无模型自适应控制的双馈风机次同步振荡附加阻尼控制方法

SSO Supplementary Damping Control Method for DFIG based on Model-free Adaptive Control

双馈风机并网系统易发生次同步振荡,受制于建模精度及控制器本身参数结构的固定性,传统的附加阻尼控制器可能存在适应性不强的问题。该文设计一种基于无模型自适应控制的次同步阻尼控制方法,依托动态线性化技术从系统输入输出数据中提取动态特征,以摆脱控制方法对建模准确性的依赖,增强控制器自适应性。首先,基于无模型控制方法设计控制器结构,并提出一种适用于阻尼控制的一步向前加权预测控制算法;进一步地,从理论上证明改进控制算法下闭环系统的跟踪误差一致最终有界性及有界输入–有界输出稳定性,并提出控制器参数的优化方法。最终,在综合考虑风速、风电场有功/无功出力、风机台数、线路串补度等影响因素的情况下,验证所提控制方法的抑制效果,结果表明,该方法具备很强的自适应性,在多种工况下均能有效抑制次同步振荡。

Doubly-fed wind power integrated systems could suffer from sub-synchronous oscillation(SSO).Due to the accuracy of modeling and the fixity of parameters and structure,the conventional sub-synchronous damping controller(SSDC)may has the problem of poor adaptability.In this paper,a sub-synchronous damping controller based on model-free adaptive control(MFAC-SSDC)was designed,using the dynamic linearization technology to extract dynamic characteristics from the input and output data of the system.By this way,the control method can get rid of the dependence on the accuracy of modeling and improve the adaptability of the controller.First,the control structure was designed based on MFAC,and a one-step-ahead weighted predictive control algorithm suitable for damping control was proposed.Furthermore,it is theoretically proved that the tracking error of the closed-loop system is uniformly ultimately bounded(UUB)and bounded input-bounded output stable under the improved control algorithm.The optimization method of the controller parameters was also proposed.Finally,comprehensively considering the influences of wind speed,active/reactive power regulation of wind farm,the number of wind turbine generators and series compensation level,the damping effects of MFAC-SSDC proposed in this paper were verified.Results show that this method achieves strong adaptability and can effectively mitigate SSO under various operating conditions.