Feedback control problems for linear periodic systems （LPSs） with interval- type parameter uncertainties are studied in the discrete-time domain. First, the stability analysis and stabilization problems are addresse...Feedback control problems for linear periodic systems （LPSs） with interval- type parameter uncertainties are studied in the discrete-time domain. First, the stability analysis and stabilization problems are addressed. Conditions based on the linear matrices inequality （LMI） for the asymptotical stability and state feedback stabilization, respec-tively, are given. Problems of L2-gain analysis and control synthesis are studied. For the L2-gain analysis problem, we obtain an LMI-based condition such that the autonomous uncertain LPS is asymptotically stable and has an L2-gain smaller than a positive scalar γ. For the control synthesis problem, we derive an LMI-based condition to build a state feedback controller ensuring that the closed-loop system is asymptotically stable and has an L2-gain smaller than the positive scalar γ. All the conditions are necessary and sufficient.展开更多
This paper investigates the globally asymptotically stable and L_(2)-gain of robust H_(∞)control for switched nonlinear systems under sampled data.By considering the relationship between the sampling period and the d...This paper investigates the globally asymptotically stable and L_(2)-gain of robust H_(∞)control for switched nonlinear systems under sampled data.By considering the relationship between the sampling period and the dwell time,the non-switching and one switching are discussed in the sampling interval,respectively.Firstly,a state feedback sampled-data controller is constructed by the back-stepping method,and the switching converts to asynchronous switching if it happens within the sampling interval.Then,under the limiting conditions of the sampling period,which are obtained by the average dwell time method,the closed-loop system is globally asymptotically stable and has L_(2)-gain.Finally,two numerical examples are provided to demonstrate the effectiveness of the proposed method.展开更多
中点电位的平衡控制是中点钳位式三电平拓扑安全可靠运行的关键,但现有文献均未能通过建立精确的数学模型对中点电位漂移的物理机理进行精确分析,控制参数整定困难。该文建立了考虑未知干扰和参数摄动影响的中点钳位式三电平D-STATCOM...中点电位的平衡控制是中点钳位式三电平拓扑安全可靠运行的关键,但现有文献均未能通过建立精确的数学模型对中点电位漂移的物理机理进行精确分析,控制参数整定困难。该文建立了考虑未知干扰和参数摄动影响的中点钳位式三电平D-STATCOM的精确数学模型,利用重复控制与无源性控制相结合的方法实现了基于鲁棒L_2性能准则的电流控制器设计,精确分析了参数摄动导致的有功能量分配不均是中点电位漂移的根本原因。通过零序分量注入,利用直流侧上下端电容器之间的有功能量交换实现了中点电位的平衡控制。通过仿真以及1.14 k V,±400 k Var煤矿供电系统的工程应用,验证了该文所建立模型的准确性以及所提控制算法的可行性和有效性。展开更多
对工作在不平衡条件下的星型连接的链式D-STATCOM提出一种控制策略。通过等效变换,考虑未知干扰和参数摄动,建立abc坐标系下精确的数学模型。一种无源性控制与重复控制相结合鲁棒L2增益性能的新方法用于实现电流控制,重复控制用于补偿...对工作在不平衡条件下的星型连接的链式D-STATCOM提出一种控制策略。通过等效变换,考虑未知干扰和参数摄动,建立abc坐标系下精确的数学模型。一种无源性控制与重复控制相结合鲁棒L2增益性能的新方法用于实现电流控制,重复控制用于补偿周期性干扰,无源控制用来保证重复控制的收敛性和对控制目标的跟踪,同时也补偿非周期干扰对系统的影响。直流电压控制由三层组成,第一层通过注入正序有功电流,第二层通过注入零序电压,第三层基于H桥单元之间有功能量的交换。控制策略的有效性通过仿真和在10 k V,±5 MVar的链式D-STATCOM装置工程测试所验证。展开更多
研究一类可部分反馈线性化且具扰动三角结构的非线性参数不确定系统的鲁棒H∞控制问题,不确定参数属于已知紧集并以非线性形式进入系统.在输入到状态稳定的理论框架下,基于李雅谱诺夫函数和反演法构造出状态反馈控制器,使得闭环系统对...研究一类可部分反馈线性化且具扰动三角结构的非线性参数不确定系统的鲁棒H∞控制问题,不确定参数属于已知紧集并以非线性形式进入系统.在输入到状态稳定的理论框架下,基于李雅谱诺夫函数和反演法构造出状态反馈控制器,使得闭环系统对所有允许的参数不确定性是内稳定的,且从扰动输入到输出有有界的L2-增益.控制器的设计不需解任何H am ilton-Jacob i方程,并给出仿真算例说明了该结论的可行性和有效性.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 60404001 and60774089)
文摘Feedback control problems for linear periodic systems （LPSs） with interval- type parameter uncertainties are studied in the discrete-time domain. First, the stability analysis and stabilization problems are addressed. Conditions based on the linear matrices inequality （LMI） for the asymptotical stability and state feedback stabilization, respec-tively, are given. Problems of L2-gain analysis and control synthesis are studied. For the L2-gain analysis problem, we obtain an LMI-based condition such that the autonomous uncertain LPS is asymptotically stable and has an L2-gain smaller than a positive scalar γ. For the control synthesis problem, we derive an LMI-based condition to build a state feedback controller ensuring that the closed-loop system is asymptotically stable and has an L2-gain smaller than the positive scalar γ. All the conditions are necessary and sufficient.
文摘This paper investigates the globally asymptotically stable and L_(2)-gain of robust H_(∞)control for switched nonlinear systems under sampled data.By considering the relationship between the sampling period and the dwell time,the non-switching and one switching are discussed in the sampling interval,respectively.Firstly,a state feedback sampled-data controller is constructed by the back-stepping method,and the switching converts to asynchronous switching if it happens within the sampling interval.Then,under the limiting conditions of the sampling period,which are obtained by the average dwell time method,the closed-loop system is globally asymptotically stable and has L_(2)-gain.Finally,two numerical examples are provided to demonstrate the effectiveness of the proposed method.
文摘中点电位的平衡控制是中点钳位式三电平拓扑安全可靠运行的关键,但现有文献均未能通过建立精确的数学模型对中点电位漂移的物理机理进行精确分析,控制参数整定困难。该文建立了考虑未知干扰和参数摄动影响的中点钳位式三电平D-STATCOM的精确数学模型,利用重复控制与无源性控制相结合的方法实现了基于鲁棒L_2性能准则的电流控制器设计,精确分析了参数摄动导致的有功能量分配不均是中点电位漂移的根本原因。通过零序分量注入,利用直流侧上下端电容器之间的有功能量交换实现了中点电位的平衡控制。通过仿真以及1.14 k V,±400 k Var煤矿供电系统的工程应用,验证了该文所建立模型的准确性以及所提控制算法的可行性和有效性。
文摘对工作在不平衡条件下的星型连接的链式D-STATCOM提出一种控制策略。通过等效变换,考虑未知干扰和参数摄动,建立abc坐标系下精确的数学模型。一种无源性控制与重复控制相结合鲁棒L2增益性能的新方法用于实现电流控制,重复控制用于补偿周期性干扰,无源控制用来保证重复控制的收敛性和对控制目标的跟踪,同时也补偿非周期干扰对系统的影响。直流电压控制由三层组成,第一层通过注入正序有功电流,第二层通过注入零序电压,第三层基于H桥单元之间有功能量的交换。控制策略的有效性通过仿真和在10 k V,±5 MVar的链式D-STATCOM装置工程测试所验证。
文摘研究一类可部分反馈线性化且具扰动三角结构的非线性参数不确定系统的鲁棒H∞控制问题,不确定参数属于已知紧集并以非线性形式进入系统.在输入到状态稳定的理论框架下,基于李雅谱诺夫函数和反演法构造出状态反馈控制器,使得闭环系统对所有允许的参数不确定性是内稳定的,且从扰动输入到输出有有界的L2-增益.控制器的设计不需解任何H am ilton-Jacob i方程,并给出仿真算例说明了该结论的可行性和有效性.
