Decentralized robust guaranteed cost control for a class of interconnected singular large-scale systems with time-delay and parameter uncertainty

The decentralized robust guaranteed cost control problem is studied for a class of interconnected singular large-scale systems with time-delay and norm-bounded time-invariant parameter uncertainty under a given quadratic cost performance function. The problem that is addressed in this study is to design a decentralized robust guaranteed cost state feedback controller such that the closed-loop system is not only regular, impulse-free and stable, but also guarantees an adequate level of performance for all admissible uncertainties. A sufficient condition for the existence of the decentralized robust guaranteed cost state feedback controllers is proposed in terms of a linear matrix inequality （LMI） via LMI approach. When this condition is feasible, the desired state feedback decentralized robust guaranteed cost controller gain matrices can be obtained. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed approach.

Non-fragile guaranteed cost control for uncertain neutral large-scale interconnected systems

This paper focuses on the problem of non-fragile decentralized guaranteed cost control for uncertain neutral large-scale interconnected systems with time-varying delays in state,control input and interconnections.A novel scheme,viewing the interconnections with time-varying delays as effective information but not disturbances,is developed.Based on Lyapunov stability theory,using various techniques of decomposing and magnifying matrices,a design method of the non-fragile decentralized guaranteed cost controller for unperturbed neutral large-scale interconnected systems is proposed and the guaranteed cost is presented.The further results are derived for the uncertain case from the criterion of unperturbed neutral large-scale interconnected systems.Finally,an illustrative example shows that the results are significantly better than the existing results in the literatures.

DECENTRALIZED STABILIZATION OF LARGE-SCALE LINEAR INTERCONNECTED SYSTEMS WITH TIME-VARYING DELAYS

The decentralized stabilization conditions for large-scale linear interconnection systems with time-varying delays were established by using some different decomposition cases of interconnection matrices, and a method for designing the decentralized local memoryless state feedback controllers was proposed. All of the considered delays are continuous function, and satisfy some conditions.

Fundamental Research on Enhancing Operation Reliability for Large-Scale Interconnected Power Grids——An interview with Zhou Xiaoxin, chief scientist of "973 Program"

At the end of last year, the editors from Power and Electrical Engineers interviewed Zhou Xiaoxin on "Fundamental Research on Enhancing Operation Reliability for Large-Scale Interconnected Power Grids", a project of "973 Program". Mr. Zhou, the chief engineer of China Electric Power Research Institute(CEPRI) and an academician of Chinese Academy of Sciences, is the chief scientist in charge of this research project.

Application research on large-scale battery energy storage system under Global Energy Interconnection framework

In the context of constructing Global Energy Interconnection(GEI), energy storage technology, as one of the important basic supporting technologies in power system, will play an important role in the energy configuration and optimization. Based on the most promising battery energy storage technology, this paper introduces the current status of the grid technology, the application of large-scale energy storage technology and the supporting role of battery energy storage for GEI. Based on several key technologies of large-scale battery energy storage system, preliminary analysis of the standard system construction of energy storage system is made, and the future prospect is put forward.

Decentralized H-infinity state feedback control for discrete-time singular large-scale systems

The decentralized H-infinity control problem for discrete-time singular large-scale systems is considered. Based on the bounded real lemma of discrete-time singular systems, a sufficient condition for the existence of decentralized H-infinity controller for discrete-time singular large-scale systems is presented in terms of the solvability to a certain system of linear matrix inequalities by linear matrix inequality (LMI) approach, and the feasible solutions to the system of LMIs provide a parameterized representation of a set of decentralized H-infinity controller. The given example shows the application of the method.

Adaptive Decentralized Asymptotic Tracking Control for Large-Scale Nonlinear Systems With Unknown Strong Interconnections

An adaptive decentralized asymptotic tracking control scheme is developed in this paper for a class of large-scale nonlinear systems with unknown strong interconnections,unknown time-varying parameters,and disturbances.First,by employing the intrinsic properties of Gaussian functions for the interconnection terms for the first time,all extra signals in the framework of decentralized control are filtered out,thereby removing all additional assumptions imposed on the interconnec-tions,such as upper bounding functions and matching conditions.Second,by introducing two integral bounded functions,asymptotic tracking control is realized.Moreover,the nonlinear filters with the compensation terms are introduced to circumvent the issue of“explosion of complexity”.It is shown that all the closed-loop signals are bounded and the tracking errors converge to zero asymptotically.In the end,a simulation example is carried out to demonstrate the effectiveness of the proposed approach.

Decentralised dynamic high-gain scaling-based output-feedback control of large-scale non-linear interconnected systems with delays

A general class of non-linear large-scale interconnected systems is considered,wherein each subsystem is comprised of a nominal part in a general strict-feedback-like structure and a set of appended dynamics.Parametric and functional uncertainties and time delays are allowed throughout the overall system structure including the nominal strictfeedback-like parts and appended dynamics of each subsystem as well as the non-linear subsystem interconnections.The controller design is based on the dual dynamic highgain scaling technique and provides a robust adaptive delay-independent globally stabilising decentralised output-feedback controller.The disturbance attenuation properties of the proposed output-feedback decentralised controller to an exogenous disturbance input are also analysed and specific conditions under which properties such as Input-toOutput-practical-Stability and asymptotic stabilisation are attained are also discussed.

Decentralized Variable Structure Control of Complex Giant Singular Uncertainty Systems

This paper, at the first time, considers the problem of decentralized variable structure control of complex giant singular uncertainty systems by using the property of diagonally dominant matrix and Frobenius-Person theorem. The splendid selection of switching manifold for each subsystem makes the design relatively straightforward and can be easily realized. An illustrate example is given.

Numerical quadrature for singular and near-singular integrals of boundary element method and its applications in large-scale acoustic problems

The numerical quadrature methods for dealing with the problems of singular and near-singular integrals caused by Burton-Miller method are proposed, by which the conventional and fast multipole BEMs （boundary element methods） for 3D acoustic problems based on constant elements are improved. To solve the problem of singular integrals, a Hadamard finite-part integral method is presented, which is a simplified combination of the methods proposed by Kirkup and Wolf. The problem of near-singular integrals is overcome by the simple method of polar transformation and the more complex method of PART （Projection and Angular ＆ Radial Transformation）. The effectiveness of these methods for solving the singular and near-singular problems is validated through comparing with the results computed by the analytical method and/or the commercial software LMS Virtual.Lab. In addition, the influence of the near-singular integral problem on the computational precisions is analyzed by computing the errors relative to the exact solution. The computational complexities of the conventional and fast multipole BEM are analyzed and compared through numerical computations. A large-scale acoustic scattering problem, whose degree of freedoms is about 340,000, is implemented successfully. The results show that, the near singularity is primarily introduced by the hyper-singular kernel, and has great influences on the precision of the solution. The precision of fast multipole BEM is the same as conventional BEM, but the computational complexities are much lower.

Recent Advances and Emerging Applications of the Singular Boundary Method for Large-Scale and High-Frequency Computational Acoustics

With the rapid development of computer technology,numerical simulation has become the third scientific research tool besides theoretical analysis and experi-mental research.As the core of numerical simulation,constructing efficient,accurate and stable numerical methods to simulate complex scientific and engineering prob-lems has become a key issue in computational mechanics.The article outlines the ap-plication of singular boundary method to the large-scale and high-frequency acoustic problems.In practical application,the key issue is to construct efficient and accurate numerical methodology to calculate the large-scale and high-frequency soundfield.This article focuses on the following two research areas.They are how to discretize partial differential equations into more appropriate linear equations,and how to solve linear equations more efficiently.The bottle neck problems encountered in the compu-tational acoustics are used as the technical routes,i.e.,efficient solution of dense linear system composed of ill-conditioned matrix and stable simulation of wave propagation at low sampling frequencies.The article reviews recent advances in emerging appli-cations of the singular boundary method for computational acoustics.This collection can provide a reference for simulating other more complex wave propagation.

不确定性关联奇异大系统时滞相关分散鲁棒镇定

针对一类不确定关联时滞奇异大系统,利用Lyapunov稳定性理论与时滞积分矩阵不等式相结合的方法,研究其时滞相关分散鲁棒镇定问题,目的是设计一无记忆状态反馈分散控制器,使闭环系统鲁棒稳定.用矩阵不等式方法,给出了该类系统时滞相关分散鲁棒镇定的充分条件.所得结果与系统时滞的大小有关,并以矩阵不等式的形式给出.最后用数值算例说明了所给方法的可行性和有效性.

离散广义大系统的Lyapunov稳定性分析

广义大系统的稳定性是广义大系统理论的基本问题之一,对其稳定性的研究要比状态空间大系统复杂得多,因为广义大系统不仅需要考虑稳定性,而且还要考虑正则性和因果性(离散广义系统)及脉冲自由(连续广义系统).本文在所有孤立子系统都是正则的且具有因果关系的条件下,利用Lyapunov方程,应用Lyapunov函数方法,研究了广义离散线性大系统和广义离散非线性大系统的稳定性和不稳定性问题,给出了离散广义大系统稳定性和不稳定性判定定理,得到了离散广义大系统的关联稳定参数域和不稳定域.

具有非线性关联的广义分散系统的镇定问题

利用变结构控制思想研究具有非线性关联的大型广义不确定系统的镇定问题。在一定条件下对系统设计了分散变结构控制器及完全分散变结构控制器。由于切换函数中动态补偿器的引入,使得设计简单,易于工程实现。

广义离散线性大系统的稳定性分析

广义大系统的稳定性是一个非常重要的问题。由于广义大系统的复杂性 ,对其稳定性的研究也是一件相当困难的事情。孤立的子系统的稳定性与线性大系统的稳定性之间的关系问题是一个非常有意义的问题 ,该文从广义线性大系统的等价变换和等价系统入手 ,应用标量和的Lyapunov函数法 ,研究了广义离散线性大系统的渐近稳定性和不稳定性 ,获得了系统的关联参数的稳定域和不稳定域。

导体线面连接问题中奇异函数积分的计算

在线面连接问题中 ,电流展开函数包含体展开函数、线展开函数和连接点展开函数三类。求解电场积分方程的积分项是电流基函数及其散度分别与自由空间格林函数的乘积 ,由于连接点展开函数含有一个奇异点 ,所以被积函数中含有两个奇异点。本文通过积分变换消除了奇异点 ,并将二重积分化为一重积分 ,使计算精度得到提高。计算实例验证了本文方法的正确性。

线性关联滞后广义大系统的变结构控制

研究了一类线性关联滞后广义大系统的变结构控制综合问题。首先根据系统的结构和控制输入的特定形式,引入了1种新的受限系统等价分解形式,把每个子系统分解成2个低维的动态子系统:1个是不带控制项的线性关联微分差分系统,另1个是带有控制项的线性关联差分系统。然后设计了带有积分动态补偿器的切换函数,给出了滑动模渐近稳定的充分条件。最后设计了可以保证系统的解的轨迹到达切换流形的多层分散变结构控制。这种控制对物理上分散等类型的线性关联滞后广义系统是合理的有效的。

奇异k紧整数的无限族

设n,s1,s2是3个正整数,使得s1<s2<n,gcd(n,s1,s2)=1,G(n;s1,s2)是n个结点的步长为s1和s2的双环网,d(n;s1,s2)是其直径.设d(n)=min{d(n;s1,s2)s1<s2<n},d1(n)=min{d(n;1,s)1<s<n}.已知d1(n)d(n)[3n]-2=lb(n).若d(n;s1,s2)=d(n)=lb(n)+k,k 0,则称双环网G(n;s1,s2)是k紧优双环网.若d1(n)>d(n)=lb(n)+k,则n称为奇异k紧整数.本文给出构造奇异k紧整数无限族的方法,并对于k=1,2,…,20,构造出这样的无限族.

不确定奇异分数阶互联系统非脆弱分散H_(∞)控制

研究了阶次在0到1上的不确定奇异分数阶互联系统的非脆弱分散H_(∞)控制问题.对现有的奇异分数阶线性系统容许且满足H_(∞)性能的判定条件进行推广,以严格线性矩阵不等式的形式给出新的判定准则;通过对互联系统特殊结构的分析,利用线性矩阵不等式方法和矩阵分解技术,分别在加法和乘法控制器增益扰动下,给出非脆弱分散H_(∞)控制器存在的充分条件和设计方法.在控制器的设计过程中,对互联矩阵没有加以限定,得到严格的线性矩阵不等式判据,在一定程度上降低了系统的保守性.利用LMI工具箱及Simulink数值仿真验证了结论的有效性.

关联时滞广义大系统的分散鲁棒镇定控制器设计

研究一类具有数值界不确定性关联时滞广义大系统的分散鲁棒镇定问题.构造Lyapunov函数,通过适当地放大不等式,利用矩阵Schur补的性质,将问题转化为一组线性矩阵不等式(LMI)的求解问题.给出了系统镇定控制器存在的条件.当条件成立时,给出了分散鲁棒反馈控制律的表示式.数值算例说明了控制器设计方法的可行性.