基于H∞控制理论的UPQC串并联单元协调控制的实现

统一电能质量控制器(UPQC)集电压型补偿装置、电流型补偿装置和储能装置于一体,统一实现多重电能质量调节功能。为了提高UPQC的综合控制性能,该文采用先进的H∞控制理论对UPQC的广义被控系统进行了深入研究,并给出了其H∞控制器的Riccati求解方法。剖析了UPQC的串联单元、并联单元之间耦合影响的根本原因,进而提出一种基于H∞控制的UPQC协调控制器的设计方法。实验结果表明所提方法可使UPQC同时实现串联单元的电压跟踪补偿和并联单元的电流跟踪补偿,并且均无稳态相位偏移和幅值衰减。从根本上消除了串联、并联单元之间的耦合影响,实现了UPQC的多重电能质量统一协调控制功能。     

Adaptive H∞ event-triggered load frequency control in islanded microgirds with limited spinning reserve constraints

Using an islanded microgrid (MG) with large-scale integration of renewable energy is the most popular way of solving the reliable power supply problem for remote areas and critical electrical users. However, compared with traditional power systems, the limited spinning reserves and network communication bandwidth may cause weak frequency stability in the presence of stochastic renewable active outputs and load demand fuctuations. In this paper, an adaptive event-triggered control (ETC) strategy for a load frequency control (LFC) system in an islanded MG is proposed. First, a bounded adaptive event-triggered communication scheme is designed. This not only saves on network resources, but also ensures that the control center has a sensitive monitoring ability for the MG operating status when the frequency deviations have been efectively damped. Secondly, by fully considering the spinning reserve constraints and uncertain communication delays, the LFC system is described as a nonlinear model with saturation terms. Design criteria for ETC parameters are strictly deduced based on Lyapunov stability theory. Finally, an ETC parameter optimization algorithm based on random direction search is developed to reconcile the bandwidth occupancy and control performance. The efectiveness of the proposed method is verifed in an MG test system.     

An integrated fault estimation and fault tolerant control method using H∞-based adaptive observers

An integrated fault estimation/fault-tolerant control (FTC) scheme is developed in this article for nonlinear Lipschitz systems in the presence of external disturbances and actuator failures. To address this problem, coupled uncertainties between the observer error dynamics and the control system are considered, which is conveniently ignored in control approaches based on the separation principle. An H_∞ -based adaptive observer is proposed to simultaneously estimate the system states and actuator faults without the restrictive strictly positive realness or persistent excitation conditions. The FTC is constructed by sliding mode control using the estimated states generated by the developed observer. A novel sufficient condition is derived in terms of linear matrix inequality (LMI) including both the system control dynamics and the estimation errors; then, the control parameters and observer gains are simultaneously obtained via solving the mentioned LMI based on the H_∞ optimization. Finally, a flexible joint robot is considered to illustrate the effectiveness of the developed method.     

Combustion optimization by coordinated monitoring of O_2/CO in flue gas

The major aims combustion engineers all over the worldare striving at are conservation of energy and allevia-tion of environmental pollution,for which the monitoring and controlof the furnace process are of prime importance to attain an optimizedcondition of combustion.Oxygen content in flue gas is generallyused as an indicator of whether the right amount of combustion air issupplied.However,it cannot directly reflect the degree of perfectionof the combustion process taking place in the furnace.On the otherhand CO is a product of chemical reaction which directly reflects the     

H∞ filtering of discrete-time interconnected systems with failed interconnections

The H_∞ filtering problem for interconnected systems is addressed in this paper. In order to facilitate the stability analysis of interconnected systems under the conditions of failed interconnections, a strategy related to switched systems is introduced. Assume that the interconnections among these subsystems disconnect based on the mode-dependent average dwell time (MDADT), a switching signal is implemented to denote the failed interconnections cases. In the aid of the MDADT method, a filter is designed such that the fault detection (FD) system is asymptotically stable and satisfies the weighted H_∞ performance. Finally, a numerical simulation is provided to show the effectiveness of the proposed filter.     

广义系统H∞分散控制

文中研究广义互联系统分散控制器的设计.按照中文方法得到的闭环系统具有联接稳定,当部分子系统断开时并不影响整个系统的稳定性.实际证明提出的方法是完全可行的.     

Realization of the 9200-MW Generation Assets

With a process of disposition obeying market rules and a result of realization at a cost of 18.7 billion Yuan which is 56% excess, the State Electricity Regulatory Commission, the organizers for realization of the 9200-MW generation assets （the so-called ＂920 Project＂） didn＇t fail to accomplish its mission and withdrew the curtain of power reform in the 11th Five-Year period with a satisfactory performance.     

H∞ filtering of discrete-time switched singular systems with time-varying delays

In this article, the analysis and design problems of H_∞ filtering for a class of discrete-time switched singular systems with time-varying delay under an arbitrary switching signal are investigated. The main attention is focused on the design of a linear mode-dependent filter guaranteeing the regularity, causality, and asymptotic stability of the resulting filtering error system with a prescribed H_∞ performance bound. By using a multiple Lyapunov-Krasovskii functional, and utilizing the linearization technique, novel sufficient conditions for the solvability of H_∞ problem are derived in terms of linear matrix inequalities. Solving that, the desired filter gains can be determined. Any model transformation of system, which often leads the large computational burden is involved. The free weighting matrix technique is introduced to provide additional degree of freedom, which improves the conservativeness of the developed method. Finally, numerical examples are given to demonstrate the effectiveness and the merit of the proposed approach and to compare the obtained results with some previous works in the literature.     

Robust estimation of power quality disturbances using unscented H∞ filter

This paper proposes a novel adaptive filtering method for tracking the power quality disturbances present in distorted power signals. The proposed filter known as unscented H_∞ filter (UHF) is the robustification of unscented Kalman filter (UKF) and is based on state space modeling. The performance of unscented H_∞ filter has been compared with other adaptive filters considering signals, which can represent worst case measurement and network conditions in a typical power system. State space modeling is used to estimate power quality disturbances like sag, swell, notch in presence of additive white Gaussian noise (AWGN). Also the amplitudes and phases of different harmonics under high noisy conditions and decaying DC are also estimated which shows the robustness of the filter. Comparison results demonstrate that under identical conditions, the performance of UHF is better compared to UKF.     

Frequency Regulation in Hybrid Power System Using Iterative Proportional-Integral-Derivative H ∞ Controller

This study considers frequency regulation in a hybrid power system consisting of conventional and distributed generation resources. The performance of two controllers—an H _∞ design via linear matrix inequalities and an iterative proportional-integral-derivative H _∞ via linear matrix inequalities—is assessed to maintain frequency deviation profile in acceptable limits. In the latter control design, the iterative linear matrix inequality approach is used to tune proportional-integral-derivative controller parameters subjected to H_∞ constraints in terms of the iterative linear matrix inequality. The efficacy of the control law and disturbance accommodation properties is shown. The robustness of these controllers is demonstrated in the hybrid power system with different load disturbance conditions, wind power, and parameter variations. Controller performance is compared with a suboptimal controller to demonstrate its superiority. It is found that the second controller design has satisfactory disturbance rejection properties and robustness against parameter variations over a wide range of conditions.     

HVDC的非线性H∞控制

基于直接反馈线性化和H∞控制理论研究了交直流联合输电系统中高压直流(HVDC)系统的附加控制器的设计,对含有交直流联络线路的两区域系统建立了非线性鲁棒控制模型.利用H∞控制理论和Matlab软件得出控制律.分析表明这种控制方法提高了交直流输电系统的稳定性及控制系统的鲁棒性.     

H∞控制中的LMI法

近年来用线性矩阵不等式（ＬＭＩ）处理Ｈ∞控制问题受到了多方的重视。本文从Ｈ∞优化设计的角度对ＬＭＩ法进行了分析，指出ＬＭＩ法实质上是一种基于分析的设计方法，并配以例题来说明这个观点。     

H∞电力系统稳定器的设计

基于Ｈ＾∞最优控制理论,利用部分极点配置技术,提出了一种电力系统稳定器的设计方法,并给出了非线性仿真结果。     

TCSC的H2/H∞控制器设计

基于直接反馈线性化和鲁棒H2／H∞控制理论研究了TCSC的控制设计，对具有TCSC的单机一无穷大系统，建立了含不确定因素的数学模型，采用LMI(线性矩阵不等式)方法，利用MATLAB／LMI工具箱得出H2／H∞控制律。分析表明这种控制方法兼有鲁棒性能和最优性能，提高了电力系统的稳定裕度及传输功率。     

估计误差方差约束混合H2/H∞滤波

考虑带有稳态误差方差约束的线性系统的混合H2／H∞滤波问题．通过解一个线性矩阵不等式(LMI)，直接获得滤波器，并且这个滤波器满足下面性能指标：滤波过程是渐近稳定的；在每个状态的稳态估计误差方差不超过规定的上界的同时，最小化系统的H∞范数指标。实例说明了这种设计方法的有效性。     

电能质量的H∞最优控制方法

将先进的H∞优化控制理论应用于电能质量调节装置的控制器设计中,提出了一种基于H∞模型匹配技术的电能质量波形跟踪补偿控制新方法,并对其控制原理和物理本质进行了深刻阐述.给出了模型匹配系统的H∞标准控制框图及其状态空间实现,此方法不但可对控制器进行优化设计、控制精度高,而且还可确保所设计出的闭环系统为内部稳定的,该研究工作为进一步提高电能质量调节装置的补偿控制性能提供了理论支持.该H∞方法不但有严格的数学基础,而且还有明确的物理意义,可方便地实现电压、电流波形动态跟踪补偿最优控制,其正确性已得到了有效验证.     

H∞鲁棒控制的分析方法及应用

分析H∞鲁棒控制方法的原理及实现,描述标准H∞鲁棒控制问题.研究一种重要的基于状态空间的系统结构奇异值μ分析方法,克服了标准H∞鲁棒控制对于结构不确定性系统分析的保守性.最后,给出基于H∞鲁棒控制方法的例子,表明此方法在解决不确定性系统控制中的优越性.     

永磁同步电机系统线性化H∞鲁棒控制

针对内埋式永磁同步电机伺服系统,研究了一种线性化H∞鲁棒控制方法。该方法基于微分几何理论,利用输入输出解耦线性化技术将系统模型转化为线性模型;然后采用最大转矩比电流控制策略增加系统的转矩输出能力;针对负载干扰设计了负载转矩观测器;最后基于线性化模型设计了H∞鲁棒控制器,提高系统对内埋式永磁同步电机系统参数变化的鲁棒性。仿真实验结果表明基于微分几何输入输出解耦H∞鲁棒控制伺服系统有较好的动态性能、抗干扰性能、跟踪性能和鲁棒性能。