Uniqueness of Local Control Sets

The local controllability behavior near an equilibrium is discussed. If the Jacobian of the linearized system is hyperbolic, uniqueness of local control sets is established.     

Hyperbolic Chain Control Sets on Flag Manifolds

In this paper, we characterize the hyperbolic chain control sets of a right-invariant control system on a flag manifold of a real semisimple Lie group. Moreover, we provide a formula for the invariance entropy of such sets, applying a recently established result that holds in a more general setting.     

超临界参数机组控制系统的特点及其控制策略

介绍了超临界参数火电机组的技术特点,分析了其控制系统中存在的问题,指出超临界直流锅炉机组是强耦合、多变量、非线性的控制对象,提出在系统设计中要充分考虑采用变参数、变设定值的控制方案代替根据偏差反馈控制的策略,适时的动态时间补偿以及静态平衡动态修正的控制方法。图1参2     

基于对角递归神经网络整定的PID解耦单元机组负荷控制系统

针对火电厂单元机组具有多变量强耦合、非线性及参数时变的受控对象，提出了基于对角递归神经网络整定的PID解耦控制方法，其主要特点是能够提供一个对角递归神经网络来辩识系统模型，进而对PID控制器参数进行整定，实现多变量解耦控制。通过对火电机组负荷控制系统的设计和仿真研究，表明系统达到了动态近似解耦、静态完全解耦和无静差跟踪，并具有响应速度快，鲁棒性好等特点。图5参6     

DCS在多台电炉控制中的开发和应用

DCS是集中管理份散控制的一种控制技术,广泛应用于工业自动化生产.在此基础上,开发了小型DCS控制多台电炉,提高了工厂集中管理水平和产品质量.     

Intrinsic Character of One Property of Hyperbolic Sets

The paper is devoted to the local premaximality property in the class of hyperbolic sets. (An invariant set F of a diffeomorphism S has this property, if it is not locally maximal, but in any neighborhood of F there exists a locally maximal invariant set containing F.) We prove that (in this class) the property of F to be or not to be locally premaximal depends only on the “interior dynamics” inside F, i.e. it depends only on the restriction S|F.     

On Noncompact Minimal Sets of the Geodesic Flow

We study nontrivial (i.e., containing more than one orbit) minimal sets of the geodesic flow on \T ¹², where is a nonelementary Fuchsian group. It is not difficult to prove that nontrivial compact minimal sets always exist. We establish the existence of nontrivial noncompact minimal sets in two cases: (1) is a Schottky group of special kind generated by infinitely many hyperbolic elements, (2) contains a parabolic element (in particular, = PSL(2, )). This is done by geometric coding of geodesic orbits and constructing a minimal set for symbolic dynamics with infinite alphabet.     

Sub-Lorentzian Structures in $\mathbb {R}^{4}$: Left-Invariance and Conformal Normal Forms

Germs of sub-Lorentzian structures on hyperplane distributions in four-dimensional space are divided into three types: elliptic, hyperbolic, and parabolic (provided the distribution satisfies some non-integrability condition). Their main quasi-homogeneous parts are non-integrable left-invariant sub-Lorentzian structures on the trivially extended Heisenberg group, and there are exactly three such structures up to isomorphisms of the group: elliptic, hyperbolic, and parabolic. For elliptic and hyperbolic germs, we normalize their next-order quasi-homogeneous terms up to conformal equivalence. A control-affine system in three-dimensional space with a disk of admissible velocities defines a sub-Lorentzian structure in the four-dimensional space-time. If the latter is elliptic and left-invariant up to conformal equivalence, then the attainable sets of the original control-affine system are diffeomorphic to the well-known sub-Riemannian ball in the Heisenberg group. The attainable sets in the hyperbolic case are described in the present paper.     

基于粗糙集理论的除氧系统智能控制器设计

1前言热力除氧是一个较为复杂的过程,除氧系统由4台除氧器组成,每台除氧器都通过汽平衡和水平衡与其它除氧器相连。各除氧器之间的压力、水位相互影响,因而除氧系统控制难度较大,系统的鲁棒性差。系统运行中经常产生振荡,出现各除氧器水位此高彼低反复变化,同时压力也不稳定,除     

The Structure of Reachable Sets and Geometric Optimality of Singular Trajectories for Certain Affine Control Systems in ℝ3. The Sub-Lorentzian Approach

In this paper, we investigate the structure of reachable sets from a given point q ₀ for a class of analytic control affine systems characterized, among other things, by possessing two singular trajectories initiating at q ₀. The aim of the paper is to establish the connection between the minimal number of analytic functions needed for describing reachable sets and the number of geometrically optimal singular trajectories. The paper is written in a language of the sub-Lorentzian geometry. Also, the sub-Lorentzian geometry methods are used to prove theorems.     

模糊模型参考学习控制在水电机组中的应用

研究了模糊模型参考学习控制的原理和方法，对模糊模型参考学习控制所具有的对模糊规则进行调节和修改的功能进行了分析，并将其应用于具有非线性、时变和非最小相位的水电机组的控制系统中。设计了水电机组的模糊模型参考学习控制器，由于该控制器引入了模糊学习机制，利用被控对象和理想参考模型间的输出误差，调整模糊控制器的规则集，从而使机组输出实时跟踪参考模型的输出。仿真结果表明：该控制方法不仅适用于水电机组系统工况小波动的情况，也适合工况发生大波动的情况，但要应用于工程实际还需作进一步的探索。图7表1参5     

电力负荷预测的模糊可变集合方法

应用模糊可变方法对电力负荷进行了预测.利用负荷与三大产业的生产总值的历史数据构造指标集,并应用差异函数建立电力负荷预测模型.该方法能够科学、合理地确定与电力负荷相关的各个研究指标处于级别区间的相对隶属函数,并根据指标重要性进行二元比较与量化,从而合理地确定各个指标的权重,得出电力负荷预测的级别特征值.实例证明,方法是合理的.     

基于粗糙集理论的火焰图像处理与状态识别

针对全炉膛火焰检测的主要问题,提出了一种基于粗糙集理论的火焰状态识别方法。该方法利用粗糙集理论的分类原则,得到火焰燃烧的高温区域,结合其它火焰图像的特征量,用基于粗糙集的知识决策系统建立火焰状态识别规则,构建全炉膛燃烧状态识别的基本模型,判断燃烧状态。由于决策表的简单属性表达,有利于操作人员的理解并为调整锅炉燃烧提供操作指导。现场试验表明,火焰图像的特征量与燃烧的好坏有密切关系。通过属性集的定量分类实现输出量的定性识别,系统状态识别准确可靠。     

Mild Solution and Constrained Local Controllability of Semilinear Boundary Control Systems

The existence of mild solution and the constrained local controllability of a retarded boundary control system with nonlocal delay condition have been established. The theory of extrapolation spaces is applied to derive the mild solution. Then, the constrained local controllability is established using the generalized open mapping theorem. In the last section, application of the result is shown through examples of control systems represented by hyperbolic partial differential equations.     

典型水轮发电机组检修实操的仿真培训系统

针对湖南省两座典型水电站立轴混流式机组和灯泡贯流式机组的实际检修过程,运用三维建模软件,结合三维计算机图形处理技术、计算机通讯及数据库技术,依托三维引擎OpenSceneGraph,开发了典型水轮发电机组检修实操的仿真培训系统。该系统通过构建检修三维模型库、检修流程仿真机、检修实操题库,在三维交互平台上模拟机组大件吊装和重要部件解体拆分的详细流程,合理的控制约束使用户交互操作自由且具体,为培养水电站检修人员提供了更具专业综合性的平台。     

基于局域波-粗糙集-神经网络的故障诊断方法研究

提出了一种基于局域波-粗糙集-神经网络的智能故障诊断方法。首先通过局域波法进行故障特征提取,获取能够反映设备运行状态的由局部能量组成的特征向量;接着应用粗糙集理论对样本特征参数进行属性约简,去除冗余信息,获取最优的决策系统;最后根据最优决策系统来构造RBF神经网络,并进行故障诊断。以柴油机缸套活塞磨损故障为例,详细说明了基于粗糙集-局域波-神经网络的故障诊断方法的原理和步骤。诊断结果证明了此方法的有效性。     

600MW亚临界空冷机组汽轮机高调门摆动问题的分析及解决方案

本文针对国内两台处于电网末端的600 MW亚临界空冷机组,在顺序阀方式下运行至高调门第三阀与第四阀重叠区域附近阀位时,出现的高调门高频摆动问题进行分析研究。最终,通过对机组实际运行参数和DEH控制逻辑的分析,发现了阀门摆动的根本原因,并采用配汽优化技术较好的解决了这一问题。这对提高目前国内占主流的600 MW级别机组的顺序阀运行方式下的安全性、经济性以及一次调频等调节性能具有一定的借鉴意义。     

汽轮发电机组故障的复杂性分析

以几个典型故障为例阐述汽轮发电机组故障的复杂性。     

基于粗糙集的电网企业低碳管理型员工绩效评价研究

基于粗糙集理论提出了一种数据挖掘方法,利用粗糙集的约简功能挖掘低碳管理型员工绩效评价规则,以统一评价标准和提高评价效率;运用粗糙集属性重度性原则确定约简后备评价指标的客观权重.在此基础上,对电网企业低碳管理型员工进行绩效评价.算例表明,该绩效评价方法有效、科学.     

大型汽轮发电机组轴系不对中振动的研究

轴系不对中可分为联轴器不对中、轴瓦中心标高偏差以及转子与静子不同心三种类型，分析讨论各种不对中情况的力学机理及振动故障特征，给出联轴器不对中的晃度控制参考标准，并介绍各种不对中故障的工程实际案例。轴振晃度是联轴器对中状态的直接反映，可利用轴振晃度数据诊断联轴器不对中。在安装和检修过程中应严格进行轴系找中、在运行过程中应避免对机组轴系形成冲击负荷，才能保证大型汽轮发电机组的安全、稳定、经济运行。图7表8参8