An Approach to the Design of Distributed Machinery Control Systems

The design and implementation of a control system consisting of a number of cooperating processes running concurrently on a group of communicating processors is a complex task. There is general agreement that the high level of complexity associated with these systems dictates a ``top-down' design approach to both hardware and software. In this paper, a design approach that is oriented toward machinery control applications is developed for distributed control systems. Principles are identified for specifying system requirements, partitioning a system into processes, allocating processes to processors, and choosing a communication network. A design example is discussed.     

Use of modern information technologies for making budgetary sectors of the economy more energy-efficient

A strategy of administrative management and technological control of heat consumption and energy conservation processes in budgetary sectors of the economy is described together with a system of integrated indicators for estimating the efficiency of these processes and the main results obtained from putting the strategy in use in the system of the Russian Federal Agency for Education are presented.     

浅析IC卡在预付费售电系统中的应用

对IC卡在预付费售电系统中的应用进行阐述,重点介绍CPU卡在预付费售电系统中的应用方法、数据传输及安全认证过程以及密钥管理体系等内容。     

Mathematical simulation of working processes in the furnace of a circulating fluidized bed boiler

A software system developed for simulating and calculating boiler furnaces with circulating fluidized beds is described. The main principles on which the system is constructed are outlined, and the physical and mathematical models of processes in circulating fluidized bed furnaces are described together with the calculation algorithm. Results from a study of analyzing the effect the grinding fineness of initial fuel particles has on the processes in a circulating fluidized bed furnace are presented.     

Calculations of the Electromechanical Processes during Parametric Optimization of the Distribution Systems of Active and Reactive Loads of Ship Power Plants

A mathematical model of a ship power plant (SPP) to study dynamic modes of the active and reactive load distribution system using the parametric optimization of adjustable parameters has been presented. The algorithm that minimizes the time of transient processes in different modes of SPP operation has been developed for parametric optimization of the active and reactive load distribution system. The calculations of electromechanical processes during of parametric optimization of the load distribution system of an SPP have been carried out in the MATLAB package using mathematical models and numerical methods.     

On the steady state behaviour of stochastic systems

The question of the existence of steady state solutions to the closed loop system equations for stochastic systems, and in particular ARMAX systems under non-linear feedback control, is addressed. Using the ergodic theory of time-invariant Markov processes, it is shown that corresponding to a large class of control laws there exist shift-invariant probabilities for the joint disturbance input-output processes. This permits an asymptotic analysis of (i) averages of functions of the state process, (ii) the probability distributions governing the state process and (iii) loss functions on the system in the steady state.     

MAS在火电生产过程智能控制中的应用

针对火电厂生产过程控制系统的组成、功能、目标、方法及其分布特性,给出了基于MAS控制的建模和拓扑结构,并对MAS控制系统协调工作过程的实现机制进行了分析,结合现场DCS进行了实际应用。投运结果表明,该方法对大滞后、非线性、多干扰、变参数的火电厂生产过程具有较好的控制能力,同时证明了MAS在解决火力发电厂生产过程控制方面的有效性。     

石化生产过程SCADA系统的报警管理

本文介绍了SCADA系统在中石化广州分公司生产过程中的应用，通过实例详细地论述了SCADA系统中的报警管理技术和方法。     

Active fault tolerant control systems by the semi‐Markov model approach

This paper investigates the active fault tolerant control problem via the H _∞ state feedback controller. Because of the limitations of Markov processes, we apply semi‐Markov process in the system modeling. Two random processes are involved in the system: the failure process and the fault detection process. Therefore, two corresponding semi‐Markov processes are integrated in the closed‐loop system model. This framework can generally accommodate different types of system faults, including the randomly happening sensor faults and actuator faults. A controller is designed to guarantee the closed‐loop system stability with a prescribed noise/disturbance attenuation level. The controller can be readily solved by using convex optimization techniques. A vertical take‐off and landing vehicle example with actuation faults is used to demonstrate the effectiveness of the proposed technique. Copyright © 2013 John Wiley & Sons, Ltd.     

燃料电池过程的效率

燃料电池是通过电化学过程将化学能直接转化为电能的装置。文章分析了燃料电池过程的理想效率和实际效率,并讨论了燃料电池与热机联合过程的理想效率和实际效率。燃料电池过程的理想效率随电池工作温度而变化,但包含可逆热机的联合过程的理想效率等于在环境温度下工作的燃料电池的理想效率,与燃料电池工作温度无关。燃料电池的效率不但取决于反应物的种类,还取决于其相态。实际电池效率因极化现象和实际电流低于反应物消耗产生的期望电流而低于理想效率。     

交直流系统的换流器动态相量模型

建立准确而有效的换流器数学模型是研究大规模交直流混联系统动态特性的关键问题。分析在交流系统不对称情况下,换流阀导通时刻偏移和三相换相角不平衡的HVDC换流器动态特性。由此,提出基于序分量的适用于各种运行工况及故障的改进换流器动态相量模型,该模型突破了传统换流器动态相量模型的应用局限性。将其应用于贵广Ⅱ回HVDC系统详细模型和CIGRE HVDC系统标准模型的交直流系统动态特性的全面仿真计算,与应用PSCAD/EMTDC电磁暂态仿真软件得到的仿真结果相比较,结果表明该模型准确有效。     

组合数学模型方法研究

适用于单一物理过程和简单区域的传统建模方式难以解决复杂大系统模拟问题和适应计算机向多核和网络化发展的趋势。多模型、多进程化的并行计算将是今后数学模型发展的一个重要方向。本文针对复杂的时间过程模拟,基于多进程和网络技术,提出了一种模型组合方法,可以组合不同尺度和性质模型来模拟一个复杂过程。该方法只需在各模型的时间控制循环内插入一个附加过程函数即可将模型组件化;采用量和网格编号实现不同交互信息的统一表示;采用中央控制的框架结构管理参与计算的各模型组件;通过指令控制模型组件的执行过程和顺序;将模型组合信息进行分层组织和管理;采用时间调度和不同插值方法解决模型组件间的耦合问题。通过一维和平面二维水动力学模型组合实例说明了模型组合方法的可行性及存在问题;通过一维热传导问题的分区耦合并行计算讨论了采用组合方法实现并行计算的性能和效率。为通过组合简单模型来模拟复杂问题提供了一条有效途径。     

嵌入式系统进程的机理

进程可以被理解成活动的程序,每个进程是相互分离的实体,是CPU正在运行的一个特定程序。因为进程能处理同时发生的多个事件,所以它对嵌入式系统的设计来说是非常重要的,介绍通常只有一个CPU的嵌入式操作系统如何让每个进程只能连续的运行很短的时间并使每个进程认为只有自己在运行的机理和一个设计时没有引入进程概念的实时嵌入式系统是非常危险的。     

Exploring the Impact of Systems Architecture and Systems Requirements on Systems Integration Complexity

The need to perform faster systems integration of complex systems require the architect and design team to understand how the selected architecture and design components will impact the systems integration processes complexity (or difficulty). Systems integration process complexity is an outcome of the interaction between degree of feasibility and level of effort required to understand, describe, implement, manage, and document the systems integration process for a given system development and operational environment. This paper analyzes the cause-and-effect relationships between the system requirements, architecture and the systems integration processes complexity. In order to address systems integration issues upfront in the design phase it is necessary to determine if the architecture and design of components, subsystems, processes, and interfaces impacts (and to what extent) systems integration process complexity. This paper also defines and analyzes the impact of the different system architecture and requirements factors on systems integration process complexity. A research framework is developed to understand the cause-and-effect relationships between system requirements, architecture, and integration process. Finally, the paper proposes recommendations based on the causality results. These conclusions are based on research undertaken by the authors on eight development projects in the government sector.     

HVDC输电系统可靠性跟踪方法

由于高压直流输电(HVDC)系统结构复杂、元件众多,各元件对系统不可靠性的影响各不相同,如能找到一种不可靠性分摊方法,给出各元件对系统不可靠性的贡献大小,以确定直流输电系统的薄弱环节,将为运行和规划人员提供一种新的可靠性分析方法。针对该问题,提出基于比例分摊思想的系统不可靠性跟踪准则,结合可靠性计算中的子系统划分,又提出了直流输电系统可靠性跟踪的2次分摊方法。在子系统可靠性跟踪中,应用比例分摊准则得到各子系统内部元件对子系统可靠性指标的分摊;在整个直流系统可靠性跟踪中,基于该准则得到各子系统可靠性指标对直流系统各可靠性指标的分摊;最后合并2次分摊结果即可得到各元件对系统可靠性指标的分摊。采用某工程算例进行测试分析,结果证实该文提出的可靠性跟踪方法能够将HVDC输电系统可靠性指标公平合理地分摊到各元件或子系统,并有效地辨识了系统的薄弱环节。     

600 MW机组全程给水自动调节系统的最新控制策略

介绍了哈三电厂3号机组(600MW)全程给水自动调节状况,分析了原设计存在的问题,提出了解决问题的办法和实现全程给水控制系统新的控制策略,提供了全程给水控制系统投入运行后的相关调整参数和运行曲线。     

利用组态软件实现对柔性物料贮运系统的监控

柔性制造系统FMS是一个自动化的制作系统，但在实现过程中，系统的运作所需时间长，白动化控制的实现比较困难。WinCC是一个具有强大功能的组态软件，可实时监控，可保证物料系统的可靠运行。在此基础上提出利用WinCC平台实现对柔性制造系统中物料贮运系统的监控。     

与仪器无关的测试系统集成技术

介绍了IVI系统结构以及IVI系统各模块的运行机制。通过使用两种开发工具LabWindowsCVI和Visual C ,详细说明了开发与仪器无关的IVI分类驱动程序的不同方法,实现测试系统的仪器互换性,并进行比较分析。     

一种不间断电源（UPS）用逆变器闭环控制系统的数字仿真

本文分析了用于UPS的逆变器闭环控制系统的特点,建立了系统数学模型,并在IPM-PC机上就给定电路参数模拟了系统的工作过程,得到了闭环系统的静态和动态特性。仿真结果与实验装置实测结果一致。     

数字化变电站的系统联调

为了正确指导系统联调,更好地完成数字化变电站的调试任务,针对联调工作内容和联调步骤进行描述和分析,从而在规范化调试方法的同时,达到节省调试时间,高效完成调试任务的目的。