基于五防逻辑文件的动态解析研究

以统一变电站监控系统与继电保护设备的五防逻辑为基础,针对变电站全站统一的五防逻辑文件,提出一种新的测控装置五防功能实现方法——PLC逻辑文件的动态解析法。相比测控装置传统的五防逻辑实现方法,此方法实现了继电保护设备与监控系统五防逻辑的统一,提高了五防逻辑运行效率和工程生产效率。     

一种在线式“五防”一体化系统的设计与实现

随着自动化技术在变电站中的推广应用,传统的“五防”模式已无法完全适应变电站安全操作的要求。介绍了一种基于监控系统设计的在线式“五防”系统,分析了该系统的结构特点和工作流程。该系统在线监视变电站内所有设备的位置信息和操作票执行过程,动态计算设备的闭锁逻辑,并通过对“五防”节点的控制,闭锁或开放设备的操作。论述了该系统在站控层、间隔层、过程层的设计与实现。     

计算机监控系统间隔层逻辑五防技术的应用

随着变电站综合自动化系统的发展和数字化变电站概念的提出,变电站一体化五防逐渐成为变电站防误操作的新技术。文章阐述了西宁750kV变电站计算机监控系统间隔层逻辑五防技术的实现,同时对一体化五防在青海变电站的应用进行探讨。     

变电站“五防”闭锁方式探讨

对传统的“五防”闭锁方法及新的“五防”方式分别作了介绍和分析，针对微机监控操作方式带来的新问题，提出了完善变电站“五防”闭锁系统的方式．     

变电站顺序控制防误系统软PLC设计

分析了顺序控制在变电站防误操作中的应用及其对五防闭锁的要求,结合IEC61131-3标准,给出了变电站顺序控制的软PLC逻辑的生成方法,设计了操作预演和五防规则一体化的变电站顺序控制系统。     

“五防”技术的比较与应用

介绍“五防”技术在上海电网的应用情况，通过对“电气连锁 电磁连锁”和“微机连锁”两项技术的分析与比较，列出其优缺点，并指出了在综合自动化变电站中，“五防”技术的运用问题，对电力系统厂、站安全运行，防止误操作，完善“五防”技术，具有参考价值。     

变电站防误系统的选型

变电站微机闭锁智能化是变电站防误系统应用的方向，也是变电站电气“五防”闭锁系统发展的趋势，受到广大用户的欢迎，值得大力推广。但在实际运用中，部分变电站闭锁防误功能不能充分发挥，无法正常运用，造成这种情况的原因就是防误系统选型的问题。本文试就变电站防误系统的选型问题进行探讨。     

智能变电站五防闭锁功能模型标准化设计及实现

以IEC 61850的模型为基础,在现有控制逻辑节点CSWI和闭锁逻辑节点CILO模型的基础上进行五防闭锁规则的设计。通过闭锁逻辑节点CILO中的引用地址intAddr和控制逻辑节点CSWI中的短地址sAddr实现五防闭锁逻辑元素的配置;通过闭锁逻辑节点CILO中的闭锁逻辑计算值stVal和控制逻辑节点CSWI中的数据源setSrcRef的关联实现闭锁逻辑信号的配置;通过闭锁逻辑节点CILO中允许分闸EnaOpn和允许合闸EnaCls中配置元素的设置,实现五防闭锁规则的定义,并通过逆波兰算法将五防闭锁逻辑转变成装置和系统可直接识别的逆波兰表达式。整个五防闭锁规则的设计完全基于变电站的变电站配置描述或智能电子设备配置描述文件,无需增加额外的文件配置,具有良好的互操作性。     

基于110 kV智能变电站的间隔层防误分析和设计

针对变电站刀闸存在操作顺序错误的问题,采用间隔层五防系统解决该问题。首先分析了间隔层五防系统的原理,然后对防误系统进行建模,建立了虚端子连接关系,分析了防误系统操作流程,最后根据模型设计了间隔层五防逻辑文本,并应用于变电站工作中。现场试验和调试表明,所设计的间隔层测控五防能有效进行刀闸防误操作,对变电站防误具有重要的作用。     

110kV变电站防误设计探讨

防误闭锁装置是变电站重要的组成部分之一.文中介绍了机械程序锁、电气闭锁、微机五防系统和"逻辑闭锁+电气闭锁"防误闭锁方式,分析了各自的特点及实现方法,指出应该根据变电站具体情况、管理方式等多方面的因素来选用不同的防误闭锁方式.最后给出了各类变电站的五防设计方案.     

Top-down design process for gate-level combinational logic design

A pedagogical process for designing gate-level combinational logic circuits is described. The process can be used for either combinational logic circuits or the combinational logic sections of sequential logic circuits. Positive logic signals (active high signals) as well as negative logic signals (active low signals) can be used in the design process. The top-down design process allows the student to draw functional logic diagrams in a rather routine manner using the positive logic convention, or the direct polarity convention. After obtaining functional logic diagrams, realizable logic diagrams can be easily obtained using any of the common off-the-shelf gate types including AND, OR, NAND, and NOR elements with appropriate inverter symbols. The advantage of the top-down design process is that students can very easily understand and implement gate-level combinational logic functions. Examples are provided to illustrate the top-down design process in teaching combinational logic design     

An interpreter for IEEE logic symbols

A CAD-system for logic design based on the use of IEEE standard logic symbols is described. The system, called DEMET, can be used to specify the operation of digital logic components entirely graphically with IEEE symbols. DEMET can automatically interpret the symbols, and generate functional simulation models for them. IEEE symbols can be simulated with a built-in logic simulator. DEMET uses computer graphics methods for visualizing the operation of logic circuits, which makes it an excellent aid for undergraduate level digital logic design courses     

Design and Application of Static Logic Directors

A digital computer program written by Westinghouse engineers aids the design of new static logic systems for metal mills. The computer program accepts logic equations specifying the functions to be performed. The program generates circuit drawings of logic circuitry plus paper tape for controlling an automatic wiring machine. The automatic wiring machine wires the back panel receptacles for plug-in cards which contain the integrated-circuit AND/NAND logic elements. The design engineer determines functional requirements to be performed by the logic circuits. He expresses these requirements in convenient logic statement form and adds comments on circuit functioning. Logic and comment statements are keypunched for input to the computer. The computer analyzes the equations, converts the functions to AND/ NAND logic circuits and generates the punched-paper tape required by the automatic wiring machine. In addition, the computer generates the circuit diagrams showing the actual AND/NAND circuits with complete (JIC) cross references and comments on circuit functioning. During computer processing diagnostic messages are generated to aid in finding design errors. Only one type of logic board is used in the new static logic system to perform all logic functions. This reduces maintenance to mere board replacement and greatly reduces spare board inventory. Triac outputs are featured in addition to normal contact closure outputs. Traic is a static ac switch which can operate pilot-operated solenoid valves, contactors, indicating lights, and other common ac loads. The logic system combines the advantages of fully wired integrated-circuit logic with the convenience and accuracy of computer aided design.     

Universal logic implementer: a general purpose tool for a digitallogic design laboratory

The authors present a general-purpose digital logic implementer, a tool designed to serve as a workstation for laboratory experiments in the digital logic and computer architecture courses taught in the Electrical and Computer Engineering Department at Washington State University. The logic implementer is a versatile tool suitable for a wide spectrum of experiments, from simple gate-level implementation of logic circuits to the implementation of microprogrammed bit-slice processors. The basic features of the logic implementer include generality of applications, easy-to-use environment, and robust, reliable interconnections     

Universal logic implementer: a general purpose tool for a digitallogic design laboratory

The authors present a general purpose digital logic implementer, a tool designed to serve as a workstation for laboratory experiments in the digital logic and computer architecture courses taught in the Department of Electrical and Computer Engineering at Washington State University. The logic implementer is a versatile tool suitable for a wide spectrum of experiments, from simple gate-level implementation of logic circuits to the implementation of microprogrammed bit-slice processors. The basic features of the logic implementer include generality of applications, easy-to-use environment, and robust, reliable interconnections     

Frequency Stabilization for Multi-area Thermal–Hydro Power System Using Genetic Algorithm-optimized Fuzzy Logic Controller in Deregulated Environment

Abstract—This article develops a model of load frequency control for an interconnected two-area thermal–hydro power system under a deregulated environment. In this article, a fuzzy logic controller is optimized by a genetic algorithm in two steps. The first step of fuzzy logic controller optimization is for variable range optimization, and the second step is for the optimization of scaling and gain parameters. Further, the genetic algorithm-optimized fuzzy logic controller is compared against a conventional proportional-integral-derivative controller and a simple fuzzy logic controller. The proposed genetic algorithm-optimized fuzzy logic controller shows better dynamic response following a step-load change with combination of poolco and bilateral contracts in a deregulated environment. In this article, the effect of the governor dead band is also considered. In addition, performance of genetic algorithm-optimized fuzzy logic controller also has been examined for various step-load changes in different distribution unit demands and compared with the proportional-integral-derivative controller and simple fuzzy logic controller.     

西门子1 000 MW汽轮机DEH控制逻辑优化

为提高上汽-西门子1 000 MW超超临界汽轮机控制系统的可靠性,分析和总结数字式电液控制（DEH）系统在机组运行期间出现的故障,在不改变原有逻辑的设计思想和保护原理的基础上,优化了跳闸电磁阀控制逻辑、阀门快关保护逻辑、主蒸汽压力切换逻辑、长甩负荷逻辑、短甩负荷逻辑、汽轮机转速控制逻辑,旁路开启后的切换逻辑,消除了“跳闸电磁阀断线引起高压抗燃油（EH）油压低跳闸、电网负荷波动引起的（长）甩负荷动作”等隐患,提高机组的安全性,而且优化后的跳闸电磁阀控制逻辑、长甩负荷逻辑等在后续的1 000 MW机组中得到应用,给国内同种类型的机组提供了参考和借鉴.     

直流保护冗余配置的"三取二"逻辑实现方法比较

目前直流输电工程的直流保护冗余配置一般采用"三取二"方式,但在工程实际中有不同实现方法。论述了"三取二"逻辑的原理特点及其优越性,并从逻辑功能以及实现策略的角度,介绍其在几个直流输电工程中的具体应用。针对直流工程中控制保护逻辑提出了改进建议,可供未来的直流输电工程建设参考。     

Tcl/Tk语言FPGA逻辑IP库实现方法研究

针对FPGA工程应用中逻辑文件版本繁多且不易管理的问题,设计并实现了一种FPGA逻辑文件IP库,将标准的通用和专用FPGA逻辑文件进行分类管理。采用Tcl/Tk脚本语言实现人机交互界面的编写,在逻辑文件使用时进行参数配置和逻辑文件的生成,避免了人为改动逻辑代码而产生的错误,降低了代码重用过程中出错的概率,对FPGA逻辑文件管理和代码标准化有重要意义。编写的人机交互界面使用简单,灵活性强,在FPGA工程开发中具有较大的实际应用价值。     

一种新的模糊控制器设计方法的研究

给出了隶属度函数曲线的矩心和形状系数的定义,提出了一种适合任意隶属度函数且类似于单值隶属度函数的模糊逻辑推理方法以及模糊逻辑推理与去模糊一体化的新方法。这种方法对不同规则的结论无需做单独的合成运算,而是通过简单的解析计算统一实现多规则推理结论的合成与去模糊,使模糊逻辑控制对任意隶属度函数都具有单值隶属度函数去模糊运算的简单性和快速性。