Java-based graphical user interface for the MRUI quantitation package

This article describes the Java-based version of the magnetic resonance user interface (MRUI) quantitation package. This package allows MR spectroscopists to easily perform time-domain analysis of in vivo MR spectroscopy data. We show that the Java programming language is very well suited for developing highly interactive graphical software applications such as the MRUI software. We have also established that MR quantitation algorithms, programmed in other languages, can easily be embedded into the Java-based MRUI by using the Java native interface (JNI). This new graphical user interface (GUI) has been conceived for the processing of large data sets and uses prior knowledge data-bases to make interactive quantitation algorithms more userfriendly.     

A case-based Windows graphic package for the education and trainingof power system restoration

This paper presents a case-based Windows graphic package developed by the authors for the education and training of power system restoration. In order to overcome the inherent complexities associated with a restoration switching sequence, a case-based reasoning (CBR) algorithm has been developed. An object-oriented Windows-based graphical user interface (GUI) has been developed to communicate with the expert system and to visualize outputs. Simulation results on a part of the Saskatchewan Power (SaskPower) network have been presented in this paper. The restoration practices of SaskPower network have been collected and stored in a knowledge database called case library. The power flow and the implementation risk analysis tools have been incorporated into the expert system. A risk analysis tool has been used to determine the implementation risk due to the imperfect switching actions. Using the GUI, a user can simulate a blackout event on the system under study. The expert system proposes a restoration proposal after reasoning with the past solutions available in the case library. Using the power flow analysis tool, the user can check the system scenarios after the restoration proposal is implemented     

A new distance relaying algorithm based on complex differential equation for symmetrical components

This paper presents a new digital impedance measuring technique for transmission lines that combines symmetrical components and the complex differential equation of an equivalent fault loop circuit. The phase voltages and currents at the relaying point are transformed into symmetrical components using Fourier filters of short window length. Depending on fault type, an appropriate fault loop circuit is formed, signals of which are the appropriate symmetrical components, while a parameter of which is the positive sequence impedance being a geometrical measure of the distance from the relaying point to a fault. The impedance, however, is measured very fast by on-line solving the complex differential equation originated for this fault loop circuit. Consequently, this approach combines frequency domain estimation of symmetrical components (accurate filtration) and time domain measurement of positive sequence impedance (high speed response).

The presented method suits well the protection of parallel lines against high-resistance faults occurring very close to the far end of a line. A new method is proposed for detecting high-resistance faults and deciding which line out of two parallel lines actually suffers a fault.

The included EMTP test results demonstrate the efficiency of the proposed relaying algorithm.     

A Windows based GUI software tool for system protection simulationsin PC environment

A graphical Windows based software tool to facilitate the analysis and training of system protection is presented in this paper. This tool is developed using Microsoft^R Visual Basic for the Windows Environment. This software package contains two components: CONFIG and DEMO. CONFIG is a user knowledge database. It is used by experienced protection engineers to create a comprehensive database for the inexperienced protection engineers. DEMO is used by the inexperienced protection engineers. DEMO can access the database created in the CONFIG, but DEMO cannot modify the database. CONFIG and DEMO have similar GUI features. Through DEMO the engineers can simulate and study the system protection. In order to effectively link the protective device settings and the fault with corresponding circuit responses, a new number system conversion algorithm is also introduced     

一种基于对称PCB结构的GaN器件高带宽电流检测方法

针对氮化镓器件高频开关动作,开关电流难以准确测量的难题,提出了一种基于对称印制电路板结构的高带宽电流检测方法.该方法利用电流分流器原理检测氮化镓器件电流,基于磁感应原理对印制电路板进行了优化设计,通过控制电流在印制电路板上的流通路径,使分流电阻的寄生电感部分被抵消,并配合适当的补偿网络和前置放大器,实现在宽频带测量范围...     

基于WINDOWS的油库监测系统

介绍了一种基于Ｗｉｎｄｏｗｓ的油库监测系统。系统适用于８个油罐以下的油库,可实时显示油位、温度的状态和数值。     

A PC based software package for the equal area criterion of powersystem transient stability

This paper presents features and applications of an interactive graphical PC (DOS based) software package for the comprehension of transient stability using the equal area criterion method. The software is specifically useful for senior level undergraduate and first year graduate students in power system analysis courses. Utility engineers working with large-scale power systems can learn some basic concepts of transient stability by simulating the single machine infinite bus power system. A distinctive feature of this package is the user-friendly method for problem definition. Problems are defined by selecting options from menus without typical editor-like entry approach, used in other mathematical software, which normally have their own strict syntax     

A computer-aided teaching package for microprocessor systemseducation

A computer-aided teaching (CAT) package for use in a microprocessor systems course is described. It uses the Z80 CPU as the basis for describing how an eight-bit CPU functions internally and as the master of a microcomputer system. The package, which consists of an assembler and a graphics simulator, aids as a powerful teaching tool that enables the student to learn about the internal architecture of a microprocessor as applied to the Z80 CPU and its instruction set with a step-by-step graphics animation of the instruction execution and timing. The package allows the user to execute a program step by step and to test the operation of the internal registers, buses, and memory contents at every clock edge. It also simulates read/write cycles from/to memory and input-output devices. Finally, it allows the user to write and debug problems at the assembly language or machine code level. The package is menu driven, interactive, flexible, and user-friendly     

基于RCP封装的芯片模型电热模拟

基于集成电路重分布封装技术(redistributed chip packaging,RCP)的发展,通过提取芯片封装体的具体参数,建立并优化了RCP芯片的热学模型。采用有限元的方法计算了该模型在一定热耗散功率下,施加不同风速条件时的温度分布情况,结果表明:强制对流条件的施加显著增强了RCP芯片封装体的散热能力,4m/s的风速可使其系统热阻降低58%,但是随着风速的增大,其影响不断减弱。所得出的具体风速与芯片结温的关系,可为RCP封装技术的散热设计提供有价值的参考。     

基于小波包变换的电能质量调节系统的数据处理

针对配电网电源侧电能综合调节系统(Active Power Line Conditioner-APLC)的功能要求,基于小波理论设计了APLC的数据处理系统.针对实时补偿检测中存在的时延问题,提出了基于小波变换的递推式预测检测方法,利用该检测系统获取的补偿指令信号可有效地解决时延问题.另外,数据的分析中,针对电能质量采集数据频带宽、数据存储量大的特点,在应用小波包变化数据进行就地分析时对存储数据进行了有效压缩,节省了大量的存储空间.仿真结果证实了所设计系统的有效性和可行性.该研究为配电源侧电能质量的分析和调节提供了一种良好的检测手段.     

基于小波包变换的电能质量调节系统的数据处理

针对配电网电源侧电能综合调节系统(ActivePowerLineConditioner-APLC)的功能要求,基于小波理论设计了APLC的数据处理系统。针对实时补偿检测中存在的时延问题,提出了基于小波变换的递推式预测检测方法,利用该检测系统获取的补偿指令信号可有效地解决时延问题。另外,数据的分析中,针对电能质量采集数据频带宽、数据存储量大的特点,在应用小波包变化数据进行就地分析时对存储数据进行了有效压缩,节省了大量的存储空间。仿真结果证实了所设计系统的有效性和可行性。该研究为配电源侧电能质量的分析和调节提供了一种良好的检测手段。     

A graphical electromagnetic simulation laboratory for power systemsengineering programs

The recent availability of Electromagnetic Transient Programs with graphical front ends now makes it possible to put together models for circuits and systems in a manner similar to the connection of components in a laboratory, In the past, the nongraphical EMT Programs required considerable expertise in their use and thus distracted the students into the details of simulation. The introduction of a graphical simulation based laboratory into undergraduate and graduate power engineering education programs is presented, based on the PSCAD/EMTDC program. The philosophy behind the design of suitable example cases is presented within the framework of an Undergraduate Power Electronics Course, an HVDC Transmission Course and a course on Power System Protection     

基于Windows CE的嵌入式GIS设计与应用

以Windows CE为操作系统,eVC为开发环境,结合eSuperMap相关工具,介绍了手持终端的嵌入式GIS开发;主要分析了嵌入式GIS的开发流程和相应的关键技术,具体涉及到WindowsCE软件开发环境的建立,电子地图的制作,GIS应用程序的开发3个方面;详细介绍了应用程序的整体架构以及eSuperMap类库在eVC中的具体运用,包括eSuperMap类库的结构分析、点按动作的实现、地图操作具体流程、GPS信息管理以及最短路径算法优化等。     

基于Fast-ICA和对称正交化的谐波检测

提出一种基于Fast-ICA和对称正交化的电能质量谐波检测方法。在简要介绍独立成分分析方法的基础上,把多次谐波信号看作多个独立成分的线性组合,采用基于负熵极大独立性准则的Fast-ICA算法实现一个独立成分的估计。再利用对称正交化方法实现多个独立成分的并行估计,分别分离出基波信号、各次谐波信号和噪声信号,以实现对谐波的检测。仿真结果表明,该方法可较准确地检测出各次谐波成分的频率和幅值且对噪声不敏感,与基于渐进正交化的Fast-ICA算法相比,该方法具有更高的检测精度和更快的收敛速度。     

A MATLAB-based graphical technique for amortization study ofadjustable speed drives

Economic justification of electric drives is the primary reason for many applications. However, the cumbersome trial-and-error calculations necessary to present this aspect often leads to omission of the topic in electric drives courses. This paper presents a MATLAB-based program that generates plots of input power and shaft torque for variable-frequency operation of three-phase induction motors. Based on these graphs, an example is presented illustrating how a cost amortization study for an adjustable speed drive application can be presented with minimal effort and lecture time     

智能变电站中基于CAD的图形化模型设计软件开发方案

提出由设计院完成智能变电站模型和站内数据流的设计,做到站内数据源统一且唯一.为实现该设计方式,同时简化设计人员工作,制定了图形化模型设计软件的开发方案.方案采用AutoCAD的ActiveX Automation 技术进行二次开发,软件分为图形编辑模块和模型编辑模块,将IEC61850模型文件与CAD图形相关联,在CAD的图块中增加建模所需的扩展属性,通过XML数据库在模型文本和图形文件间交换模型信息,以提高访问和搜索模型的速度.使用绘图加定义属性值的方式最终完成图纸和模型的双重设计.     

A flexible graphical user interface for embedding heterogeneousneural network simulators

A graphical user interface (GUI) for heterogeneous neural network simulators proposed in this article is intended to be of use both for the novice and for the experienced neural network user. For the novice, it provides an easy-to-use neural network simulation package that insulates the user from the requirements of knowing the simulator implementation details or the configuration file syntax. For the experienced neural network professional it provides an interface that is easily extensible to include any additional neural network simulator in its binary form. To satisfy both academic and personal computer environments, the GUI has been developed by using the free TCL/TK software package, available on workstations running Unix and on PCs running the free Linux operating system. Although the GUI and the embedded simulators have been successfully tested both in neural network research and training programs, a more extensive testing in undergraduate and graduate level classes is in progress     

基于图形化界面的配电网随机潮流仿真

利用具有图形化界面的PSCAD/EMTDC软件,建立了基于蒙特卡洛法的配网随机潮流的仿真模型。利用PSCAD软件中随机数产生模块和数学计算元件构成累积分布反函数模块,产生按照某种特定分布的随机数,称为"伪随机数"。同时,利用PI环节控制电源的功角,使之跟踪输出伪随机数模块生成的随机功率。该模型能模拟各种概率分布的随机电源,仿真复杂拓扑结构的配电网潮流,并满足快速计算要求。IEEE9节点系统的仿真统计结果,证明了仿真模型的正确性。     

Windows CE下蓝牙协议栈驱动的实现

文中介绍了如何在WindowsCE下以驱动程序的形式编写蓝牙协议栈进行了设计与实现。文章对流接口模型中的接口及接口间关系进行了定义与说明,并重点介绍了子模块间相互关系、数据结构以及应用程序模块和接口间的对应关系,指出了程序的测试跟踪方法,最后对多层驱动模式的扩展与升级进行了思考。