Interactive computer program for planning the expansion of meshed transmission networks

A scheme is described for the interactive development of expansion strategies for transmission networks in which stability and voltage considerations are not of prime importance. According to the planning methodology adopted, the transmission/generation system is to be reinforced when it can no longer feed the peak demand without equipment overload in a single contigency. Outages of generators are considered, as well as the outages of transmission lines and transformers. Generation can be redispatched in order to eliminate overloads. If this is not possible, the model minimizes the load curtailment and identifies the weak parts of the system. It also ranks the possible investments according to their effectiveness in reducing the load curtailment. The planning engineer can build, interactively, several expansion policies by successive investment decisions. The model computes the discounted costs of the various policies developed. The files containing the expansion policies created are also automatically managed by the interactive package.The scheme has been implemented in a package called Tranex which consists of two separate interactive computer programs. An example illustrating the application of the method via this package to the Yugoslav network is given, along with computer performance details and an overview of the program structure.     

Parallel implementation of probabilistic short-circuit analysis bythe Monte Carlo approach

This paper describes the implementation of a Monte Carlo based short-circuit analysis package in a hypercube parallel computer. The program generates accurate estimates of short-circuit current probability distribution curves which can be used in a variety of planning and design studies. Both network modeling aspects, such as network reduced equivalencing and mutual coupling representation, as well as the impact of the sample sizes used in Monte Carlo simulations are fully analyzed and illustrated by numerical results obtained testing on real-world systems, These examples clearly illustrate how computational efficiency in parallel machines varies with the ratio of communication to computation (communication overhead) and of the load balancing among the parallel computer processors     

C.A.E. Software for Transmission Protection System: Puget Power Experience

One major concern of a protection engineer is to achieve successful coordination of all relays in a transmission network. This tedious and laborious process is usually accomplished manually at present. In this paper we present the results of a Computer-Aided Protection System based on our experimentation with the entire 115 kV transmission network of Puget Sound Power and Light Company (Puget Power), which consists of 38 buses and 61 lines. The protection package entails algorithms for both overcurrent and distance relays. Effective man-machine interaction is provided by means of computer-graphics. Such interaction is invaluable in providing the protection engineer with both the details of coordination process and the control over this process. A novel feature of the package is the performance and analysis feature for overcurrent relays. The results for the above system are provided and the execution times for different test cases using an IBM 4341 computer system are also presented.     

配电网可靠性定量评估及成本/效益分析软件包研究

在综合应用配电系统可靠性理论、成本 /效益分析理论、图论以及面向对象的计算机编程技术基础上 ,研究开发了用于定量评估配电网供电可靠性以及进行可靠性成本 /效益分析的软件包系统。介绍了该系统的设计开发思路、软件包工作流程和功能以及有关的主要技术特点等。最后 ,应用该软件包系统对我国某地区中压配电网的供电可靠性进行了定量计算 ,并对为提高可靠性而投入的成本以及所获得的效益进行了分析比较。研究结果可以为电网的规划人员与运行管理人员提供决策依据     

基于地理信息系统的城市电网规划软件包的开发

分析了地理信息系统(GIS)在城市电网规划应用中的特点，开发了一个基于地理信息系统的城市电网规划软件包，并以此为例说明了地理信息在城市电网规划中的应用。介绍了该软件包的总体结构，基本算法和主要实现的功能。该软件包用Delphi开发，界面友好，并提供了专家干预模式，经实例计算表明，本软件包性能稳定，计算迅速，并且充分利用了GIS的特点，使得规划结果更加准确，更加直观，更加实用。     

基于KVM over IP技术的变电站微机监控系统移动工程师站

为了使变电站监控系统软件维护工作不再局限在主控制室内,针对变电站微机监控系统软件维护和故障排查的实际需要,提出利用键盘、显示器、鼠标的KVM over IP技术构建移动工程师站.KVM over IP技术从计算机键盘、显示器、鼠标的接口中获得模拟信号后,转换成数字信息包,并经过加密和压缩,在网络中利用TCP/IP连接进行传输,实现对计算机设备的远程控制.论述了移动工程师站的实现方法、设备接口、网络构建,给出了网络结构图,以及相应的安全机制(访问权限、数据加密、访问控制、信号仿真、网络隔离)等.     

Modeling and analysis of rural electric distribution feeders

The quality of service provided to rural electric customers can be improved with the accurate modeling and analysis of a distribution feeder. With the use of an analysis program developed for a personal computer, it is possible for an engineer to solve existing feeder voltage profile and loss problems and to plan feeder additions that will improve the quality of service to the customers with reduced losses to the cooperative. The authors describe the accurate model of a distribution feeder and its devices that are incorporated into a radial distribution analysis program (RDAP) developed for the personal computer. An example rural distribution feeder is modeled to demonstrate how the program is used to solve typical design and operational problems     

Unit commitment of main transformers for electrified mass rapid transit systems

This paper proposes the transformer planning for an electrified mass rapid transit (MRT) system so that the overall cost of main transformers is minimized over the life cycle. The unit commitment is applied to derive the optimal transformer capacity to meet the annual peak demand and provide reserve for service reliability. The motion equation of train sets is used to derive the dynamic power consumption and travel distance as each time snapshot. The Simulink package is applied to solve the power demand of each train set by the simulation of VVVF inverters and induction motors. The DC/AC load flow analysis is performed to find the annual power loading of traction substations (TSS) and whole Taipei MRT network. The transformer loss, investment, and service reliability are used to define the equivalent cost of all feasible states for each dynamic programming (DP) stage. According to the computer simulation, very significant cost saving is obtained by the proposed methodology for transformer capacity planning of an MRT network.     

改进的模糊层次分析法在配电网规划中的应用

针对配电网规划综合决策中普遍存在的信息不完整和一致性难以满足的问题,改进了基于模糊区间层次分析法的配电网规划辅助决策方法,提出了计及残缺判断的模糊区间层次分析法(FAHP)。在提出的配电网规划整体框架的基础上,结合某个实例介绍了采用该方法进行方案确定的具体实现步骤:先通过FAHP得到主观权值,再对该值进行修正形成可变的综合权重,最后给出方案排序,并设计了相应的计算机递归算法,提高了排序的计算效率。实例计算表明,该方法更符合配电网规划的柔性要求,是一种实用和可行的配电网规划综合决策方法。     

Computer versus Slide Rule

A report is presented on progress and problems encountered in introducing a computer program as an aid in undergraduate teaching rather than as a topic of study per se. A computer-trained engineer differs in outlook from his predecessor reared on the slide rule. These conflicting orientations pose new problems and occasionally supply new fuel to old controversies. Reactions of the administration, of the faculty, and of the engineering student facing the changes are examined. Instructors planning to introduce similar programs, may find it helpful to anticipate these responses and to recognize their motivation. Like other so-called unorthodox teaching methods, the computer program depends for its success as a teaching aid largely on the instructor's ability to develop sound "public relations," solicit constructive criticism, and meet unjustified attacks effectively.     

Calculation of current division in parallel single-conductor powercables for generating station applications

A matrix solution method is presented that enables the engineer to determine the phase current distribution among the individual conductors in parallel single-conductor power cables. Use of a commercial mathematics software package on a desktop MS-DOS personal computer to solve the resulting matrices is illustrated. Results of field measurements on a six-conductor-per-phase cable installation are compared with calculation results. Application of the results to cable assessment activities is discussed, including ampacity verification for increased loads, cable insulation life assessment studies, and cable impedance input into station service system analysis     

工程延误责任研究

工程延误在工程实践中普遍存在，但由于其影响因素多、牵涉面广，使得界定相关各方责任已成为建筑行业中大量诉讼案件和争议的焦点。本文采用原计划网络计划与实际执行网络计划相比较的方法，提出了工程延误责任分摊模型，在比较分析的基础上，即可把工程延误的责任分摊到每个相关工序，然后针对具体工序再分析业主和承包商双方各自应承担的责任。整个模型的分析计算过程建立在一系列公式的基础上，可操作性强，易于编制程序实现。最后，通过一个例子说明了模型的操作运用过程，并对计算结果进行了具体分析。     

江门城区配电网络规划实践和探索

做好配网规划工作,可以为配电网建设和优化提供依据和指引。配网规划应该注重变电站供电范围的分区优化,注重中压线路主网架结构规划和调整,注重变电站间中压线路联络规划,从而增强规划成果的适应性和实用性。介绍了配网规划的工作流程、负荷预测基本原则、配电网的现状评估、计算机辅助配网规划系统应用,最后阐述了江门城区配网规划建设重点,并对规划后效果进行分析。     

电力系统拓朴可观测性和量测量配置的辅助分析

本文提出了一种简便、有效的电力系统可观测性和量测量配置的计算机辅助分析算法。相应的辅助分析软件可以为电力系统调度中心的工作人员在进行电网量测量的合理配置,或者为在远动装置检修、更新时进行量测量的调整补充,提供辅助分析的手段。该方法可以从在线实时数据库获得系统结构,开关状态和量测系统信息,通过网络结线分析和网络可观测生成树分析网络可观测性,保证电力系统状态估计软件的正常运行。     

Numerical computation of fields in electrostatic devices:experience and applications

A computer package developed for the numerical field computation of electrostatic fields is presented. The package is composed of an interactive preprocessor for data definition, a field computation program based on the general purpose field computation code COMPELL, and a program for the interactive analysis of results and postprocessing. It has been devised to simplify as far as possible its management by users not skilled in numerical methods and is provided with a quasiautomatic grid-generation algorithm and a powerful data definition system for advanced users. The package has been field proven with good results on many practical cases, both of scientific and technical interest, and some obtained results are shown and discussed     

基于可靠性成本- 效益分析的电网规划

传统电网规划是以电网的直接投资费用最小为目标来满足一定可靠度的电网规划。电网规划的目的是保证电网的供电可靠性,而没有考虑由于电网的扩展所产生的经济效益,这样规划出的电网并不能获得最佳的社会效益。该文通过引入缺电成本,将可靠性与经济性结合在一起,在此基础上提出了一种新的电网规划成本-效益分析方法与数学模型,该方法将缺电成本作为供电总成本的重要组成部分,并且用缺电成本的大小来衡量可靠性效益的高低,将规划的可靠性成本与可靠性效益统一在对电网的经济性评估上。对规划方案进行了分析和评价,进一步完善了成本-效益分析方     

配电网接线模式研究

在配电网变电站优化布点及网架优化有关理论基础上，进行了配电网规划中接红模式的相关研究，提出了配电网我中配电站布点及其网架和联络线设计的优化模型，着重介绍了高压配电网中的树状接线模式和联络线优化设计方面的研究及其相应程序与基于GS的配电网规划软件包的接口，实现了不同负荷水平变电站布点和网架结构的优化，以及不同变电站故障方式下的联络线的优化，从而配合了整个配电网规划软件包的功以现现，研究是基于高压配电网的，但其所用的算法和方法也适用于其他电压等级的配电网络。     

当前电力体制下考虑需求侧管理的电网规划新思路

电力需求侧管理(DSM)因其能有效调控负荷已成为电力公司的一种常态化工作,这就需要在电网规划中考虑DSM的影响。在电网规划中考虑DSM的影响不仅有利于发挥DSM的作用而且能提高电网规划的经济性。在对传统电网规划和综合资源优化规划分析的基础上提出几点考虑DSM的电网规划新思路,算例验证了提出模型的有效性。     

配电网规划计算分析软件研发与应用

针对目前国内配电网规划人员多依靠人力和经验进行相关分析,缺乏相应的量化分析工具支持的问题,基于供电可靠性的规划理念,采用面向服务的架构体系、组件化设计理念、版本化管理机制以及基于CIM模型的数据交换技术,研发了配电网规划计算分析软件,实现了供电安全分析、可靠性计算、无功优化、经济性评价等核心计算分析功能,为配电网现状分析、规划方案优选及规划成效分析等配电网规划业务提供了数据支撑。该软件从满足国内配电网规划的个性化业务需求出发,实现了利用计算机技术和规划人员的实践经验对不同配电网规划方案进行量化分析。该软件已经在某市的典型区域配电网规划工作中进行了成功应用,显著提升了配电网规划的精确性和有效性。     

开关磁阻电动机自适应有限元计算的实现

本文介绍了一个适用于开关磁阻电动机的自适应有限元软件包,该软件可在PC微机上运行.针对开关磁阻电动机的特点,描述了有限元计算时自动剖分和自适应加密的方法与过程,以及对计算结果的处理.应用该软件可减少用户的工作量,提高计算精度和工作效率.