Wyes and wye nots of three-phase distribution transformerconnections

The advantages and disadvantages of various three-phase transformer connections are summarized. Recommendations are provided regarding the standard types of connections a utility should offer for various service requirements. Warehousing costs, ferroresonance, neutral grounding, core construction, overvoltages, unbalanced loading, zero sequence source, and through faults are considered. Emphasis is placed on the exchange of information between customer and utility. An Application for Three-Phase Service form is provided. It can be used to determine service requirements including voltage, grounded, ungrounded, three-phase load, single-phase load, motor characteristics, and fault current interruption rating of secondary breakers and switchgear. Suggestions on utility-supplied information such as maximum available three-phase and line-to-ground fault currents and a discussion of the operation of ungrounded systems are also provided     

Quantifying Reliability and Service Quality for Distribution Systems

Reliability indices for distribution systems are used by utilities and regulators to benchmark performance and prioritize investments in projects to improve performance. However, there can be many variations in the methods used to describe reliability levels, and the indices used may not be the best measures of system performance in terms of the impacts on customers. This paper describes the concept of a "service quality index" that can be used to characterize system performance in a manner that is more appropriate for customers, taking into account customer quality and reliability requirements and expectations     

Information Service Architecture for International Multimodal Logistic Corridor

This paper describes how an information service architecture was developed for the international multimodal logistic corridor Pol-Corridor. It describes how the information services needed by Pol-Corridor were identified and how these service needs were transformed into system component requirements. An analysis was carried out to investigate how existing off-the-shelf and already-operational systems can fulfil these information needs by ldquomappingrdquo several information systems into the service architecture. The theory and trends in the research of software architectures are discussed in order to explain the foundation for defining the service architecture for Pol-Corridor. European Union policies concerning interoperability of technical systems in international transport, as well as their efficiency, are also discussed in this paper.     

电网GIS空间信息服务平台设计与实现

随着电网企业信息化建设的发展和深化,对建设高效、智能化电网提出更高的要求。电网GIS空间信息服务平台实现电网资源的图形化展现与结构化管理,提高电网企业的生产、管理水平。文章分析了电网GIS空间信息服务平台设计与实施的关键技术,深入研究该平台与其他业务应用系统之间的集成技术,实现输、变、配电网的设备空间信息管理,提高了电网企业空间图形化综合管理水平,具有广阔的应用前景。     

电力企业智能营业厅综合服务平台设计

以提升电力企业营销服务水平为目的,根据智能用电服务体系建设要求, 依托电力企业现有营销业务信息化以及当前主流的流媒体技术、海量数据存储技术、智能分析技术等,建设了电力企业智能营业厅综合服务平台,实现对营业网点的服务质量监控,推进了电力企业营销管理方式的转变。     

Issues of standardizing requirements for resistance and strength of railroad automation and signaling systems used in high-speed railways versus external mechanical impact

We discuss the problems of adaptation of requirements for resistance and strength versus external mechanical impact for railroad automation and signaling systems used for Russian high-speed railways. We present an analysis of the requirements and test methods for resistance and strength versus external mechanical impact for railway railroad automation and signaling systems in the current Russian standards. Based on the classification of automation and signaling equipment, the requirements and tests are compared to the similar ones of the European standards used for the design of high-speed railway railroad automation and signaling systems. It is proven necessary to change the mechanical strength requirements imposed by Russian standards in the design of railway railroad automation and signaling systems. We considered the possibility of adaptation of requirements and test methods for railroad automation and signaling systems in the present Russian standards to the problems of design of high-speed railway equipment. In this paper, we provide recommendations for designers on how to select the requirements for resistance and strength versus external mechanical impact and test methods for railroad automation and signaling systems used in high-speed railways.     

Monitoring frequency control in the Turkish power system

Frequency control is a key ancillary service for the secure and reliable operation of power systems, and especially in isolated power systems such as Turkey which is not yet synchronously connected to the UCTE European system. Frequency control has been defined in the Turkish power system as a mandatory remunerable ancillary service that is provided by generating units and managed by the system operator. This paper develops a centralized monitoring system of frequency that informs the System Operator if the generating units comply with the technical requirements of the Turkish Grid Code. The system consists of a reference model that validates the real operation of the primary and secondary regulation of the generating units comparing it with the desired behavior established by the technical requirements of the Turkish Grid Code. A number of quantitative measures, based on the deviation between the real and the desired response are proposed to evaluate the adequacy of each unit behavior. Application examples of the proposed monitoring system of frequency control are provided using real data of different Turkish power plants.     

Internet在电力市场中的应用

首先简要论述了在电力市场环境下为确保电力系统的安全、可靠运行而对信息的要求，阐明了信息系统应该具有的特征与功能，指出了Internet是理想的解决办法。之后，介绍了与Internet相关的一些事务，重点放在如何保征Internet的性能和安全性方面。在此基础上，概述了电力市场中Internet的应用现状，介绍了Internet应用的一个重要分支(即Web服务方面)的研究与技术进展情况及其可能对将来Internet在电力市场中的应用所带来的影响。最后，介绍了应用服务提供者模型并展望了其在电力市场中广阔的应用前景。     

电力网格体系初探:（二）电力网格体系结构

在分析电网现有调度自动化系统结构特点的基础上,提出了既符合互联电网运行特点,又满足新一代调度自动化系统实际需求的高可用和可扩展的电力网格体系结构,确定了电力网格的服务层次,对网格基础服务、电网应用服务进行了有效的划分和组合,为进一步构建电力网格示范系统勾绘了蓝图。     

基于5G通信的继电保护技术研究

为应对电力系统现有通信信道故障定位困难和长距离通信可靠性不足等难题,基于继电保护通信性能要求,从报文格式、带宽需求、传输延时、通信架构、安全性和数据同步技术等方面探讨了5G通信在继电保护中应用的可行性.进一步地,明确基于5G通信的纵联保护在配电系统中应用的优越性和在中高压电力系统中应用时基于网络结构和转发协议的优化方向...     

一种应用于智能变电站和调度主站之间的通信映射方法

随着智能电网建设的深入推进,主站和变电站间模型及信息共享要求剧增,而目前子站与主站间的常用通信规约已无法满足通信的需求。提出了一种实时服务通信协议,它以IEC61850为基础,在特定通信服务映射开放性的基础上,直接将抽象通信服务接口(ACSI)映射到TCP/IP通信协议栈,构建适应于智能电网建设需要的通信规约,满足智能变电站与主站间无缝通信要求。同时还提出了相关模型的转换方法及校验方法。     

Electric Motor Vibration-Cause, Prevention, and Cure

The trend of industry toward higher speed machines and longer periods between downtimes has fostered closer surveillance of those parameters that can interrupt satisfactory service. Vibration of electric motors and systems containing motors are areas identified for consideration. Electric motor vibration is discussed from the viewpoint of its causes and cures. Also covered are the important considerations in establishing purchase specifications consistent with final installation requirements.     

Some Significant Effects of the New National Electrical Code on Our Industries

The increased concern for human safety is one of several factors which makes the National Electrical Code increasingly important to engineers involved in plant electrical systems. New requirements are extending into areas not previously covered by the Code. This paper discusses some selected major changes which are of most interest to industries using large amounts of power, and some changes which are apt to be controversial. Included are: ground-fault protection, service entrance arrangements, autotransformers, transformer primary and secondary protection, separately-derived systems, and new product possibilities.     

Considerations of Ground Fault Protection as Influenced by the Occupational Safety and Health Act and the Mining Enforcement and Safety Administration

The first step in recognizing the necessity of low voltage ground fault protection was taken by the 1971 National Electrical Code (NEC), Section 230-95. With the passage of the Occupational Safety and Health Act (OSHA) of 1970, more emphasis has been placed on adherence to the code. Since the establishment of OSHA, questions have been raised as to the jurisdiction between the Occupational Safety and Health Administration and the Mining Enforcement and Safety Administration (MESA). This has resulted in both agencies considering and deciding on design standards for cement plant electrical systems. Indications are that in the future, MESA standards will also recognize the necessity of adequate ground fault protection. Since the introduction of ground fault protection in the codes, there have been arguments for and against the methods of applying ground fault protection. It is for this reason that the present code requirements are minimal. In order to provide the electrical service reliability required by modern cement plants, more extensive protection is required. The intent of this paper is to evaluate the new requirements of ground fault protection. It also examines how we, as engineers concerned with electrical power systems in cement plants, approach the problems of providing safe reliable electrical systems which meet applicable code requirements and which also function satisfactorily in relation to plant operation.     

基于Web服务的电力企业实时信息应用集成

分析了电力企业实时应用各异构系统间难以共享信息的现状.基于Web服务技术设计了能提供业务服务、应用服务、客户服务和编制服务等多种服务的标准化的松耦合的一体化电力实时信息应用集成框架,应用Web服务提供通用基础架构支持,使用基于知识库的编制服务实现SCADA、EMS、DMS等实时应用系统间的实时信息互通和互操作.集成框架...     

Trust and Security in RFID-Based Product Authentication Systems

Product authentication is needed to detect counterfeit products and to prevent them from entering the distribution channels of genuine products. Security is a critical property of product authentication systems. In this paper, we study trust and security in RFID-based product authentication systems. We first present a formal definition for product authentication process and then derive the general chain of trust as well as functional and nonfunctional security requirements for product authentication. Most of the scientific literature that covers the topic focuses on cryptographic tag authentication only. This paper, however, provides a broader view including also other known approaches, most notably location-based authentication. To derive the functional security requirements, we employ the concept of misuse cases that extends the use case paradigm well known in the field of requirements engineering. We argue that the level of security of any RFID-based product authentication application is determined by how it fulfills the derived set of functional and nonfunctional requirements. The security of different RFID-based product authentication approaches is analyzed. To study how RFID supports secure product authentication in practice, we investigate how the current EPC standards conform to the functional security requirements of product authentication and show how the unaddressed requirements could be fulfilled. The benefits of implementing a service that detects the cloned tags in the level of the network's core services are identified.     

矩形多跳蜂窝结构及其容量分析

为满足用户数量及数据速率增加对传统蜂窝小区提出的覆盖及容量增加的要求,文中分析多跳通信模式的基础上,提出矩形蜂窝结构。此结构提供在低成本条件下完成区域覆盖及提高系统容量的方法。它将基站的容量提高大约1/3,从而可以在一定系统成本的基础上提高系统收益。     

电力系统继电保护及故障信息子站系统的方案设计

电力系统继电保护及故障信息子站系统,既可以作为构成继电保护及故障信息管理系统的(配置在变电站端的)子系统,同时也可以作为一个独立的“通信网关”供其它层次化的电力自动化系统使用。该系统根据IEC 61850标准中的“信息模型”和“抽象通讯服务接口”的概念设计,采用OMG的分布式系统标准和技术实现,使得PRFIS子站系统完全可以满足以分布式系统体系构建的继电保护及故障信息系统要求。     

Service-life evaluations of low-voltage power circuit breakers andmolded-case circuit breakers

This paper summarizes the methods that are typically used in industry to evaluate the service life of low-voltage power circuit breakers and molded-case circuit breakers. It reviews the electrical ratings and endurance requirements set forth in manufacturing standards, the ways that these endurance requirements can be used to develop expectations of circuit breaker life, the methods of maintenance inspections, and the interpretations of these inspections     

ACC radar sensor technology, test requirements, and test solutions

This paper presents an overview of the radar sensor technology used in adaptive cruise control (ACC) applications. The performance tradeoffs of the different modulation schemes and scanning antenna types used by these radar sensors are discussed. The test requirements of these millimeter wave radar sensors during production, installation on a vehicle, and during after-market service are also discussed. Different test methods used for characterizing and aligning these radar sensors are presented.