母线保护原理的现状与发展

母线保护是电力系统继电保护的重要组成部分。本文介绍了母线保护的基本原理,分析了CT饱和对母线保护的影响以及CT饱和的判据。并在此基础上,通过介绍和分析目前国内外关于母线保护的研究现状和存在问题,提出了关于母线保护的研究思路和面临的问题。     

母线保护死区问题的探讨

在母线保护中存在一个死区问题,现在投入运行的母线保护是靠先后切除两段母线上的所有连接元件来解决母线保护的死区问题。由于微机保护的广泛应用,在母线保护中引入大差和小差概念,能比较满意地解决母线保护死区问题。     

母线保护原理及发展前景分析

介绍了母线保护的基本原理,分析了电流互感器（current transformer,CT）饱和对母线保护的影响以及CT饱和的判别原理;在此基础上,通过分析目前国内外关于母线保护的研究现状和存在问题,提出了母线保护的研究思路和所面临的问题。     

华能玉环电厂1000MW机组厂用电系统快速母线保护的分析

对华能玉环电厂厂用电系统6kV母线的结构和母线保护存在问题进行了分析和讨论,论述了装设6kV快速母线保护的必要性及提出目前在玉环电厂应用的一种新的快速母线保护的方案。     

220 kV双母线接线电压互感器配置方式的改进

对当前普遍采用的220kV双母线接线配电装置电压互感器按母线配置存在的问题进行了全面分析，对存在的问题提出了改进建议，并作了经济技术比较。     

6 kV F-C开关爆炸事故原因分析及处理

针对高压厂用母线的保护配置问题,阐述了1起600 MW发电厂厂用6 kVF-C开关爆炸的事故处理经过及6 kV母线装设快速母线保护的必要性.分析了该厂低电压配电系统继电保护存在的问题,提出了快速母线保护方案.实践验证,采用该方案可避免母线事故对设备造成的损坏.     

母线保护死区问题的探讨

在母线保护中存在一个死区问题,现在投入运行的母线保护是靠先后切除两段母线上的所有连接元件来解决母线保护的死区问题.由于微机保护的广泛应用,在母线保护中引入大差和小差概念,能比较满意地解决母线保护死区问题.     

变电站10kv母线保护的分析和研究

对高压变电站10kV母线的保护现状和存在的问题进行了分析,论述了装设10kV母线专用快速保护的必要性和可行性,并提出了两种母线保护的新方案。     

一种网络化10 kV母线快速保护系统的试验分析

利用GOOSE技术组建网络化母线快速保护系统是实现10 kV母线故障快速保护的新方法。基于一个110 kV变电站的10 kV母线快速保护系统试验,对GOOSE通信机制的实时性、快速母线保护逻辑功能、容错功能三个方面进行了系统的分析,并提出了仍存在的三个问题。针对各个问题提出了相应的解决方案,完成了对现有10 kV母线快速保护方案的优化。     

高压变电站10 kV母线保护的分析和研究

对高压变电站10 kV母线的保护现状和存在问题进行了分析和讨论,论述了装设10 kV母线专用快速保护的必要性和可行性,并提出了两种母线保护的新方案.     

Ready to leap to neo-creationism

Like the master puppet makers of the classic folk tales, artificial intelligence (AI) engineers have built some marvelous machines. The first 50 years of AI focused on programming computers to perform tasks that previously only humans could do tasks such as speech, driving, planning, problem solving and vacuuming. The principal challenges have been to create suitable language systems and inference engines and then to more or less manually stuff those with sufficient facts, heuristics and algorithms to perform well-defined tasks. To get there, we need a singularity of artificial neo-creationism, where we launch artificial beings into the world that can adapt, learn and evolve themselves. The term neo-creationism means an intentional effort to populate the world with intelligent entities initially engineered by humans. The biblical story of Genesis, the heart of creationism, provides an apt foil for understanding the goals and scope of the R&D program advocated here. To reach the goal reasonably quickly, we should equip these creatures with as much capability and knowledge as possible.     

使用Winsock控件实现对网络的访问

介绍了在进行网络通信时如何选用TCP／IP协议，并结合实践经验重点描述了用Winsock控件访问网络的client/server程序的设计步骤。用Winsock控件访问网络的方法，系统设置布局合理，软件编程可靠简单，可编写成模块或封装为类模块。最后，给出了2个通用的例程以供参考。     

Using contests to teach design to EE juniors

Most electrical engineering programs have a capstone design course, but lack a suitable design experience in the junior year. This makes the capstone course very difficult for students and compromises its pedagogical aims. A good design experience offers opportunities for learning to identify key operational concepts, to identify and remedy procedural and factual knowledge deficits, and to exercise judgment. The design problem should be open-ended, moderately difficult, and common to all groups. We use a design contest as a vehicle for teaching design in the junior-year analog electronics course, in lieu of conventional laboratories. Students design and build analog circuitry to autonomously control a small robotic vehicle. The contest culminates in a competitive tournament. Students' questionnaire responses indicate that the contest is a useful learning tool, increasing interest in electrical engineering and well worth the time spent. They indicate that contests are preferable to conventional labs for learning and understanding course material, for motivating them, and for providing an engineering experience     

适用主动配电网的差动保护方案研究

为了解决主动配电网双向潮流对电缆型配电网保护影响,分析了DER接入电缆型配电网对保护带来的问题,提出了适用于主动配电网的差动保护方案。差动保护方案配置集中式线路差动与就地式母线差动保护,适用于电缆线路的配电自动化。DTU采用内置以太网通信技术,采用专用光纤通道"手拉手"连接。基于光纤通道实现DTU数据同步,DTU进出电流传输至集中式差动保护装置,由集中式差动保护装置实现配电网线路保护,DTU就地实现环网柜母线保护,能很好地满足电缆线路ADN接入DG对保护的要求。设计开发了相应的DTU及集中式差动保护装置,应用在实际的电缆线路ADN系统,具有很好的应用前景。     

电压稳定裕度对参数灵敏度求解的新方法

针对与鞍结分岔相关的电压稳定裕度对参数的灵敏度计算问题，该文提出了一种解线性方程组求灵敏度的新方法。与以往方法不同的是：该方法无需求解鞍结分岔点处潮流雅可比矩阵零特征值对应的左特征向量，而只需求解一个左端系数阵为扩展潮流雅可比矩阵的线性方程组。由于避免了左特征向量的迭代求解，因此该方法简单实用，计算量小，适于在线静态电压稳定分析的使用。另外文中还对另一种普遍存在的分岔形式--限值诱导分岔的特点与灵敏度计算作了探讨。在EPRI 1000母线系统算例下的计算表明，本文方法切实可行并具有较高的精度。     

Criteria to estimate the voltage unbalances due to high-speedrailway demands

This paper has presented simple criteria to estimate the voltage unbalances due to high-speed railway demands that are generally single-phase loads. Feeding traction loads from the public power system may lead to some voltage unbalance on the latter and consequently affect the operation of its energy supply system and other equipments connected with it. Three transformer connection schemes that are commonly used in power supply systems for high-speed railways are discussed and compared. The estimating criteria have been derived and represented by simple formulae that can be easily applied to evaluate this voltage unbalance. The results are of value to related engineers and consultants especially during periods of planning and design     

A probabilistic approach to determining generation equivalence to atransmission facility

The electricity transmission system will be planned, operated and maintained by an independent transmission administrator in the new electric industry structure. The primary objective of any electricity transmission system administrator in the new competitive environment would be to increase the market value of the services it provides with the right amount of reliability and, at the same time, lower its costs for operation, maintenance and construction of new facilities in order to provide lower rates for customers. The electricity transmission administrator will strive to achieve this objective via many different means, one of which is to defer capital transmission facility requirements in favor of a generation solution by an independent generator to meet the growing customer load demand. In this case, the transmission capital investment deferral credit received by the independent generator will be dependent on the incremental system reliability improvement rendered by the transmission solution. In other words, the size, location and the reliability of the independent generator will be based on comparable incremental reliability provided by the transmission solution under consideration. This paper presents a probabilistic technique for determining generation equivalence to a transmission facility for use in transmission system planning studies in the new competitive environment     

用PCM传来电显示信号

以NEC PCM设备为例，介绍了来电显示信号的传输原理，并探讨了利用PCM设备传送来电显示信号的几种方法。     

Voyage to safety

The power requirements on modern marine vessels are increasing. Many of the loads are changing from mechanical to electrical, and the propulsion systems are becoming all electric. Traditional low-voltage (LV) 480-V systems do not have the ratings to handle these large power requirements. Power will have to be generated at higher voltages, typically 4,160 V, 6,600 V, or above. These voltages must have medium-voltage (MV)-rated switchgear. Presently, commercial marine standards call for off-the-shelf-type switchgear. MV switchgear is not common in today's marine industry. The isolation of being in open waters demands that the personnel on board perform some maintenance and repair to the switchgear to keep the vessel operating. The inexperience of the personnel on such equipment can be life threatening if the proper safety devices are not provided. Focus must be placed on the operation, repair, and maintenance of MV marine switchboards and the variables that differentiate it from land-based applications. This article reviews effective apparatuses that would enhance safe operation and maintenance if installed in commercial off-the-shelf MV switchgear. Some of the apparatuses to be considered are remote controls, arc-resistant switchgear, glow tubes, earthing switches, ground-and-test (G&T) devices, and remote electric racking.     

Open to growth

A CONTRACTING economy may be bad news for many business sectors, but it could provide a fillip for the fortunes of the opensource software (OSS) ideal, in two key areas. First, the opensource 'community' has reached a maturity point where its proponents are able to make a credible case for its ability to support both enterprise-class operating environments and personal productivity tools. Second, with IT initiatives increasingly having to demonstrate cost efficiencies in order to see proposals approved, the savings that OSS delivers mean it is making inroads into organisations of all sizes.