浅析500 kV系统中3/2接线方式线路重合闸

500 kV超高压电力系统为保障供电可靠性,大部分采用3/2接线方式,突出问题是断路器保护与自动重合闸装置的配合。根据3/2接线方式较为灵活的特点,利用3/2接线断路器保护自身原理及重合闸装置重合原则,找出其共同点,并结合500 kV变电站的运行和工作实际,分析论证线路重合闸有关问题,给出了3/2接线断路器重合闸的保护配合方法,对优化运行操作、提高系统运行稳定性和可靠性提供帮助。     

浅析500kV系统中3/2接线方式线路重合闸

500 kV超高压电力系统为保障供电可靠性,大部分采用3/2接线方式,突出问题是断路器保护与自动重合闸装置的配合.根据3/2接线方式较为灵活的特点,利用3/2接线断路器保护自身原理及重合闸装置重合原则,找出其共同点,并结合500 kV变电站的运行和工作实际,分析论证线路重合闸有关问题,给出了3/2接线断路器重合闸的保护配合方法,对优化运行操作、提高系统运行稳定性和可靠性提供帮助.     

浅谈断路器失灵保护

主要介绍断路器失灵保护的工作原理,从3/2断路器接线方式和双母线接线方式两种接线方式分析比较和总结断路器失灵保护的工作原理及其运行注意事项。     

500 kV变电站220 kV接线采用3/2断路器和双母线分段方案的综合比较

上海一些老的 5 0 0 k V接变电站的 2 2 0 k V线方式均为双母线分段带旁路接线 ,而新建 5 0 0k V变电站则采用了 3/2断路器接线方式 ,并已投入运行。这两类接线方式均在实际运行中得到了考验 ,笔者从技术经济方面以及实际建设和运行中所遇到的问题做一个综合比较。1　两种接线方式的比较对于同为 8元件 (线路或变压器的 2 2 0 k V系统 ,图 1为 3/2断路器方式 ,图 2为双母线 4分段带旁路方式。图 1　 3/2断路器接线　　　　图 2双母线分段带旁路接线1 .1　供电可靠性比较 (表 1 )表 1　供电可靠性 (故障停电范围 )比较 %故障情况 3/2断路器…     

3/2断路器接线的运行分析及保护配置

目前,我国绝大多数500 kV变电所采用3/2断路器接线。其突出的优点是:供电可靠性高;运行方式多样、灵活;断路器拒跳的后果不特别严重,任意一条母线故障不影响线路或主变的运行;隔离开关操作简单,降低了误操作的几率。3/2断路器接线方式的一个显著特点是线路比母线重要,由此带来的保护配置不同于常规的双母线接线方式。     

电流互感器切换部件防误操作改进

1 3/2接线方式的特点及电流互感器的作用 　　在3/2接线方式运行时,须由2台断路器合闸对线路或主变单元进行供电.以500kV一次接线为例,如图1所示,线路XL或主变ZB由1DL与2DL或2DL与3DL断路器同时合闸来供电,此时2个断路器上将同时流过线路或主变电流.为了正确反映线路或主变实际流过的电流,必须将对应供电断路器上的电流互感器(以下简称CT)二次回路采用“和电流“的接线方式.这样接线的优点是,当某一断路器需要检修时,可以将该断路器退出运行,而不影响对线路或主变的连续供电,提高了电网的稳定性能,但同时给检修操作提出了更高的要求.……     

1000kV变电站电气主接线研究

通过对比双断路器接线及3/2断路器接线形式,并引入GO法对双断路器接线与3/2断路器接线进行可靠性研究后,推荐1 000kV主接线采用3/2断路器接线。     

变电运行倒闸操作顺序分析

通过包头地区电网变电运行实例,分析了常规变电站单出线停、送电,主变压器低压侧及双电源变电站倒电源等的倒闸操作顺序,对可能由于操作顺序引发的带负荷拉隔离开关的操作提出优化操作方案;对500 kV3/2接线方式的变电站3/2断路器、母线侧断路器及中间断路器接线方式的倒闸操作顺序进行了关键点和危险点分析和探讨,提出了优化合理的操作步骤。为规范变电运行倒闸操作顺序,减少误操作提供经验。     

500kV非典型断路器接线的母线保护接线设计

500 kV变电站典型接线为3/2断路器接线,2段母线,其保护方案及接线均为标准化设计。某500 kV变电站扩建中受多个因素限制,形成非典型3/2断路器及4段母线的接线形式。针对该非典型的500 kV母线接线,分析并提出相应的母线保护设计方案及接线方案,保证电网的安全运行。     

对500kV继保配置与二次回路的改进建议

华东电网500kV升压站和变电站大都采用3/2断路器接线。3/2断路器接线,运行方式灵活。当一个断路器停役,出线(包括线路、主变)可以通过另一个断路器供电,停役断路器可以检修,而出线保护不能停用。当出线停役,在线路隔离开关拉开后,出线所对应的两个断路器可以合上,作为联络断路器用,出线可以检修,而保护除PT     

一相开路双三相永磁同步电机建模与控制

根据一相开路故障状态下四种不同的中线连接方式以及相应的电流约束条件,采用矢量空间解耦的建模方法,确定了不同的坐标变换阵,建立了一相开路双三相永磁同步电机的数学模型。每一个模型都被分别映射到参与机电能量转换的d-q子空间和与机电能量转换无关的z1-z2-z3子空间中,各模型在d-q子空间的方程具有相同的结构形式和不同的系数矩阵。通过将z1-z2-z3子空间的电流给定值设为零,就可以得到各种连接方式下的定子铜耗最小矢量控制策略。仿真与实验结果表明,电机在各种连接方式下缺相运转正常,从而有效提高了整个系统的容错能力。     

三相异步电动机电源反接制动的数值仿真方法

利用MATLAB软件中的动态仿真工具SIMULINK ,构造了三相异步电动机电源反接制动的仿真模型 ,通过实例仿真证明了该方法的有效性     

Unconventional CT and VT connections and how to get them right

This paper describes current and voltage instrument transformer connections that are not physically conventionally connected as portrayed in ANSI Standards and Guides or relay manufacturers' literature. A three-line diagram of basic conventional current transformer connections for a two-winding-delta wye power transformer differential relaying is presented. The unconventional scenarios presented are: 1) one set of current transformers (CTs) being reversed or "rolled out"; 2) the other set reversed; and 3) both sets reversed from the conventional connection. Proper connection of these unconventional connected CTs is then explained. Also, the effect of reversed voltage transformer (VT) connections on directional overcurrent and directional power relay elements is presented. An example of how symmetrical component metering screens of a numeric relay were used to diagnose an incorrect VT connection is also presented. This paper is a primer on analyzing unconventional instrument transformer polarity connections and how to obtain the right connection to achieve the desired direction of operation or polarity as indicated in protective relay manufacturers' literature.     

Effects of winding connections on characteristics of a five‐phase stepping motor

A method for calculating the single‐step response of five‐phase hybrid stepping motors is obtained. The effects of winding connecting methods—(1) star‐bipolar SB, (2) pentagon PD, and (3) new pentagon NP—on the single‐step response are investigated. By application of the above calculation method, the continuous rotating characteristics are studied. It is found that the maximum slewing pulse rate of NP is higher than that of SB and PD connections, and that the variation of the rotor speed at high speed with the SB and PD connections is larger than that with the NP connection. The effects of the current waveform on the oscillation characteristics and relations between the current waveform and the winding connections are investigated. © 2001 Scripta Technica, Electr Eng Jpn, 136(1): 47–56, 2001     

Active device‐less voltage equalization charger using capacitors,diodes, and an AC power source

Conventional cell/module voltage equalizers or equalization chargers based on traditional DC‐DC converters require numerous switches or transformers as the number of series connections increases; therefore, their cost and complexity tend to increase and their reliability decreases as the number of connections increases. This paper proposes a novel voltage equalization charger that consists only of passive components such as capacitors, diodes, and a transformer. The fundamental operating principle, major features, and derivation of equivalent DC circuits are presented. A symmetrical configuration is also proposed to mitigate the RMS current flowing through energy storage cells in the charging process. Simulations and experimental charging and cycle tests were performed on series‐connected electric double‐layer capacitor modules to demonstrate the equalization performance. The experimental and simulation results were in good agreement, and the voltage imbalances were gradually eliminated as time elapsed even during charge‐discharge cycling. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(3): 39‐48, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21288     

245～550kV户外超高压新型组合电器

对ABB公司、阿尔斯通公司、三菱公司、西门子公司等生产的245-550kV户外超高压新型组合电器进行了较详尽地介绍和分析,主要是：①基本结构及特点;②主要技术参数;③适用电气主接线形式;④超高压配电装置的布置;⑤二次控制及保护;⑥主要优缺点。     

Summary of the `Guide for the protection of shunt reactors' ANSIC37.109

An introduction to the Guide for the Protection of Shunt Reactors (ANSI/IEEE C37.109-198X) is presented. The material contained in the Guide is briefly described and some examples are presented. Reactor construction and characteristics are described along with dry-type reactor connections. Dry-type reactor failure modes, types of faults, and relaying practices are outlined. Oil-immersed rector connections, failure nodes, and types of faults encountered are discussed     

Microelectronic packaging for retinal prostheses.

An innovative parylene-based high-density chip-level integrated interconnect (CL-I/sup 2/) packaging system for retinal implants id discussed. The implications of this CL-I/sup 2/ technology for retinal prosthesis packaging effort are far-reaching. This technology obviates the need for a technician to create electrical and mechanical connections one by one. Instead, the technology is limited only by standard photolithography and standard microfabrication techniques, providing the capability for a reduction of an order of magnitude or more in the center-to-center pad distances that can be accommodated in the process. High-density electrode arrays are thereby feasible, because the fabrication process places no limit on the number of output pads that can reasonably be connected to the array.     

Design and Development of Ferroelectric Tunable Coplanar Waveguide Components for Ku- and K-Band Applications

In the past several years, we have demonstrated electrically tunable microstrip components such as resonators, filters, diplexers, and couplers based on conductor/ferroelectrics/dielectric two-layered structure. Recently, we are focusing our efforts on tunable coplanar waveguide (CPW) components in collaboration with NASA Glenn Research Center, Cleveland, OH. The advantages of CPW components include higher dielectric tunability compared to microstrip structure, ease of shunt connections, and ease of testing. To date, we have modeled several CPW structures with ferroelectric thin-film to study the effect of inserting the ferroelectric thin-film on electric tunability, attenuation and dispersion. Also, we have designed and fabricated devices such as resonators, and filters. The ferroelectric tunable CPW filters were tunable by more than 3% at bias voltage levels of - 100V. The BSTO based CPW filters offer higher sensitivity parameter as well as lower loss parameter compared to BSTO tunable 2-pole microstrip filters.     

Rationalization of Energy in an All-Electric Building Complex

A 3 000 000 ft2 modern day office complex is a highly sophisticated container of active business life for people and one which also provides amenities today's technology can make possible for the occupants who spend a great deal of their time in and around the building. Such a complex has spacious office areas, is noise-free, is well-lighted, and has complete temperature and humidity control, and is served with the most advanced life safety protection system. Completing the business life is a vast assembly of conveniences: shopping concourse, restaurants, parking area, subway connections, and auditoriums. To meet the needs of a sophisticated business community, the complex is centrally controlled by computer. Energy management is a major priority in design and continues to be in the operation of the business community complex.