户内高、低压成套开关柜母线设计

母线是作为高、低压成套电器一次设备间相互联接的重要元件,其设计的合理性与否,直接关系到系统能否安全运行。文中概述了高、低压成套开关电器设计中遇到的各类设计问题,对户内高、低压成套开关柜母线的设计进行归纳和总结。     

浅谈10KV变压器的保护配置和熔断器的使用运行和维护

10kV配电变压器的保护配置主要有断路器、负荷开关或负荷开关加熔断器等。负荷开关投资省,但不能开断短路电流,很少采用;断路器技术性能好,但设备投资较高,使用复杂,广泛应用不现实;负荷开关加熔断器组合的保护配置方式,无论是在环网供电单元、箱式变电站或是终端用户的高压室结线方式中,如配电变压器发生短路故障时,保护配置能快速可靠地切除故障,对保护10kV高压开关设备和变压器都非常重要。     

探讨与分析影响配电系统可靠性因素

本文以IEEE可靠性测试系统的母线4为研究对象,进行可靠性指标计算。母线4其38个负荷点,系统规模不大,采用解析法进行计算。通过定量分析系统接线方式、元件故障率、元件故障时间对配电系统可靠性的影响,发现接线方式五可靠性最高。但由于变压器造价昂贵,出于经济因素的考虑通常选接线方式一作为基本接线方式,即主馈线有隔离开关、分支线有保护、有备用电源、变压器无备用。元件故障率和元件故障时间的升高会降低系统供电可靠性。     

大容量变压器及真空馈电开关应用中瓶颈问题的解决

随着煤矿生产的发展，煤矿井下用电设备的总功率和单一功率也在不断增加．相应地提出了对大容量变压器和真空馈电开关的需求。但从目前井下供电系统的实际状况来看，大容量变压器和真空馈电开关在煤矿井下使用时存在着一些制约因素，从而限制了大容量变压器和真空馈电开关的应用、针对这一问题，我们设计和实施了一套解决方案，该解决方案设备投入少、施工简捷，可充分利用已有的设备及接线系统，并具有较为完善的保护性能，成功解决了大容量变压器和真空馈电开关应用中的瓶颈问题。     

无线电脑万能遥控开关

一种新颖的无线电脑万能遥控开关由温州市东风电猫厂研制成功,并投入批量生产。它填补了目前国内外无线电脑遥控开关的空白。东风牌电脑万能遥控开关由两个手指头大小的发射机和一个肥皂盒似的接收机组合成套,由发射机发出超短波频率信号,接收机接受,互相配合以控制220V的各种电器及工作设备的开启或关闭,与其他遥控开关相比,它具有全方位使用无方向性,灵敏度高、抗干扰性强、耗电省、有效控制距离远等优点。在30米以内,可随意控制任何位置电器的开启或关闭。它从根本上改变了长期以来使用接触式普通开关,如拉线、拨动、按钮等开关使用不够方便、安全的缺陷。     

浅谈V/V接线方式牵引变压器的差动保护

近年来,我国的电气化铁路科学技术飞速发展,BT供电方式的牵引变电所采用的牵引变压器接线方式不断更新,牵引变压器的主保护差动保护交流回路的接线方式随着牵引变压器接线方式不断更新而发生变化,就此主要针对V/V接线牵引变压器差动保护的交流回路接线方式、接线方式判断、整定原则及其保护范围的原理进行了详细地介绍,确保V/V接线牵引变压器受电投运的安全运行和差动保护交流回路的接线正确、判断灵敏和动作可靠。     

一种新型的变压器六角图测试方法

变压器是电力系统中十分重要的电气设备,它的故障将对电力系统的供电可靠性和正常运行产生严重的影响。在实际使用变压器设备时,应该根据电力变压器的额定容量和重要程度等级来装设专用的保护装置。但是在实际应用中却很难保证继电保护装置接线的正确性,如果继电保护装置接线方式出现错误,在设备运行中它将起不到应有的保护作用,而且还会由于保护装置的误动作,造成大面积停电事故。提出了一种在变压器投运前测量六角图的新方法,可以有效保证变压器投运后极性的正确性。     

专注自主研发 创国际一流电力企业

沈阳飞驰电气设备有限公司是一家专业研发和制造小型化中压开关电器及成套电器设备的公司,其主导产品包括小型化环保型中压中置式开关柜、直流开关成套设备、真空固体绝缘型环网开关设备、单通道预装式变电站等系列产品,均具有"小型化、免维护、环保节能"鲜明的技术特征,并获得多项国家发明专利,在同行业市场中业绩显著。     

10kV跌落式熔断器的使用和运行维护

跌落式熔断器是10kV配电线路分支线和配电变压器最常用的一种短路保护开关,它具有经济、操作方便、适应户外环境性强等特点,被广泛应用于10kV配电线路和配电变压器一次侧作为保护和进行设备投、切操作之用。它安装在10kV配电线路分支线上,可缩小停电范围,因其有一个明显的断开点,具备了隔离开关的功能,给检修段线路和设备创造了一个安全作业环境,增加了检修人员的安全感。     

浅淡10KV配电变压器的保护

在10kV终端用户配电变压器的保护通常有三种方式：一是利用跌落式熔断器，二是利用负荷开关加高压熔断器所构成的组合电器，三是利用真空断路器。这三种配置方式在技术和经济上各有优缺点，现对这三种方式进行综合比较分析。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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