共查询到20条相似文献,搜索用时 93 毫秒
1.
2.
3.
1高压限流熔断器的用途高电压大容量限流熔断器有了长足的发展,特别是全范围熔断器面向未来可作为中压设备的完全保护。(1)保护变压器。这是最常用的情况,熔断器制造厂家规定了熔断器的额定电流与变压器容量的配合表。 相似文献
4.
介绍了高压真空接触器和高压限流熔断器的技术特性,以及二者应用于电厂内控制系统的选配原则。文章认为,在1600kVA及以下的变压器回路、1200kW及以下的高压电动机回路和1200kvar及以下的电容器组,更适合选用高压真空接触器高压限流熔断器组合电器;如果负荷超出此范围时,则应使用真空断路器柜供电。 相似文献
5.
介绍一种低压真空式全范围熔断器的结构和基本原理。此外,描述了该熔断器的试验及其结果分析,并得出很多特点和结论。 相似文献
6.
7.
S&C电气公司研制的XS型户外高压跌落式熔断器广泛应用于10 kV高压架空配电系统中,对系统中的变压器、电容器、电缆或架空线路分段点和分支线路提供全范围的保护.…… 相似文献
8.
1引言美式箱变20世纪90年代进入我国市场,一般称为组合式变压器。它将变压器、高压负荷开关、无励磁分接开关、熔断器等元件共装于一个油箱内,以变压器油作为绝缘、散热和灭弧介质,箱体直接暴露于空气中。以其散热效果好、占地面积小、造价低、全绝缘、全封闭、少维护、防护等级高、选位灵活、安装使用方便等优点在“两网”改造建设中被广泛使用,目前有超过10000台的美式箱变在全国各地挂网运行。因此了解常用的美变保护设备对美式变压器的应用非常重要,可避免误操作而导致的严重安全事故。2过载保护和二次保护典型的美式箱变采用“插入式熔断器 后备保护熔断器”串联起来实现全范围保护。厂家根据变压器的容量和电压等级推荐二者的参数配合列表,用户可以根据需要选定。2.1插入式熔断器插入式熔断器是插入式可外部更换的熔断器。插入式熔断器安装于箱变的前面板上(有的可安装于箱变的顶盖上),伸入到变压器的油中。可以用带电操作杆操作更换熔断器(如图1所示)。用于二次侧短路及过载保护。它分为两种:(1)只用于故障电流保护的电流型熔断器。(2)用于故障电流和变压器油温保护的双敏或双因素熔断器(是在中国市场上应用最广泛的美变保护熔断器,用户的认知程度较高)。当... 相似文献
9.
介绍了35kV风电用组合变压器中使用的高压熔断器及其布置方式。风电用35kV组合变是一种集高、低压保护于一体的变压器。高压引线中串联熔断器以保护变压器主体免受短路或过电流造成的故障损伤。国内多个厂家生产的风电35kV高压限流全范围保护熔断器外形虽略有不同,但结构大致都为插入式,尺寸相对于适配容量的组合变比较大,它在结构设计中的布置方式直 相似文献
10.
文章扼要地论述了发电厂中压厂用电系统中,熔断器和真空接触器(F C)组合回路熔断器及回路电缆截面的选择原则和方法,以及需要注意的问题。文中较详细地介绍了根据变压器励磁电流峰值、变压器额定电流、二次侧故障电流等因素选择变压器熔断器的原则与方法,以及工程上电缆截面选择方法。文中还介绍了熔断器保护特性的配合原则。 相似文献
11.
目前,国际上还没有能够完全保护电压互感器的熔断器,以及相应的IEC标准。笔者研究了一种新型的真空混合式全范围限流熔断器来保护电压互感器,为制定出相应的IEC标准提供技术支持,并指导该类产品的设计、制造、试验和运行。该产品是由真空熔断器和限流熔断器串联组成,采用环氧树脂工艺浇铸而成。根据熔断器的基本工作原理,利用真空熔断器具有特别陡的时间-电流特性,来开断小过载电流;利用限流熔断器来开断大过载电流和短路电流。试验结果验证该熔断器能够保证在额定电压因数波动范围为1~1.2时能够长期正常工作,额定电压因数为1.9时可以在30s内可靠动作,并且顺利开断了31.5kA的短路电流,实现了对电压互感器的妥贴保护。该产品具有结构新颖、性能安全可靠、性价比高等优点。 相似文献
12.
Many electric utility systems are reaching the point where available short-circuit currents, during severe faults, exceed the interrupting capability of available circuit interrupters of conventional types such as circuit breakers, distribution-circuit reclosers, and expulsion fuses. The needs are being met by the use of current-limiting fuses to protect individual distribution transformers or, sometimes, groups of distribution transformers, but there are difficult problems of coordination. The current-limiting fuses are not inherently capable of covering the full range of short-circuit currents, so that they must be used in addition to, or in combination with, interrupters of other types. This paper studies these problems in depth and makes recommendations for even wider use of current-limiting fuses to achieve more effective protection of the entire distribution system, including protection of distribution feeders at the substation. This approach also provides effective preventive measures to inhibit disruptive transformer failures which have become a severe problem with increasing short-circuit-current capability. 相似文献
13.
《Power Delivery, IEEE Transactions on》1990,5(3):1288-1291
A summary is given of C37.108-198X, a new IEEE Guide. The summary describes the equipment used in a typical network transformer system. The performance of this equipment is described during fault and nonfault system conditions. The limitations of the present protection are addressed, most importantly, for low-voltage, low-current arcing faults. Protective devices that can be added to the existing network transformer protection are listed. Some of these devices sense conventional input quantities such as phase current, ground current, impedance, and transformer rate-of-pressure rise, whereas others sense heat, ultraviolet light, and smoke. The application of interrupting devices such as circuit breakers, vacuum interrupters, fuses, and current-limiting fuses including an electronic fuse are discussed with special application considerations identified. An example demonstrating how a protective system can be designed utilizing the devices described within the guide is included as an appendix to the guide 相似文献
14.
15.
16.
发电机变压器组成套保护装置采用发电机纵向零序过电压及故障分量负序方向型匝间保护,当发电机出口电压互感器一次熔断器熔断时保护会误动,经过分析此类型的匝间保护原理及逻辑框图,通过整改及运行调整等相应措施.避免发电机匝间保护误动作跳闸。 相似文献
17.
为提升变压器在真空注油阶段抽真空压力及注油状态监测的可靠性,设计了以后台显示告警控制器为核心,无线传输为纽带的变压器真空注油监测装置。通过现场实际检修情况所要达到的要求,该装置能自动感知真空压力值和液位值,采用Zigbee无线电实时传输,配套设计后台显示和告警装置。该装置可为变压器真空注油状态监测提供实时信息源,其有效性和实用性在试验阶段和工作现场均得到了可靠性验证。 相似文献
18.
This investigation aims to develop a comprehensive microcomputer based fault protection scheme for indicating various types of faults in a radial transformer feeder in subtransmission or distribution circuits and its protection against those faults. The type of fault in the feeder can also be determined by observing the phase angles of the primary currents of the transformer with which the feeder is connected at its secondary. This method dispenses off conventional electromagnetic relays and HRC fuses in feeder protection schemes. The developed system provides necessary information regarding the faulted phase and displays appropriate symbols on the display screen of the microcomputer about the type of fault. 相似文献
19.
Hao Jiang Shuttleworth R. Al Zahawi B.A.T. Tian X. Power A. 《Power Delivery, IEEE Transactions on》2001,16(1):111-115
A new type of GTO thyristor assisted tap changer is outlined which addresses the problems of traditional schemes. The scheme minimizes conduction losses in the solid state devices and also permits a fast response speed through the adoption of fast actuator driven vacuum switches. This paper describes a prototype tap changer for a low voltage 300 kVA transformer using the new method of tap changing. The prototype operates at current levels similar to those at which a full scale tap changer would work. Test results are presented 相似文献