浅谈高压负荷开关─熔断器组合电器

针对目前国内兴起的负荷开关及负荷开关─熔断器组合电器研究开发热,介绍有关的一些概念。着重讲述了有关负荷开关与熔断器的配合以及转移电流的特点,并对组合电器中熔断器参数的选取作了特别说明。     

变电站熔断器的选择与管理

介绍了变电站常用回路熔断器的选择经验，以及对运行中的熔断器的管理、维护方法。     

带限温装置的高压熔断器

按 IEC2 82 -和 VDE0 60 7,4/ 4 0 2部分的规定作型式试验的熔断器主要指定用于配电变压器的保护 ,他们切断和限制不容许的短路电流 ,而且能够通过其撞击器的动作使负荷开关三极全部自动分闸 ,切断过负荷电流。由于过电流可导致熔断器内部温度上升至摄氏几百度 ,在这种情况下 ,熔断器装入 SF6 气体绝缘或狭窄的封闭开关设备内时 ,周围的环氧树脂或塑料材料必须能耐受这种温度。当额定电流较高的负荷开关 -熔断器组合电器按 IEC42 0规定作型式试验时 ,温升可以达到不能容许的数值 ,导致熔断器封装的老化 ,微裂或接触削弱。根据多次不同…     

根据熔断器烧熔现象判断电动机的故障原因

低压熔断器是低压配电系统中的一种保护元件，主要作短路保护，在一定的条件下也可起过载保护作用。     

选用并联谐振电路测试高压限流熔断器的时间-电流特性

介绍了选用并联谐振电路组成的电路作高压限流熔断器的特点、结构原理和测试方法，以及电容器、电抗器的设计计算。     

配网PT熔断器故障分析及故障监测系统研究

PT熔断器是电力系统中重要设备,针对PT熔断器故障造成的原因,提出一种新的电压、电流双检测的方法。通过Matlab/Simulink建立熔断器故障模型进行仿真计算,分析了PT熔断器故障电压电流与故障原因之间的关系,并对熔断器故障的诊断技术进行研究。结果表明,铁磁谐振故障和系统中的低频饱和电流是造成PT熔断器熔断故障的主要原因。因此,检测电压、电流特征值对PT熔断器故障的诊断具有重要意义。     

单台并联电容器保护用溶断器试验情况及使用问题的分析

结合DL442—1991修订要求，对国内主要的熔断器厂的产品进行抽检及验证试验，分析并提出了对熔断器使用中的具体要求和应注意的问题。     

电动机熔断器的选配

分析了主令电器控制的电动机熔断器的特性，并提出了熔断器选型和参数配合的条件。     

无刷励磁系统研究改造

本通过对无刷励磁系统的理论分析，解决了励磁变压器高压侧熔断器的有关问题，论证了取消励磁变压器高压侧熔断器的可行性。该理论填补了国内空白，具有较高的推广价值。     

利用振荡回路进行限流熔断器试验的可行性分析

介绍了用振荡回路作限流熔断器分断能力试验的可行性，分析了限流熔断器在分断短路电流过程中的物理现象。推荐了一种作限流熔断器试验的振荡回路，并例举了限流熔断器在振荡回路上作短路电流分断试验的结果。     

600 V dc Time-Delay Fuses for Mines and Industry

All fuses used on dc circuits in mines must be approved by the Mine Safety and Health Administration (MSHA) and approval is based on meeting MSHA test requirements. All Underwriters Laboratories, Inc. listed 600 V time-delay commercial fuses are marked ``600V.A.C. or Less' and most do not meet MSHA requirements, unless modified. A simple modification is discussed, which makes UL listed time-delay fuses acceptable for mines and industrial dc applications such as overload and short-circuit protection for individual motors in a group of motors supplied by a single converter or adjustable speed drive.     

配电网TV高压熔断器熔断影响因素的分析

针对配电网时常发生的TV高压熔断器熔断的事故,分析了造成事故发生的主要原因为铁磁谐振和低频非线性振荡。利用ATP-EMTP建立仿真模型,对母线出线总长度、TV励磁特性、TV直流电阻和单相接地过渡电阻这4种TV高压熔断器熔断的主要影响因素进行仿真分析,得出了它们对TV高压侧过电流和系统谐振状态影响的一般规律。总结了现有的几种TV高压熔断器熔断的防治措施的优缺点,并对其消谐效果进行了仿真对比分析。     

The application of current limiting to distribution circuit protection

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.     

Reliability Investigation of NiPtSi Electrical Fuse With Different Programming Mechanisms

The reliability of NiPtSi/p-poly Si electrical fuses with different programming mechanisms, i.e., electromigration and thermal rupture, was investigated in terms of fuse resistance stability and fuse array functionality for the 65-nm technology node. The resistance of the fuses programmed within the electromigration programming window was found to be very stable; resistance shift was only observed on fuses programmed in the underprogrammed mode, which results in incomplete electromigration. For fuses programmed with the thermal rupture mechanism, both resistance shift and functional sensing fails were observed. Furthermore, a guard band was defined for fuses programmed with an electromigration mechanism to ensure sufficient margins for fuse reliability. However, a guard band cannot be defined for fuses programmed with a rupture mode due to the unpredictable nature of the rupture programming mechanism. The unprogrammed fuse elements were shown to be stable through extensive reliability evaluations.      

Coordination principles for applying expulsion and backupcurrent-limiting fuses for protecting distribution transformers

Fundamental principles related to the application and coordination of backup current-limiting fuses and expulsion fuses are presented. A step-by-step process for selecting the most suitable sizes of fuses to assure proper coordination is delineated. The types and placement of fuses is discussed     

低压熔断器和断路器的比较及应用

从配电线路的保护要求和保护电器发展的角度，分析和比较了熔断器和断路器的主要优缺点。在此基础上，给出了设计中有关熔断器和断路器的选型方案。指出应正确认识熔断器和断路器各自的作用和特点，以及它们在不同条件下所发挥的作用。     

从电气事故谈熔断器的选用

以典型的电气事故为引子,从保护的需求和保护装置的发展角度,介绍了熔断器的不同分类方法和主要优缺点。结合熔断器在电路中所扮演的角色和动作特征,介绍了它的选用方法,以期为使用者安全使用熔断器提供参考。     

基于欧式距离法的变压器故障BBA模型建立与分析

针对变压器故障诊断中油溶气体技术的改良三比值法存在故障区域边界值判断模糊的问题,在分析改良三比值法的基础上,以欧式距离来表征隶属每种故障概率大小的形式,建立了不同故障下的基本信任分配函数(BBA)诊断模型进行变压器故障诊断,并采用D-S合成规则对不同故障的BBA进行融合,实现了对多BBA模型函数重新构造以及归一表述的功能。利用该模型对长春某500 k VA变电站的变压器故障进行实例计算,并通过改良三比值法和模糊算法进行对比分析。结果表明:该诊断模型能准确、有效地对变压器的多种常见故障进行诊断;用计算隶属故障概率的形式弥补了改良三比值法边界值计算模糊的缺陷,使故障的判别更加趋于真实准确,为电力变压器故障诊断提供了一种有效的方法。     

基于信息融合技术的并发故障诊断的研究

为了诊断并发故障，文中扩展了证据理论：将并发故障状态作为设备的运行状态引入分辨框Θ中，视其为独立的运行状态，并根据不同证据体的差异程度，提出了两种不同的证据组合算法。然后，应用此两种不同的证据组合算法于并发故障诊断：第一种融合算法用来处理有相同焦点元素的证据体；第二种融合算法用来处理有不同焦点元素的证据体。该算法有利于充分利用各种证据体的有用信息，具有较强处理不确定性、不一致性证据体的能力。通过实验台转子轴承系统并发故障的诊断事例，证实了该算法的有效性。     

Temperature distribution of fuse elements during the pre-arcing period

This work models the function of medium and low voltage fuses so as to estimate the increase in temperature across the fuse elements during nominal current operation for different types, diameters, element lengths and currents. The power balance in a thin metallic conductor, which simulates the fuse element, was derived and the resulting differential equation solved analytically. The theoretical results were close to the experimental measurements that we made, and the experimental work of other authors. The mathematical model that was developed will be useful in the design of fuses, as the computation of the axial temperature distribution across the fuse elements for the different parameters mentioned above is relatively simple.