JDM9系列电子式计数继电器

一、概述计数继电器不仅广泛用于机床行业,其它如化工、轻工和纺织等行业也广泛采用,在自动控制系统中作计数元件,按预置的数字接通或分断电路.目前国内市场上主要是电磁式计数继电器,这远不能满足高精度、高频响、高可靠性和低功耗等的要求.供电子式计数继电器专用CMOS大规模集成电路的研制成功,为满足上述要求,开发电子式计数继电器提供了保证.     

阻抗继电器与距离继电器分类的补充说明

给出阻抗继电器与距离继电器新的定义.进一步阐明了阻抗继电器与距离继电器的特点.说明了阻抗继电器是建立在测量阻抗概念上的一类继电器;距离继电器是建立在补偿电压特点基础上的一类继电器.规定了测量阻抗动作特性和支接阻抗动作特性的适用范围.提出了阻抗继电器的两条性质,并给出这两条性质的应用实例.最后对距离继电器的进一步发展给予展望.     

继电器接触可靠性及失效的研究

对现场使用的继电器实现可靠性评估及失效预测,不仅能避免"纳伪"造成的系统故障,还能减少"弃真"带来的经济损失;特别对航天、钻探等不易维修设备及电力系统等一些关键设备中使用的继电器有重要的应用价值.对电磁继电器触头的静态接触电阻,及闭合过程的(动态)接触电阻峰值和弹跳时间进一步分析表明:继电器的失效行为与这些参数随操作次数的变化规律、均值、方差及概率分布有关.为可靠性评估及失效预测提供了依据.     

混合输出型功率继电器的设计

如今功率继电器小型化和长寿命的要求变得越来越重要了。目前固态的和机电式的开关器件都有自己的优缺点: 1.固态继电器的特点是使用寿命长,但由于它导通时的压降较机械式继电器的压降大,出于对散热的考虑,较大的热耗散必须采用某种辐射散热片,从而使尺寸增大。2.机械式继电器结构紧凑,当触头转换时,由于受电弧影响,致使接触性能降     

新型静态继电器综述

综合性地介绍了数字式动作延时继电器、数字式返回延时继电器、数字式动作延时中间继电器、数字式返回延时中间继电器、无源静态电流继电器、无源静态电压继电器、静态信号继电器、静态数字重合闸继电器等的主要用途、电磁兼容性、抗干扰性能、主要特点以及同类继电器的相互代换关系。     

PPR型极化继电器

一、概述脱扣继电器是电磁式漏电保护电器的一个关键部件,其性能好坏对漏电保护电器的产品质量影响极大.目前普遍认为脱扣继电器制造工艺复杂、操作要求严格,质量较难控制,产品成本较高.其实这一切均是由于产品结构欠合理造成的.嘉兴市物资产业(集团)总公司同泰电器分公司最近研制成功的PPR型极化继电器就较好地解决了上述问题.     

过电流继电器特性模拟的一种新方法

提出了一种模拟过电流继电器特性曲线的新方法.该模型以模糊逻辑和人工神经网络为基础.多层感知器的前馈神经网络常用来计算具有各种时间刻度盘整定值(TDS)和时间乘法器整定值(TMS)的过电流继电器的动作时间.该方法比传统的方法更精确.     

SZH—2型周波继电器中滑差闭锁电路的功能与原理

我国电网普遍采用的SZH型数字式频率继电器对电网的安全运行发挥了很大作用,但运行中该型继电器也多次出现误发信号或误动作的现象.为保证该型继电器动作的正确率,提高电网的安全稳定运行水平,对该型继电器又增加了滑差闭锁功能,型号定为SZH-2型周波继电器(简称SZH-2型继电器).本文对滑差闭锁功能的作用、整定原理及工作原理简介如下.1 滑差闭锁功能的作用1.1 防止SZH-2型继电器内部清零回路,计数回路等元件损坏引起的误动作.1.2 防止输入电压相位接连突变(如-相电压变化保险对地闪络、短路故障、冲击负荷等引起的母线     

Ⅲ段距离保护作为后备保护的性能分析

在阻抗继电器与距离继电器分类的基础上,对Ⅰ、Ⅱ、Ⅲ段阻抗继电器的配合问题和Ⅰ、Ⅱ、Ⅲ段距离继电器的配合问题进行了深入的探讨,分析了Ⅲ段距离保护作为后备保护应具有的条件.由于阻抗继电器具有性质1,Ⅲ段阻抗继电器作为Ⅰ、Ⅱ段阻抗继电器的后备,在任何一次系统条件下都是成立的.由于距离继电器不具有性质1,一次系统结构、参数、运行方式、短路类型变化对Ⅰ、Ⅱ、Ⅲ段距离继电器的配合都产生影响.如果Ⅲ段距离继电器支接阻抗特性不能够涵盖Ⅰ、Ⅱ段距离继电器的支接阻抗动作特性,则Ⅲ段保护起不到后备保护的作用.     

阻抗继电器与距离继电器的特点

把距离保护测量元件划分为阻抗继电器与距离继电器两大类.分别讨论了阻抗继电器与距离继电器的特点.对测量阻抗、支接阻抗这两个概念进行了分析.     

无源厚膜电路构成的静态型电流和电压继电器

论述了无需直流辅助电源、用厚膜电路构成的静态型电流和电压继电器。与原有的集成电路型继电器相比 ,具有高的抗干扰能力和工作可靠性 ,运行维护更加简单方便 ,因此可把它们看成是一个“傻瓜”继电器     

A solid-state PWM phase-shifter

A solid-state, pulse-width-modulated (PWM) phase shifter, based on gate-turn-off )GTO) thyristors or other valves with force commutation capabilities, is described. Besides serving the phase-shifter function, it offers regulated control over three independent quantities: the real power passing through it and the VAR (volt-ampere reactive) on both sides to which it is connected. The power transferred can be bidirectional, and the VArs can be leading or lagging. Digital simulations show that the PWM phase-shifter reported here is capable of regulated control of bidirectional real power flow and independent regulated control of positive or negative VArs on both sides of the phase shifter     

Ultrabroadband infrared solid-state lasers

Ultrabroadband infrared transition metal ion-doped solid-state lasers have come of age and are increasingly being used in trace gas monitoring, remote sensing, telecommunications, ophthalmology, and neurosurgery. Operating at room temperature, they are stable, versatile, and easy to handle successors to the color center lasers. They are becoming the critical components in optical frequency standards, space-based remote sensing systems, and may soon find application in femtochemistry and attosecond science. The article reviews the principles and basic physics of these types of lasers, which are distinguished by their ability to support the shortest pulses down to single optical cycle durations and the ultimately broad tuning ranges. The paper further reviews the state of the art in the existing diode-pumped sources of broadly tunable continuous wave, and ultrashort pulsed radiation in the infrared, and provides examples of their successful application to supercontinuum generation, trace gas measurements, and ultrasensitive intracavity spectroscopy. Developments in such lasers as Cr:YAG, Cr:ZnSe, Cr:ZnS, as well as the recently proposed mixed Cr:ZnS/sub x/Se/sub 1-x/ laser, are discussed in more detail. These lasers nearly continuously cover the infrared spectral region between 1.3 and 3.1 /spl mu/m. The gain spectra of these lasers perfectly match and extend toward the infrared spectra of such established ultrabroadband lasers, operating at shorter wavelengths between /spl sim/0.7-1.3 /spl mu/m, as Ti:sapphire, Cr:LiSAF/Cr:LiSGaF and Cr:forsterite. This opens up new opportunities for synthesis of single-cycle optical pulses and frequency combs in the infrared.     

Generalized solid-state marx modulator topology

A generalized circuit topology for bipolar or unipolar high voltage repetitive pulse power applications is proposed. This circuit merges the negative and positive solid state Marx modulator concepts, which take advantage of the intensive use of semiconductor devices to increase the performance of the original dissipative Marx modulators. The flexibility of the proposed modular circuit enables the operation with negative and/or positive pulses, selectable duty cycles, frequencies and relaxation times between the positive and negative pulse. Additionally, the switching topology enables the discharge of the parasitic capacitances after each pulse, allowing the use of capacitive loads, and the clamping of inductive loads, recovering the reset energy back to the main capacitors. Analysis of efficiency and power loss will be addressed, as well as experimental details for different conditions based on laboratory prototype, with 1200 volt Insulated Gate Bipolar Transistors (IGBT), diodes, and 4.5 μF capacitors.     

新型智能固态断路器研制

提出了一种基于非对称型集成门极换向晶闸管(AS-IGCT)的新型智能固态断路器设计方案.该固态断路器的整体结构主要为开关主体和测控系统2个部分:开关主体部分由AS-IGCT开关模块、门极驱动模块、保护模块及强力风冷系统等组成;测控系统由基于双核DSP处理器控制、光纤电压/电流等传感器组成的探测及通信、人机接口等模块组成.给出了开关模块拓扑结构和新型智能固态断路器结构框图.并利用电力仿真软件PSIM进行测试.结果表明装置开、断参数符合要求.     

A solid-state high-performance reactive-power compensator

A high-performance reactive-power compensator is presented and analyzed. The VAR compensator consists of a three-phase current-regulated pulse width modulated voltage-source inverter connected to a self-controlled DC bus. Reactive-power compensation is achieved by forcing the inverter output current to follow a reactive sinusoidal reference waveform at a constant switching frequency. The main advantages of this scheme are that it reduces the stresses on the switching devices (as compared with other current regulated techniques), and it has a fast response time, which allows almost instantaneous reactive current control, and low harmonic distortion in the line currents. In particular, the authors discuss the proposed scheme in terms of principles of operation, power and control system design, and the analysis under transient operating conditions. Simulated results obtained with the Spice simulating package for steady-state and transient operating conditions are presented and validated on an experimental unit     

Perspectives on solid-state flying qubits

We review recent efforts toward the numerical modeling of prototypes of one- and two-qubit gates based on coherent electron transport in semiconductor quantum wires. The basics of the proposed devices are presented and a theoretical approach aimed at quantifying the decoherence induced by electron-electron coupling is described.     

Applications for advanced solid-state lamps

Since lighting accounts for a large fraction of electrical usage in the industrial sector, the energy efficiency of lamp systems is of major interest. One promising technology which has the potential for use in specialised energy-efficieny lighting applications is solid-state lamp technology. There are many reasons solid-state lamps may be especially useful for new applications. They exhibit long lifetimes, in the order of 100000 hours. Coupled with the ruggedness inherent in solid-state devices, this indicates usefulness for low maintenance applications. Fast response times also make them ideal for some applications. This review surveys the state-of-the-art in solid-state semiconductor lamp technology, with a focus on the potential for such applications, and on energy efficiency and brightness considerations. The different types of solid state light source are described: LED, diode lasers, superluminescent diodes and electroluminescent diodes. Their operating characteristics are discussed and the following applications described: illuminated signs, exit-signs, traffic control lights, airport runway lighting, vision sensors illumination, spotlighting, interactive and fast adaptive lighting and fibre-optic channeled lighting     

The promise of cryogenic solid-state lasers

Cryogenic cooling of solid-state lasers has a number of important benefits, including the near vanishing of optical distortion in high average power lasers, as well as enhanced spectroscopic and lasing properties. These benefits are just beginning to be exploited to produce compact high average power lasers whose output is scalable, near diffraction limited, and whose efficiencies will exceed those of modern bulk solid-state lasers. In this paper, we review the history of cryogenically cooled solid-state lasers and the benefits of cryogenic cooling, including optical and laser properties and thermal and thermooptic properties; examine cryogenic amplifiers and cooling methods, including a straight-through propagation thin-disk configuration that does not perform well at room temperature, and summarize the experimental performance demonstrated to date. As a specific example, we examine the spectroscopic and lasing properties of Yb:YAG and show that compact high efficiency and high average power, near diffraction limited lasers (>100 kW) can be realized in the near future using presently available technology.