500kV母线侧刀闸分闸操作异常的分析及处理

本文主要对某500kV变电站在进行500kV线路停电倒闸操作中,500kV母线侧刀闸多次出现分闸异常事件进行分析,得出主要原因以及提出发生类似事件应该如何正确处置.该事件主要是因为500kV母线侧垂直伸缩式刀闸因动静触头无法正常分开而导致分闸异常,进一步可能发生母线扯落事故.总结经验,提出正确的应急处置方法,减少刀闸操作异常时间,对保证电网稳定安全运行有重大意义.     

基于云计算资源的弹性伸缩创新及应用

随着信息技术和互联网的飞速发展,海量数据处理的需求日益增大,云计算作为一种资源共享模型应运而生.云计算的弹性伸缩控制技术因其以弹性可伸缩方式提供资源,提高了资源利用率和用户满意度.弹性伸缩有垂直和水平两个方面,水平伸缩主要是增加或减少虚拟机的数目,垂直伸缩是更改虚拟机的配置大小.然而,水平伸缩是一种粗力度的弹性调整方式,而且在应用过程中需要暂停应用,停顿时间比较大,会造成了资源的开销及成本浪费,而垂直伸缩虽然可以不中断服务即可对虚拟机大小进行重新配置,但是伸缩规模有限.针对水平伸缩和垂直伸缩各自的缺点,本文提出将水平伸缩和垂直伸缩两种方式相结合,既保证可以对大规模的伸缩需求做出及时响应,还可以满足短时间内对小规模需求进行资源调整,充分地利用了弹性伸缩的两个方面的优点,从而更大程度上地提高了资源利用率,降低了云计算资源的使用成本,进一步增大了用户的满意度.     

基于T 型稀疏发射阵列的傅里叶望远镜

傅里叶望远镜通过改变任意两个发射望远镜的位置来获取目标不同的空间频率分量,采集足够多的傅里叶分量值后进行信号处理即可重构目标图像。为了降低系统成本且尽量获得目标的细节信息,提出了一种T 型稀疏发射阵列的激光束发射配置方案,对4 种目标与均匀间隔发射阵列重构的图像进行了对比研究。T 型单臂放置11 个发射望远镜,连续抽取目标的8 个低频信息,再抽取3个高频分量。通过与单臂11 和16 个的均匀间隔发射阵列的重构图像进行对比发现:文中采用的发射阵列重构图像远优于同等数量发射器个数的单臂均匀放置方式,但整体成像能力略差于均匀16,这也是稀疏发射阵列不可避免的。     

螺旋型光纤传感软体操作臂状态测量及特性分析

微创手术软体操作臂是微创外科和机器人领域的科学前沿和研究热点,对提升微创手术水平至关重要。现有视觉、电子和光电等传感方法尚未解决软体操作臂的状态测量问题,以直线型布设在软体操作臂中的光纤传感器,在柔性操作臂伸展和弯曲等运动时存在易断裂和可重复性差等问题,未能实现手术操作臂的闭环控制,限制了其手术应用。为此,提出了一种基于螺旋型光纤传感的软体操作臂状态测量方法,并对其传感特性进行了研究。不同于直线布设光纤的传感方法,螺旋型布设光纤的传感方法可以实现可伸缩软体操作臂的测量,防止光纤在软体操作臂中的错位,满足可伸缩弯曲软体操作臂的测量需求。通过理论分析气动驱动软体操作臂伸缩和弯曲的运动特性,利用光纤上刻写的布拉格光栅传感点,建立软体操作臂中螺旋型光纤光栅的传感模型,推导出光纤光栅中心波长漂移量和软体操作臂弯曲曲率之间的关系。最后,为了验证螺旋型光纤光栅在软体操作臂中的传感性能,对其传感灵敏度和稳定性等进行了实验测试。实验结果表明:提出的螺旋型光纤传感方法可实现操作臂伸长10%、弯曲角度达到180°时的状态测量,且操作臂理论弯曲角度和光纤传感的误差最大为9%,传感灵敏度可达12.55 pm/(°),满足软体操作臂伸缩和各向弯曲操作时的测量需求。     

接插元件、表面安装件、继电器、开关、熔断器

0600284 采用垂直对准碳纳米管的场致发射真空电源开关= Field emission vacuum power switch uNng vertically Nigned carbon nanotubes[刊,英]／N．L．Rupesinghe,M． Chhowalla／／Journal of Vacuum Science ＆ Technology B．-2003,21(1)．-338-343(E) 0600285 GW16／17型隔离开关在运行中出现的问题及解决方案[刊,中]／肖辉／／长沙电力学院学报(自然科学     

智能变电站新型母差刀闸位置指示装置研究

目前智能变电站中所用的母线保护装置尚未有刀闸位置指示功能，运维人员在日常巡视、操作时无法得知母线保护中线路母线侧刀闸的实际位置。针对这一问题，本文提出一种智能变电站新型母差刀闸位置指示装置，用于给运维人员在操作过程中及时、直观地获取母差保护中线路间隔母线侧刀闸位置。该装置集合一套母线保护装置中对应母线上的多条线路母线侧刀闸位置指示，具备刀闸变位情况和变位时间记录、刀闸位置异常告警功能，解决了母线保护装置无直观刀闸位置指示、不便于作业人员确认刀闸位置、存在造成母差保护误动风险的问题，排除了电力系统安全隐患，提高供电可靠性。     

某导弹双摆喷管电动伺服系统运动分析及建模仿真

首先分析了某导弹双摆喷管电动伺服系统的结构原理,通过对系统的运动分析和建模,研究了2个垂直安装位置的机电作动器的非线性运动特性和耦合干扰情况,给出了控制器在任意摆角指令下对作动器伸缩位移的解耦运算;同时,研究了摆动力臂与喷管摆角之间的非线性关系,在此基础上建立含有非线性环节的单个伺服机构数学模型,调节控制器参数,分别采用基于时域的阶跃响应法和基于频域的正弦相关分析法,在Simulink仿真平台上进行仿真,通过与真实实验数据的比对,验证了模型的准确性,为后续深入研究该型伺服机构性能测试打下坚实基础。     

继电保护在变电站母线倒闸操作过程中的应用

随着电力技术的发展,变电站综合自动化改造工作也在稳步推进,期间使变电站母线倒闸操作的次数增加,由于设备在母线倒闸操作中出现故障造成电力事故发生的概率也升高.本文基于某变电站中GIS设备在220kV母线倒闸操作中,因刀闸一次接头未良好接触造成带负荷拉刀闸事故,最终使母线全停.通过分析,为了降低变电站母线倒闸操作中出现的不良事件,对母线倒闸操作中继电保护自动化的应用进行探讨.     

DDZ-Ⅲ型电动执行机构与DCS系统连接技改

我厂于2002年建成投产，在电动调节阀门上大部分采用了国产的DDZ-Ⅲ型电动执行机构，通过操作放大器与DCS系统连接，随着设备服役年限的加长，设备特别是操作放大器逐渐出现问题。严重影响机组的安全运行，为解决这个安全隐患，使机组更安全稳定的运行，笔者对此进行了技术改造。     

锁相技术在超声波发生器中的应用

锁相技术在超声波发生器中的应用根据电子部十三所研制生产的单臂、双臂超声键合台，利用十三所自制的磁致伸缩换能器，采用了锁相环路反馈跟踪频率。推出了电路新颖、匹配良好、整机电路集成化的超声波发生器。该机比ＲＣ移相频率跟踪方法准确，使整机在稳定性、焊接可靠...     

GW35型隔离开关操作过程中触头烧毁问题分析

随着电力企业的快速发展,隔离开关被广泛使用.现在,电力系统中的GW35型隔离开关在运行过程中不仅受外界环境的影响还受自身结构的影响使得GW35型隔离开关在使用操作过程常出现触头烧毁问题,影响着供电系统的安全稳定性.     

Design of an ATM switch for handoff support

In a wireless ATM system, a network must provide seamless services to mobile users. To support this, mobility function should be added to existing ATM networks. Through a handoff operation, a mobile user can receive a service from the network without disconnecting the communication. A handoff results in connection path rerouting during an active connection. To avoid cell loss during a handoff, cell buffering and rerouting are required in the network. A handoff switch is a connection breakdown point on an original connection path in the network from which a new connection sub‐path is established. It performs cell buffering and rerouting during a handoff. Cell buffering and rerouting can introduce a cell out‐of‐sequence problem. In this paper we propose a handoff switch architecture with a shared memory. The architecture performs cell buffering and rerouting efficiently by managing logical queues of virtual connections in the shared memory and sorting head‐of‐line cells for transmission, thus achieving in‐sequence cell delivery during a handoff. We also present simulation results to understand the impacts of handoffs on switch performance. This revised version was published online in July 2006 with corrections to the Cover Date.     

不受网络拓扑约束的就地型馈线自动化故障处理方案研究

传统就地型馈线自动化整定参数受网络拓扑结构的约束较大,当电网结构发生变化时,原整定参数需要随之进行修正,增加了操作的复杂性。为此,通过分段开关和联络开关分别对供电区域和负荷点序号进行逻辑编号,探究各个逻辑序号下各开关运行参数的整定原则,提出了一种不受网络拓扑约束的就地型馈线自动化故障处理方案。通过对发生故障后分段开关和联络开关的动作特性进行分析,提出了拓扑改变后的故障处理流程。案例分析结果表明,本文所提方案具有自适应性,能够适应变化的网络拓扑结构,完成对故障区段的隔离并恢复非故障区域的供电。     

VS1断路器常见故障分析

随着电力行业的不断发展,高压开关柜的使用频率越来越高。而VS1断路器的使用情况对于高压开关柜的运行具有至关重要的作用。本文从VS1断路器的控制原理出发,对VS1断路器的常见故障进行分析,同时提出处理措施。     

A 1.8 Gb/s GaAs optoelectronic universal switch LSI withmonolithically integrated photodetector and laser driver

A high-speed monolithic optical interface switch LSI is developed using a GaAs MSM photodetector and large-scale integrated electric circuits. This LSI operates universally as a 1.8 Gb/s optical-input/optical-output four-channel time-division switch, a 1.8 Gb/s optical-input/electrical-output 1:4 demultiplexer, a 2.0 Gb/s electrical-output 4:1 multiplexer, and a 2.8 Gb/s electrical-input/electrical-output 4×4 space-division switch. It uses a new multistage 2×2 switch block with small hardware and high-speed operation. It can be expanded to a 16×16 optical-input/optical-output time-division switch operating at up to 1.8 Gb/s for broadband-ISDN     

Wavelength add-drop switching using tilting micromirrors

This paper describes a single-mode optical fiber switch which routes individual signals into and out of a wavelength multiplexed data stream without interrupting the remaining channels. The switch uses free-space optical wavelength multiplexing and a column of micromechanical tilt-mirrors to switch 16 channels at 200 GHz spacing from 1531 to 1556 nm. The electrostatically actuated tilt mirrors use an 80 V peak-to-peak 300 KHz sinusoidal drive signal to switch between ±10° with a 20 μs response. The total fiber-to-fiber insertion loss for the packaged switch is 5 dB for the passed signals and 8 dB for added and dropped signals, with 0.2 dB polarization dependence. Switching contrast was 30 dB or more for all 16 channels and all input and output states. We demonstrate operation by switching 622 Mb/s data on eight wavelength channels between the two input and output ports with negligible eye closure     

Dynamic SVL and body bias for low leakage power and high performance in CMOS digital circuits

In this article, a new complementary metal oxide semiconductor design scheme called dynamic self-controllable voltage level (DSVL) is proposed. In the proposed scheme, leakage power is controlled by dynamically disconnecting supply to inactive blocks and adjusting body bias to further limit leakage and to maintain performance. Leakage power measurements at 1.8?V, 75°C demonstrate power reduction by 59.4% in case of 1?bit full adder and by 43.0% in case of a chain of four inverters using SVL circuit as a power switch. Furthermore, we achieve leakage power reduction by 94.7% in case of 1?bit full adder and by 91.8% in case of a chain of four inverters using dynamic body bias. The forward body bias of 0.45?V applied in active mode improves the maximum operating frequency by 16% in case of 1?bit full adder and 5.55% in case of a chain of inverters. Analysis shows that additional benefits of using the DSVL and body bias include high performance, low leakage power consumption in sleep mode, single threshold implementation and state retention even in standby mode.     

Six-port self-calibration based on active loads synthesis

An automatic method for self-calibrating six-port reflectometers is reported in this paper. It is based on the use of an active impedance synthesis system. This self-calibration method allows a completely autonomous operation, reduces measurement errors caused by the frequent connecting and disconnecting of calibration standards, and is suitable for low and high frequencies, where sliding shorts are difficult to manufacture. In addition, it simplifies operation of six-port reflectometers to nonspecialized users. The experimented impedance synthesis presented relies on an in-phase and quadrature vector modulator, and the entire system is computer controlled     

All-Optical Comb Switch for Multiwavelength Message Routing in Silicon Photonic Networks

Simultaneous all-optical switching of 20 continuous-wave wavelength channels is achieved in a microring resonator-based silicon broadband 12 comb switch. Moreover, single-channel power penalty measurements are performed during active operation of the switch at both the through and the drop output ports. A statistical characterization of the drop-port insertion losses and extinction ratios of both ports shows broad spectral uniformity, and bit-error-rate measurements during passive operation indicate a negligible increase in signal degradation as the number of wavelength channels exiting the drop port are scaled from one to 16, with peak powers of 6 dBm per channel. A high-speed broadband switching device, such as the one described here, is a crucial element for the deployment of interconnection networks based on silicon photonic integrated circuits.     

A Parallel Power Amplifier With a Novel Mode Switching Control

Two parallel operating power amplifiers (PAs) are controlled by a novel mode switch for high efficiencies at both the back-off power region and high power region. The mode switch is realized by the base-collector (BC) junction diode which reuses the dc current of the low power mode amplifier. A 836 MHz CDMA PA has been demonstrated using InGaP/GaAs heterojunction bipolar transistor with fully integrated matching component for small package and low cost. It shows a 13 mA idle current, 15.4% power added efficiency (PAE), ACPR1 at 16 dBm of the low power mode operation and a 40.5% PAE, ACPR1 at 28 dBm of the high power mode operation.