灭磁过电压保护装置氧化锌阀片损坏处理分析

针对某300MW机组灭磁过电压保护装置氧化锌阀片存在泄漏电流超标缺陷的问题,指出了其给运行设备带来的安全隐患,提出了更换氧化锌阀片和提高氧化锌阀片转折电压的处理措施,并通过励磁电压在线测量试验验证了处理措施的有效性.     

用氧化锌避雷器限制发电厂中压系统操作电压的探讨

带串联间隙，三叉载接线的氧化锌避雷器用作限制发电厂中压系统操作过电压的保护装置是可行的。与其他保护装置对比，此保护装置具有明显的优越性，其通流容量较大，有较长的运行寿命。     

用氧化锌避雷器限制发电厂中压系统操作过电压的探讨

带串联间隙、三叉戟接线的氧化锌避雷器用作限制发电厂中压系统操作过电压的保护装置是可行的。与其他保护装置对比，此保护装置具有明显的优越性，其通流容量较大，有较长的运行寿命。     

10kV合成套氧化锌避雷器及其热特性试验研究

１０ｋＶ合成套氧化锌避雷器及其热特性试验研究杭州电力学校金祖山本文介绍了合成套氧化锌避雷器的结构特点以及在电力系统中应用合成套氧化锌避雷器的优点，着重分析了１０ｋＶ合成套氧化锌避雷器的热特性。温升试验结果对分析合成套氧化锌避雷器的氧化锌非线性电阻片能...     

一种新型氧化锌避雷器劣化保护装置

针对当前交流无间隙氧化锌避雷器劣化问题,分析了国内外的研究成果和解决手段以及各自的成效。着重介绍了一种能大大提高电站安全运行、保证生产连续性的新型避雷器在线保护装置。     

氧化锌避雷器带电检测方法探讨

氧化锌避雷器带电检测方法探讨广州电力工业局李鸣洋随着电力系统的发展，氧化锌避雷器应用日益普及。目前广州电网１０ｋＶ～５００ｋＶ系统基本上全部使用氧化锌避雷器，而这些产品的制造厂很多，国内的主要制造厂有西安电瓷厂、抚顺电瓷厂、还有牡丹江电瓷厂、广州华盛...     

一种氧化锌避雷器阻性电流的提取方法

氧化锌避雷器作为电力输变电系统的一个核心保护设备,必须进行在线状态监测。文章在研究氧化锌避雷器常用的在线监测方法的基础上,提出了一种基于谐波分析法的新的氧化锌避雷器阻性电流提取方法。该方法采用准同步DFT谐波分析线性修正算法来实现氧化锌避雷器的阻性电流的测量。仿真实验和现场实验表明,该方法可行、有效,有极高的应用价值。     

基于泄漏电流分析的氧化锌避雷器故障诊断与处理

氧化锌避雷器是电网运行时防止各类电气设备遭受过电压伤害的重要保护装置,在电网中具有十分广泛的应用,因此对避雷器健康状况的监测非常重要,而测量泄漏电流是最普遍的一种监测手段.由于氧化锌阀片在发生受潮或老化后,泄漏电流尤其是阻性电流分量会有显著的变化,因此准确分析泄漏电流对诊断避雷器性能及保障电网安全意义重大.从氧化锌避雷器的结构和特性入手,对泄漏电流的分析方法进行了介绍,并将分析方法与实际案例相结合,希望能为避雷器的检修和运维提供一定的帮助.     

氧化锌避雷器在电力系统中的应用

介绍了金属氧化锌避雷器（MOA）的特性,在分析电力系统中几种典型回路操作过电压产生原因的基础上,对以MOA为主的过电压保护装置及其接线方式进行了讨论,并阐述了MOA的四星接法（TBP）在中性点非有效性接地系统中的应用,旨在全面介绍MOA在电力系统中的应用。     

氧化锌避雷器带电测量

氧化锌避雷器带电测量襄樊供电局（４４１００２）汪必生随着我国电力事业的飞速发展，氧化避雷器广泛使用于我国１０～５００ｋＶ电网中，氧化锌避雷器以优异非线性，大通流容量，持久抗老化性能显示出巨大的优势，逐步取代老式ＦＳ、Ｐｚ、ＦＣｚ、ＦＣＤ系列避雷器。氧...     

氧化锌避雷器的监测和诊断方法研究

本文氧化锌避雷器（ＭＯＡ）运行状态监测中的几个主要问题,监测原理,相间干扰电流的影响和电流信号取样方法作了简要介绍,并对ＭＯＡ运行状态的诊断方法进行了探讨。     

基于IR2103的方波逆变电路设计与分析

介绍了一种基于IR公司的2103的DC／AC方波逆变电路的设计与实现。由于全桥驱动芯片IR2103有自举供电能力,能在不使用外加隔离电源的情况下方便驱动小功率的全桥电路,与传统的逆变电路相比使用的元件少,且结构更为紧凑。并可用作HID灯的高性能的工作电源。实验结果验证了该方案是可行的。     

一种金属氧化物限压器动作电流不平衡度的预测算法

金属氧化物限压器（MOV）是串补（FSC）与可控串补（TCSC）设备中对串联电容器组进行工频过电压保护的重要设备之一,工频过电压具有作用时间长、能耗极大的特点,目前采用氧化锌阀片柱并联的方式解决耗能问题。因此,研究出合适的配片方法以及限压器电流不平衡度的预测算法对确保限压器的安全运行十分必要。文章给出了用于精确描述氧化锌阀片及阀片柱伏安特性的计算公式,并给出了经配片后的MOV阀片柱动作电流不平衡度的一种预测算法。测算结果显示,经配片后,限压器最大电流不平衡度不会超过5％。     

Investigate Weld Quality of Gas Metal Arc Welding Process Through Online Monitoring of Input Parameters

Gas metal arc welding (GMAW) is also referred as the metal inert gas (MIG) welding which is a process of welding done by the formation of an electric arc between the consumable wire electrode and the workpiece. Through the welding process, a continuous flow of inert gas is supplied, and it avoids the weld being subjected to react with at-mospheric air. The process can be automatic or semi-automatic where the main input parameters like current and the voltage can be direct and constant, respectively. Not only the current and voltage the welding quality depends on some more input parameters such as arc gap, velocity, and temperature. In this paper, we explain about a setup which is capable of real-time monitoring of input parameters mentioned above and selecting the best MIG welding parame-ters for the mild steel. The setup is composed of several sensors and microcontrollers for the collection and the measurement of the input parameters. The samples were categorized according to the federate and the voltage ad-justment of the selected welding machine. Then the final objective was to identify the samples of the weld with dif-ferent parameter changes which are monitored through the system. For the analysis, the samples were subjected to tensile and hardness tests, and microstructure tests to find the dependence of the input parameters which effect for the weld quality. Finally, the experimental results verified the effectiveness of the system for the selection of the quality weld.     

Impact of platinum contamination on ferroelectric memories

Abstract

The impact of platinum contamination on the breakdown properties of gate oxide is reported. Wafers were intentionally contaminated with 1×10¹³ to 4×10¹⁴ at/cm² Pt after a 7.5 nm gate oxide growth, 300 nm poly-silicon deposition and subsequent phosphorus doping. Breakdown characteristics were evaluated using a voltage ramp method. The current-voltage curves of MOS capacitors show very few low field breakdown events, and the main field breakdown occurs at 12 MV/cm. If compared to clean wafers, platinum does not increase the defect density seriously. It is found from the E-Ramp results that platinum contamination up to 4×10¹⁴ at/cm² does not have a pronounced effect on the gate oxide integrity if the contamination occurs after front-end-of-line processing of device fabrication.     

DSMC versus WENO-BTE: A double gate MOSFET example

Time-dependent solutions to the Boltzmann-Poisson system in two spatial dimensions and three-dimensional velocity space are obtained by using a recently developed high order WENO scheme. The collision operator of the Boltzmann equation models the scattering processes between electrons and phonons which are assumed to be in thermal equilibrium. In this paper, the deterministic numerical solutions for a double gate silicon MOSFET are compared with Monte Carlo simulations. The main aim of this investigation is to show how direct solutions of the Boltzmann transport equation coupled with the Poisson equation can, through comparisons, suggest improvements of the DSMC algorithms such as, in particular, the charge assignment to the mesh, the treatment of the boundary conditions and the free flight duration.     

金属氧化物对镉电极的影响

本文研究了几种金属氧化物对镉电极活性物质利用率以及对密封Cd/Ni蓄电池荷电保持能力的影响。结果表明,镉电极中添加MgO、ZnO和Fe_2O_3可提高活性物质利用率;添加o_2O_3则显著降低活性物质利用率。MgO、In_2O_3和ZnO的添加,提高了密封Cd/Ni蓄电池的荷电保持能力;Co_2O_3和Fe_2O_3的添加,降低了其荷电保持能力。最后,探讨了MgO和ZnO在镐电极中的适宜添加量。     

基于软件分析方法的氧化锌避雷器泄漏电流在线监测

MOA(金属氧化锌避雷器 )由于其优良的过电压保护特性 ,在电网中得到广泛应用 ,对MOA绝缘状况的监测具有重要意义。总结 4种常见的MOA泄漏电流的监测方法 ,指出各自的优点和存在的问题 ,得出一些有用的结论。设计一种基于软件分析的MOA泄漏电流测量仪 ,该测量仪在在线监测中有很好的应用前景。     

基于物联网的智能环网柜控制器的开发研究

通过技术手段实现环网柜的遥测、遥信和遥控是智能电网的发展趋势,提出了一种基于物联网的智能环网柜控制器设计,利用太阳能电池作为供电电源,改进的电力载波系统作为通信手段,实现了环网柜的智能化;设计方案性价比高,可行性较好,相对于传统的解决方案提出了一种全新的设计理念和实现方法。     

A New Design of Wide-Area MIMO Coupling Robust HVDC Supplementary Controller

A new multi-input multi-output (MIMO) robust coordination approach for the controller design of multi-infeed high voltage direct current (HVDC) system is proposed. This design will enhance the damping of certain low frequency oscillation mode. The dominant mode ratio (DMR) is applied to choose the appropriate feedback signals, while time delay of wide-area signals is considered. The Total Least Squares-Estimation on Signal Parameters via Rotational Technique (TLS-ESPRIT) algorithm serves in identifying the MIMO system model. To reach the best control effect and disturbance suppression level, the mixed H₂/H_∞ robust theory with regional poles placement is introduced to design the controller. The new MIMO design approach avoids system decoupling in complex situation, and it uses the interactions of different control loops to enhance the system's stability when most MIMO HVDC controllers are designed by decoupling strategy. Simulation results of a multi-infeed HVDC system validate the control effect and robustness of the proposed method.