126kV高压开关电器产品的简介

通过各种开关电器进行不同组合,来实现相同的功能,对于126kV开关电器产品的应用及选型进行简单介绍.     

电容式接近开关

一、概述电容式接近开关在国外应用十分广泛,已成为工业自动控制中不可缺少的检测电器.这种开关在我国刚刚诞生,就深受各行业的欢迎,为各行各业自动化水平的进一步提高创造了有利条件.该接近开关的主要特点:既能无接触地检测金属材料,又能无接触地检测非金属材料(如木料、玻璃、塑     

接近开关的选型方法

0引言 近几年,接近开关的应用越来越广泛,并逐步取代了传统的限位开关.接近开关与传统的限位开关相比,具有限位准确,精确度及使用频率高,响应快等特点,在现代企业中应用广泛.     

一种ATE开关最短路径搜索算法

在自动测试系统中,开关矩阵起到连接被测组件与信号激励/测量仪器的重要作用.测试系统需要在已知的矩阵资源中进行自动的路径搜索,进而提供所需的电路连接.本文通过归纳自动测试系统中几种常用的开关形式及互连关系,从而提出了一种新的开关模型建立方法.使用这种方法建立的模型,将开关矩阵表示为三种统一的二叉树结构,便于转化为相应的数据结构供计算机处理.在此模型的基础上,应用宽度优先搜索算法寻找矩阵开关最短路径.结合在实际应用中的使用特点,对算法进行改进,进一步提高了算法的搜索效率.最后通过一个具体的实例,建立模型并应用算法予以实现.     

直流开关的设计及其动态特性

本文介绍了一种可用于磁流体发电机与负荷调节系统联接的保护用高速直流开关.分析了MHD发电机和逆变器的模型.并通过对不同工况下直流开关动态过程的模拟.给出了开关中各器件参数的选择原则.     

大功率开关磁阻电机无位置控制系统

与传统电机控制系统相比,开关磁阻电机(Switched Reluctance Motors,简称SRM)结构简单、经济、高效,但电磁特性呈现复杂非线性,运行依赖于转子轴位置编码器限制了SRM控制系统应用场合.此处给出一种建立SRM非线性模型的方法,基于样机132 kW SRM样机非线性模型,设计了一种基于TI微处理器T...     

多次重燃弧VFTO的仿真隔离开关模型研究

目前的VFTO仿真用隔离开关数学模型过于简单,不能反映开关动作全过程的波形。本文在对1100kVGIS隔离开关分合小电容电流实验的基础上,初步建立了可以反映多次重燃弧过程的隔离开关模型,并从间隙击穿、高频电弧熄弧判据、弧道电阻模型等方面进行了相关的讨论,得到了与实验负载电容上"台阶"状电压波形相符较好的仿真波形,为后续仿真隔离开关模型研究做好铺垫。     

谐振软开关技术及其在逆变电源中的应用

为了获得更高的性能指标、更高的效率、更高的功率密度，软开关技术已经在DC／AC逆变器中得到了广泛的应用。然而，在这一领域中所做的大量工作并没有得到广泛的认识，撰写本的目的在于尝试着对软开关技术的DC／AC电路进行一个简单的分类，并对其工作原理、性能、设计上的局限性及其优缺点进行扼要的分析。也重点讨论了谐振软开关技术在逆变电源中的应用。     

基于结构参数的开关磁阻电机非线性模型

开关磁阻电机(SRM)具有简单的结构,但其电磁关系却很复杂,且具有深度局部饱和效应,从而造成其高度的非线性。这是导致其精确数学模型难以建立的主要原因之一。文章根据给定的一套完整的电机结构参数,应用改进的快速非线性法和快速非线性仿真法,并给出相应的改进程序,将其应用在Matlab/Simulink环境下,建立了一种新型的开关磁阻电动机非线性仿真模型。仿真结果证明:该模型与现有的线性模型和准线性模型相比有很大改进,其结构较为简单,结果较为精确,能够准确反映开关磁阻电机的各项稳态性能,若在此模型基础上加上调速控制环节,对于有效分析开关磁阻电机各项性能和深一步研究SRM控制算法具有深刻意义。     

正反调管型开关的结构特点

1前言 为满足无励磁分接开关加大容量的需求,我公司研发了具有自主知识产权的正反调管型分接开关.该开关构造严谨,操作简明.下面对其作一简单介绍.     

Modeling threats

This paper discusses the prior information of choosing model parameters for constant threat from well planned, sophisticated and coordinated terrorist operations against geographically diverse targets, which causes significant loss to human life and property. A semiautomated model-based tool to detect and track terrorist activity are developed based on the analysis of prior terrorist attacks through the clues about the enabling events and the information from open sources. A pattern of transactions is a potential realization and prediction of a possible terrorist event. The HMMs is a stochastic model used to detect the monitored terrorist activity and measure local threat levels. The Bayesian network probabilistic model is well-suited for modelling the global threats and for computing/assessing the overall threat. Optimization techniques can be used to allocate counter terrorism resources and software to track multiple terrorist activities using multitarget tracking algorithms for intelligence analysis.     

HBT Modeling

III-V heterojunction bipolar transistors (HBTs) enjoy several advantages over their conventional silicon cousins. These include: (1) a thinner base and lower base resistance which yields higher gain and f_max; (2) high breakdown voltage; (3) low parasitics; (4) high power density. The combination of a thin base (higher f_T), low base resistance (higher f_max), and low parasitics in particular make HBTs a suitable choice for high- frequency applications.     

Modeling flight

The author described a program, which provides a framework and a simple set of generic equations that may be used to simulate the in-flight characteristics of a conventional aircraft. Secondarily, the model will have realistic behavior when compared to existing aircraft. The implementation is explained by describing the major areas that constitute the model. These areas are: constants, aircraft parameters, variables, model equations, time history calculations, control input, and graphical presentation. The simulation will run, in real-time, on an IBM PC/AT class of computer. The model framework is sufficiently robust to allow the accuracy and completeness of the simulation to be modified and extended     

面向负荷建模的微型燃气轮机建模及其等效描述

为研究考虑微型燃气轮机(MT)的配电网综合负荷建模,在构建适合分布式电源的MT发电系统的基础上,详细阐述了各功能模块的模型和控制策略;通过对暂态过程中MT发电系统的动态运行特性分析,可以将MT看做是一个功率消耗为负的广义动态负荷,进而提出一种以永磁同步发电机转子角速度为状态变量的一阶微分状态方程模型来等效描述MT发电系统的动态特性;通过对不同程度扰动下的仿真建模比较分析,验证了该等效描述模型的有效性.     

Modeling Electricity Auctions

The recent debates over discriminatory versus uniform-price auctions in the U.K. and elsewhere have revealed an incomplete understanding of the limitations of some popular auction models when applied to real-world electricity markets. This has led some regulatory authorities to prefer discriminatory auctions on the basis of reasoning from models which are not directly applicable to any existing electricity market. Vickrey auctions, although often recommended by economists, have also been ignored in these debates.     

Ferroic Hysteresis Modeling

Ferroic hysteresis modeling is an approach applicable to study lagging relationship between ferroic properties and external-dynamic-perturbation behaviors. The understanding to the lagging hysteresis behaviors, such as hysteresis area, coercive field, or remnant magnetization/polarization, is essential to the material-industry development. In this review, fundamental analysis as a microscopic study, including spin models, mean-field method and Monte Carlo simulation, and data processing analysis as a linking bridge between macroscopic analysis and the experiment results, such as the artificial neutral network (ANN) and Fourier analysis, were elaborated on how they can be used to model the dynamic ferroic hysteresis. Then, ferroic behaviors were explained on how they depend on the external perturbations, such as the field parameters and temperature. The responses of ferroic behaviors on these factors, in both qualitatively and quantitatively, were also discussed in details.     

Modeling ESD protection

This work presents the modeling and simulation of ESD circuit design protection. The electrostatic discharge (ESD) is a charge rebalancing process between two adjacent ICs. The ESD can cause IC failure during the manufacturing, the testing, the handling and the assembly of integrated circuits (ICs). ESD protection design methodology needs to be as systematic and transferable as possible. The empirical, trial and error method for creating ESD protection schemes is based on fabricating several test protection structures, gradually applying increasing voltage pulses and then measuring the functionality of the protection structures. This method is time consuming and destructive in nature. The model could be used to optimize the ESD circuit's design and predict its protection performance. A combination of bias conditions and layout parameters could maximize the ESD robustness device. This optimization can be achieved by developing simulation tools for ESD circuits. ESD is a phenomenon that causes reliability problems and even permanent damages to the IC since the goal is to find the voltage and the current limits before the device fails permanently.     

开关变换器的传输线模型与数字仿真研究

针对变换器的平均分析法无法分析变换器瞬态过程和分布参数对系统动态性能影响的问题,研究了基于变换器传输线建模技术的数字仿真方法,提出了电路元件电容、电感、开关器件和开关变换器的数字离散仿真模型,并进行了实验研究。这种离散建模技术以传输线理论为分析基础,得到的变换器数字仿真模型只与系统组成结构有关,而与系统中的开关状态无关。实验结果表明,与原有的分析变换器暂态过程的离散分析方法相比,该方法使用简单,物理概念明确,由于采用无源线性网络作为建模基础,变换器传输线建模方法的数字仿真算法具有无条件的数值收敛。     

Modeling and simulation for hybrid electric vehicles. I. Modeling

A model for the hybrid electric vehicle (HEV) powertrain simulation has been constructed with a specific power control strategy for an electric-assisted HEV in parallel configuration. The HEV was built by the University of Tennessee, Knoxville. Experimental procedures and data analysis for characterizing power output from the battery and the auxiliary power unit (APU) are presented. The model is implemented based on the empirical formulation and power control scheme, a power control strategy by means of throttle position. It also incorporates regeneration and regenerative braking for battery capacity recovery. The model allows for real time evaluation of a wide range of parameters in vehicle operation as a HEV, a pure electric vehicle, or as a conventional vehicle.     

Modeling of laser annealing

Processes inducing micro- and nano-structural modifications of materials play a crucial role in the advanced technology. In particular, laser irradiation attracts a great interest as a tool for the localized thermal treatment (laser thermal annealing) when the global heating of the sample could be detrimental. With the expansion of the application fields, a research effort is required to understand the kinetics in systems subjected to extreme transient excitations induced by the interaction with the laser light. Modeling and simulations cover a relevant part of this research effort. In this paper we review the current status of the laser annealing modeling. The theoretical analysis will be restricted to the heating stage of the irradiation, i.e. the ultrafast energy transfer from the electronic states to the lattice vibrations will not be considered. Therefore, the timescale of the process must be larger than ～1 ns. Models, numerical methods and applications to the experiments will be presented to deal with different questions. Among them: the simulation of the thermal field when the heat absorption depends consistently on the temperature, the prediction of a phase change kinetics in a melting process including the redistribution of alloyed systems, the damage evolution in the transient non-uniform thermal field promoted by the irradiation induced kinetics, the related dopant activation kinetics. Numerical techniques include: continuum, kinetic Monte Carlo and molecular dynamics approaches.