基于故障映射的并行故障仿真方法

提出了基于故障映射的4值并行故障仿真方法.这一方法首先把电路划分成无扇出区域和扇出茎区域,然后将非扇出茎故障映射为扇出茎故障,减少了需要显式并行仿真的故障数目,提高了仿真器的性能.实验结果验证了文中方法的有效性.     

混合云环境中改进的工作负载分配方案

研究了混合云环境下计算任务在公有云和私有云中的高效安全分布机制;然后,针对使用公共云引入的不同层级约束,将最优风险感知工作负载分布问题描述为工作负载响应对间最小化问题,提出一种可以实现检索工作量最优分布的动态规划算法,可在已知检索工作负载和公共云使用边界(资源分配成本和敏感性数据泄露)的条件下,搜索出最优计算和数据划分方案;最后,在各种参数配置下,基于标准的TPC-H基本数据集,对提出的算法进行了全面评估.实验结果表明,新方案通过利用混合云组件,且不违反先前确定的任何公共云使用约束的情况下,显著提升了系统性能.     

Fault Modeling and Fault Simulation in Mixed Micro-Fluidic Microelectronic Systems

Developments in electronic/fluidic microsystems are progressing rapidly. The ultimate goal is to deliver products in the 10,000 fluidic reaction-wells range. Exciting applications include massive parallel DNA analysis and automatic drug synthesis. Until now, only functional testing has been used to guarantee the quality of micro-fluidic systems after manufacturing.In this paper, defect-oriented test approaches developed in analogue fault modeling and simulation have been used to predict for the first time the faulty behavior of micro-electronic fluidic microsystems. The modeling is targeted for use in complex electronic/fluidic microsystems employing commercial microsystem CAD tools. It enables a measure for the quality of these systems based on the performed (functional) tests and can be a guide for future test-stimuli generation and yield prediction.     

相位法配电网故障定位系统的仿真分析

根据零序电流相位法故障定位的原理,可以判断配电网的故障区段。文中利用Matlab/Simulink中的仿真模块,对中性点不接地系统进行仿真分析。介绍了仿真模型的搭建,对不同状况下的接地故障进行仿真分析,包括改变接地电阻的大小、线路长度以及有无负载等,总结其影响因素。仿真结果与理论推导一致,从而为其实用化奠定了基础。     

Parallel sequence fault simulation for synchronous sequential circuits

A novel parallel sequence fault simulation (PSF) algorithm for synchronous sequential circuits is presented. The algorithm successfully extend the parallel pattern method for combinational circuits to sequential circuits by proposing a multiple-pass mechanism to overcome the state dependency in sequential circuits. The fault simulation is performed in parallel by partitioning the entire sequence into subsequences of equal length. Furthermore, techniques are developed to minimize the number of simulation passes. Notably, two compact counters, C _x and C _d , are proposed to faciliate the early stabilization detection of faulty circuit simulation with minimum space overhead. The experimental results on the benchmark circuits show that the speedup ratio over a serial sequence fault simulator based on ROOFS is 9.16 on average for pseudo random vectors. The parallel sequence algorithm of PSF is especially adaptable to parallel and distributed simulation which exploits sequence partition.     

Fault Modeling and Simulation Using VHDL-AMS

Fault simulation is an accepted part of the test generation procedure for digital circuits. With complex analog and mixed-signal integrated circuits, such techniques must now be extended. Analog simulation is slow and fault simulation can be prohibitively expensive because of the large number of potential faults. We describe how the number of faults to be simulated in an analog circuit can be reduced by fault collapsing, and how the simulation time can be reduced by behavioral modeling of fault-free and faulty circuit blocks. These behavioral models can be implemented in SPICE or in VHDL-AMS and we discuss the merits of each approach. VHDL-AMS does potentially offer advantages in tackling this problem, but there are a number of computational difficulties to be overcome.     

配电网故障选线与定位发展现状

本文主要从配电网故障选线与定位发展现状出发.首先分别简单重点介绍了三种接地线路故障的相特征改变分量,利用三种接地线路故障的相特征暂态分量特征,以及利用三种接地线路故障的相特征暂态分量的三种定位选线技术方法,分别为智能识别特征分析法、行波定位测距法和智能化行波测距选线技术.针对各种分析方法的优劣势等并做出了详细分析和总结...     

Test Generation and Fault Simulation for Cell Fault Model using Stuck-at Fault Model based Test Tools

Cell Fault Model (CFM) is a well-adopted functional fault model used for cell-based circuits. Despite of the wide adoption of CFM, no test tool is available for the estimation of CFM testability. The vast majority of test tools are based on the single stuck-at fault model.In this paper we introduce a method to calculate the CFM testability of a cell-based circuit using any single stuck-at fault based test tool. Cells are substituted by equivalent cells and Test Generation and Fault Simulation for CFM are emulated by Test Generation and Fault Simulation for a set of single stuck-at faults of the equivalent cells. The equivalent cell is constructed from the original cell with a simple procedure, with no need of knowledge of gate-level implementation, or its function. With the proposed methodology, the maturity and effectiveness of stuck-at fault based tools is used in testing of digital circuits, with respect to Cell Fault Model, without developing new tools.     

Hybrid Fault Simulation for Synchronous Sequential Circuits

We present a fault simulator for synchronous sequential circuits that combines the efficiency of three-valued logic simulation with the exactness of a symbolic approach. The simulator is hybrid in the sense that three different modes of operation—three-valued, symbolic and mixed—are supported. We demonstrate how an automatic switching between the modes depending on the computational resources and the properties of the circuit under test can be realized, thus trading off time/space for accuracy of the computation. Furthermore, besides the usual Single Observation Time Test Strategy (SOT) for the evaluation of the fault coverage, the simulator supports evaluation according to the more general Multiple Observation Time Test Strategy (MOT). Numerous experiments are given to demonstrate the feasibility and efficiency of our approach. In particular, it is shown that, at the expense of a reasonable time penalty, the exactness of the fault coverage computation can be improved even for the largest benchmark functions.     

智能型故障指示器在配网中的应用

随着社会发展和人们生活水平的不断提高,提高供电质量和供电可靠性是每个供电企业都面临的最实际和迫切的需求。由于县城配电网存在点多、线长、面广及接线方式复杂多变等特点,因此在线路故障时,要靠配电运行人员沿线查线,直到发现故障点,且故障查找困难,难以保障及时恢复供电。近年来,线路故障指示器在10 kV配电线路上得到了广泛应用,减轻了巡线人员的劳动强度,大大提高了工作效率,缩短了停电时间。文中介绍一种集短路、接地监测、远程通信为一体的智能型故障指示器在德清配网中的应用情况。     

三相异步电动机故障仿真

通过Matlab／Simulink软件搭建三相异步电动机模型,对其过载、堵转、短路、定子匝间短路等典型故障进行仿真分析,给出定子电流的变化特征,为以电流为判据的电动机保护装置设计提供理论依据。     

Fault Simulation for Analog Circuits Under Parameter Variations

Analog integrated circuit testing and diagnosis is a very challenging problem. The inaccuracy of measurements, the infinite domain of possible values and the parameter deviations are among the major difficulties. During the process of optimizing production tests, Monte Carlo simulation is often needed due to parameter variations, but because of its expensive computational cost, it becomes the bottleneck of such a process. This paper describes a new technique to reduce the number of simulations required during analog fault simulation. This leads to the optimization of production tests subjected to parameter variations. In Section 1 a review of the state of the art is presented, Section 2 introduces the algorithm and describes the methodology of our approach. The results on CMOS 2-stage opamp and Fifth-order Low-pass switched-capacitor Filter are given in Sections 3 and conclusions in Section 4.     

基于PSpice的电路故障注入仿真分析方法研究

研究了一种利用EDA软件来进行电路故障注入仿真分析的方法,对故障检测率进行了估算.以某型导弹的舵机控制电路为例,进行了验证.结果表明,该方法对提高系统的测试性有一定的实用价值.     

基于故障树分析法的配电终端失效研究

配电终端的可靠性对配电自动化有效运维至关重要,文章结合故障树分析法与比例分摊原则,提出了适用于配电终端失效研究的一种方法。该方法通过分析各配电终端各模块工作与失效机理,建立配电终端的故障树分析模型,采用故障树分析法推导顶端事件失效计算公式;根据失效分摊法计算出各模块对系统失效的贡献比例,并据此识别配电终端的薄弱环节。最后以重庆某地区配电终端现场运行数据为样本,验证了该方法的有效性。     

水电仿真系统中厂用变压器模糊故障综合诊断

在总结领域专家经验基础上,采用模糊诊断方法,列出了仿真系统中变压器的征兆集和故障集,并根据征兆集和故障集的相互关系构建模糊诊断矩阵;通过模糊关系矩阵运算,提出最大隶属度原则判断变压器故障原因。测试和评价结果表明模糊诊断在仿真系统中的有效性和可行性。     

配电网故障自动定位系统的应用研究

随着生活品质的提高,居民对用电水平和供电质量的要求也在不断提高.但由于配电网涉及范围较广,出现故障时势必会给相关用户供电质量造成影响,因此在大范围下如何有效的查找故障非常关键.故障自动定位系统是一种自动化新技术,在准确判断故障位置,提高工作效率上有着非常重要的作用.文中对故障自动定位系统的相关情况进行了简单分析,并对其实际运用情况进行了论述.     

10kV配电网线路故障自动定位及监测系统

文章重点介绍了对10 kV配电网非接地系统的故障预警和故障定位的监测系统,利用安装在线路上的故障定位仪对故障电压和电流行波实现多点同步监测,通过GPRS网络将故障信息发送到控制中心,在GIS系统上标定故障地点,指示维护人员快速隔离故障,及时恢复供电。     

一种基于计算机的电控发动机故障模拟实验台设计

针对现有电控发动机故障模拟实验台用于实训教学中的不足,设计了基于计算机测控技术的实验平台方案。通过在计算机上设置故障点,模拟各种工况下的发动机电气线路故障,并把发动机节点电压和传感器波形投影在荧幕上,解决了仪表测量的场地限制问题。该实验台故障设置方便,教学效率高,适合整班教学。     

含光伏系统的微网并入配电网的故障区段定位研究

为解决传统配电网继电保护故障定位系统难以应对含光伏系统的微网并网运行的问题,提出了一种集中与分布式相结合的故障区域检测与隔离的保护方法。根据配电网的拓扑结构和假定的网络功率流向形成网络描述矩阵,在配电系统发生短路故障时,根据被保护线路故障的电压、电流分量的相位关系确定故障正方向,并形成故障信息矩阵。以故障信息矩阵对网络描述矩阵进行修正而形成故障判断矩阵,利用故障定位判据逐一查询故障判断矩阵即可快速准确地定位出故障位置,从而发出跳闸命令切除故障。     

基于故障仿真和粗糙集的复杂电路板测试性分析

针对关联模型在复杂电路板测试性分析中对不确定问题描述与分析的缺陷,提出了基于故障仿真和粗糙集的测试性分析方法.通过故障仿真生成条件属性集,利用粗糙集将其约简,最终形成分辨矩阵,从而评价电路的测试性水平.最后通过实例分析验证了方法的有效性.