故障

As a fault occurred on a distribution line, the breaker and non-communication Protection in the faulted segment's ends will operate to clear the fault segment. The segments of lost power supply will again get power supply from back-up source by the control unit, so that its power supply will be restored.

配电线路发生故障后，故障区段两端的断路器在配电线路无通道保护的作用下动作跳闸，切除故障部分；失去电源的非故障区段在备用电源自动投入单元的控制下，投入备用电源，恢复相应区段的正常供电。

Taximeters installed in taxis are made by using of single-chip technology in our country. For common faults and according to the internal structure of the taximeter, working principles and functions of different part in its circuit, this article described how to determine fault locations quickly and made deep analyses about how to eliminate faults effectively. And specific methods to deal with failure are given too.

摘 要：我国出租汽车上所用的计价器是应用单片计算机技术制造的，针对微电脑式出租汽车计价器使用中出现的常见故障，根据出租汽车计价器的内部结构和各部分电路的工作原理及功能，就如何迅速确定故障点从而有效排除故障进行了分析，并给出处理故障的具体方法。

Main research content includes:1 The relationship between common faults and the dissolved gases in the transformer oil are analyzed. Been exposed to the effects of heat and electricity, the oil and the organic insulation material of the oil-filled transformer which is running will be aged and decomposed gradually, several kinds of gases will be produced, moreover the components and contents of dissolved gases are tied up to the type and degree of the fault.

主要研究内容有：①电力变压器运行中常见故障与油中气体关系研究，对于运行中的充油变压器：在热和电的作用下，变压器油和有机绝缘材料将逐渐老化和分解，产生多种特征气体，而特征气体的组分含量与故障类型及故障严重程度有非常密切的关系，变压器油中溶解气体的成分和含量能有效体现运行变压器内部的绝缘故障情况。

Firstly, This text has described information fusion technology characteristic, form structure and concrete processing method, and application of information fusion in fault diagnosis proves the feasibility and validity from the angle of information theory. Based on this,it is combined the fault diagnosis of aeroengine with Information fusion, a method and model which the fault diagnosis of aeroengine information fusion is brought forward. a research which combined neural networks with D-S evidence is brought forward. Based on the analysis of single neural network characteristic, the model of roted neural network is put forward. With the simulation based on the example, we can know evidence theory fusion improved the fault diagnosis It is hard to give the basic probability function in the process of using the evidence theory, So the model based on network and D-S evidence is put forword.

本文首先论述了信息融合技术的特点、形式结构和具体的处理方法，并从信息论的角度论证了信息融合技术在故障诊断中的可行性和有效性；在此基础上，将航空发动机故障诊断与信息融合相结合，提出了一种基于信息融合技术的发动机故障诊断模型和方法，并在此基础上，提出和分析了基于人工神经网络和D-S证据理论的信息融合故障诊断，研究了神经网络的建模方法、组建原则和实现策略，并结合诊断实例进行了分析；提出了基于D-S证据理论的决策融合，阐述了D-S证据理论的方法，模型，并结合算例进行了分析。

Based on the analysis of the research in the faults diagnosis of electromechanical system and its application both in home and abroad at present, this thesis researches into the selection of observation modes, the collection of fault portents and the pattern recognition of system faults in the faults diagnosis of electromechanical system.

本文在分析目前国内外机电系统故障诊断研究和应用状况的基础上，研究了机电系统故障诊断中观测方式的选择、故障征兆的提取、系统故障模式识别这三个主要环节。

Firstly, a mathematic model was constructed to deal with fault isolation. This model mainly considered the associations among fault sources and available testing of hierarchical system, the affiliation of faults with replaceable units in different levels, the prior probability of fault sources and the available testing costs. Secondly, a quasi multi-step look-ahead search algorithm was presented which employed the information gain as its heuristics. This algorithm could realize optimization of testing sequence in different isolation levels.

首先基于层次系统故障与测试之间的关联关系，以及故障与不同层级可更换单元的隶属关系，结合故障的先验概率与可用测试成本，构造了层次系统故障隔离问题的数学描述模型；然后以信息增益为启发策略，提出了一种准多步前向搜索算法，实现了不同隔离级的测试顺序优化。

This dissertation, orienting to practical engineering applications, takes the lead in carrying out domestic investigations on expert system of fault detection and diagnosis for aerospace propulsion system and has successfully established a well-performed expert system for fault detection and diagnosis based on advanced theories and technologies. What is more, some research has been conducted on the new algorithmic method for fault detection and diagnosis; bondgragh method has been successfully used for fault detection and diagnosis in aerospace propulsion in the dissertation.

本文在国内首先应用先进的理论和技术，面向工程应用的实际，开展了空间推进系统故障检测与诊断专家系统的研究工作，并建立性能良好的故障检测与诊断专家系统；还进行了故障检测与诊断新算法研究，成功的运用键合图理论完成了空间推进系统的故障检测与诊断研究。

The frequency changer Surpasses the voltage fail safe is the frequencychanger middle DC voltage after achieved the degree of hazard adoptsprotective measures, this is a big flaw which the frequency changerdesigns, causes this breakdown reason in the frequency changer actualmovement many, may adopt the measure are also more, when processesthis kind of breakdown must analyze the clear breakdown reason, haspointed takes the corresponding measure to process.

变频器过电压故障保护是变频器中间直流电压达到危险程度后采取的保护措施，这是变频器设计上的一大缺陷，在变频器实际运行中引起此故障的原因较多，可以采取的措施也较多，在处理此类故障时要分析清楚故障原因，有针对性的采取相应的措施去处理。

The frequency changer Surpasses the voltage fail safe is the frequencychanger middle DC voltage after achieved the degree of hazard adoptsprotective measures, this is a big flaw which the frequency changerdesigns, causes this breakdown reason in the frequency changer actualmovement many, may adopt the measure are also more, when processesthis kind of breakdown must analyze the clear breakdown reason, haspointed takes the corresponding measure to process.

摘 要：摘要变频器过电压故障保护是变频器中间直流电压达到危险程度后采取的保护措施，这是变频器设计上的一大缺陷，在变频器实际运行中引起此故障的原因较多，可以采取的措施也较多，在处理此类故障时要分析清楚故障原因，有针对性的采取相应的措施去处理。关键词变频器电动机整流 Abstract ：The frequenc。。

This article analyzes systematically the work process of fuel injection system in detail. It analyzes the fault fundamentals and its influence of three coupling parts in the high pressure oil road and the injection process, three coupling parts include plunger coupling parts, delivery valve coupling parts and needle valve coupling parts. It discusses the pulse situation of fuel pressure under the every kind of typical fault model, and regarding this as according to pick up the pulse signal of pressure from the high pressure pipeline, and process wavelet decomposition, picks up the of parameter fault, make use of the model identification technique, realizes to the intelligent diagnosis of fuel injection system fault.

文中系统地分析了燃油系统的工作过程，对高压油路中三偶件(柱塞偶件、出油阀偶件、针阀偶件)、喷油过程等的故障机理及其影响进行了分析，讨论了各种典型故障状态下的燃油压力波动情况，并以此为根据，从高压油管处提取压力波动信号，提取故障参数，利用模式识别技术，实现了对燃油系统故障的智能化诊断。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。