Motor fault diagnosis technology is a part of that of the equipment fault diagnosis . large - sized d . c . motors are the key equipment in metallurgical enterprise , which have complicated structure and operating condition with faults in multiple source , non - linearity and in connection with wide range of knowledge . therefore , on - line faults diagnosis on d . c . motors is the important point which engineers and scientists pay great concerns on 电机故障诊断是设备故障诊断技术的一个分支，直流大电机是冶金企业的关键设备，结构复杂、工况复杂，故障呈多源性，非线性，涉及知识领域较广，因此，直流电机故障在线诊断工作一直是现场工程技术人员和科技人员关注的重点。
The multiwavelet analysis is first introduced into fault signal processing in power system , including time - frequency analysis , signal de - noising and data compression for transmission lines fault transient signal . through a great deal of simulation test , it is shown that the applications are successful and outperform the traditional wavelet analysis as a whole 本文首次将多小波分析应用于电力系统故障信号处理，包括输电线故障暂态信号的时频分析、去噪和数据压缩，通过大量仿真试验，表明多小波分析在电力系统故障信号处理领域应用总体上优于传统小波分析。
This article angle has analyzed the higher professional technical education from cbe / dacum " the electrical control technology " the curriculum ability localization , according to the higher professional technical education " the electrical control technology " the curriculum ability localization , point out the insufficiency and flaw existed in commonly used control electric appliance choice , electrical pilot wire road map , electricity control system installment , wiring craft , electrical control line fault diagnosis system approach , new starting velocity modulation equipment and control circuit , control circuit and main circuit aspect and so on 摘要本文从cbe / dacum角度分析了高职“电气控制技术”课程的能力定位，根据高职“电气控制技术”课程的能力定位，指出了现行高职“电气控制技术”教材在常用控制电器选择、电气控制线路图、电气控制系统安装、接线工艺、电气控制线路故障诊断的系统方法、新型起动调速设备及控制电路、控制电路与主电路的连接等方面存在的不足和缺陷。
This paper analyses the steady and transient character of line fault when the neutral point connects to ground in different ways . from the angle of signal processing , the wavelet analysis theory and the artificial neural networks are introduced to fault location , in which the fault character is not the steady signal but the transient signal 本文在中性点不同接地方式下，研究和分析了线路零序故障特征量的稳态和暂态特点，主要从信号处理的角度，提出将小波分析理论和人工神经网络原理运用到故障定位，将基于稳态信号的定位原理转移到基于故障特征量暂态信号的定位原理。
The feeder net model for distribution automation is built based on the nod information matrix and the line information matrix , and the nods represent the switches and the fault indicator in the distribution net . the method of fault locating offered by this paper called line fault probability method , which locates fault by calculating the fault probability of line in the net . this paper also provides a method called volts d . c . for restoration and offers the regulation of restoration 采用节点、支路信息矩阵来描述配电网络，形成面向故障自动化处理的网络数据结构；提出了基于支路故障概率的故障定位算法，并结合短路电流特性判据法来定位故障支路；在定义直流等值网的基础上，提出了优化供电恢复的直流电压降法；开发了配电网故障自动处理软件系统，并用于实际配电自动化工程中。
Based on the comprehensive analysis of the application status and the existed problems of transmission line fault location , this dissertation presented a new algorithm for fault location based on two - terminal asynchronous data , which can make correction for the integrate error of line parameter , length of transmission line , sampling value and so on . at the same time , it can work out the two - terminal asynchronous phase angle with the corrected parameters 本论文在充分分析了国内外故障测距的理论与技术以及存在的问题后，针对输电线路故障定位因线路参数变化对定位准确度的影响，提出了能够对线路的参数、长度和采样值等误差等进行综合误差修正( cie )的新算法，并利用修正后的参数来求解两端的不同步相角差。
Fault location techniques are used to pinpoint location of the fault on a tra - nsmission line . transmission line faults must be located accurately to allow maintena - nce crew to arrive at the scene and repair the faulted section as soon as possible , which can relief the burdens of patrol personnel and reduce the revenue losses due to power outage . the accurate fault location alogrithms play an important role in power system safety , economy and reliability . in this paper , diversified fault location algorithms are summarized . according to the principles of algorithms , they can be classified into two categories : impedence based algorithm and traveling wave based algorithm . based on the analysis and comparission of each algorithm , the corresponding merits and app - lication limitations are presented 精确的故障定位为现场巡线工作人员及时提供准确、可靠的信息，减轻人工巡线的负担，同时加快线路的恢复供电，减少因停电造成的综合经济损失，为提高电力系统运行的安全性、经济性和可靠性发挥重要的作用。本文总结了现有的各种测距方法，根据测距的原理将其分为阻抗法和行波法两大类，对各种算法的优缺点及适用范围进行了分析，在此基础上提出了一种组合的测距方案，并对算法进行了仿真分析。
In case of complicated dc circuit , any type of symmetrical ac system fault . dc line fault and dc line ' s recovery after fault can be more accurately simulated , and the dc line ' s dynamic response can be better represented . all the above is very important when doing the research on dc power support to ac system under emergency conditions , and has laid a solid foundation for the interaction study which will be met in a hybrid ac / dc power systems 该模型能够在对交流网络进行机电暂态计算的同时，对直流网络进行电磁暂态的计算，因而能较精确地考察暂态过程中直流线路的动态行为，并可对任意对称的交流系统故障、直流线路故障以及故障后直流输电系统的恢复等过程进行仿真，且仿真时间较短，为在复杂系统中研究直流输电系统与交流输电系统间的相互作用奠定了基础。
The safety of transmission line plays a important role in power system safety it is not only the requirement of ensure supply power reliability , but also the necessary precondition of enhance power system stabilization , to remove faulty line quickly and accurately , also keep non - faulty line continuous work when some transmission line faults current differential protection is a kind of simple , reliable and good - selective protection manner to any variety of transmission lines , power system development needs current differential protection apply to transmission lines , moreover the advancement of electric and communication technology enable current differential protection apply to transmission lines firstly , the paper discusses , analyses the research and application transmission line protection in detail , compare the principle and realistic presupposition of general line pilot protections secondly , because conventional current vector differential protection are influenced easily by load current and transitional resistance , in order to at the same time quicken protection act , the principle and criterion include work characteristic of differential protect based on fault component sampled values are studied , results shows that differential protect based on fault component sampled values excels general vector current differential protection in reliability , sensitivity and anti - saturation of current transformer in addition , synchronous current sampling methods at all terminals of line is analyzed and estimated lastly , the principle and criterion . also device design about current sampling values differential protection based on optical fiber communication , which apply to short transmission lines are concretely investigated , 基于基尔霍夫定律的电流差动保护无论对于何种形式的输电线路都是一种简单、可靠、选择性强的保护形式，电力系统的发展使得电流差动保护应用于线路保护成为需要，而电子、通信技术的发展使得电流差动保护应用于输电线路成为可能。首先，本文对目前线路保护的研究和实际应用情况进行了讨论和分析，比较了常用线路纵联保护的实现原理和实现条件及优缺点。其次，针对常规相量电流差动保护易受正常负荷电流和故障过渡电阻影响的缺点，同时为加快差动保护的动作速度，对基于故障分量瞬时采样值电流差动保护的原理、判据、动作特性等作了讨论和分析，结果表明基于故障分量瞬时采样值电流差动保护在可靠性、灵敏度、抗电流互感器饱和方面明显优于常规相量电流差动保护，对电流差动保护各端的同步采样方法和数据通信也进行了分析和评价。
And the main tasks of the article are as follows : ( 1 ) the research object , ship electric power system and its faults are analyzed systematically , including the reasons of the faults , the evolvement relationship of the faults , the line fault and the electrical equipment fault 针对这种情况，本论文开展了用专家系统的方法对船舶电力系统进行故障诊断的研究工作，其具体工作如下： ( 1 )对研究对象，即船舶电力系统以及船舶电力系统的故障进行了系统的分析。包括船舶电力系统的故障产生原因、故障演变关系、输电线路及各电力设备的故障分析。
