故障电流

This paper presents synthetic detecting fault feeder method based on the method of summation of mutual integral of transient current for intermittent arc earth fault and the method of summation of admittance mutual difference and fused current method for steady earth fault.

提出了基于电弧接地故障的暂态电流互积求和选线法和针对稳态接地故障的导纳互差求和选线法和融合电流选线法的综合选线方法。

The feasibility,effectiveness and limitation of four improvement measures are studied:raise protection settings or prolong protection delay;apply inverse time limit ;use additional criterion to distinguish valve fault from AC system fault;and adjust 100 Hz protection configuration principle.

为减小交流系统故障期间直流100Hz保护动作的概率，利用PSCAD/EMTDC仿真分析软件，就阀故障和交流系统故障时直流线路50Hz/100Hz电流特性进行了分析，研究了提高保护定值或延长保护动作延时、采用反时限特性、利用附加判据区分交流故障和阀故障、调整直流100Hz保护配置原则4种措施的可行性、使用后的效果及局限性。

According to the superposition principle of electric circuits, the post-fault power network is equivalent to the superposition of network in normal state and that composed by fault components; then taking single-phase system for example, the fault distance and asynchronous time are taken as unknown numbers and the fault location equations for normal voltage and current phasors as well as fault components are established; and then the analytical expression for fault distance is deduced, in addition the recognition method of false root is given.

该算法根据电路叠加原理，将故障后的网络等效为正常状态网络和故障分量网络的叠加，然后以单相系统为例，以故障距离和非同步时间作为未知数，对正常电流电压相量和故障分量分别建立测距方程组，推导出故障距离的解析表达式，并给出了伪根的识别方法。

And based on the analysis on the relationship of the positive and the negative sequence impedance,also the positive and negative fault component current under simple and duplicate fault conditions,a cross-country fault identifier is proposed in this paper.

同时通过对线路发生单纯性故障与跨线故障情况下的正、负序故障分量阻抗关系和正、负序故障分量电流幅值关系的分析，提出了一种判别电力系统发生跨线故障的判别元件。

Based on the analysis on the relationship of the positive and the negative sequence impedance, also the positive and negative fault component current under simple and duplicate fault conditions, a cross-country fault identifier is proposed.

通过对线路发生单纯性故障与跨线故障情况下的正、负序故障分量阻抗关系和正、负序故障分量电流幅值关系的分析，提出了一种判别电力系统发生跨线故障的判别元件。

Under the circumstance of simple fault on double circuit transmission lines, the positive-sequence impedance is equal to the negative-sequence impedance, and the positive fault component current is equal to or greater than the negative circuit.

文中通过对线路发生简单故障与跨线故障情况下的正、负序故障分量阻抗关系和正、负序故障分量电流幅值关系的分析，提出了一种判别电力系统发生跨线故障的判别元件。

Moreover, in IDDT diagnosis, the conception of fault feature curve and feature space is proposed to diagnose the fault in the analog and mixed-signal circuit.

此外，对动态电流故障诊断算法提出特征空间和特征曲线的概念，以实现对动态电流信号中的故障信息的有效提取。

So, it is very difficult to monitor and protect the rotating rectifier. This paper theoretically analyses the armature current and magnetomotive force in AC exciter of brushless synchronous machine with rotating rectifier. Under the normal or fault conditions of rotating rectifier, the mathematical expressions of the armature current, the m.m.f and induced electromotive force are approached.

本文通过对旋转整流器在正常与故障状态下的交流励磁机电枢电流和电枢电势作了初步的理论分析，推导出旋转整流器在正常与故障状态下电枢电流、空间谐波合成磁势及其感应电势的数学表达式。

The paper puts forward a set of faults diagnosis methods of testing the noise of the three-phase motor current which shows the characteristics of the motor faults, and multi-varieties time series models of the noise is established, the multi-varieties residual series is changed to the monistical as the fault detection index.

提出以测试电机的三相电流噪声为电机故障特征信号的诊断方法，建立电机电流噪声多元时序模型，将时序模型的多元残差序列化为一元序列作为故障总体检测指标。

Based on the voltage pulse width modulation control strategy with single transistor chopped, the behavior patterns of chopping current and freewheeling current were analyzed under the single phase faults of power converter.

基于电压脉宽调制斩单管控制策略，分析变换器单相功率管故障情况下，斩波电流和续流电流的故障表现。

Life. But the intrinsic way of the Internet by wire confines accessing and using of the network information.

然而，Internet固有的有线连接方式大大限制了人们对网络信息的访问和使用。

I have a strong persuasion that this is true .

我坚信这是正确的。