电源故障

This paper proposes an application of the method of fault-diagnosis with fuzzy abduction in electric power systems.

讨论了一种模糊外展故障诊断方法在电源系统应用。

Because of short of power sources in the altiplano, very long feed line of power distribution system have to be used when one of the substations is failed to operate, in order to g.

由于正在建设中的青藏铁路地处高原、电源稀缺，在某些变电所退出运行的情况下，不得已采用超长距离供电以保障对沿线负荷的电力供给，因此，超长距离供电线路的单相接地故障选线问题值得研究。

First of all, we analogize out the calculation formula of short circuit current in the distribution systems with dispersed generations through basic circuit theory.

文中首先以电路分析原理推导出含有分散式电源之配电系统的各种短路故障电流计算公式，续由这些公式分析在甚麼情况下的短路电流会最大以及并联位置和产生之短路电流的关系如何，最后利用电脑程式模拟并验证推论结果的正确性。

The existence of fault resistance may add an additional reactive or capacitive component to the impedance seen by the protection.

在双电源系统中，由于对侧系统助增电流的影响，保护测量到的阻抗会偏离故障线路的实际值，从而引起距离保护发生超越或缩短保护距离。

This paper shows the mathematic models and the calculation methods of the transient simulation in port equation form with full consideration of the periodic part and the nonperiodic part of the short circuit current and put the transformer, transmission line and the infinite power source in consideration. In resistance style fault it has perfect flexibility.

本文在充分考虑到短路电流的周期分量、非周期分量及带有变压器、线路和无穷大电源的情况下，给出了端口方程方法的机网暂态仿真研究数学模型和求解方法，结合电阻型故障模型，使故障仿真具有很强的灵活性。

Such failures are usually due to memory or power quality problems, of course, the system restarts there may be adverse or other CPU cooling caused by human error, which can only use step-by-step rule out the possibility of elimination.

此类故障一般是由于内存条或电源质量有问题造成，当然，系统重新启动还有可能是CPU散热不良或其他人为故障造成，对此，唯有用排除法一步一步排除。

According to the analysis of reasons of transformer mal-operation in Pingdingshan Electric Power Bureac for years , and according to the present situation of transformer protection studies and applications at home and abroad. This paper points out the shortcomings of discrimination between internal faults and magnetizing inrush, the problems existing in differentiating the slight faults of turn-to-turn in transformer are also advanced. On the base of the electromagnetic characteristics of transformer, the relations between fluxional differential current and voltage of source side analyzed, all the operating states of transformer simulated by EMTP/ATP, the criterion of magnetizing inrush in transformer is got. Through the wavelet analysis of current waveform, using the intense reaction of wavelet transform to the little change of signal, the internal faults of transformer are distinguished by testing local extremum.

本文根据平顶山市电业局历年来变压器保护误动的原因分析，并根据国内外变压器保护使用和研究的现状，指出了现有变压器保护在区分变压器励磁涌流和内部故障方面以及在判断变压器匝间轻微故障方面存在的问题和不足；从变压器电磁特性出发，分析了电源侧电压和电流微分之间的关系，利用电磁暂态仿真程序对变压器各种运行状态进行了仿真，并以此建立了判断变压器是否含有励磁涌流的判据；通过对电流波形的小波分析，利用小波变换对信号微小变化极强的反映能力，通过检测电流的局部极值点来区分变压器运行状态，并作为上述判据的补充。

The secondaries of the transformers are connected in parallel through a special type of device, called a network protector, to a secondary bus.

二次点状网络对大负荷供电最可靠，只有当所有的一次馈电线同时发生故障，或故障发生在二次母线上，电源才会中断。

Considering the shortage of voltage sensitivity in small source impedance ratio systems and with high resistance earth fault, the voltage fault component is replaced by memory voltage component to determine the fault's direction.

针对无穷大电源系统中和经高阻接地时存在的电压灵敏度不足的问题，采用保护安装处的记忆电压代替其电压故障分量，从而使保护可以可靠地判别出故障的方向。

In the implementation process, to judge the fault condition and found that failure, the immediate alarm display, while the output volume of a group of relay switch signal to the user, and cut off electrical power supply.

在执行过程中，判断各种故障状态，发现故障，立即报警显示，同时输出一组继电器开关量信号给用户，并切断电机电源。

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。