1) small current neutral grounding system
小电流接地系统
1.
Selection methods of single phase grounding fault line in small current neutral grounding system
小电流接地系统单相接地故障选线方法分析
2.
A synergetic theory based faulty line detection method for single-phase to ground fault occurred in small current neutral grounding system is proposed.
提出了一种基于协同学理论的小电流接地系统单相接地故障选线方法。
3.
Based on information fusion and fuzzy reasoning,a new device for single-phase grounding fault location of distribution feeders in small current neutral grounding system is developed by using GSM(global system for mobile communication) network.
研究了一种基于信息融合模糊推理,利用GSM网络的小电流接地系统馈线单相接地故障定位装置。
2) small current grounding system
小电流接地系统
1.
Analysis for voltage unbalance phenomenon of small current grounding system in unattended substation;
无人值班变电所小电流接地系统电压不平衡现象分析
2.
Ground fault discrimination for small current grounding systems and relevant treatment;
小电流接地系统真假接地判断处理方法
3.
Line selection for single-phase ground faults of 10 kV small current grounding systems;
10kV小电流接地系统单相接地故障的选线方式
3) non-solidly earthed network
小电流接地系统
1.
Since no short-circuit loop is formed so that the fault current is small and the three phase line to line voltages are still symmetric when single-phase to earth fault occurs in a non-solidly earthed network, the load can be in normal operation for a period of time .
小电流接地系统发生单相接地故障时,虽然不形成短路回路,没有量值很大的短路电流,且三相线间电压依然对称,不影响负载的正常工作,可以继续运行一定时间,但是在发生单相接地后,非接地相对地的电压会升高,断续性电弧接地时还会产生弧光过电压,长期运行可能会损坏其绝缘,引发严重的相间故障。
2.
Distribution system are universally the non-solidly earthed networks, and the single-phase to earth fault happens most frequently in the power system with ungrounded neutral.
小电流接地系统是配电网普遍采用的接地方式,同时单相接地故障是小电流接地系统发生率最高的故障。
4) neutral indirectly grounded system
小电流接地系统
1.
Fault line detection for single-phase-to-earth faults in the neutral indirectly grounded system based on Prony method;
基于Prony算法的小电流接地系统单相接地故障选线研究
2.
Research on Fault Line Detection for Single-Phase to Ground Faults in the Neutral Indirectly Grounded System Based on Transient Feature;
基于暂态特征的小电流接地系统单相接地选线研究
3.
Detecting the fault line correctly is important to clear the fault and improve power supply reliability when single phase fault occurs in neutral indirectly grounded system.
小电流接地系统发生单相接地故障时,准确检出故障线路对快速排除故障、提高供电可靠性具有重要意义。
5) non-solidly grounded system
小电流接地系统
1.
A simulation model of non-solidly grounded system with arc procedure is presented in the paper.
建立了伴有电弧过程的小电流接地系统的仿真模型,利用电磁暂态程序EMTP全面仿真了不同故障情况对故障稳态和暂态电压、电流幅值特征和相位特征产生的影响。
2.
A more accurate fault model based on the distributed parameters of non-solidly grounded system is presented to analyze the transient characteristics of single-phase grounding fault and to improve the faulty feeder selection criterion based on transient signals.
提出了一种基于线路分布参数的小电流接地系统的高精度故障模型,用于分析单相接地故障产生的暂态信号特征及进一步完善基于暂态信息的小电流接地故障选线判据。
3.
Correct fault line detection for the non-solidly grounded system is a longstanding and hard problem in its operation.
正确接地故障选线是小电流接地系统长期存在的难题,通常采用的单一故障选线方法只对部分故障信息进行处理,选线的可靠性不高。
6) small current grounding power system
小电流接地系统
1.
Because the fault current is very small and many others reasons, it has not been solved completely to detect fault line in small current grounding power system.
小电流接地系统在提高供电可靠性上具有优越性,从而在我国的配电网中得到广泛应用。
2.
In a small current grounding power system, single phase earth fault is the most frequent of all faults.
在小电流接地系统中,经常发生单相接地故障,能否及时找出故障线路,关系到电力系统的供电可靠性。
3.
The single-phase grounding fault happens in the small current grounding power system,the voltage of unfault phase will jump higer;In order to prevent the fault from enlarging two pots\' or more pots\' grounding fault or even short-circuit betweem phases,action should be taken to eliminate the fault in time.
小电流接地系统发生单相接地故障导致非故障相电压升高,为防止进一步扩大成两点或多点接地甚至相间短路,应及时采取措施消除该故障。
补充资料:电力系统中性点接地变压器接地
电力系统中性点接地变压器接地
earthing transformer for neutral grounding
d旧n]一x .tong之hongx旧gd一onj旧d一b旧nyoq一j旧d-电力系统中性点接地变压器接地(earthingtransformer for neutral grounding)电力系统中利用接地变压器获得中性点与大地连接,也称中性点辅助变压器接地。当系统中的变压器不具备接人电阻器或接地故障消除器的条件(例如变压器三相绕组为△接线或虽为Y接线但容量不符合要求)时,要利用辅助的变压器提供一个用于接地的中性点。这种变压器应具备零序阻抗低、激磁阻抗大、功率损耗小的特性。绕组为曲折(Z)接线的变压器符合要求,如图1(a)所示。它可以带二次侧绕组,也可以只有一次侧绕组。 这种变压器每相由匝数相等的两个串联分绕组组成,每个磁芯上的两个分绕组间以及它们对二次侧绕组的零序互磁为零。很明显,这种变压器的零序电抗XTo只为变压器一次侧绕组的漏电抗Xs,,即XTo-Xs;,而系统中性点与地之间的计算阻抗Z。为Z。一25,+Z。,其中Z。为中性点电阻器或电抗器的阻抗。见图1(b)。2.为激磁阻抗。见图2,YN,d接线的变压器二次侧绕组可以带一定负荷。从过负荷能力考虑已经知道.接YN,d接线的双绕组变压器中性点的接地设备的容t不应超过变压器额定容t的50%.由此可认为,当变压器额定容t按中性点接地设备的容t设计时,允许二次侧绕组带50%额定容t的负荷. 还有一种特殊接线的接地变压器和接地设备的组合,是1918年鲍赫(R.Bauch)发明的,故也称饱鹅变压器,见图3。变压器一次侧中性点直接接地,开口三角形接线的二次侧连接接地设备,这与一次侧中性点接有接地设备是等效的。单相接地时,不对称的电压可分解为对称的正序和零序,磁通也可分解为对应的分量。磁通人m、人。、人.需要极小的激磁电流,并对应于正序电压U.。、U、。、U。。,零序电压UO.对各相是一样的,故三个磁柱中有相同的磁通式,对零序磁通来说,变压器相当一个单相变压器,只不过分裂为3个磁柱和3个绕组,见图3(c)。单相接地时,这种变压器每个分绕组上的电压为少尹z‘一.哟.!|||一下咖l!补丰气l一!{屯犷!{屯享!孟=zl息)一刃川l|拍--l--﹄·图1绕组为曲折(Z)接线的变压器 (a)接线图.(b)零序阻抗图会‘价“相“压,·““”的““是中”点接地“备电流的1/3,即夸。因而变压器的额定功率为3x2‘会‘争即中性点接地设备“率”1.15倍。
说明:补充资料仅用于学习参考,请勿用于其它任何用途。
参考词条