高阻型单相接地故障信号的暂态分量影响因素研究

Research on Influence Factors of Transient Component of High-impedance Single-phase Grounding Fault Signal

高阻型单相接地故障信号的暂态分量,在故障过渡电阻这一主要影响因素之外,还受到以下影响因素的制约,进而影响暂态判据选线的准确度:配电网发生故障时所运用的系统接地方式、故障发生时的相角、故障发生点距母线的距离、故障发生出线的长度等。其中系统接地方式由于为配电网系统本身的设计所导致,不受故障本身随机性的影响,因而其影响对于研究高阻型单相接地故障特征的暂态分量具有基础意义。本文利用了Matlab-Simulink仿真平台,重点针对过渡电阻阻值、中性点接地方式对高阻型单相接地故障暂态分量的影响进行了仿真分析,着重探究了过渡电阻阻值以及几种中性点非有效接地方式,在接近真实情况的三相不平衡条件下对高阻型单相接地故障暂态分量的影响。结果表明高阻型单相接地故障的过渡电阻较小、系统消弧线圈补偿度较小或中性点不接地,将影响高阻型单相接地故障信号的暂态分量并使得其强度较大、信噪比较高。

The transient component of the high-resistance single-phase grounding fault signal is not only the main influencing factor of the fault transition resistance,but also restricted by the following influencing factors,which in turn affects the accuracy of the transient criterion line selection:In case of fault of distribution network the grounding mode of the used system phase angle,the distance from the fault point to the bus,the length of the outgoing line of the fault,etc.Among them,the grounding mode of the system is caused by the design of the distribution network system itself and is not affected by the randomness of the fault itself.Therefore,its influence is fundamental to the study of the transient components of the highresistance single-phase grounding fault characteristics.In this paper the Matlab-Simulink simulation platform is used to focus on the simulation analysis of the transition resistance value and the neutral grounding mode on the transient component of the high-resistance single-phase grounding fault.The influence of high transition value and several non-effective grounding mode of several neutral point affects on the transient component of the high-resistance single-phase grounding fault under the three-phase unbalanced condition close to the real situation is particularly explored.The results show that the transition resistance of high-resistance single-phase grounding fault is smaller,the compensation of arc suppression coil of system is smaller or the neutral point is not grounded,which will affect the transient component of high resistance single phase grounding fault and keep its strength larger and signal to noise ratio higher.