摘要
分析了中性点经高阻电网发生单相接地时的故障特性。基于电力系统发生故障后产生的信号具有奇异性、变化较快的特点,而利用小波分析此类信号有较大优势,提出了一种新判据:先求所有出线零序电流幅频特性的最大值,选取幅值特性最大值出线作为准故障线路,再利用小波包对各线路零序电流进行五层分解,对比某节点内的相位,可较准确地选出故障线路,当母线故障时,算法不会发生误判。针对现场中出现的三类接地故障进行仿真,仿真结果验证,方案能够准确地选出故障线路。
This paper analyses the characteristics of single-phase earth fault in neutral grounded through high-resistance system.When the fault occurs in the power system,the accompanied signals has singularity and changes rapidly and using Wavelet Analysis has more superiorities.Thus,the paper puts forward a new criteria.Firstly,obtains the maximum values of amplitude-frequency characteristics of the zero sequence current of all lines.Secondly,select the maximum amplitude characteristics line qualified as a prospective fault line.Then using the wavelet packet decomposes the zero sequence current five layers.Eventually the proposed scheme can select the fault line accurately comparing the phase of a node.Even though the bus faults,the algorithm can still select correctly.Using three type of fault happening in real case to simulate,the simulated result proved that this scheme can select the fault line accurately.
出处
《电气自动化》
2011年第4期50-53,共4页
Electrical Automation
关键词
高阻
小波包
特征频带
首半波
幅频特性
选线判据
high-resistance wavelet packet special frequency band first half-wave amplitude-frequency characteristics selection criteria
