基于小波包分析的谐振接地系统高阻故障选线方法

High Impedance Fault Line Selection Method for Resonant Grounding System Based on Wavelet Packet Analysis

配电网谐振接地系统的高阻接地故障处理一直是一个研究重点,由于故障电流微弱、故障发生时刻不确定、受线路参数和随机因素影响等原因,一直缺乏可靠的高阻接地故障选线方法。现根据谐振接地系统单相高阻接地的故障特性,用小波包分析和能量熵相结合对故障暂态零序电流进行分析,将能量熵作为单相高阻接地故障的暂态特征量,可以定量地对复杂的暂态故障信息进行分析。分析故障零序电流暂态信号能量熵分布的规律,定义平均能量熵来统计信号能量的复杂度。提出基于平均能量熵的故障模式分类方法,将单相高阻接地故障分为低频故障、强故障2类故障类型,并且依据不同的故障类型,使用不用的算法进行故障线路的选择,最后使用仿真的数据来证明此方法的正确性和可行性。

The high resistance grounding fault of the distribution network resonant grounding system has been a research focus.Due to the weak fault current,the uncertainty of the time of failure,the influence of line parameters and random factors,there is a lack of reliable method for selecting the high resistance grounding fault.Now according to single-phase high resistance grounding fault characteristics of the resonant grounded system,by combining wavelet packet energy entropy analysis and analysis of fault transient zero sequence current,energy entropy as a single phase of high resistance earth fault transient characteristics,can quantitatively analyze the complex transient fault information.This paper analyzes the law of energy entropy distribution of transient signal of zero sequence current,and defines the average energy entropy to calculate the complexity of signal energy.Putting forward fault pattern classification method based on the average energy entropy,the single phase high resistance earth fault can be divided into strong fault,the low frequency fault 2 class type,and according to the different fault types,using different algorithms for fault line selection,the final use simulation data to prove the correctness and feasibility of the method.