基于暂态行波的配电网故障仿真分析

摘要

通过对配电网中故障点产生的暂态行波信号进行模量分析得出,故障的初始行波包含零模分最和线模分量,各模分量的幅值与过渡电阻有关,与线路长度无关.本文基于Matlab的Simulink仿真环境,搭建小电流接地系统的配电网仿真模型,利用行波线模分量作为故障检测信号,对不同条件下的单相接地故障进行了大量仿真.仿真分析结果表明可根据任意两线电压信号确定故障相;故障行波的暂态特征量不受中性点运行方式、故障距离的影响,为单相接地故障测距的研究提供了理论依据.%Through analyzing the mode component of transient traveling waves generated by faullt point in distribution network, the results show that original transient traveling waves contain zero mode component of traveling wave and aerial mode component of traveling waves, the amplitudes of each component are relevant to transition resistance and irrelevant to the line length. Based on the Simulink of Matlab,the distribution network simulation model is established for the ground-fault of ungrounded system. Using aerial mode component of traveling waves as fault measurement signals,the single-phase grounded faults in different conditions are simulated so as to research the transient characteristics of single-phase grounded fault in distribution network. The simulated results show that the fault phase can be determined by any two circuit voltage;transient characteristics of traveling waves almost not affected by the neutral grounding and fault distances,which provide a theory basis to study the fault distance detection for the single-phase to ground fault in distribution network.