基于行波固有频率的电网故障定位方法

A Power System Fault Location Method Based on Natural Frequencies of Traveling Waves

基于行波固有频率的输电线路故障定位方法,无需识别行波波头及检测行波到达时刻即可实现精确故障定位,具有一定优势。电网发生故障时,故障行波将沿不同的路径传播,且其频谱中包含反映不同传播路径的固有频率分量,该频率值与行波传播路径的长度间存在一定的关系。基于此,提出一种基于行波传播路径及其固有频率的电网故障单端定位方法,该方法首先根据故障行波的固有频率值判断故障线路,然后根据反映包含故障点的行波传播路径的固有频率值精确计算故障距离。大量仿真分析表明,该方法能准确地判断出故障线路,精确地估算故障距离,且不受故障位置、故障类型、故障电阻、故障初相角的影响,具有较好的适应性和一定的实用价值。

The fault location methods based on natural frequency of traveling wave for transmission line can accurately determine the fault position without identifying the wavefront of traveling wave and detecting the arrival time of traveling wave, so these methods possess a certain advantage. When fault occurs in power grid, fault traveling waves transmit along different paths and the natural frequency components reflecting different transmission paths are included in the frequency spectrums. Moreover, there is a certain relationship between the value of natural frequency and the length of the transmission path. Upon this foundation, a single-terminal fault location method based on transmission path of traveling wave and its natural frequency is presented in this paper. Firstly, the faulty line is judged by identifying the value of natural frequencies of the fault-traveling wave. And then according to the value of the natural frequency component reflecting the certain transmission path of fault-traveling wave, in which the fault point is included, the fault distance can be calculated accurately. A lot of simulation results show that the faulty line can be judged precisely and the fault distance can be estimated accurately base on the presented method, and the result of the fault location is not affected by fault positions, fault types, fault resistances and inception angles. Thus the presented method possesses better adaptability.