基于变压器外壳接地线的输电网故障行波信号提取新方法

A Novel Method for Power Grid Fault Traveling Wave Extracted Based on the Grounding line of Transformer

输电线路发生故障时,暂态信号会沿线路传入到变压器中,提出一种通过在变压器绕组波过程中产生的电磁辐射对外壳的作用,从而获取架空线路故障时暂态行波信号的新方法。以单相绕组变压器数学模型为基础,用单相变压器表征三相变压器的某相,导出三相之间在冲击过电压下的数学模型,并以实际的变压器参数模型对其行波传变特性和变压器地线提取的暂态电流进行仿真分析,结果表明能够有效传变行波波头信号,满足行波故障测距要求。

When transmission line failure is occured, a transient signal will be generated spread along the path to the transformer. This paper presentes a new method that through the propagation process of electromagnetic radiation generated by the shell of transformer winding. It can obtain fault transient traveling wave signals of the overhead line. The mathematical model is based on single-phase winding transformer, and the characterization of sin- gle-phase transformer with a three-phase transformer is analyzed, and the actual parameters of the transformer model of its transfer characteristics of traveling wave and transformers is carried out. Results show that the method can effectively detect the first transient signal, and meet the demands of traveling wave fault location.