基于二次谐波分量衰减特性的变压器励磁涌流识别方法

A Novel Inrush Current Distinguishing Scheme Based on Second harmonic Component Decaying Characteristics of Transformer Current

变压器空载合闸时将产生大的励磁涌流,受剩磁、合闸角、变压器参数等因素影响,涌流特性复杂,辨识困难。这一现象在包含变压器匝间短路场景下,体现尤为明显。目前尚缺少考虑匝间短路因素下励磁涌流特性的数学表征和辨识判据。本文笔者提出了一种基于二次谐波分量衰减特性的励磁涌流表征方法,采用基于变压器二次谐波分量与基波分量幅值比的涌流判定依据,可实现包含匝间短路等多场景下励磁涌流的快速辨识。

When the transformer is closed at no load, a large inrush current will be generated, which is affected by factors such as residual magnetism, closing angle, transformer parameters, etc. The inrush current characteristics are complex and the identification is difficult.This phenomenon is particularly evident in scenarios involving transformer turn-to-turn short circuits. Moreover, there is still a lack of mathematical characterization and identification criteria for the inrush current characteristics considering the inter-turn short-circuit factor. This paper proposes a magnetizing inrush current characterization method based on the decay characteristics of the second harmonic component.This method adopts the inrush current judgment basis based on the amplitude ratio of the transformer second harmonic component and the fundamental wave component,which can realize the rapid identification of the excitation inrush current in multiple scenarios including inter-turn short circuit.