基于振动信号的变压器铁心与绕组故障区分方法

Discrimination method of transformer core and winding fault based on vibration signal

针对变压器铁心、绕组由于机械结构相连,铁心故障与绕组故障区分困难的问题,提出采用基于振动信号的变压器铁心与绕组故障的区分方法,通过对比分析铁磁材料磁致伸缩和绝缘垫块弹性形变的非线性特性差异,结合实验分别获取变压器铁心、绕组振动信号,在频域研究了变压器铁心、绕组振动信号的非线性特性,通过分析不同条件下振动信号高次谐波能量占比,提出采用振动信号基频与高次谐波幅值的变化规律来区分铁心故障和绕组故障。研究表明,变压器运行中振动信号基频分量由铁心和绕组振动共同决定,高次谐波分量主要来源于铁心振动。当变压器绕组故障时,仅振动信号基频幅值发生突增;铁心故障时基频和高次谐波分量幅值均发生突增,可以有效区分铁心和绕组故障。

In view of the difficulty in distinguishing the core fault from the winding fault due to the connection of the mechanical structure of the transformer core and winding,a discrimination method of transformer core and winding fault based on vibration signal is proposed in this paper.By comparing and analyzing the non-linear characteristics of magnetostriction of ferromagnetic materials and elastic deformation of insulating pads,the vibration signals of the transformer core and winding are obtained respectively through experiments.The non-linear characteristics of vibration signals of transformer cores and windings are studied in frequency domain.By analyzing the proportion of high-order harmonic energy of vibration signals under different conditions,it is proposed that the core fault and winding fault can be distinguished by the variation law of fundamental frequency and high-order harmonic amplitude of vibration signals.The research shows that the fundamental frequency component of vibration signal in transformer operation is determined by the vibration of core and winding,and the high-order harmonic component mainly comes from the vibration of core.When transformer winding faults occur,only the fundamental frequency amplitude of vibration signal increases sharply,when core faults occur,both the fundamental frequency and the high-order harmonic components increase sharply,which,can effectively distinguish core and winding faults.