基于振动的变压器铁芯松动定位

为对油浸式电力变压器铁芯松动进行定位判断,对变压器油箱表面测得的振动进行分析研究.首先理论分析变压器空载运行时油箱表面不同位置振动信号的特点以及变压器在铁芯松动前后振动信号的变化规律,然后对一台油浸式变压器进行实验,分析铁芯松动对油箱测点的影响.实验结果表明：振动信号基频分量幅值与空载电压的平方呈线性关系;当A、B、C 三相中某一相铁芯发生松动故障时,此相铁芯上方对应位置测点的振动信号基频分量幅值比正常时增大,且随铁芯松动程度增大而变大,其他两点的振动幅值先减小后增大.可根据此规律进行铁芯松动诊断以及初步定位.

Positioning of Transformer Core Loosening Based on the Vibration Signals

In order to diagnose and locate the core loose failure of oil-immersed power transformer,this paper studies the vibration signals measured on the surface of the transformer tank.Firstly,the characteristics of vibration signals with different locations of the tank surface is theoretically analyzed under the condition of no-load operation of transformers and the variation of the vibration signals of the transformer tank surface before and after core loosening is discussed.And then experiment on an oil-immersed transformer is carried out and the variation of characteristic frequency of the vibration signals before and after core loosening is analyzed.Experimental results show that the value of fundamental component amplitude of the vibration signal is in linear with the value of the square of no-load voltage.When one phase core of the three phases A,B,C loosens,the fundamental frequency component amplitude of the vibration signal increases with the degree of core loosening of the corresponding position measuring point above the phase iron core.And the vibration amplitude of the other two points firstly decreases and then increases.The core loose fault can be diagnosed and located according to this principle.