变压器可听声信号特征分析

Characteristic analysis of transformer audible acoustic signals

振动与可听声的变压器诊断技术凭借与被监测设备无电气连接、抗干扰能力强和灵敏度高等优点成为研究热点。针对变压器可听声信号特征,分析了变压器可听声产生机理及其影响因素。运用分层阈值消噪法对信号进行消噪,采用快速傅里叶变换和小波分解法对不同运行年限、不同电压等级、不同采集位置、不同负载率情况下的在运变压器可听声信号进行分析,得到信号的频谱和小波能量特征向量。结果表明,理论上变压器可听声信号主频为100 Hz,并存在200 Hz、300 Hz等高次谐波分量。但是,随着变压器运行年限、电压等级的升高,主频增大为200 Hz,高次谐波占比及高频段能量特征值增大,信号频谱与能量特征值受采集位置影响,检测时应根据变压器结构等实际情况选取合适的采集位置。

Transformer diagnostic technology based on vibration and audible sound has become a research hot advantages of no electrical connection with the monitored equipment, strong anti-interference ability and order to analyze the characteristics of the audible acoustic signal of the transformer, the mechanism the transformer is analyzed theoretically. The fast Fourier transform and wavelet decomposition metliodacoustic signals of transformers under different operating periods, different voltage levels, different acquisition positions and different load rates. The frequency spectral and wavelet energy eigenvectors of the signals are obtained. The results audible signal is 100 Hz, and there are 200 Hz, ; 00 Hz and other high Sub-harmonic compooperating life and voltage level, the main frequency increased to 200 Hz, the high Sub-harmonic ratio and high-frequency energy characteristic value increased; The signal spectrum and energy characteristic value are afected by the acquisition position, and the appropriate collection position should be selected according to the actual situation of the transforme