基于改进的HHT变压器铁芯振动信号检测研究

Research on Detection of Transformer Core Vibration Signal Based on Improved HHT

随着全国电网互联,电力系统的结构日益复杂,变压器故障时有发生,对电力系统安全造成了严重威胁,因而对变压器运行状态的监测和分析越来越受到人们的关注。将小波包变换和HHT (hilbert-huang transform,HHT)相结合的方法引入到变压器铁芯振动信号分析中。由于实测信号中往往含有大量噪声,不利于对振动信号特征信息的提取,因此提出运用小波包变换对其进行阈值处理,然后将处理后的振动信号进行HHT变换,再计算其边际谱,通过边际谱中的频率分布,对变压器铁芯振动实现在线监测分析。最后利用大量数值仿真和现场实测数据分析,表明了该分析方法在变压器上述故障诊断中的可行性和有效性。

With the interconnection of the national power grid,the structure of the power system is becoming more and more complex,and the transformer fault occurs frequently,which causes a serious threat to the security of the power system. Therefore,more and more people pay attention to the monitoring and analysis of the transformer operating state. The wavelet packet transform and hilbert-huang transform( HHT) are combined into the analysis of transformer core vibration signal. Because the measured signal often contains a lot of noise,which is not conducive to the extraction of characteristic information of vibration signals. It proposes using the wavelet packet transform threshold processing,and then the vibration signals processed by HHT transform,and calculates the marginal spectrum.Though the frequency distribution of marginal spectra,it analysizes the on-line monitoring for transformer core vibration. Finally,the feasibility and effectiveness of the proposed method in the fault diagnosis of the transformer is demonstrated by a large number of numerical simulation and field measurement data analysis.