基于小波包能量熵的电力变压器运行状态评估方法研究

Research on Evaluation Method of Power Transformer Operation State Based on Wavelet Packet Energy Entropy

振动在线检测法在电力变压器机械故障诊断中的应用越来越广泛,在此基础上将能量熵引入电力变压器绕组振动信号的特征提取中。通过实验提取一台电力变压器绕组正常运行和短路冲击运行时的振动信号,运用小波包分解重构原理分解出信号的子频带,采用频段-能量熵方法来检测电力变压器绕组不同运行条件下短路故障类型。实验结果表明,不同机械状态下电力变压器绕组振动信号特征向量之间的差异性可作为故障诊断的依据。

The vibration online detection method is more and more widely used in the mechanical fault diagnosis of power transformers.On this basis,energy entropy is introduced into the feature extraction of the vibration signal of the power transformer winding.The vibration signals of a power transformer windings during normal operation and short-circuit impact operation were extracted by experiments.The sub-frequency band of the signal was decomposed by the principle of wavelet packet decomposition and reconstruction,and the band-energy entropy method was used to detect the short-circuit fault types of power transformer windings under different operating conditions.The experimental results show that the difference between the characteristic vectors of winding vibration signals in different mechanical states can be used as the basis for fault diagnosis.