基于小波理论的电力变压器振动信号特征研究

通过监测电力变压器的器身振动信号预估变压器机械故障的振动法的关键在于如何从振动信号中提取有效特征。为有效诊断铁心和绕组的机械状态,利用小波变换对变压器振动信号进行时域与频域综合分析,提出基于频段—能量分布的变压器铁心和绕组机械故障诊断新方法。试验结果表明,小波变换能够有效地提取振动信号的特征,得到实时振动信号各频段上的能量分布状态,据此可有效在线诊断变压器机械故障。

Features of Vibration Signal of Power Transformer Using the Wavelet Theory

The mechanical faults of a transformer are predicted with monitoring its vibration, which is a new technology put forward recently for condition based monitoring of transformers. The key technology of vibration method is how to identify the effective features of the vibration signal. Based on analyzing the vibration signal in time-domain and frequency-domain with wavelet transform, a frequency bands-energy method for diagnosing the mechanical status of the core and winding of a transformer is proposed in this paper. Experimental results demonstrate that the features of the vibration signal can be effectively found out with wavelet transform, and the energy distribution of the vibration signal to the frequency bands can be obtained. The mechanical status of the core and winding of a transformer can be effectively diagnosed by the frequency bands-energy distribution. This is effective method for diagnosing the mechanical faults of transformers.