Ni Ruizheng, Qiu Ruichang, Jin Zheming, Chen Jie, Liu Zhigang
School of Electrical Engineering, Beijing Jiaotong University, Beijing, 100044, China.
Sci Rep. 2022 Oct 20;12(1):17533. doi: 10.1038/s41598-022-22519-z.
The resonant frequency of the transformer contains information related to its structure. It is easier to identify the resonance frequency in the vibration signal during the hammer test and power on than in the operation of the transformer, because the vibration caused by the load current does not need to be considered during the hammer test and power on. Therefore, an analysis method with simple calculation, fast calculation speed and easy real-time monitoring is needed to deal with these two non-stationary vibrations. Vibration monitoring can understand the health status of transformer in real time, improve the reliability of power supply and give early warning in the early stage of faults. A new frequency domain segmentation method is proposed in this paper. This method can effectively process the vibration signal of transformer and identify its resonant frequency. Eleven different load states are set on the transformer. The method proposed in this paper can extract the resonant frequency of the transformer from the hammering test signal. Compared with the original empirical wavelet transform method, this method can divide the frequency domain more effectively, has higher time-frequency resolution, and the running time of the modified method is shortened from 80 to 2 s. The universality of this method is proved by experiments on three different types of transformers.
变压器的谐振频率包含与其结构相关的信息。在锤击试验和通电过程中，比在变压器运行时更容易从振动信号中识别谐振频率，因为在锤击试验和通电过程中无需考虑负载电流引起的振动。因此，需要一种计算简单、计算速度快且易于实时监测的分析方法来处理这两种非平稳振动。振动监测可以实时了解变压器的健康状况，提高供电可靠性，并在故障早期发出预警。本文提出了一种新的频域分割方法。该方法可以有效处理变压器的振动信号并识别其谐振频率。在变压器上设置了十一种不同的负载状态。本文提出的方法可以从锤击试验信号中提取变压器的谐振频率。与原始经验小波变换方法相比，该方法能更有效地划分频域，具有更高的时频分辨率，且改进方法的运行时间从80秒缩短至2秒。通过对三种不同类型变压器的实验证明了该方法的通用性。
