29 / 2021-05-24 21:54:27

基于高频电流监测的有载分接开关触头状态诊断

有载分接开关是电力变压器完成调压操作的核心装置，其具有载流滑动电接触特点，分接过程易产生磨损、火花和烧蚀等现象，易造成分接触头性能下降。为此，本文结合有载分接开关触头实际结构特点，搭建有载分接开关触头模拟实验平台。基于实验平台，运用高频电流传感器分别采集触头正常状态、松脱状态、磨损状态和故障状态的高频电流信号。然后，采用小波包变换分别对触头不同状态的高频电流信号进行降噪；最后，采用集合经验模态分解和Hilbert变换依次对降噪后的高频电流信号进行分解、特征提取和分析。通过分析有载分接开关触头在不同状态下高频电流信号的特征变化过程，可获得有载分接开关触头从正常状态到故障状态的衍化特征；研究结果可与有载分接开关振动信号故障分析相结合，以提高变压器有载分接开关状态监测和故障诊断精度。



 The on-load tap changer is the core device for the power transformer to complete the voltage regulation operation. It has the characteristics of current-carrying sliding electrical contact. The tapping process is prone to wear, sparks and ablation, and it is easy to cause the performance of the contacts to decrease. Thus, this paper combines the actual structure characteristics of the on-load tap changer contacts to build an on-load tap changer contact simulation experiment platform. Based on the experimental platform, a high frequency current transducer is used to collect the high frequency current signals of the normal state, loose state, wear state and fault state of the contacts. Then, the wavelet packet transform is used to denoise the high-frequency current signals in different states of contacts. Finally, the ensemble empirical mode decomposition and Hilbert transform are used to decompose, feature extraction and analysis of the denoised high frequency current signals in sequence. By analyzing the characteristic change process of the high frequency current signal of the on-load tap changer contacts in different states, the derived characteristics of the on-load tap changer contacts from the normal state to the fault state can be obtained. The research results can be combined with the vibration signal fault analysis of on-load tap changer to improve the condition monitoring and fault diagnosis accuracy of on-load tap changer.