基于多端脉冲幅值比的变压器局部放电信号聚类分离方法

Clustering separation method of partial discharge signals in transformers based on multi-terminal pulses amplitude ratio

对电力变压器进行局部放电试验与检测时,多源脉冲混叠严重影响着局部放电信号的识别。本文提出一种基于多端脉冲幅值比的局放信号聚类分离方法。首先,开展220 kV变压器局放试验,对不同试验电压下PRPD、T-F谱图中存在的脉冲混叠现象进行分析;然后,基于不同类型脉冲在变压器中的传播衰减规律,提出了基于变压器多端检测的三维幅值比脉冲聚类分离方法,并结合DBSCAN算法实现该方法;最后,在220 kV变压器局放试验过程中开展了多端检测,并对脉冲进行聚类分离与来源分析。结果表明:利用多端脉冲幅值比聚类分离方法能够将局放试验过程中的多源混叠脉冲准确分为干扰脉冲以及两类放电脉冲,并且可以根据幅值比实现脉冲源的初步定位。多端脉冲幅值比聚类分离方法实现了变压器局放脉冲的提取,其发展和应用将有利于提升变压器局部放电检测中的抗干扰水平和检测准确度。

In the partial discharge test and detection of power transformers,multi-source pulse overlap seriously affects the identification of partial discharge signals.In this paper,a clustering separation method of partial discharge signals based on multi-terminal pulse amplitude ratio was proposed.Firstly,the partial discharge test of 220 kV transformer was carried out,and the pulse overlapping phenomena in PRPD and T-F spectra under different test voltages were analyzed.Then,based on the propagation attenuation law of different types of pulses in transformer,a three-dimensional amplitude ratio pulse clustering separation method based on multi-terminal detection of transformer was proposed,and the method was realized by DBSCAN algorithm.Finaly,multi-terminal detection was carried out during the partial discharge test of 220 kV transformer,and the clustering separation and pulse source analysis of the pulse were carried out.The results show that utilizing the multi-terminal amplitude ratio clustering separation method can accurately divide the multi-source overlap pulses during partial discharge process in to interference pulse and two kinds of discharge pulse,and the initial location of the pulse source can be realized according to the amplitude ratio.The multi-terminal pulse amplitude ratio clustering separation method realizes the extraction of transformer partial discharge pulse,and its development and application will be conductive to improve the anti-interference capability and detection accuracy in transformer partial discharge testing.