基于光纤声发射的局部放电信号识别方法分析
Analysis of partial discharge signal recognition method based on fiber optic acoustic emission
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摘要: 局部放电(PD)是电气设备绝缘退化的主要原因,相较于传统的检测方法,光纤声发射检测技术具有不影响设备运行方式、抗电磁干扰能力强等优点。设计并制作了尖端放电、气泡放电、悬浮放电和沿面放电4种典型局部放电模型,搭建了基于光纤声发射的局部放电声发射信号采集试验平台,采集了梯度施加电压下的局部放电声发射信号并对其进行了参量统计分析,提出了将去噪后信号时频图作为卷积神经网络特征输入的识别模型。试验结果表明,该识别模型对于淹没在噪声中的微弱局部放电信号具有良好的识别效果,识别准确率可达98%。Abstract: Partial discharge (PD) is the main cause of insulation degradation in electrical equipment. Compared with traditional detection methods, fiber optic acoustic emission detection technology has advantages such as not affecting equipment operation mode and strong resistance to electromagnetic interference. This paper designed and produced four typical partial discharge models: tip discharge, bubble discharge, suspended discharge, and surface discharge. A partial discharge acoustic emission signal acquisition experimental platform based on fiber optic acoustic emission was built, and the partial discharge acoustic emission signals under gradient applied voltage were collected and analyzed for parameter statistics. A recognition model was proposed that took the denoised signal time-frequency map as the feature input of a convolutional neural network. The results showed that the recognition model had good recognition performance for weak partial discharge signals submerged in noise, with a recognition accuracy of 98%.