小波包变换与支持向量机的电力变压器故障诊断方法  

Fault Diagnosis Method for Power Transformer Based on Wavelet Packet Transform and Support Vector Machine

作　　者：黄道友 任丽佳 康健 HUANG Daoyou;REN Lijia;KANG Jian(Equipment Department,State Grid Anhui Electric Power Co.,Ltd.,Hefei 230022,China;College of Electronic and Electrical Engineering,Shanghai University of Engineering Science,Shanghai 201620,China)

机构地区：[1]国网安徽省电力有限公司设备部,合肥230022 [2]上海工程技术大学电子电气工程学院,上海201620

出　　处：《电源学报》2025年第1期251-258,共8页Journal of Power Supply

摘　　要：针对传统电力变压器故障诊断方法无法实现电力故障准确检测并保证电力变压器正常运行的问题,提出1种小波包变换与支持向量机相结合的电力变压器故障诊断方法。对采集的电力变压器电力信号,利用改进最小噪声分离MNF(minimum noise fraction)变换实施去噪,并通过加权邻域均值法对噪声矩阵进行估计,利用改进的MNF变换有效实现图像降维、去噪处理,提取信号特征;利用小波包变换方法将信号分为低频部分与高频部分,以获取小波包能量特征向量,将所获取小波包能量特征向量输入支持向量机分类器中,利用支持向量机分类器输出结果,实现电力变压器状态识别和故障诊断。实验结果表明,所提方法可有效诊断电力变压器中的铁芯短路、线圈层间短路、套管对地击穿、线圈绝缘电阻下降和套管间放电等故障,故障诊断精度高于98.5%。The traditional fault diagnosis methods for power transformers cannot detect the power faults accurately or ensure their normal operation.Therefore,a fault diagnosis method for power transformers based on wavelet packet transform and support vector machine(SVM)is proposed.For the power signal collected from a power transformer,the improved minimum noise fraction(MNF)transform denoising is used to denoise,and the noise matrix is estimated by the weighted neighborhood mean method.After the estimation,the improved MNF transform is used to effectively realize image dimensionality reduction and denoising,extract the signal characteristics,and divide the signal into low-and high-frequency part by means of wavelet packet transform to obtain the wavelet packet energy feature vector.The obtained wavelet packet energy feature vector is input into an SVM classifier,and the output results from the SVM classifier are used to realize the state recognition and fault diagnosis of power transformer.Experimental results show that the proposed method can effectively diagnose the faults in the power transformer,such as iron core short-circuit,coil interlayer short-circuit,bushing-to-ground breakdown,coil insulation resistance drop and bushing-to-bushing discharge,and the fault diagnosis accuracy was higher than 98.5%.

关 键 词：小波包变换 电力变压器 故障诊断 支持向量机 

分 类 号：TM77[电气工程—电力系统及自动化]