基于VMD-小波包的10 kV配电站断路器异常跳闸故障诊断
Diagnosis of Abnormal Tripping Fault of 10 kV Distribution Station Circuit Breaker Based on VMD Wavelet Packet
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摘要: 配电站断路器异常跳闸故障诊断方法主要通过对断路器信号的时域特征进行提取并结合阈值判别实现故障分类,由于难以捕捉故障发生时电流信号中的瞬态能量突变,因此诊断精度不佳。为此,提出了基于VMD-小波包的10 kV配电站断路器异常跳闸故障诊断。结合VMD方法构建变分问题,对断路器电流信号进行多模态分解。采用小波包分解的方式量化各频带能量分布,并计算能量熵作为特征向量,将时域信号转化为频域能量突变表征。利用高斯核函数将能量熵特征映射至高维空间,通过选择最大概率类别作为输出结果,实现异常跳闸故障分类与诊断。在实验中,对提出的方法进行了诊断精度的检验。最终测试结果表明,采用提出的方法进行断路器异常故障诊断时,算法误判率低于5%,具备较为理想的诊断效果。Abstract: The diagnosis method for abnormal tripping of circuit breakers in distribution stations mainly extracts the time-domain characteristics of circuit breaker signals and combines threshold discrimination to achieve fault classification. Due to the difficulty in capturing transient energy changes in current signals when faults occur, the diagnostic accuracy is poor. Regarding this, a diagnosis of abnormal tripping faults in 10 kV distribution station circuit breakers based on VMD wavelet packet is proposed. Construct a variational problem using VMD method and perform multimodal decomposition on circuit breaker current signals. Quantify the energy distribution of each frequency band using wavelet packet decomposition, and calculate the energy entropy as the feature vector to transform the time-domain signal into a frequency-domain energy mutation representation. By using Gaussian kernel function to map energy entropy features to high-dimensional space, and selecting the maximum probability category as the output result, abnormal trip fault classification and diagnosis can be achieved. In the experiment, the diagnostic accuracy of the proposed method was tested. The final test results show that when using the proposed method for diagnosing abnormal faults in circuit breakers, the algorithm has a misjudgment rate of less than 5% and has a relatively ideal diagnostic effect.
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