基于VMD与包络谱分析的水力机械振动故障特性研究  

Study on Vibration Fault Characteristics of Hydraulic Machinery Based on VMD and Envelope Spectrum Analysis

作　　者：刘旻 邹小林 LIU Min;ZOU Xiao-lin(China Energy Science and Technology Research Institute Co.Ltd.Chengdu Branch,Chengdu 610072,Sichuan Province,China)

机构地区：[1]国家能源集团科学技术研究院有限公司成都分公司,四川成都610072

出　　处：《中国农村水利水电》2023年第12期280-288,共9页China Rural Water and Hydropower

摘　　要：水力机械振动信号具有噪声强烈、非平稳、非线性等特点,振动信号特征量的有效提取和识别对故障诊断有着重要影响。通过试验台模拟了水力机械不对中与松动两种常见振动故障,采用变分模态分解和Hilbert包络谱分析对故障信号进行故障特征提取。首先利用分量瞬时频率均值确定变分模态分量数量K,对信号进行VMD分析,再对分解后以及重组的信号进行包络谱分析。研究表明,VMD能有效提取出信号的特征量,有利于故障的识别。对比了不同故障情况下以及同种故障不同程度情况下重组信号包络谱特征的差异,发现不对中故障情况下高次谐波信息较为突出,高次谐波随着不对中程度增加而增加;松动故障引起的振动具有方向性,振动信号中伴随着间谐波。这些振动故障特征可以为故障智能诊断提供参考。The vibration signal of hydraulic machinery has the characteristics of strong noise,non-stationary,non-linearity,etc.The effec⁃tive extraction and identification of the fault characteristic of the vibration signal has an important influence on the fault diagnosis.In this pa⁃per,two common vibration faults of misalignment and loosening of hydraulic machinery are simulated by test bench.The fault signal is ex⁃tracted by variational mode decomposition and Hilbert envelope spectrum analysis.First,use the instantaneous frequency average of the com⁃ponents to determine the number K of variational modal components,decompose the signal,and then the envelope spectrum analysis of the decomposed and reconstructed signals is performed.Studies have shown that VMD can effectively extract the feature quantity of the signal,which is beneficial to the identification of the fault.The difference of the envelope spectrum characteristics of the reconstructed signal under different fault conditions and different degrees of the same fault is compared.It is found that the higher harmonic information is more promi⁃nent in the case of misalignment faults,and the higher harmonics increase with the increase of the degree of misalignment.The vibration caused by looseness fault is directional,and the vibration signal is accompanied by inter-harmonics.These vibration fault characteristics can provide reference for intelligent fault diagnosis.

关 键 词：故障特征 变分模态分解 包络谱 间谐波 

分 类 号：TK73[交通运输工程—轮机工程]