基于变模态分解的异步电机转子断条故障诊断  

Fault Diagnosis of Rotor Broken Bar in Induction Motor Based on Variable Mode Decomposition

作　　者：夏志凌 胡凯波 刘心悦 李彬华 史婷娜 Xia Zhiling;Hu Kaibo;Liu Xinyue;Li Binhua;Shi Tingna(Zhejiang Zheneng Lanxi Power Generation Co.Ltd,Jinhua 321199 China;College of Electrical Engineering Zhejiang University,Hangzhou 310027 China)

机构地区：[1]浙江浙能兰溪发电有限责任公司,金华321199 [2]浙江大学电气工程学院,杭州310027

出　　处：《电工技术学报》2023年第8期2048-2059,共12页Transactions of China Electrotechnical Society

基　　金：浙能集团科技资助项目(208020210582)。

摘　　要：电机稳态运行时的故障特征频率与基频接近,难以实现转子断条时的故障电流分量的有效提取。对此,该文根据起动过程中转子断条故障特征信号频率易与基频区分的特点,采用变模态分解(VMD)方法对起动过程中的定子电流进行分析并对故障进行诊断。首先,基于平均瞬时频率对VMD的模态个数进行优化,准确分解出能量集中的断条故障特征信号。在此基础上,利用维格纳准概率分布高时频分辨率的特点绘制断条故障特征信号的时频分布图,引入大津算法对图片进行抗噪处理,突出故障特征部分。然后,以故障特征信号能量值作为故障量化因子,以不同故障状态下多组实验数据的均值和标准差为依据设置阈值,实现系统自动故障预警的目的。最后,在一台5.5 kW异步电机上进行了实验,结果表明,所提诊断方法不仅能够实现包括不完全断条在内的故障诊断,还能够实现对断条故障严重程度的判断。When the induction motor is operated under the steady-state operating condition with a light load,the fault characteristic frequency of the broken bar fault is close to the fundamental frequency,making it difficult to extract the fault current component from the stator current effectively.Moreover,the fault characteristic signal energy shares a fairly minor fraction of the total stator current energy in the early stages of incomplete broken bars,which increases the difficulty of fault current component extraction.In order to improve the diagnosis effect of the broken bar fault at the early stage when the motor is running at light load,according to the characteristics of distinguishing the characteristic signal of the broken bar fault from the fundamental signal during the starting period,this paper proposes the variational mode decomposition(VMD)method to process the stator start-up current,and the broken bar fault diagnosis is carried out by utilised the energy value of the fault characteristic current obtained by decomposition.The proposed broken bar fault diagnosis scheme is mainly divided into three stages:stator current pre-processing,fault characteristic current extraction,fault characteristic current energy time-frequency distribution calculation and fault severity quantification.In the first stage,the Clarke transformation is applied to obtain the current space vector,and the amplitude variation of the current space vector during the starting process is utilised to adaptively extract the stator current for analysis,and the influence of high frequency interference on low frequency signal is removed by an anti-aliasing filter.In the second stage,a VMD algorithm based on the optimisation of the mean instantaneous frequency is proposed to extract the left frequency component of the fault characteristic current.In order to optimise the extraction effect,it is necessary to determine the appropriate parameters for the penalty factor and the number of modes in the VMD algorithm.The penalty factor should take into

关 键 词：异步电机 转子断条 故障诊断 变模态分析(VMD) 本征模态函数(IMF) 大津算法(OTSU) 

分 类 号：TM307[电气工程—电机]