笼型感应电动机转子断条故障引发振动特性的研究

发布时间：2018-01-18 02:15

本文关键词：笼型感应电动机转子断条故障引发振动特性的研究　出处：《哈尔滨理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：笼型感应电机广泛应用于工农业生产以及人们的日常生活，因此保障电机安全可靠地运行至关重要。转子断条故障是一种常见的故障类型，国内外研究人员利用定子电流特征量实现了故障诊断及在线监测。断条故障会引发电机内多种物理场的畸变，如电磁场、温度场、应力场等。本文从电机电磁场出发，分析电机发生断条故障前后电磁力波的变化特征，计算由此而引发的电磁振动特性，，并找出故障特征量。以一台Y80-2笼型感应电动机为例，分别建立了健康电机和转子断条电机的二维有限元模型，并进行瞬态电磁场计算，得到了时空变化的气隙磁密波并与实验测量值进行了比较。基于麦克斯韦应力方程计算了电机健康及断条故障运行时气隙中的电磁力波，综合运用二维快速傅里叶变换、频谱分析比值校正等方法对电磁力波的阶数、频率和幅值进行了详尽计算和分析。同时利用传统公式计算了气隙磁密波以及电磁力波的阶数和频率，与数值计算的结果进行了比较，得出了电机断条前后电磁力波的一些变化规律。采用锤击法进行模态试验，试验对象包括不带绕组的定子、带有未浸漆绕组的定子、带有浸漆绕组的定子、带有去掉端部绕组的定子以及整机，同时保证所有试验模型的定子均为同一个定子。通过试验测得的加速度频响函数的幅值和相角判定了定子径向二阶固有频率。基于模态试验结果分析了绕组浸漆前后定子固有频率的变化以及端部绕组对定子固有频率的影响。用有限元法分别计算了不带绕组定子及去掉端部绕组定子的固有频率；建立了试验样机的三维全域有限元计算模型，并且在转子和轴承连接处施加了约束条件，充分考虑了转子对电机模态的影响，计算与试验结果进行了比较，并且讨论了转子、端盖和机壳对定子模态的作用。建立了电机瞬态动力学计算的三维有限元模型，以瞬态电磁场计算的电磁力作为载荷循环加载到定子齿内表面，分别对健康电机和断条故障电机进行瞬态动力学响应计算。提取电机机壳上方某点的振动位移并对其进行频谱分析，最后找出由转子断条故障引发的振动特征量。
[Abstract]:Cage induction motor is widely used in industrial and agricultural production and people's daily life, so it is very important to ensure the safe and reliable operation of motor. Domestic and foreign researchers use stator current characteristic to realize fault diagnosis and on-line monitoring. Broken bar fault will lead to the distortion of many physical fields in the motor such as electromagnetic field and temperature field. In this paper, starting from the electromagnetic field of the motor, the variation characteristics of the electromagnetic force wave before and after the broken bar fault of the motor are analyzed, the electromagnetic vibration characteristics caused by the electromagnetic wave are calculated, and the fault characteristic quantity is found out. Taking a Y80-2 cage induction motor as an example, the two-dimensional finite element models of the health motor and the rotor broken bar motor are established, and the transient electromagnetic field is calculated. The airgap magnetic density wave with space-time variation is obtained and compared with the experimental results. Based on Maxwell's stress equation, the electromagnetic force waves in the air gap during the operation of the motor's health and broken strip faults are calculated. The order of electromagnetic force wave is obtained by using two dimensional fast Fourier transform and the ratio correction of spectrum analysis. The frequency and amplitude are calculated and analyzed in detail. At the same time, the order and frequency of air-gap magnetic dense wave and electromagnetic force wave are calculated by traditional formula, and the results are compared with those of numerical calculation. Some changes of the electromagnetic force wave before and after the breakage of the motor are obtained. The modal test was carried out by hammering method. The test objects included the stator without winding, the stator with unvarnished winding, the stator with varnish winding, the stator with removing end winding and the whole machine. At the same time, the stator of all the test models is guaranteed to be the same stator. The radial second order natural frequency of the stator is determined by the amplitude and phase angle of the acceleration frequency response function measured in the experiment. The winding impregnation is analyzed based on the modal test results. The change of stator natural frequency before and after, and the effect of end winding on stator natural frequency are calculated by finite element method, and the natural frequencies of stator without winding and without end winding are calculated by finite element method. The 3D global finite element model of the test prototype is established, and the constraint condition is applied at the connection of the rotor and the bearing. The influence of the rotor on the mode of the motor is fully considered, and the calculation results are compared with the test results. The effects of rotor, end cap and shell on stator mode are discussed. A three-dimensional finite element model for transient dynamic calculation of motor is established. The electromagnetic force calculated by transient electromagnetic field is cyclically loaded on the inner surface of the stator tooth. The transient dynamic response of the health motor and the broken bar motor were calculated respectively. The vibration displacement of a point above the motor shell was extracted and the frequency spectrum was analyzed. Finally, the vibration characteristic quantity caused by rotor broken bar fault is found out.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM346

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