旋转磁化下磁致伸缩特性研究

发布时间：2018-07-03 18:15

本文选题：主应变 + 磁致伸缩模型　；参考：《沈阳工业大学》2017年硕士论文

【摘要】：电工钢片的磁致伸缩被广泛认为是引起电气设备振动的主要来源之一,其特性与磁化方式、磁化频率、应力等因素密切有关,准确测量、模拟电工钢片的磁致伸缩特性对电机、变压器等电工设备的振动噪声研究具有重要意义。电机铁心及三相变压器铁心T型结合部存在大量旋转磁通,国外对旋转磁化下电工钢片磁致伸缩特性的测量与模拟研究仍处于起步阶段,而国内还未见报道。本文基于实验室研发的旋转磁化电工钢片磁致伸缩特性测量系统,测量并分析了不同磁化轨迹下单片电工钢片的磁致伸缩特性,提出了描述旋转磁致伸缩特性的动态矢量模型,并推导了模型参数计算方法。通过实验验证了模型的有效性,定量地分析了一台同步发电机定子铁心磁致伸缩及其引起的局部形变,为准确计算电机铁心振动噪声打下基础。主要研究内容有:首先,改进了实验室自行研制的旋转磁化下磁致伸缩特性测量系统。为提高测量精度,将原系统中应变片的粘贴位置移动到样片的中心区域,并测量了不同旋转磁化轨迹下磁致伸缩数据。然后,分析了不同磁化条件下,不同时刻沿任意方向上的应变分布、主应变和主应变角在一个磁化周期内的变化波形和主应变峰值变化规律;讨论了主应变波形的谐波含量及主应变和磁通密度之间的矢量和磁滞特性。再次,提出了描述磁致伸缩主应变与磁通密度矢量关系的动态矢量模型。将磁致伸缩主应变沿水平和垂直两个方向的分量表达为三项之和,即一个与磁化轨迹有关的常数项、磁通密度随时间变化项及磁通密度对时间的导数项。详细推导了模型中参数的数学表达式,基于测量数据计算了模型参数,建立了模型参数数据库。并验证了模型的有效性。最后,基于磁致伸缩模型对一台同步发电机的磁致伸缩形变进行建模仿真。在一个周期内,对定子铁心单元离散时刻的磁场数据采集并输出;基于模型参数数据库插值计算得到每个单元的模型参数;最后计算出每个单元的磁致伸缩数据,得到了电机铁心主应变的分布,及其引起的局部形变。
[Abstract]:The magnetostriction of electrical steel sheet is widely regarded as one of the main sources of electrical equipment vibration. Its characteristics are closely related to the factors such as magnetization mode, magnetization frequency, stress and so on. It is of great significance to study the vibration and noise of electrical equipment such as transformer. There is a large number of rotating flux in the T-type junction of the core of motor and three-phase transformer. The measurement and simulation of magnetostrictive characteristics of electrical steel sheet under rotating magnetization are still in the initial stage in foreign countries, but no reports have been reported in China. Based on the magnetostrictive characteristic measurement system developed by the laboratory, the magnetostrictive characteristics of electric steel sheet with different magnetization trajectories are measured and analyzed, and a dynamic vector model is proposed to describe the magnetostrictive characteristics of rotating magnetostrictive steel sheet. The calculation method of model parameters is deduced. The validity of the model is verified by experiments. The magnetostriction of stator core and the local deformation caused by the magnetostriction of a synchronous generator are quantitatively analyzed, which lays a foundation for the accurate calculation of the vibration and noise of the motor core. The main research contents are as follows: firstly, the measurement system of magnetostriction under rotating magnetization developed by the laboratory is improved. In order to improve the measurement accuracy, the sticking position of the strain gauge in the original system was moved to the center of the sample, and the magnetostrictive data were measured under different rotating magnetization trajectories. Then, the variation waveform and peak value of principal strain and principal strain angle in a magnetization period under different magnetization conditions are analyzed. The harmonic content of the principal strain waveform and the vector and hysteresis characteristics between the principal strain and flux density are discussed. Thirdly, a dynamic vector model is proposed to describe the relationship between magnetostrictive principal strain and flux density vector. The components of magnetostrictive principal strain along horizontal and vertical directions are expressed as the sum of three terms, that is, a constant term related to the magnetization trajectory, the flux density variation term with time and the derivative term of flux density to time. The mathematical expressions of the parameters in the model are derived in detail. The model parameters are calculated based on the measurement data and the database of the model parameters is established. The validity of the model is verified. Finally, the magnetostrictive deformation of a synchronous generator is modeled and simulated based on the magnetostrictive model. In a period, the magnetic field data of stator core unit at discrete time are collected and output; the model parameters of each unit are calculated by interpolation based on the model parameter database; finally, the magnetostrictive data of each unit are calculated. The distribution of the principal strain of the motor core and the local deformation caused by it are obtained.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM275

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