基于ANSYS的开关磁阻电机电磁场数值模拟与分析

发布时间：2018-01-24 20:44

本文关键词： 开关磁阻电机转矩波动非线性有限元分析静态特性　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：开关磁阻电机(SRM)因其结构简单、成本低廉、调速范围广等突出特点而广受企业和研究人员的关注,但转矩波动和噪声也是其两大不可忽视的缺点。为了提高开关磁阻电机的性能,拓宽其应用领域,转矩波动抑止研究和控制参数优化成为开关磁阻电机深入研究的热点,而电磁特性的精确计算则是其中的重要基础。开关磁阻电机的特殊结构以及电磁材料的非线性导致其内部电磁场是高度非线性变化的,加之磁场复杂的边界条件,选择合适的计算模型和方法尤为重要,而有限元法(FEM)无疑是一种有效的手段,为此采用ANSYS软件对开关磁阻电机电磁场进行有限元计算。根据样机提供的基本数据,再通过电机设计经验公式可以计算出开关磁阻电机的具体结构参数,这些参数为构建有限元模型提供几何数据。通过ANSYS有限元求解和后处理得到的各磁场参数分布云图,可以得出开关磁阻电机的电磁场分布规律是非线性的,各磁场参数的具体值不仅与绕组电流有关,还随着转子的位移角变化而变化。开关磁阻电机静态特性的计算基础是磁化曲线(Ψ-i-θ曲线)。基于电磁场的基本理论和方程,利用ANSYS内部的宏命令可以计算不同电流密度载荷以及不同转子位移角时的磁链,得到磁化曲线。通过对磁化曲线的分析可以得出开关磁阻电机的磁链是随电流和转子位移角而非线性变化,并且变化趋势还受到磁路饱和效应的影响。通过对在磁化曲线基础上得出的转矩特性分析可知,开关磁阻电机的转矩在初始位置达到了最大,开通角提前开启可以使开关磁阻电机在较短的时间内达到最大的电磁转矩;转矩波动与电流的大小有关,电流越大波动幅度越大,转矩特性曲线变化趋势也越剧烈。电流密度为3A/mm2时,电磁转矩的峰值最小,转矩波动最小,转矩特性曲线也最为平滑;电流密度为7A/mm2时,电磁转矩的峰值最大,转矩波动也最大,转矩特性曲线变化趋势最剧烈;电流密度为5A/mm2时,转矩峰值和波动介于两者之间,开关磁阻电机既具有较大的电磁转矩,又具有较小的转矩波动。
[Abstract]:Switched reluctance motor (SRM) has attracted the attention of enterprises and researchers because of its simple structure, low cost and wide speed range. In order to improve the performance of switched reluctance motor (SRM) and broaden its application field, torque ripple and noise are also two shortcomings that can not be ignored. Torque ripple suppression and control parameter optimization have become a hot spot in the research of switched reluctance motor (SRM). The accurate calculation of electromagnetic characteristics is an important foundation. The special structure of switched reluctance motor and the nonlinearity of electromagnetic materials lead to the highly nonlinear variation of the internal electromagnetic field. In addition, due to the complex boundary conditions of magnetic field, it is very important to choose the appropriate calculation model and method, and the finite element method (FEMM) is undoubtedly an effective method. For this reason, the electromagnetic field of switched reluctance motor is calculated by using ANSYS software, and the basic data provided by the prototype are given. Then the structural parameters of switched reluctance motor can be calculated by the empirical formula of motor design. These parameters provide geometric data for building the finite element model. The distribution of magnetic field parameters is obtained by ANSYS finite element solution and post-processing. It can be concluded that the electromagnetic field distribution law of switched reluctance motor is nonlinear, and the specific value of each magnetic field parameter is not only related to winding current. The static characteristics of switched reluctance motor (SRM) are calculated on the basis of magnetization curve (蠄 -i- 胃 curve), based on the basic theory and equation of electromagnetic field. The flux chains with different current density loads and different rotor displacement angles can be calculated by using the macro commands in ANSYS. Through the analysis of the magnetization curve, it can be concluded that the flux of switched reluctance motor is nonlinear with the current and rotor displacement angle. And the change trend is also affected by the saturation effect of magnetic circuit. Through the analysis of torque characteristics obtained on the basis of magnetization curve, the torque of switched reluctance motor reached the maximum in the initial position. The switched reluctance motor can reach the maximum electromagnetic torque in a short time by opening the switch angle in advance. Torque ripple is related to the magnitude of current. The larger the current is, the more the variation trend of torque characteristic curve is. When the current density is 3A / mm2, the peak value of electromagnetic torque is the minimum, and the torque fluctuation is minimum. The torque characteristic curve is the smoothest. When the current density is 7A / mm2, the peak value of electromagnetic torque is the biggest, the torque ripple is the biggest, and the change trend of the torque characteristic curve is the sharpest. When the current density is 5A / mm2, the torque peak and fluctuation are between them. The switched reluctance motor (SRM) has both larger electromagnetic torque and smaller torque ripple.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM352

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