【作者】 李强；

【导师】 张艳丽；

【作者基本信息】 沈阳工业大学 ， 电气工程， 2016， 硕士

【摘要】 电机定子铁心是由无取向电工钢片叠积而成,电工钢片的磁致伸缩效应会使大功率电机定子铁心发生形变加剧电机振动噪声。因此,准确测量与分析电工钢片的磁致伸缩特性是研究电机铁心振动噪声的前提和基础。近年来,随着实验测试技术的不断发展,国外已开展电工钢片磁致伸缩的测量与特性研究工作,国内还处于起步阶段。为探明电工钢片的磁致伸缩特性,本文开发了基于三轴应变片测量技术的电工钢片磁致伸缩测量系统,测量并分析了无取向电工钢片在典型磁化条件下的磁致伸缩特性,模拟了磁通密度与磁致伸缩主应变的矢量关系,通过环形铁心样件磁致伸缩测量实验验证了模拟方法的有效性,研究成果对分析并抑制磁致伸缩引起的铁心振动噪声提供参考和依据。主要研究内容有:首先,搭建磁致伸缩特性检测系统的硬件平台。该硬件平台由磁场发生装置,灵敏栅长度为10mm的三轴应变片,BNC适配器,NI PXIe-6368数据采集板卡,应变桥盒和应变放大器组成,其中磁场发生装置使用实验室现有的一套交变磁场励磁装置和一套旋转磁化励磁装置。其次,完成了磁致伸缩特性检测系统的软件设计,并对比校验了测量系统的检测精度。在虚拟仪器LABVIEW平台上编写了测量程序软件代码,包括数据初始化模块,数据采集模块,滤波模块,主应变计算模块等程序。再次,测量了交变磁化与旋转磁化下电工钢片的磁致伸缩特性曲线,讨论了磁化条件对磁致伸缩特性的影响。基于开发的测量系统,得到了椭圆磁化轨迹在不同轴比、倾斜角及磁通密度下电工钢片磁致伸缩三轴应变曲线,计算了主应变大小及方向,分析了一个磁化周期内主应变矢量与磁通密度矢量的位置关系,研究表明旋转磁化下磁致伸缩形变明显大于交变磁化下磁致伸缩。最后,建立了描述不同轴比下磁致伸缩主应变与磁通密度矢量关系的插值曲面,以环形铁心样件为例,实验测量了典型位置处磁致伸缩数据,将测量值与插值数据进行了对比分析,验证了磁致伸缩主应变与磁通密度矢量关系模型的有效性,为磁致伸缩力场与电磁场的联合仿真提供了参考数据。更多还原

【Abstract】 The stator core in the electrical machine is laminated by non-oriented electrical steel sheets, and the magnetostrictive effect of the electrical steel sheet will make the high-power motor core deforming and make the vibration and noise of motor more serious. Therefore, the accurate measurement and analysis of magnetostrictive property in the electrical steel sheet are the prerequisite and basis for studying vibration and noise of the motor core. In recent years, with continuous development of test technology, the magnetostrictive measurement and property study on electrical steel sheet have been carried out overseas, but the relevant research in China is still in the initial stage. In order to investigate the magnetostrictive property of electrical steel sheet, in this paper, the alternating and rotating magnetostriction measurement systems were developed based on a three-axial strain gauge measuring technology, and the magnetostrictive property of non-oriented electrical steel sheet under some typical magnetization conditions was measured and analyzed. The vector relationship between the magnetic flux density and the magnetostrictive strain was modeled and its validity was verified through a ring core sample magnetostriction test. Research results can provide reference to the analysis and inhibition of core vibration and noise caused by magnetostriction. Main contents are as follows:First of all, the hardware platform of magnetostrictive characteristic-testing system was built. The hardware platform consisted of magnetic field generating device, a triaxial strain gauge with a gauge length of 10 mm, BNC adapter, Ni PXIe-6368 data acquisition card, the strain bridge box and the strain amplifier, in which the magnetic field generation system was from an alternating magnetic field excitation device and a rotating magnetic excitation device in the laboratory.Secondly, the software design of the magnetostrictive characteristic testing system was completed and the accuracy of the measurement system was comparatively validated. The measurement software code was complied based on the virtual instrument LABVIEW platform and it includes data initialization module, data acquisition module, filter module, principal strain calculation module, and so on.Then, the magnetostrictive characteristic curve of the electrical steel under the alternating and the rotation magnetization was measured, and the influence of the magnetization condition on the magnetostrictive properties was discussed. Based on the developed measurement system, the three-axial strain curves under various elliptical magnetization trajectories with different axial ratios, inclination angles and magnetic flux density values were obtained, the principal strain magnitudes and directions were computed, and the vector relationship of principal strain and magnetic flux density under a magnetization cycle was developed. The results show that the magnetostrictive strain under the rotating field is significantly greater than that under the alternating field.Finally, the interpolation surfaces describing the relationship between the principal strain and magnetic flux density vector under different axial ratios were built. Taking a ring core sample experiment as an example, the magnetostrictive data on several typical positions were measured, and the measured results and interpolated ones were compared and analyzed. The validation of the vector relationship model was verified. The results can provide reference data to the joint simulation of magnetostrictive force field and the electromagnetic field.更多还原