| Precise modeling of magnetic properties of electrical steel sheets includes three contents. The first is to obtain the data of properties of material by measurement method. Then build up the proper mathematic model to describe those properties. At last, couple the model of magnetic properties with calculation method of electromagnetic field to analyze the electromagnetic device. The destination of study is to improve the precision of calculation to analyze the dynamic properties of electromagnetic device. Basing on the accurate analysis, optimize the design of electromagnetic device in order to decrease the iron loss and local overheating to improve the efficiency and security of the device. In this dissertation, basing on the measurement methods, above contents are studied.In this dissertation, two kinds of 1D measurement methods are analyzied and the disadvantages of the two methods are discussed. Because apstein frame method is simple and widely used, this method is improved to test the anisotropy of electrical steel sheets. The measurement data are applied to engneering analysis. The problem and range of application of the method are discussed.Basing on 1D measurement method, 2D measurement method is investigated. The measurement system of 2D single sheet test is designed and feedback control of measurement system is realized. The measurement system can generate alternating and ellipse magnetic fields by criterion of sinusoidal magnetic field. The magnetic characters of grain-oriented electrical steel sheet 30ZH120 and nonoriented electrical steel sheet 50A1300 are measured under the two kinds of magnetic fields. In order to consider the behavior of ferromagnetic material of device in real working states, a measurement method by criterion of sinusoidal voltage is proposed. In this method, the behavior of electrical steel sheet under harmonic magnetic field is test and grain-oriented electrical steel sheet 30ZH120 and nonoriented electrical steel sheet 50A1300 are measured.In order to model the behavior of ferromagnetic material by using measurement data under different condition considering anisotropy and dynamic hysteresis characters, several models have been investigated. Two kinds of vector models are proposed to couple with finite element method so that the model can be used conveniently and rapidly. One model is improved E&S model solved by tensor method, the other is Fourier model solved by M-B method.According to tensor method and M-B method and anisotropy and dynamic hysteresis characters, format of finite element method is studied. Combining with characters of electrical steel sheet in real working state, the nonlinear iteration format is studied. Because of the difference between materials, the transformer core and motor core is designed and analyzed with finite element method.A single phase transformer core is designed and made. Tips method is adopted to measure the magnetic character of the core. Comparing the calculation result with experiment result, the validity of the proposed method is proved. |
PDF Full Text Request