Research On Magnetization Characteristic And Magnetic Circuit Of Silicon-Iron Materials

The magnetization characteristic of transformer core material is one of the main factors which influence transformer technical performance. In addition to its high magnetic permeadility, another important characteristic of core materials is hysteresis phenomenon which magnetic flux density B always lags behind the magnetic field intensity H change in magnetized process, hysteresis phenomenon. Magnetic hysteresis loop is a reflection of the ferromagnetic materials’ hysteresis characteristics of the important characteristic curve, connection magnetic hysteresis loop the vertices of the cluster of ferromagnetic materials that get basic magnetization curve. The simplified calculation in common use in the magnetization curve to describe electromagnetic properties of electrical equipment. It is important for the design, manufacture and operation characteristics of the transformers’s family to study silicon steel materials magnetic hysteresis loop and the magnetization curve and provides certain basis for ferromagnetic materials and for the new development and application.The magnetization characteristics measurement methods, principle and its classification are studied and the magnetization characteristics of the transformer core, no-load excitation current are measured in the thesis. It is analyzed that the magnetization characteristic of transformer core varies with frequency. Secondly, the magnetic parameters of silicon with different air-gaps are measured by using Epstein to study how the air-gaps influence magnetizing characteristics of silicon-iron. Then the magnetic circuit-electrical circuit coupled model is selected to calculate the transformer magnetizing current by using the measured magnetization curves and hysteresis loop. It is found that the calculated results of magnetizing currents by using hysteresis loop are better than the calculated ones by using the traditional simplified magnetization curve by comparing with the measured data. Finally.3-D model of the transformer is built by electromagnetic field finite element software to analyze the magnetic field distribution, excitation current and other variables in the transformer.