| Electrical steel sheet is an important electrical material, and electrical equipment whose core is made by the steel sheet is widely used in different fields, like electricity, electronics, information industries and so on. With the continuous development of the national industry, the demand for electrical steel sheet is also increasing. Its quality directly affects the performance of electrical equipment, thus the country’s economic development is affected indirectly, while the magnetic properties are key factors to measure the quality of electrical steel sheet. Therefore, accurate measurement of the magnetic properties of electrical steel sheet is of great importance. At present, the main measuring methods of the magnetic properties of electrical steel sheet can be divided into one-dimensional measurement method and two-dimensional measurement method. The one-dimensional measurement method is mainly focus on the means of an Epstein frame and the means of a single sheet tester. And two-dimensional measurement method is a method which is improved on the basis of the one dimensional measurement method.Firstly, the paper introduces the commonly several methods of measurement, then puts forward a nondestructive measurement technology of the magnetic properties of electrical steel sheet, and designs a new type of measuring device and deduces the measuring principle. To optimally design the measuring device, the electromagnetic field simulation of measuring device is provided through ANSYS software, on this basis, the key technical parameters are determined, such as the size of the yoke of measurement device, the thickness of air gap between the device and the measured electrical steel and the reasonable area to place the measuring coils. Secondly, the nondestructive measuring and sensing system of magnetic properties of electrical steel sheet based on Lab VIEW is set up. The system consists of measuring sensor device, signal conditioning circuit and data acquisition and analytical unit. In this system, the excitation and the signal output of magnetic flux and magnetic potential are achieved by the measuring and sensing device, and the signal conditioning, acquisition and processing functions are realized through the signal conditioning circuit and data acquisition and analytical unit. Finally, the error of experimental data is analyzed, and the method of error compensation is proposed. On the basis, using the least squares method, the curve fitting for experimental data is completed through, thus the magnetization curve of electrical sheet steel and iron loss curve are obtained. By comparing the experimental curves with the standard curves, the correctness of the designed measuring device is proved, and the feasibility of the nondestructive measurement technology of the magnetic properties of electrical steel sheet is verified. |
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