Research On Some Issues Of 2D And 3D Magnetic Property Measurement Of Electrical Steel Sheets

Electrical steel sheet has very complex non-linear magnetization characteristics. It is the most widely used as magnetic material in electrotechnical products. In order to reduce loss and realize the optimization performance of production, accurate simulation of the electrical steel sheet magnetic properties is needed in the numerical analysis of electromagnetic field in electrical machines and apparatus. Presently, the measuring methods of magnetization characteristics are 1D and 2D measuring method. The 1D measuring methods of magnetization characteristics are mature. But these methods have some disadvantage. The methods of 2D magnetic property measurement are the current research focus. These research topics are still developing. The 3D measurement of magnetic properties is just in its infancy. Aimed to the 2D and 3D measuring system, several key problems are deeply researched in this paper.Tasks accomplished in this paper are as follows:First, the background and development of measuring method of magnetic characteristics of electrical steel sheet are introduced. The two-level amplification filter system is proposed to solve the problem of small and noised signal for H vector in magnetic characteristic measurement of silicon steel sheet, including hardware design and software design, and a check of the amplifier circuit.Second, the calibration of H coil is a key part when 2D and 3D magnetic properties are measured. The solenoid's magnetic field simulation is completed. The calibration device and the entire measurement system are designed. The measurement computer program which is based on LabVIEW is written. The calibration experiment data acquisition is implemented. Accordingly, the calibration results of H coil is obtained.Third, the electromagnetic measurement model simulation of the middle of the region where H coil is placed is completed. The magnetic field unevenness is obtained in different excitation condition. Based on the simulation results, the improvements of coil H is fulfilled. Last, the conclusions of the whole research are given, and some unsolved problems are presented and some advices are proposed for further study.This thesis is a part of the national natural scientific foundation project,"The fine simulation of comprehensive electromagnetic properties of the electrical steel sheet and its composite structures in the computational electromagnetics".