Research On Sensing Structure And Compensation Methods Of The Three Dimensional Magnetic Properties

Magnetic materials have a wide application in the area of electrical engineering, which is the key part that directly determines the property of electric equipments. From a variety of parameters that reflect the property of magnetic material, hysteresis loop is a very important one which describes the relation between magnetic field strength H and magnetic flux density B. In 3-D magnetic property measurement, how to design sensing coil’s structure, how to ascertain coil’s factor, how to design signal detection circuit and how to correct measuring data are the important elements that determine the accuracy of measurement. This study has important implications for the measurement accuracy and detective level, the conclusions and methods will be the necessary base of theories to develop high-accuracy 3-D measuring equipment in the future. The main contributions in this thesis have been listed as below: 1.The design of improvement of sensing structureOn the basis of comparing different sensing structures and summarizing the advantages and disadvantages, and according to the measuring equipment and sample’s requirements, this part improves the structure of the cubic sensing box. 2.The ascertainment of sensing coil’s factorTo ensure measurement accuracy, the coil factor has to be ascertained accurately through experiments before measuring magnetic field strength H and magnetic flux density B. On the basis of theoretical analysis and a large amount experiments, abundant experiment data are obtained and based on these data every coil factor is calculated. 3.The design of signal detecting circuitIn the measurement, the inducted voltage and exciting current must be processed before data acquisition. This part designs the signal detecting circuit, by which the electrical parameter will be processed before acquisition. 4.Calibration of measuring dataThe axes of exciting system and sensing system should be coincide with each other in ideal conditions, but it is almost impossible in practical application, the non-coincidence is bound to lead to some error. To calibrate the data is necessary for the measurement accuracy. The methods of calibration is studied on by use of coordinate transformation...