| With the rapid development of industrial technology, permanent magnetic materials are widely used in many fields such as transportation, power electronics and so on. The Magnetizing apparatus is the key equipment to produce and develop all kinds of permanent magnet devices and it sets a higher demand on the magnetizing apparatuses, such as energy consumption, magnetic effect, and the volume and so on. However, the high temperature superconducting (HTS) wires run in zero resistance in the superconducting state and their current carrying capacity is far better than that of ordinary copper wires. When they are applied to magnetizing apparatus, the volume will be reduced with an improved performance. In this thesis, the test values and the simulation values of the center magnetic field were analyzed to mutually validate and the attenuation characteristics of the magnetic field at the center of two YBCO exciting coils, which are located oppositely and closed resorting to a superconducting switch, were experimentally studied.Firstly, based on the design objectives, this thesis has derived basic design equations of magnetic circuit from the laws of electromagnetic field and has establishes calculation method of equivalent magnetic circuit network model. Through the simulation software and the theoretical formula, this thesis designed HTS coils and magnetic pole apex angle. A finite element model of the magnetizing apparatus was established and analyzed using3D electromagnetic field simulation software and it has validated the theory. The performance of superconducting strip welding resistance and four double pancake HTS coil was experimentally studied.Secondly, the experiment tested magnetic intensity of HTS magnetizing apparatus in different poles and air gaps of different excitation current, when the gap is4mm, center magnetic induction can achieve as high as2.5T. A detailed analysis of the test values and simulation values on relative error was carried out, which can provide reference for the HTS magnetizing apparatus designed by the software. After adding a superconducting switch to form a closed loop, the test finds that decay time constant of center field reaches104seconds. The dependence of the time constant of the magnetic field attenuation upon the exciting current and the gap between the poles was investigated and the validity of conclusion was validated by simulation calculation.Based on the discussion and analysis of the experimental results, the structure can be optimized in order to enhance the performance of the superconducting magnetic apparatus, and it provides recommendations for future development of large superconducting magnetizing equipment. The application of superconducting switch provides references for future permanent magnetic field and HTS energy storage system. |
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