Electromagnetic Design And Analysis Of High Temperature Superconducting And Normal Conducting Hybrid Electromagnetic Levitation System

Aiming at the problems existing in the normal conducting electromagnetic suspension(EMS)system,such as the serious energy consumption of the normal conducting coil,the easy heating of the magnet,and the high cost of the track due to the small suspension gap,combined with the development trend of the current carrying performance of the second generation(2G)high temperature superconducting(HTS)tape YBCO and the continuous reduction of the production cost,based on the existing structure of the normal conducting electromagnet of Changsha Maglev Express,the design scheme of HTS and normal conducting hybrid suspension is proposed.In this thesis,the structure design of the basic unit of HTS and normal conducting hybrid suspension electromagnet for maglev train is carried out,and its suspension performance is analyzed by finite element simulation software;The experimental device of hybrid suspension electromagnet is designed and manufactured,and the experimental platform of levitation force is designed and built to test the levitation force of the experimental device;By comparing the simulation results with the experimental results,the feasibility of the design scheme of hybrid suspension electromagnet is verified.In this thesis,two methods of predicting the critical current of HTS magnet by using the field calculator of ANSYS Maxwell are introduced.The distribution of the vertical magnetic field on the surface of the designed superconducting magnet is simulated,combined with the attenuation curve of the critical current of the HTS tape under the vertical magnetic field,the critical current of the superconducting magnet is calculated,and it is concluded that the current range set for the superconducting coil can fully meet the requirements of safe operation.In addition,the suspension performance and energy consumption of the designed HTS and normal conducting hybrid suspension electromagnet are evaluated.The conclusion is that the designed hybrid suspension electromagnet can fully meet the suspension load requirements of the system,and has great energy saving advantages compared with the normal conducting electromagnet.In the process of designing the hybrid suspension electromagnet experimental device,this thesis optimizes the core structure of the suspension electromagnet,and proposes the W-shape core structure with better performance than the U-shape core structure.Compared with the U-shape core structure,the W-shape core structure has more advantages in reducing the coil material use,saving cost and improving the levitation force.A set of hybrid suspension electromagnet experimental device is designed and manufactured,and the critical current of superconducting magnet is measured.By comparing the measured results with the simulation results,the feasibility and accuracy of the method of predicting the critical current of superconducting magnet by using the finite element simulation software ANSYS Maxwell are verified.In this thesis,the experimental platform of levitation force test is designed and built to measure the levitation force of levitation electromagnet under specific levitation conditions,and the test data is compared with the simulation results and theoretical calculation formula.The mutual verification of theoretical calculation formula of levitation force,finite element simulation calculation of levitation force and experimental measurement of levitation force is realized.Finally,it is concluded that it is feasible to use HTS and normal conducting hybrid levitation electromagnet to replace normal conducting electromagnet.In conclusion,the proposed hybrid levitation scheme is feasible,and it is necessary to further study its levitation control system and AC loss under background magnetic field in the future.