| Rotating field electrodynamic suspension has many advantages, such as in-situ static levitation and does not need feedback control. However, the permanent rotating field electrodynamic suspension (or is named permanent wheel electrodynamic suspension) has some disadvantages, such as big weight, mechanical loss and noise. Furthermore, the conventional conductors rotating magnetic field electrodynamic suspension allowed input current small and output levitation force limited. To solve these problems, in this dissertation a novel high temperature superconducting electrodynamic suspension scheme is proposed and a series of research is taken around the proposed scheme which focuses on principle of electromagnetic, force characteristic, HTS AC losses and design methods.High temperature superconducting suspension motor air-gap magnetic field two-dimensional analytical model is established. This model can be used to calculate any position’s magnetic field distribution in the motor. Adopt this model, the influences of slip, the input current amplitude and frequency on the air-gap magnetic field are analyzed. Research results show that increasing current amplitude and frequency can increase the motor air-gap magnetic field effectively.Levitation force and horizontal force’s analytical model for the high temperature superconducting suspension motor is established. And the influences of the input current amplitude, frequency, slip and thickness of the secondary on force characteristic of the motor are analyzed. Meanwhile, force characteristic of the motor is analyzed under the conditions of the secondary conductor plate is removing out and there is crack in the middle of the secondary and there is a deflection angle between primary and secondary. Research results show that increasing input current amplitude, frequency and slip can increase levitation force effectively. Furthermore, the proposed suspension motor has stability in horizontal direction when it is arranged above paralleled nonmagnetic secondary board.In allusion to the significant magnetic field dependency and anisotropy to high temperature superconducting material, the magnetic field distribution analytical model in slot part of the HTS suspension motor is established. With the help of finite element method and analytic method, the influence of slot size and main dimensions of winding on internal magnetic field of HTS winding is analyzed and summarized some rules. Calculation results show that increasing slot width can effectively reduce perpendicular magnetic field on HTS coil, and in turn, improve the critical current of the coil.High temperature superconducting one-dimension strip AC losses model is established. AC losses of high temperature superconducting strip under different n values and different frequency are calculated. Based on the calculation results, the scaling law in strip model is proved to be correct.High temperature superconducting material two-dimensional AC losses model is established. In this model, magnetic field dependency and anisotropy is taking into consideration. The characteristics of the magnetic field distribution and its influence factors in HTS quasi-stack model and coil model are analyzed. Research results show that double-layer structure can improve the critical current of the coil and increasing the radius of coil can reduce AC losses of the coil.Established the HTS coil critical current and AC losses test platform. Critical current and AC losses test of the HTS coil are taken, and test results and calculation results are basically identical. The performance of HTS coil meets the engineering requirements.A high temperature superconducting suspension motor and its test platform are developed. The motor adopts variable slot width design, which can effectively reduce the motor’s weight, saving amount of thread and improve material utilization. Levitation force test is performed, and test results proved the feasibility and correctness of the theoretical analysis of the suspension scheme. |
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