Analysis Of Electromagnetic Performance Of Superconducting Magnet And Efficiency Of An HTS Flux-Switching Machine With Stationary Seal

As a new type of special motor,HTS motor has a very broad application prospect in large-scale wind power and ship-driving fields due to its small size,light weight and high power density.HTS Flux-Switching Machine(HTS-FSM)greatly improves the performance of superconducting machines,and solves the shortcomings of traditional superconducting machines,such as complex structure and high operating cost.HTS machine offers a new option for motor application.Therefore,in order to understand the operating characteristics of high-temperature superconducting flux switching motors,this paper focuses on the motor characteristics of superconducting and flux-switching,by comprehensively applies knowledge in many fields such as electromagnetics,mechanics and materials to conduct a series of research and calculations.The performance and application value of the motor is of great significance.The paper first introduces several methods for calculating the iron loss of conventional motors,and discusses the difficulty and application of them.Aiming at the actual situation of high temperature superconducting flux switching motor and considering its magnetic field distribution,a variable coefficient harmonic orthogonal decomposition iron loss calculation model suitable for complex magnetic density distribution is proposed.The model can be applied to different motor magnetic density.The distribution can also have high accuracy in complex magnetic fields.Then the stator core loss is calculated according to the variable coefficient harmonic orthogonal decomposition model and the conclusions of the proposedmodel,the original orthogonal decomposition model,and the finite element simulation approach are discussed.And finally consider the variable coefficient harmonics orthogonal decomposition model suitable for the complex magnetic density distribution can accurately and simply calculate the iron loss conclusion.Secondly,considering the anisotropic characteristics of the first-generation high-temperature superconducting tape,the heat loss of superconductor is discussed and calculated,and the copper loss and mechanical loss of the motor.Then,according to the obtained iron loss,the efficiency curve of the flux switching motor is abtained.Then,in order to reduce the iron loss of the motor,a new type of high temperature superconducting flux switching motor with air core stator was proposed.In order to study the difference between the two motors,the performance comparison and analysis of the two structures were carried out.The results show that although the core stator structure motor is dominant in most performances,the air core stator structure motor can greatly reduces the motor iron loss and has certain research value.Finally,in order to analyze the working characteristics of superconducting magnets during motor operation,a three-dimensional superconducting coil model for electromagnetic force calculation is established.Based on Maxwell’s electromagnetic law,the general formula of electromagnetic force calculation for static superconducting single-turn wire is proposed based on field theory.The motor simulation model is built by using JMAG simulation software.The correctness of the proposed electromagnetic force calculation method is verified by finite element method.The electromagnetic forces of the whole superconducting coil,the single-turn superconducting coil and the inner and outer dewars under normal operation status were analyzed,and their bearing range was discussed to ensure the security operation of the motor.