Electromagnetic Field Calculation And Structural Optimization Of High Temperature Superconducting Statorless Motor

High temperature superconducting(HTS)statorless motors have the advantages of light weight,high specific power and high efficiency which becomes a much-talked-about research topic in both domestic and overseas in recent years.The current carrying capacity of HTS coated conductors is tens of times more than that of conventional copper strips.High magnetic field can be generated and the smaller scale would be realized easily by using the HTS windings regarding to the high power motor.Unfortunately,the current of superconducting windings can’t be high enough due to the full flux saturation,so in this case the advantages of superconducting motor cannot be reflected very well.In order to make the most use of the high magnetic field generated by the HTS windings,a small HTS motor without stator has been designed,and thus the analysis of electromagnetic characteristics and optimal design have been further explored.Firstly,the application prospect of superconducting motor is introduced in this thesis.Following that,the technical advantages and market demand of superconducting motors as well as the research actuality,basic principle and structure of HTS statorless motor are presented.On this basis,a small size HTS induction motor with saddle-shaped superconducting armature winding and without stator is designed.The winding method of the saddle-shaped superconducting coil is proposed,and meanwhile the rotor,cooling system and air gap are structurally designed,and the preliminary design profile of HTS statorless motor is finally determined.Secondly,electromagnetic characteristics of the preliminarily designed HTS statorless motor are analyzed.Based on the classical theory of electromagnetic field,magnetic field formula of saddle-shaped superconducting coil is derived from Monte Carlo method.The two-dimensional transient simulation model for HTS statorless motor is established by finite element analysis software Ansoft Maxwell.The electromagnetic characteristics of HTS statorless motor are simulated and analyzed under no-load condition and load condition,respectively.Finally,optimization for the preliminary design of HTS statorless motor is conducted.The effect of rotor slot number,turns and the bending radius of the saddle superconducting coil,superconducting winding arrangement as well as the size of the air gap on the behavior of HTS statorless motor have been researched.The optimal design scheme of HTS statorless motor has been achieved.