The use of nonlinear superconducting material in high temperature superconducting (HTS) induction motor leads to the problem of accuracy of traditional motor vector analysis method, the electromagnetic mechanism of HTS induction motor is studied by numerical solution of the differential equation of LR circuit in this paper. According to the electromagnetic constitutive relationship of HTS material, the variation law of resistivity of HTS materials is revealed. Combined with the E-J rule of superconducting material, the LR form ordinary material equation of stator current and rotor current is deduced, and the differential equations are discretized by Euler method differential equation. The discrete form of stator current rotor current of motor is finally obtained. Based on the Power-Law principle, the rotor resistant expression of HTS Induction Motor with HTS rotor and the armature resistant expression of HTS Induction Motor with HTS Armature are derived. And the electromagnetic characteristics and operational performances of HTS induction motor with HTS rotor, HTS induction motor with HTS armature and fully superconducting HTS induction motor are discussed respectively. The results show that the ratio of rotor current peak value to superconducting critical current is greater than 1 for both HTS induction motor with HTS rotor and fully superconducting HTS induction motor, and there is a risk of superconducting quench.

Introduction

SINCE entering the new century, people’s pursuit of environmental protection and efficiency of transportation has become more and more high. At the same time, faced with the double pressure of environment and energy, countries all over the world are looking for better solutions, hoping that electricity can replace other forms of secondary energy. The application of superconducting material can not only reduce the quality and volume of power equipment, but also improve the efficiency of the same capacity motor and enhance environmental adaptability [1–۶]. Especially the HTS motor developed by liquid nitrogen cooling is a major solution in the development and application of national energy, information and military technology. Compared with the traditional equipment of the same power, the HTS motor has the advantages of small volume, light weight, high power density and low maintenance cost, and can be widely used in many fields such as ship propulsion, wind power generation, magnetic levitation and flywheel energy storage, which has important academic research value and economic application prospect, and has become the research hotspot of many research institutions [7–۱۴]. It is well known that HTS materials are nonlinear materials [15], and when designing superconducting motors, superconducting materials are often simply equivalent to copper materials for simulation calculations.