Selecting a best point of Critical Current for the HTS Tapes of an HTS Induction/Synchronous Motor by Analytical Hierarchy Process

This paper represents the performance of a squirrel-cage High Temperature Superconducting Induction/ Synchronous Motor (HTS-ISM) based on nonlinear electrical equivalent circuit. The structure of the HTS-ISM is the same with that of the squirrel-cage type induction machine, and the secondary windings are fabricated by the use of the HTS wires. It has already been shown based on the experiments that even this simple replacement realizes the excellent improvement of the performances such as coexistence of slip and synchronous rotations, higher efficiency thanks to the synchronous operation, robustness against the overload. In this paper the transient modeling of this motor is performed by Matlab Simulink. Also it is shown by FEM that starting and synchronous torque extremely is dependent to input voltage and critical current of superconducting tapes of rotor. So the starting and synchronous torque of the HTS induction motor can be improved with adjustment of the input voltage and critical current of the rotor HTS tapes. Also, in order to optimize both the starting and synchronous torques simultaneously, the relationship between these torques and the critical current of the HTS tapes have been investigated. At the end according to variation of the critical current we optimized the designing of the motor by analytical hierarchy process with finding the appropriate critical current for HTS tapes of rotor. The equations obtained are nonlinear, and then the typical Newton–Raphson method is used for the calculation

Keywords:

HTS induction motor optimization , superconducting rotor , HTS-ISM , Analytica lHierarchy Process