Taketsune Nakamura,Kyoto University
We have been developing so-called High Temperature Supperconductor Induction/Synchronous Machine (HTS-ISM).Although basic structure of the HTS-ISM is the same as that of the conventional squirrel-cage type induction machine, we could show for first time in the world that the wonderful performance can be realized by replacing the secondary windings with the HTS wires, i.e., (1) co-existence of synchronous and slip roration modes, (2) high efficiency thanks to the steady state syncchronous rotation, (3) realization of higher torque density and/or higher power density, (4) robustness against the overload condition, (5) availability of continuous operation form non-superconductivity state to the superconductivity state, etc. In order to realize the industrial applications of the HTS-ISM, we have to show that such machine possesses the merits compared to the conventional machines, when the motor is operated at the variable speed that is depending upon the target applications. Then, we have to model the nonlinear current transport properties of the HTS windings, perform the characteristic analysis by using such modeled expressions, and realize the optimal drive technology. The current status of the aforementioned study will be reported.