Calculated Characteristics of HTS Induction/Synchronous Machine Below and Above Its Critical Temperature

In this study, we analyzed the characteristics of high-temperature superconducting (HTS) induction synchronous motor below and above its critical temperature, based upon the electrical equivalent circuit. First, we calculate the equivalent circuit constants by no-load and locked-rotor simulations using finite element method. Second, we measure the nonlinear characteristics of the rotor bar and incorporate them converted to the equivalent circuit. Finally, we develop an analysis method for such motor that possesses secondary windings made of the HTS and copper rotor bars. As a result, we get its torque curves and efficiency contours at several temperatures. These results are important in order to realize the wide operational range of the HTS induction synchronous motor above its critical temperature.