Quantitative evaluation of DC voltage– current characteristics of a high temperature superconducting stator winding located in silicon steel core at 77 K

Abstract In this paper, we report on the quantitative characteristics of the DC current transport property of a superconducting bismuth strontium calcium copper oxide (BSCCO) stator winding that is used in a superconducting motor. The winding is in a slot of silicon steel core, and the DC voltage of such a winding is measured as a function of the transport current in atmospheric liquid nitrogen. Precise distribution of the magnetic field vector on the winding is also obtained using a three-dimensional finite element method, and thereafter used for the quantitative calculation of the local electric field with the aid of nonlinear and distributed circuits. The total (end-to-end) voltage of the winding is obtained by summing up the local value. It is demonstrated that the developed analysis procedure reproduces the measured results of the DC voltage vs. current characteristics even though the tape experiences a complicated magnetic field vector. Our method is effective for the precise design of a high-temperature superconducting stator.