Two-Dimensional Model of a High-T_cSuperconducting Dynamo

High temperature superconducting dynamos are capable of low loss contactless pumping large dc currents into superconducting magnet coils. We present a mathematical model of such devices and use it for computing the 2-D loop currents and electric fields induced by a dynamo rotor-mounted permanent magnet in a thin superconducting stator strip. Two numerical methods for thin film superconductivity problems, the mixed finite element method, and the fast Fourier transform based method, are employed and compared. We find voltages generated in the stator under open-circuit conditions and losses in the stator. It is shown that if the length of a permanent magnet is comparable to or smaller than the strip width, the 1-D model employed in the previous works can be inaccurate.