Magnetic processes in hysteresis motors equipped with melt-textured YBCO

Abstract

Several hysteresis motors have been constructed with an output power up to 500 W at T=77 K. The rotors of these machines consist of melt-textured YBCO. In this work, the authors present detailed investigations on the magnetic processes in these rotors. Spheres were cut from melt-textured YBCO and investigated by rotating in vector-VSM. From these measurements, torque moments on the sample, hysteretic losses and the slip between external field and the sample can be calculated. The same dependence of the output power on the magnetic field for the samples as for the constructed motors can be derived. Influences of the critical current density and the domain size can be separated by changing the temperature.