Magnetization of Superconducting Pellets in Highly Inhomogeneous Magnetic Field

The magnetization of superconducting pellets is a worth point in the development of trapped flux superconducting motors. Experimental and simulated data have been reported extensively according to the framework of one or several pulses of a homogeneous magnetizing field applied to a pellet or a set of pellets. In case of radial rotors of low power motors, however, the use of the copper coils to produce the starting magnetization of the pellets produces a highly inhomogeneous magnetic field. In this work we present an analysis of the magnetization of the superconducting cylindrical rotor of a small motor by using a commercial FEM program, being the rotor magnetized by the working copper coils of the motor. We report on the magnetization obtained and heat generated in the HTSC pellets, in several possible configurations.