Force Interaction in Magnetic Systems with a Volumetric High-Temperature Superconductor

Abstract

The paper presents the results of the theoretical and experimental studies of force interactions between permanent magnets and volumetric high-temperature superconductors (HTCs). The obtained data are of interest for the design of various devices with HTC elements: magnetic bearings, transport systems with magnetic levitation, electric machines, etc. Numerical analysis of the electromagnetic field was performed by the method of spatial integral equations for the field sources. The properties of the HTC materials and YBaCuO ceramics are represented by a traditional model for transport currents and a combined model that considers the types of field sources inside the superconductor—the transport current density and the related currents (magnetization). For the transport current density, a modification of the critical state model is applied. In this model, the specific electric resistance of the superconductor is presented by a hyperbolic function of the following three parameters: absolute temperature, magnetic field strength, and current density. The model for magnetization is based on the definition of the related currents in the form of the density of the magnetic moments’ combination of the small superconducting cylinders throughout the sample of a high-temperature superconductor. Experimental studies were performed on a specially designed installations with the HТС cryostatting system in a liquid-nitrogen atmosphere and equipment for precision force sensing. Comparison of the experimental results and calculation data confirms the reliability of the developed modeling methods.