Finite element analysis of anisotropic bulk superconductor in electric power applications

This thesis presents the development and use of a transient finite element model of the electromagnetic behavior of high temperature superconductors (HTS). The thesis contributes to the understanding of the penetrated field and numerical modeling of HTS by the finite element method. Of particular interest are the AC losses in anisotropic bulk superconductors.; The finite element method using the magnetic vector potential and the electric scalar potential are presented. Modeling of anisotropic field dependent critical current density of HTS is constructed. Effect of grain misalignment is considered for the case of a polycrystalline cylindrical HTS rod. The E-J power law is extended for anisotropic bulk superconductors. The Newton-Raphson method is used for the nonlinearity arising from the anisotropic E-J power law and critical current density. A relaxation technique is used to enhance the convergence of the numerical computation.; Case studies of AC losses in a cylindrical and a rectangular HTS rod in the presence of a pulsating magnetic field are presented. In each study, the self-field loss and the magnetizing loss components are analyzed from the combined action of a transport current and an external field. The AC losses are calculated by varying the phase angle between the transport current and the external field. The condition for minimum AC losses is obtained.; Case studies of torque calculations in a HTS cylindrical ring in the presence of a traveling magnetic field are investigated. The dependence of the torque calculated on the field penetration is demonstrated. The torque is calculated with different numbers of segment. The effect of skew on the reduction of torque ripple is presented.