We study the zero temperature (T50) quantum rotor model with on-site disorder in the charging energy. Such a model may serve as an idealized Hamiltonian for an array of Josephson-coupled small superconducting grains or superfluid He in a disordered environment. In the approximation of small-amplitude phase fluctuations, the Hamiltonian maps onto a system of coupled harmonic oscillators with on-...

Taking into consideration the development and integration of electrical machines with lower dimensions and higher performance, this paper presents the design and development of a three-phase axial flux disc motor, with 50 Hz frequency supply. It is made with two conventional semi-stators and a rotor, which can be implemented with a conventional aluminum disc or a high temperature-superconductin...

Magnetic flux trapped on the surface of superconducting rotors of the Gravity Probe B ~GP-B! experiment produces some signal in the superconducting quantum interference device readout. For the needs of GP-B error analysis and simulation of data reduction, this signal is calculated and analyzed in this article. We first solve a magnetostatic problem for a point source on the surface of a sphere,...

An analytical computation of the magnetic field distribution in a wholly superconducting synchronous reluctance motor is proposed. The stator of the studied motor consists of three-phase HTS armature windings fed by AC currents. The rotor is made with HTS bulks which present the specificity to have a diamagnetic behavior under zerofield cooling. The electromagnetic torque is obtained by the int...

In order to harness the kinetic energy of marine currents, we propose a novel ocean-current turbine with a horizontal axis. The turbine can be moored to the seabed and function similarly to kites in a water flow. To operate such turbines in a marine current, the resulting rotor torque needs to be canceled. Therefore, the proposed turbine is designed with a float at its top and a counterweight a...

This paper investigates the potential benefits of utilizing superconducting materials in machines. The project focuses on replacing conventional copper windings with a machine. machine is modelled and simulated using ANSYS software, both windings. A 3.7kw 11kw 3 phase Induction machines are YBCO material applied to stator rotor results show that use can significantly reduce energy losses improv...