Study of the magnetic field in superconducting alternators

In this paper, the radial and tangential components of the magnetic field inside a three-phase turbogenerator with superconducting field winding and with a rotating screen of any number of elements are calculated with reference to a twodimensional study and to steady state and transient running. The expressions obtained are valid for any order of the field harmonic and any number of pole-pairs of the generator, and refer to a finite thickness of the rotor and stator windings and take account of the real distribution of the eddy currents in the screen elements. As an example of the applications, with reference to a preliminary design for a two-pole turboalternator of around 1300 MVA with "double" rotor screen, the distribution of the flux density with no load and its content of harmonics are found and the steady state and transient behaviour of the rotor screen is analyzed. © 1980 Springer-Verlag.