Magnetic Field Analysis of the 70MW Class Superconducting Generator Using 3D Finite Element Method

Abstract

The three-dimensional magnetic field and eddy current distribution of the 70MW class superconducting generator was calculated by a finite element method. The condition for the exciting armature coil was calculated by the j ω method. In the magnetic flux distribution of the armature winding bore, the analysis value had good agreement with the measurement. An analysis that let the rotor move by the synchronizing speed was also done. The armature voltage for the no-load condition and the armature current for the three-phase short circuit condition obtained by calculations had good agreement with the measurements. The validity of the analysis model for three-dimensional magnetic field analysis of superconducting generator was confirmed from these results. And the synchronous reactances were calculated by these results with eddy current in the facing. As a results, the facing had effect of decrease the synchronous reactance about 5%.