Reactance calculation of a 500 MVA hydro-generator using a finite element analysis with superelements

The finite element analysis of large synchronous generators provides a significant improvement in the accuracy of the predicted performance. In case of fractional slot stator windings, the inclusion of more than one or two pole pitches is necessary for consideration of a precise model of the synchronous machine. These large finite element models require highly efficient analysis methods for an implementation in the design optimization. The presented analysis method uses a domain decomposition algorithm, whereby only one finite element model for all angular rotor positions is necessary. Moreover, a significantly reduced calculation time of successive rotor positions is established. This analysis method is utilized for the determination and comparison with measurements of the steady-state parameters of a 500 MVA hydro-generator with 14 poles