SPECTRAL CURRENT ANALYSIS FOR HIGH POWER TURBO-GENERATORS AT INTERNAL ASYMMETRY OF WINDINGS

The paper presents a mathematical model of high power turbo-generator, which allows to consider an arbitrary asymmetry of stator and field windings. In the model, individual one-turn stator coils and coils of the field winding located in common slot are represented. Full spectra of coil's MMF are considered, however dumping windings are omitted. An arbitrary connections of those elementary coils are modelled by the constrain matrix technique. Resulting model equations are arranged by introducing the symmetrical components of stator currents and voltages. Spectral analysis of currents has been done by the harmonic balance method. Exemplary spectra of currents have been calculated and presented for chosen cases of short circuited elementary stator and field coils. The characteristic features of these spectra have been discussed from diagnostics point of view. Calculations in this paper have been done for approximated design data of turbo-generator, so results have only qualitative character.