Rotor flux distribution in Guy-type medium-frequency inductor alternators

The paper discusses flux distribution in the rotor teeth and core of a 44.4 kVA Guy-type inductor alternator. Flux measurements, made under open-circuit and load conditions, showed the similarity between stator and rotor flux waveforms over a rotor pitch, modified by the heteropolar flux which links the rotor teeth and core. For any given load condition, the flux waveforms on the rotor can easily be determined by relating the output of a search coil on the rotor to a given reference on the stator surface. From an understanding of the flux distribution at the tooth surface and at the tooth root, it was possible to estimate the losses in the rotor teeth and in the core. Airgap and stator flux distribution are discussed in a companion paper (see p. 377).