The Six-Phhase Generator and Transformer into a Three-Phase Power System

A model six-phase generator has been tested together with model transformers giving six-to three-phase conversion with a view to assessing the harmonic performance of the system. The measured harmonic currents are shown to be consistent with those calculated from the equivalent circuits of the generatDr and transformer. It is shown that voltage harmonics of order 12k±1 are passed into the power system but those of order 12k±5 can only produce circulating current within the generator and transformer when the h.v. output windings are put in parallel. Because the leakage reactances of large transformers are about 15% even at fundamental frequency it is not thought that harmonic effects would seriously compromise performance.