Polyphase transformer magnetizing-current wave-forms

The paper deals with the analyses of the magnetizing currents taken by groups of transformers, connected in various manners for operating on polyphase (and particularly on three-phase) systems. The method of treatment employed is to assume that a sine wave of flux necessitates the application of a peaked wave of magnetizing current, and that the difference between this desired wave and the wave actually obtained brings about various modifications in the behaviour of the apparatus. The properties of the star, delta, tee-and vee-connected windings are discussed, particularly with reference to harmonics, oscillographic confirmation being given where possible. Various six-phase systems are also discussed, in view of their importance in connection with rotary-converter work. For convenience, a number of oscillograms have been omitted, only the results being quoted in the paper itself.