Theory and calculation of alternating current phenomena . projections in the magnetic field, the reactionsof the machine must be resolved into two components, one inline and the other in quadrature with the center line of the field-poles, or the direction of the impressed or field-excitation,Fo. Denoting then the components in line with the field-polesor parallel with the field-excitation, Fo, by prime, as /, F, etc.,and the components facing midway between the field-poles, orin quadrature position with the field-excitation, Fq, by second,as /, F, the diagram of the alternator reactions
Theory and calculation of alternating current phenomena . projections in the magnetic field, the reactionsof the machine must be resolved into two components, one inline and the other in quadrature with the center line of the field-poles, or the direction of the impressed or field-excitation,Fo. Denoting then the components in line with the field-polesor parallel with the field-excitation, Fo, by prime, as /, F, etc.,and the components facing midway between the field-poles, orin quadrature position with the field-excitation, Fq, by second,as /, F, the diagram of the alternator reactions is modifiedfrom that given in Fig. 139. Choosing again, in Fig. 140, the impressed or field-excitation, /^o, as vertical vector OFq, the current, 0/, consists 280 AL TERN A TING-C URREN T PHENOMENA of the component, 01, in line with Fo, or vertical, and 01 inquadrature with Fo, or horizontal. The armature reaction,OFi, gives the components, OFi and OFi, and the therefore consists of two components, OF = OFi) —OFi, and OF = Fig. 140. Let now(P = permeance of the field magnetic circuit; (23) (? — permeance of the magnetic circuit through the armaturein quadrature position to the field-poles; (24) the components of the resultant magnetic flux are, = (PF, represented by 0$; and $ = 6F, representedby 0$, - and the resultant magnetic flux, by combination of 0$ and0^, is 0$, and is not in line with OF, but differs therefrom,being usually nearer to OFq. ARMATURE REACTIONS OF ALTERNATORS 281 The virtual generated is E2 = a^, and represented ])y OE2, 90° behind 0$.Let now x = self-inductive reactance of the armature when facingthe field-poles, and thus corresponding to the compo-nent, /, of the current, (25) and x = self-inductive reactance of the armature when facingmidway between the field-poles, and thus correspondingto the component, /, of the current. (26) Then £3 = xT — consumed by the self-induction of thecurrent component, /,a
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectelectriccurrentsalte
