Journal of the Association of Engineering Societies . Here, Oi2 coincides with Oe2 in phase, and Orx and Oxx assumption is also made that OM is in phase with 0, which isvery closely approximated in reality. The useful power delivered by the motor is, in watts, the prod-uct of OE0 by Oi\, the latter being the component of Oia in phasewith OE0; the other component of current ijiu or wattless current,represents no power, hut it requires just as much copper sectionper ampere as the useful current; and, in addition, it has a bad effectupon the voltage regulation of the system supplying t
Journal of the Association of Engineering Societies . Here, Oi2 coincides with Oe2 in phase, and Orx and Oxx assumption is also made that OM is in phase with 0, which isvery closely approximated in reality. The useful power delivered by the motor is, in watts, the prod-uct of OE0 by Oi\, the latter being the component of Oia in phasewith OE0; the other component of current ijiu or wattless current,represents no power, hut it requires just as much copper sectionper ampere as the useful current; and, in addition, it has a bad effectupon the voltage regulation of the system supplying the is obvious that if i^, can he eliminated, the angle &x will becomezero, its cosine, and, therefore, the power factor will become unity,and the characteristics of the system will be improved. This is theprincipal object of the invention of Mr. Heyland, now to be ex-plained. The heavy lines of Fig. 7 are a reproduction of part of Fig. B, is to become zero, i. e., Oi, shifted to Oi\, it is clear that OiL,. must be at the same time shifted to Oi2, since their resultant muststill be OM. This latter change may be effected by introducing intothe armature conductors from some external source an auxiliary alter-nating current whose magnetizing force is represented in magnitudeand phase by the line \j\. This result is accomplished by windingthe armature with an ordinary closed coil wave winding, such as is 70 ASSOCIATION OF ENGINEERING SOCIETIES. commonly used in D. C. machines, and adding a commutator at oneend. At the other end the winding is tapped to collector rings, fourof these being provided for two-phase, three for three-phase ma-chines ; these rings are then connected to variable resistances. Itcan thus be seen that the winding is a combination of the ordinarydirect current winding and the short circuited or squirrel-cagearrangement so common in induction motors. The auxiliary compensating current is introduced through thecommutator by means of brushes; this c
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectenginee, bookyear1881
