TransactionsPublished under the care of the General Secretary and the Treasurer . enting the development of the circumference of the armature, lengths equal to the distance from the axes of the slots, and on successive ordinates, the variations of the magnetic potential tlms calculated. The horizontal mean line is then traced of the curve so obtained, and which indicates the zero of tlie magnetic potential. The fluxes will be at every point proportional to the ordinate of the curve from the zero point, and inversely proportional to the reluctance per unit of surface corresponding to the abscis
TransactionsPublished under the care of the General Secretary and the Treasurer . enting the development of the circumference of the armature, lengths equal to the distance from the axes of the slots, and on successive ordinates, the variations of the magnetic potential tlms calculated. The horizontal mean line is then traced of the curve so obtained, and which indicates the zero of tlie magnetic potential. The fluxes will be at every point proportional to the ordinate of the curve from the zero point, and inversely proportional to the reluctance per unit of surface corresponding to the abscissa considered. For simplicity, the reluctance may first be assumed constant, and BLOXDEL: ARMATURE REACTIONS. account is only taken of its variations in order to arrive at a definitecorrection for a second approximation. To simplify the calcu-lation, there is attributed to the maximum amplitude of the poly-phase currents an arbitran value I^, and it is supposed that thecurrents follow a sinusoidal law. Since the form of the curves ia jL_Ji 2 -*\ 3 \ 1, X,^ J, > C? jiij. r I St. pliMe OAJsnd. phaaa K/a (^Urd. phaae -H/ol/s Fig. 8. reproduced for every one-sixth of a period in the three-phase cur-rents (or in one-fourth of a period in two-phase currents), itsuffices to study them during such an interval, and even to outlinethe extreme forms. Let us take, for example, a three-phase machine with six slotsin the field, each containing N/6 wires, calling N the total numberof peripheral wires per double field (Fig. 8). The potential pro-duced by each is r (N/6)i, calling i the current which traversesthe winding, and it suffices to construct the curve of i, to which thatof the potentials should be proportional. We take two positions; one for which the current is nil in the slots 1 and 4 and«equals \2 in the others, the otlier position for which the current is equal to 2J< sX IN 2,<
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