US955171A - Exciting-alternator. - Google Patents

Description

c. H. KIGKLIGHTBR. EXCITING ALTERNATOR. APPLICATION FILED NQV. 9, 1908.

Patented Apr. 19, 1910.

4 SHBETS-SHEET l.

G. H. KICKLIGHTER.

EXCITING ALTERNATOR. Arl moulox FILED 11011.9, 190a.

Patented Apr. 19, 1910.

4 SHEETS-SHEET 2.

vwowtoz maw 'm O. H. KIGKLIGHTBR. EXCITING ALTERNATOR, APPLICATION FILED NOV. 9, 1908.

4 SHEETS-SHBET 3.

after, 0 13:

Patented Apr. 19, 1910.

c. H. KIGKL IGHTER. EXCITING ALTERNATOR. APPLICATION FILED NOV. 9, 1908.

955,171 Patented Apr. 19, 1910. I 4 snnmssnnm 4. 26" I .5: Q 9 14 N; L5." l f CHARLES H. KICKLIGHTER, OF NEWBERRY, SOUTH CAROLINA.

EXCITING-ALTERNATOR.

Specification of Letters Iacent.

Patented Apr. 19, 1910.

Application filed November 9, 1908. Serial No. 461,761.

T 0 all whom it may concern:

Be it known that 1, CHARLES H. K1010 LIGHTER, a citizen of the United States, and resident of Newberry, in the county of Newberry and State of South Carolina, have invented certain new and useful Improvements in Exciting-Alternators, of which the following is a specification.

The object of the present invention is to provide simple and etficient apparatus whereby an alternator may be rendered self exciting, that is, the current for exciting the field coils being derived from the armature coils, and whereby the pressure generated will be automatically regulated.

The invention can be best set forth in connection with the accompanying drawings in which,

Figure 1 is a side elevation of apparatus embodying the invention; Fig. 2 is a diagran'i showing the electrical commctions of the ap 'iaratus shown in Fig. 1.; Fig. I; is a side elevation of modified apparatus embodying the invention; Fig. 4t is a diagram of the electrical connections suitable for the apparatus of Fig. 3; Fig. 5 is a side elevation of a still further modifi-ation; and,

Fig. 6 is a diagram of the electrical connec- .tions of the apparatus of Fig. 5.

Referring to the drawings, and first to Figs. 1 and 2, the apparatus comprises a bed plate A having pedestals B and O which carry the bearings for the rotatable main shaft D. Also mounted upon the bed plate A is a frame E of the main alternator, which in this case carries the field winding, while the armature of this alternator is fixed upon and rotated with the shaft D. Also mounted upon the shaft D is the core F. Upon this core is placed a winding which on the one hand receives alternating current from the armature coils of the alternator, in this case three phase, and on the other is provided with the connnutat or G through which, and the brushes H and I, current to field winding of the alternator is supplied. The main current is taken from the alternator through the slip rings K. The brushes referred to are stationary, being mounted upon the bearing of the pedestal C. Also mounted upon the shaft D and rotating therewith is an armature L of a direct current exciter having the field frame M. Upon the commutator of the armature bear the brushes N through which current is supplied to the field winding of the alternator.

Referring now to Fig. 2, the armature windings of the different phases 1, 2 and 3 i are connected by conductors l, 5 and 6 with a distributed winding upon the core F,

8 and S), each of said sections extending over approximately 120 of the core. One end of each of the armature windings is connected to an end of one of the distributed winding sections, while the other ends of those sections are connected by conductors 10, 11 and 12 with the slip rings K whence connection is made with the main line conductors 13, 14 and 15. The core F as shown is of annular form and constitutes the magnetic circuit of the distributed winding, there being no other means provided for completing the circuit of this winding such as the field framewhich is ordinarily employed in dynamo electric machines for completiug the magnetic circuits through the winding on the arn'iature. As will be seen. the core F is provided with holes as 16 through which the distributed winding is passed and by this means magnetic circuits completed by magnetic material are formed about the various portions of the distributed winding.

\Vouud side by side with the distributed winding just referred to and in close inductire relation thereto, is a second distributed winding 17 to which is connected the commutator G. From the brushes H and I which bear upon the commutator G extend the conductors 18 and 19 which lead to the direct current winding 20 upon the field of the main alternator. This winding 20 may be termed the compounding winding of the alternator. It will be seen that the tween the respective phases of the armature windings of the alternator and the main line conductors and that therefore the distributed winding sections referred to carry current in proportion to the current flowing in the armature windings which is of course proportional to the load upon the external circuit. The rotating magnetic field set up in the core F by the currents of different phase in the winding sections will induce in the winding 17 an electrornotive force which is proportional to the current flowing therein and since the resistance of the circuit across the brushes'H and I is substantially constant the current through the circuit across those brushes will be substantially which winding is wound in three sections 7,

sections 7, S and 9 are connected in series he proportional tothe working current, that is the current flowing-in the armature windings of the alternator. I

The excitation produced by the winding may be adjusted in any suitable manner.

'In the present instance an adjustable re' sistance 21 is shunted across the'field windmg so that a greater or less amountcf current can be shunted from the winding by decreasing or increasing the resistance :21. Moreover, upon heavy loads the field may approach saturation so that a larger change in current is required to produce a given change in the magnetic field than isthe case when the magnetic circuit is far from saturation. To compensate for this effect, the

. shunt 21 may be'inade of material, such as through thefield. The compounding wind-I ing 20 it will be seen, therefore is for varyiron wire, which has a high temperature coefiicient. ith this arrangement, when the current is heavy the resistance of the shunt will rise rapidly thereby shunting a larger portion of current through the field winding 'so that the larger the exciting current, and therefore the'higher the magnetic eXc tation,'

the more current in proportion will pass ing the excitation of themachine in accordancewith' the load upon the exterior circuit. Itis'usual. to provide a Winding for producing a substantially constant excitation.

The direct current field winding .22 is such a winding connected across the armature L that the'alternator is supplied with direct current field windings and alternating current armaturewindings and that the field is supplied with {I'COHStHUtBXCItatIOH and "alsowith an excitation which varies with the load upon the'inacliine. In other words,

the alternator is compounded whereby the potential at its terminals may be maintained constant or caused-torise 0.1"(l1IT11I11Sl1 with increase inload according to the adjustments as is well understood in connectionwith the compounding of generators.

While the commutator brushes are shown as directly connected to the compounding field winding it willbe'ap parent to those skilled in the art that the effect of this current might be communicated to the field of the alternator in many other ways and the apparatus varied in numerous particulars without departing from the spirit .or'the present invention.

' Int-he apparatus just described {the field of the alternator has been, described as stationary while the-armature was the movable member. Also the core F with its winding and con'imutator was described as movable while the brushes were stationary. Also-two distributed windings were provided upon.

the core F. The invention, however is ap plicable to an alternator in which the armaturei'vindi-ngs are stationary and the field movable; also where there is but a single distributed winding upon the core F and also where the core F with its wiiidingand commutator are stationary while the brushes are movable. The apparatus embodying these changes in construction is shown in Figs. 3 and to which reference is now made. Upon the shaft D" otthe alternator I is mounted a revolving field excited by a directcurrent Winding.

windings l, 2 and 3' are mounted upon the stationary frame E and from the ter ininals of these windings extend the con.-

ductors 10, 11 and 12 which are fcoyn nected through the transformer ri aries 2G, 27 and ZS'tothe external circuitline wires 13, H and 15. The SGCOlldflllGS'Of "the transformers are connected through conductoi's 29, 30 and 31 with the distributed winding 32. upon the core F. 'A

phase alternator being shown, the conduc-.

tors 29 30 and. 31 are connected to the dis tributed winding at points displaced at up proximately120 from each other. The distributcd winding is connected to a coininib tator G, as shown, and the brushes Hi and l which bear upon the commutator arecar ried by a holder J which isiixcd to and rolatcs with the shaft D. The core F together with its distributed winding and the commutator therefor is stationary, being mounted upon the base plate as shown. Thebrushes H and l are connected by conductors 33 and 34: with the terminals of the compounding winding 20. upon the rotating The armature.

field structure, a shunt- Ql, similar to that described in connection with Figs. 1 and 2,

being placed across the compounding winding, The ficldstructurc is also provided with a winding 22, for furnishing a substantially constant excitation, the current for, this winding being supplied by the exciter having the ,field member M and armature L, the armature being .mounted upon the shift I). In all respects the exciter of Figs. 3-and 4 is similar to the exciter shown and described in connection with Figs. 1 and 2, it being provided with the field winding 25 and a regulating resistance 24 therefor. Also a regulating resistance 23' in series with the winding 22 is provided. Inas-- much however as the field windings rotate while the excited. brushes are statioiiary slip rings 0 are provided through which connection is made with the windingQQ.

The apparatus illustrated in Figs. '5 and '6 comprises a bed plate Absupporting the pedestals l5 and G which carry the bear in Fig. 4. The core F is be apparent.

ings in which the shaft D is rotatably supported. The statimiary frame of the alternator E" is carried by the bed plate and upon this frame the armature coils are mounted, the field coils being rotatable with the shaft D" in a manner as is well understood in the art. The terminals of the field winding are brought out to the slip rings 0" while the terminals of the armature windings, in this case three-phase, are connected by the conductors 1O, 11 and 12 through the transformer primaries 2G", 27" and 28" with the mains 13, 1s and 15", these primaries being thus connected in series with the mains and carrying currents proportional to the armature currents. The secondaries 29, 30 and 31, oi the transformers are connected in Y and to the slip rings T. These slip rings are connected with the distributed winding W upon the core F, the winding just referred to being also connected with the commutator G. The construction and arrangement of the core F, its winding and connected conimutator and slip rings are the same as that fixed to and retates with the shaft 1), this core being mounted outside the pedestal B. A rocker arm. J" carries the brushes H and I for collecting the currents from the commutator ir", this rocker being carried by the pedestal B and adapted to be rocked or adjusted thereon to facilitate proper adjustment of the brushes.

Carried by the bed plate I is the stationary field frame M of a direct current exciter having an armature L. Upon the commutator of this exciter bear brushes N which are carried by an adjustable arm mounted upon the pedestal B.

The electrical connections will be best un derstood from the diagram of Fig. 6 from which it will be seen that the eXciter is provided, in addition to the armature L, with a shunt field winding 25 which is connected across theterminals oi the armature in series with an adjustable resistance 24". Also this exciter is provided with a. compounding field winding 20 which is connected across the brushes I and I" while a regulating shunt 21", similar to that described in connection with the previous apparatus, is connected across the winding 20". As a further means of regulation an adjustable resistance 23 may be connected in series with the exciter armature L and the rotating field winding .22" of the alternator which is connected with the armature L through the slip rings 0.

The operation of the apparatus will now The current flowing from the stationary armature windings 1, 2 and 3 through the primaries 26, 27 and 28 to the- mains 13', 14 and 15 will induce in the secondaries 29", 30 and 31 currents which will flow through the slip rings T' to the distributed winding upon the core F and thence they will flow through the commutator G and brushes 1 and I as direct current, to the compounding winding 20 of the exciter. The result is that the field excitation of the exciter will vary with the current flowing to the mains and consequently the voltage and current supplied to the field winding 22 of the alternator will vary. It will be observed however that with the apparatus just described it is simply necessary for the transformers, the core F, the winding thereon and connected apparatus to be of suiiicient capacity to supply compounding current to the exciter. ()bviously this compounding current is much less, and therefore the apparatus may. be made smaller, than is required when the compounding current is supplied directly to the field winding of the alternator as in apparatus hereinbefore referred to. Also but a single winding upon the field of the alternator is required. However, both modes of influencing the field excitation of the alternator are within the scope of the present invention and either may be employed as circumstances may dictate. It. will, of course, be understood also that the above described methods of compounding may be employed whether the exciter is direct connected or belt driven, or where separate excitation is employed.

Other embodiments of the invention may also be employed and while it has been illustrated in what is considered its best application it may be included in other structures than those shown without departing from the spirit of the invention, which is not therefore limited to the structures shown in the drawings.

What I claim is- 1. The combination with an alternator including direct current field windings and polyphase armature windings, of a converter including a core of magnetic material, distributed windings thereon, said core constituting the magnetic circuit for said distributed windings, connections between the armature windings and a part of said distributed windings to produce a rotating field in said core, a commutator, brushes bearing on said commutator, connections between a part of said distributed windings and one or said last two elements, means connected to the other of said last two elements for supplying said field windings with a current varying with the current passing through said distributed windings, said commutator and brushes being relatively movable, and means connecting 'the movable of said last two elements with the shaft of the alternator, said converterfiprming a unit with said alternator.

2. The. combination with an alternator tribute armature windings and a part of said dis- 't'ibuted windings to produce a rotating including direct, current field windicgs and tributedwindings thereon, said core constitutin I the magnetic circuit for said diswindings, connections between the field in said core, a, commutator, brushes bearing on said commutator, connections between a part of said distributed windings and one of said last two elements, and means connected to the other of said last two ,elements for supplying said field windings with a current varying with the cur'ent passing through said distributed windings, said commutator and brushes being relatively inovable, the movable of said last two elements being directly mounted upon the shaft of the alternator.

3. The combination with an alternator including direct current field windings and polyphase armature windings, of a converter including a core of magnetic material, a distributed winding thereon, connections be- "tweethe armature windings and said distributed Winding to produce a rotating field in said core, a" second distributed winding on said core in inductive relation to the first distributed Winding, said core constituting the inagneticcircults for said windings, a commutator, brushes bearing on said cornmutator, connections betweensaid second distributed winding and one of said last two elements, means connected to the other of said last two elements for supplying said field windings with a current varying with the current passing through said distributed 4, comm including a core of magnetic naterial, dis.

tributed windings thereon, i. core constituting the magnetic circuit for said distrib uted windings, connections between the armature windings and a part of said distributed windin to reduce a rotatin field in said core, a root current dynamo mounted upon the shaft of the alternator and connected to ,the direct current field windings, a commutator, brushes bearing on said com-- mutator, connections between a part of said distributed windings and one of said last two elements,means connected to the other of said last two elements and operating in connection with the'direct current dynamo ior supplying said direct current field windngs with a current varying with the'current passing through said distributed wind ings, said commutator and brushes being relatively movable and meansconnecting the movable of said last two elements with the shaft of the alternator, said converter and dynamo forming a unit with alternato. In testimony whereof I afiin my signature in presenceof two witnesses.

CHARLES H. 'KIGKLiGHTEE.

' Witnesses:

JNo, M, Knnnnn, J. N. nioilla'ocnum,

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