US513006A - Dobkowolsky - Google Patents

Description

(No' Model.) I

M. VON DOLIVO-DOBROWOLSKY.

GONTINUOUS ELECTRIC CURRENT DISTRIBUTING SYSTEM. No. 513,006. Patented Jan. 16, 1894.

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UNITED STATES PATENT OFFICE.

MICHAEL VON DOLIVO-DOBROXVOLSKY, OF BERLIN, GERMANY, ASSIGNOR TO THE ALLGEMEINE ELEKTRIOITATS-GESELLSCHAET, OE SAME PLACE.

CONTINUOUS-ELECTRlC-CURRENT DISTRIBUTING SYSTEM.

SPECIFICATION forming part of Letters Patent No. 513,006, dated January 16, 1894.

Application filed November 24, 1893. Serial No. 91.908. (No model.)

To aZZ whom it may concern.-

Be it known that I, MICHAEL voN DOLIVO- DoBRowoLsKY, a subject of the Emperor of Russia, residing at Berlin, in the Kingdom of Prussia, German Empire, have invented an Improved Continuous-Electric-Ourrent Distributing System, of which the following is a specification.

This invention relates to the distribution [0 of continuous electric current and more especially to the feedingwith such current of two series connected consumption circuits by the aid of the so called three wire system, and its object is to enable this system to be worked by the medium of but one current generating machine without sparking being caused at the point of connection between the neutral or compensating wire and the dynamo machine.

It is a well known fact that electric current distributing systems can be carried out with great saving of conducting material by employing high tension currents. \Vhere the consuming apparatus are bound-to a predeterminate maximum tension, the tension of the system can be caused to redouble or to treble or to increase to a still higher degree by uniting some of the consuming apparatus into groups and connecting the latter in series.

Now the ordinary mode of establishing series connection of groups of consuming apparatus is very defective in rendering the groups dependent on each other. To prevent this use is frequently made of Hopkinsons so 3 5 called threeconductor system. In this system there are two series connected groups of consuming apparatus, two series connected generating machines, two main conductors tor connecting the former with the latter,and

a third conductor, called neutral or compensating conductor, which is branched off from the point of connection of the two generating machines and connects in series the two current consuming groups. The princi- 5 pal disadvantage of the so combined system resides in the absolute necessity of providing for at least two generating machines. The attempts hitherto made to enable this three conductor system to be worked by the aid of but one current generating machine have been without any practical result from the reason of the sparking caused on the commutator by the third brush required to connect the compensating conductor with the generating dynamo. Now I have discovered that the feeding of two series connected consumption circuits of like tension with continuous current from but one generating machine can be arrived at without the collector of the latter being subject to sparking by properly applying the following principle: dividing the exceeding current flowing back through the compensating wire into two partial currents and causing the latter to directly flow at diametrical opposite points into the armature winding of adynamo connected with the mains, the said dynamo consisting either in the generating dynamo itself or in a compensating machine, viz: a dynamo, receiving current from the mains and running as an electro motor.

Based on this principle the present invention consists in connecting the compensating conductor with the armature winding whether of the generating dynamo or a compensating dynamo by the medium of a self induction coil in such a manner that the center of the latter is connected with the compensating conductor, while by its ends it is connected with the armature winding at diametrically opposite points. Moreover, the said winding is given such a high self induction as is necessary to prevent it from being traversed by alternating current impulsions while the resistance opposed by it to the pas- S5 sage of a continuous current is but insignificant. By virtue of this organization on the one hand the alternating current impulsions generated in the armature winding are prevented from passing over into the compeno sating conductor by way of the induction coil, while on the other hand the continuous current flowing back through the said conductor is permitted to pass into the armature winding by the way of the induction coil without resistance, so that the feeding of the two series connected circuits continues without the tension of the latter being altered. The said self induction coil may be so arranged as to rotate with the armature of the ICC generating machine, or so as to be stationary, each end forming a brush that is caused to slide on a ring shaped conductor fixed on the armature shaft and electrically connected rotate with the same.

with one of two diametrically opposed points of the armature winding.

In order that the present invention may be fully understood I proceed to describe the same in a more detailed manner reference being made to the annexed drawings forming part of this specification.

Figure 1 is a diagram of the improved three conductor system with the self induction coil rotating with the armature of the current generating machine, the latter being supposed to be a bipolar dynamo. Fig. 2 is a diagram of the improved three conductor system with the induction coil being stationary, the generating bipolar dynamo being represented in side elevation in order to show the arrangement of the brushes and contact rings establishing permanent electrical connection between diametrically opposed points of the armature winding and the ends of the self induction coil. Fig. 3 is a diagram of a form of the improved system inwhich the compensatin g conductor is connected through the self induction coil with the armature winding of a compensating machine, the self induction coil being stationary and connected with the armature winding in the same way asin Fig. 2.

Referring to Fig. 1 adenotes the ringshaped armature of the bipolar generating dynamo A; a. the armature winding; N and S respectively the north and south poles of the field magnet,

and b, b the brushes feeding the mains m and m To simplify the drawings the coinmut-ator has been omitted, and the brushes are supposed to slide directly on the armature winding a.

i is the self induction coil. The coil 'i is arranged within the armature and, moreover, it is attached to the armature shaft so as to The ends 7." and i of coil 1' are respectively in electricalconnection with diametrically opposed points of armature winding a, as for instance with the points a and a".

m is the neutral or compensating conductor connecting in series the two consuming circuits lettered o and '0 and containing for instance lamps respectively Z and 1*. This neutral conductor is electrically connected with the center i of self induction coil '6. When the armature a is caused to rotate, an

' alternating tension takes place at the points of connection, a and a but, as the construction of coil 2' is such as to give rise to a high deg'rce'of self induction, thiscoil will not permit any appreciable quantity 'of alternating currents to flow through it. The center i of coil i-ha'sthe mean potential relatively to all the points of the armature winding a; from this it results not only that the difierence of tension between 11' and 2' is equal to that between 2' and i but that likewise thedifierence of tension from brush 1) toward the point t is equalto that from brush b toward the said'point. As known the connecting'coil team he made with a very high degree of self mature.

induction by coiling it on a closed body of iron e. As long as the number of working lamps respectively Z and Z is alike in each of the circuits 0' and 12 the tension in the circuit o is equal to that in the circuit 12 and there exists no current in the conductor 'm as it is in the middle between the two tensions. But as soon as there are more lamps working in one circuit than in the other, the consumption of current is greater in the former than in the latter and the exceeding current will flow through the compensating conductor m in the direction of the arrow, 'L. e toward the center 2' of the connecting COll/L. Arrived at this point the current splits up into two partial currents, one'of which passes toward and through the point a in the armature winding a, while the other passes toward and through the point a As'the returning current is a continuous current the passage of the two partial currents resulting from its splitting up in the point't' will not be resisted in any appreciable degree by the coil 41. Thus the tension of the two wires connected groups of consuming apparatus is maintained at the same degree; whether there is a greater consumption of current in the one or the other.group,the exceeding current is always allowed to flow back immediately intotho armature'of the generatingmachine through the conductor m and the coil t. It is bythis means that the two series connected groups of consuming apparatus are rendered perfectly independent on each other notwithstanding there is but one generating machine for feeding them with current.

In many cases it will not be possiblenor will it be advantageous in all instances to place the connecting self induction coil within the armature and so as to rotate with the same, sothat the said coil must be disposed out of the generating machine. In such cases, the coil is preferably arranged stationary and provision is made for'causing uninterrupted connection of its ends with diametrically opposed points of the rotating armature winding. Such an arrangement is diagrammatically represented in Fig. 2.

As in Fig. 1 N and S'denote're'spectively the north and south poles of the field magnet of a bipolar generating dynamo A; a the ring shaped armature of same being fixed on'the shaft 5; c the commutator to which the mains m and m are connected through the medium of the brushes b and b i the self induction coil for establishing electricalconnection between the compensating conductor m and I two diametrically opposed points of the armature, and e the'closed body of iron-placed within coil c'.

sulated from each other. These r ingsa're connected by means of two wires, 2' and i with diametrically opposed points of the-ar- The end 2" of the'self induction coil t' is connected by a wire t to abrush i,- that rests'permanently on contact ring i and the On the shafts are fixed t'wo ring shaped contacts, i and 43", which are inother end 2' of coil 1' is connected by a wire with a brush U, which is permanently resting on contact ring i Thus, when the armature is caused to rotate, the contact rings i and i are forced to rotate with it and in doing so they rub against the brushes i and f, whereby the permanency of electrical connection between the ends of coils t' and the said two opposed points of the armature winding is maintained, and consequently the free return of the exceeding current to the same allowed to take place at all times.

Fig. 3 illustrates diagrammatically a three conductor system in which the two series connected groups of consuming apparatus are fed with current by one common generating machine, and in which the connecting selfinduction coil t' is made use of in combina' tion with a so called compensating machine, t'. e. a dynamo running as a motor and serving for taking up the exceeding current. A denotes the generating bipolar dynamo having the brushes 1) and b to which are connected the mains m and m 1; and are the two consuming circuits to be fed with current at like tension from the dynamo A, and m is the compensating conductor by which the circuits o and o are connected in series. 111 proximity of the latter is arranged a bipolar dynamo A with ring shaped armature a the coil a of which is connected with the mains through the collector 0*, the brushes I) and I) and the conductors m and an. e is the shaft carrying the armature a and the collector 0*. t' denotes the self induction coil to the center 2' of which is connected the compensating conductor m In this case the coil 2' is not brought into relation with the armature winding of the generating dynamo A, but with the armature winding (t of the compensating machine A the arrangement being supposed to be made as described with reference to Fig. 2. That is to say, the coil 4. provided with the closed iron body 6 is arranged out of the armature and stationary, and its ends t" and t are connected by wires 2' and tiwith brushes 1' and 2' rubbing against ring shaped contact pieces 2' and "i fixed on the armature shaft .9 and connected by wires t and 2' and the collector c with diametrically opposed points a and c of the armature winding d. hen the system is working the dynamo A is fed with current from the mains m and m through the conductors m and on, whereby it is caused to rotate, the high self induction of coil 2' preventing the current from passing through this coil. As long as there is a like number of consuming apparatus working on the circuits 'vand 0 there will also be a like tension in both of them; consequently the middle conductor hi will receive no current and the dynamo A will work at the same rate. But as soon as the number of working apparatus is changed in one or the other consuming circuit 1; or 22 the excess of current will be led through the conductor 071 (see direction of arrow) toward the center i of coil i, where it splits up into two partial currents passing into the armature winding a as described with reference to the winding a of the system represented in Fig. 1. It will readilybe seen that by this arrangement the same effect as to the independency of the consuming circuits on each other is obtained as in the system Fig. 1. Moreover, a certain saving of conducting material is obtained inasmuch as the compensating conductor need not be continued to the generating dynamo. The arrangement represented in Fi 3 will therefore be the more advantageous the more the generating plant is distant from the series connected consuming groups.

In the preceding description the generating machine has been supposed to be a bipolar one, but this has only been done for the sake of simplicity of the drawings and it will readily be understood by any electrician that the invention can also be made use of in combination with multipolar machine and with armature windings of any description. Moreover, the invention is not limited to the use of but one generating machine, but it may also be combined with several generating machines connected in parallel, which arrangement is a well known equivalent for one generating machine.

I am aware that attempts have been made to feed with current three conductor systems by the aid of one common generating machine, and I do not claim the use of such a common generating machine in combination with two series connected groups of current consuming apparatus, but

WVhat I claim as my invention is- 1. In a system for distributing electricity to two series connected groups of consuming apparatus by the aid of two main conductors and a compensating conductor the combination with the compensating conductor and a continuous current-dynamo connected with the mains of a coil of high self-induction connected at both ends with diametrically opposed points of the armature winding of said dynamo, and in its center with the said compensating conductor, as and for the purpose stated.

2. In a system for distributing electricity the combination with two series connected groups of current consuming apparatus, two main conductors, a compensating conductor and one continuous current generating machine or its described equivalent, of a coil of high self induction connected at both ends with diametrically opposed points of the armature winding of the generating machine and connected in its center with the said compensating conductor, as and for the purpose stated.

3. In a system for distributing electricity the combination with two series connected groups of current consuming apparatus, two main conductors, a compensating conductor, a continuous current generating machine, and a compensating machine running as an electronotor, of a coil of high selfinduetion connected at both ends with diametrically opposed points of the armature winding of said compensating machine and connected in its center with the said compensating conductor, as and for the purpose stated.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

MICHAEL VON "DOLIVO-DOBROWOLSKY. Witnessesz' SOHMOLLER, A. WEBER,

Ingenieurs, Berlin.

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