US1085375A - Sectioning means for electric stations. - Google Patents

Description

, E. BRANDENBURG.

SEGTIONING MEANS FOR ELECTRIC STATIONS.

Patented Jan. 27, 1914.

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Witnesses:

E. BRANDENBURG.

SEGTIONING MEANS FOR. ELECTRIC STATIONS.

APPLICATION FILED 00T.2, 1911.

Patented Jan. 27, 1914.

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' Attorney.

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E. BRANDENBURG.

SEGTIONING MEANS FOR ELECTRIC STATIONS.

APPLICATION FILED 0GT.Z, 1911.

Patented Jan. 27, 1914.

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E. BRANDENBURG.

SECTIONING MEANS FOR ELECTRIC STATIONS.

APPLIOATION FILED 0012, 1911.

1,085,375. Patented Jan. 27, 1914.

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Witnesses:

LCILUMDIA PLANDGRAPH CO..WASHINGTON D. c,

EDWIN BRANDENBUR-G, OF BRUSSELS, BELGIUM.

SECTIONING MEANS FOR ELECTRIC STATIONS.

Application filed October 2, 1911.

To all whom it may concern:

Be it known that I, EDWIN BRANDEN- none, a subject of the King of Belgium, residing at 14 Rue dEstouvelle, Brussels, in the Kingdom of Belgium, have invented certain new and useful Improvements in Sectioning Means for Electric Stations, of which the following is a specification.

It is known that, in certain central electric stations, in order to limit the accidental interruptions of the current supply, the parallel running of the dynamos is replaced during the hours of heavy load by multiple unit running. The bus bars are sectioned, and each circuit is supplied by a special dynamo in such a manner that the perturbances in case of accident are limited, and the risk of total stoppage of the works is eliminated. The excess voltages which occur on opening the interrupters and cutting out heavy loads, are localized by the previous opening of the sectioning interrupters.

The present invention has for its object to render this system of sectioning more efiicacious, by making the sectioning interrupters automatic in their action and more sensitive than the interrupters arranged upon the direct path of the current, so that they may operate more rapidly, while, at the same time, permitting of efficient running in parallel. In normal running sectioning only exists virtually, but in case of accident it takes place automatically with certainty and precision. Furthermore, the device is sufficicntly flexible to permit of limiting, according to requirements the size of the sections, and consequently the number of feeders served by a running unit. This point is essential in order to insure a sufficient service, because in case of accident it is important to prevent weakly loaded feeders, from which a running alternating current generator is not directly branched, from being deprived of current by the operation of the sectioning interrupters.

In the accompanying drawing which is given by way of example, Figure 1 shows diagrammatically a general view of a central station equipped in accordance with the invention. Fig. 2 is a diagrammatic detail view of a section in cases in which triphase current is used. Fig. 3 is a diagrammatic view showing the manner of rendering the reserve dynamo operative in case of accident. Fig. 4 is a diagrammatic view of a Specification of Letters Patent.

Patented Jan. 27 1914.

Serial No. 652,315.

section in cases in which the safety cut out of the dynamo is automatically controlled a maximum relay. Fig. 5 shows the automatic control of the safety cut out by a reversing relay and Fig. 6 is a similar view showing the control of this cut out by the combination of a maximum relay and of a reversing relay.

The bus bars 1 are preferably arranged ring-fashion. Between each alternator connection a sectioning interrupter 2 is ar ranged. The feeders 3 are grouped in numbers proportionate to the power of the units. Each group may be connected directly with the different sections of the ring 1.

The bars of each section are supplied by an alternating current generator 4, provided in the usual manner with a safety interrupter 5. The conductors of the first and of the second phase of the generator 4, are each provided with a primary winding 6 which acts upon a secondary coil 7 connected with a maximum relay 8. These two relays are sufficient for protecting the alternator eflicaciously, because an increase of intensity in the conductor of the third phase makes itself felt in the conductors of one or other of the two other phases. The relays 8 are branched off a general line 9,,10 in which a battery of cells 12 is provided to serve for all the sections. In the circuit of this battery there is interposed a solenoid which acts upon an intermediate interrupter 13 serving to connect bridge-fashion the circuit of the battery 12 with the third wire 11 of the general line. The conductors of the circuits 14 terminate at the wires 9 and 11 of the general line; solenoids 15 are mounted in these conductors and control the sectioning interrupters 2. Each of these circuits 14 likewise comprises a locking contact 16 actuated by the safety interrupter 5. This may be of the known oil break type and can be provided with a pin 17 which, upon the operation of the alternating current generator 4 and consequently the closing of the interrupter 5, closes the locking contact 16, thus rendering possible the passage of a current through the controlling solenoid 15. It will therefore be seen that. owing to the contact locking device, the passage of the current is not possible except in the circuits 14 which correspond to a running alternating current generator so that it is possible to vary the size of the section. when, for example, during the hours of low consumption only a single generator is employed for supplying the feeders of the several sections.

Assuming that the central station in question comprises four dynamos a b 0 (Z as shown in Fig. 1, and that each of the latter operates to supply the mains, the four corresponding locking contacts will be closed in such a manner as to permit of the disconnection of all the sectioning interrupters c g 71 The bus bars will thus be divided into four sections, and in case of accident or trouble of any kind producing an overload on the dynamos, the disconnection of these interrupters takes place automatically, in such a manner as to isolate the sections and thus prevent injury to or stoppage of the corresponding dynamos. This automatic disconnection is produced as follows: The maximum relays 8 of each over-loaded dynamo act and close the circuit of the battery 12; the solenoid of the interrupter 13 is energized and attracts its armature in such a. manner as to inter-pose the battery 12 in the disconnecting circuit 14. The locking contact 16 being closed the current is able to pass through the coil 15 and thus produce the disengagement of the sectioning interrupter 2 in such amanner as to isolate the section of the over-loaded generator. It will be seen that when several dynamo units are in. service each of the sections will be defined by the position of the connection of these units relatively to the bus bars 1. The extent of the sections thus composed diminishes in proportion as the number of units in service increases.

If two of the dynamos of the electricity works, for example the dynamos Z) and (Z, are suiiicient for supplying the mains at a given moment, the bus bars will be divided into two sections defined by the sectioning interrupters la, the disconnecting coils of which are the only ones through which the current of the battery 12 is able to pass, the locking contact 16 of the other disconnecting coils being open owing to the opening of the safety interrupters 5 of the stopped alternators. Instead of being operated by hand these intcrrupters 5 may also be controlled automatically by a maximum relay as seen in Fig. l, sometimes by a reversing relay as seen in Fig. 5, but more generally by a reversing relay'and a maximum relay employed in conjunction as seen in Fig. 6.

As shown in Fig. 4 the safety cutout is, in this case, controlled by a solenoid 18, in the circuit of which maximum relays 19 are interposed, their operation depending upon the intensity of the current passing through the conductors connecting the dynamo with the bars 1. is connected with a source of current of any convenient kind which may be the same for the entire installation. The battery 12, already rcferred to, may serve this purpose The circuit of the solenoid 18 by addin to the general line 5), 1O, 11., a fourth conductor 20 to which the second terminal of the battery 12 is connected. In the case of three phase current two relays 19 are used, but the arrangement of the conductors is such that the solenoid 18 is energized when one or other of the relays has acted, as clearly shown in the drawing.

ll hen the solenoid 18 is controlled by a reversing relay 21 the arr: ngement remains the same as shown in Fig. 5, but the contact of the relay, instead of being actuated only by the primary coil 22 which acts upon the secondary winding 23 of the relay, also depends upon a winding 2% mounted in shunt on the conductors of the dynamo.

Fig. 6 shows the combination of the maximum relay with reversing rel r ys for the control of the cutout These relays are mounted in parallel and the operation of one of them is suliicient for releasing the cutout In this case the relays 8 which control the sectioning interrupter should be more sensitive than the relay of the safety interrupter. as otherwise in case of overload the latter would be disconnected more rapidly than the sectioning interrupter 2. and the adjacent sections thus remaining connected with the defective section by the bus bars 1 would then ha vc to provide the supply for the mains, preriou ly served by the dynan'io whose safctv interrupter has just opened, and would thus be over-loaded in their turn, and their successive disconnection and consequently the total stoppage of the installation would result.

The relays 8 of the sectioning interrupter being more sensitive than the maximum relays of the safety interrupter the latter might really be dispensed with and only reversing relays employed for S21111G,l')0('2\1140 in case of overload the relays 8 act for disconnecting the sectioning interruptcrs and isolating the over-loaded section from the adjacent sections. the dynamos of the sec tion under consideration being then pro tected from any over-load in the latter by the safety apparatus of the feeders of the section, such oil relays in the case of alternating current, or fuses in the case of the employment of continuous current. The arrangement, therefore, permits of retaining for the direct protection of the alter nators only reversing relays. by transferring the maximum action to the sole point at which it is neither an impediment nor a danger, that is to say, upon the path of the exchange currents.

lVhen the safety interrupter 5 of the dynamo is operated automzu icallv the locking contact 16, instead of depending upon this interrupter, may be controlled by the interrupter of the excitation circuit of the dynamo generally operated by hand. This arrangement is represented in 41-, in

which 25 designates the energizing winding of the dynamo 41-, 26 designates the regulating rheostat and 27 the excitation switch, the excitation current being obtained from the battery 12. The locking device 16 is replaced by a third switch key 28 added to the switch 27. This key actuated simultaneously with the switch :27 closes the circuit of the solenoid 15, the corresponding dynamo of which is energized. This arrangement is even preferable when the dynamo is protected directly by rapid action reversing relays which act upon the safety interrupter 5 and might cause its disconnection before that of the corresponding sectioning interrupter.

In certain cases the locking contact 16 might even be dispensed with and the maximum relays 8 connected directly without the intermediary of general line 9, 10, 11. with the disengaging solenoid 15, by employing a separate battery of cells for each section, these relays being able to act only when the corresponding dynamo is running. This arrangement which at first sight would ap pear to be simpler than that previously described nevertheless presents the defect that if a return should take place into one of the running dynamos protected by sensitive reversing relays the latter in acting directly upon the safety interrupter 5 might prevent the operation of the relay 8 and consequently of the interrupters 2, and the object aimed at would not be attained, while the complete arrangement, comprising as principal intermediaries a general line 9, 10, 11 and auxi iary locking contacts 16, insures all the necessary precision to the sectioning. This defect is, however, eliminated when the re versing relay which controls the interrupter 5 is caused to act upon the interrupter 2 also.

Fig. 3 shows diagrammatically the very simple means which, with the arrangement in accordance with the invention, permits of rendering a reserve dynamo operative in case of accident by the employment of switches is Z m n 0 adapted to connect each alternator a 7) c d i with the right or left hand sections. Thus assuming at the moment in question that the dynamos a 0 cl 2' are running, the dynamo 6 being in reserve, and that it is desired to stop the dynamo (Z for example for inspection or repairs it is only necessary to arrange the switches Z and m in the positions indicated in broken lines; the switches 7c and 0 may retain their initial positions while the switch a is set in the neutral position.

Although in the preceding description only triphase alternating current generators have been referred to it is obvious that the arrangement is equally applicable to any other type of generator. In the case of continuous current dynamos the relay 8 instead of being controlled by the current introduced in a secondary coil. 7 is branched directly off the terminals of a shunt interposed in the circuit of the dynamo.

The intermediary interrupter 13 is not indispensable but is an economical auxiliary, because it permits of employing relays of ordinary construction which could not with stand the passage of powerful currents with out injury. If desired the solenoids controlling the automatic interrupters might also be replaced by small electric motors, the shaft of which carries a pinion meshing with a small rack which operates the arm of the interrupter.

Obviously without departing from the principle of the invention numerous other modifications might be introduced into the arrangements described above which are given by way of example only.

What I claim and desire to secure by Letters Patent of the United States is 1. In an electric supply system, in combination with the generators, bus bars conducting current to the feeders, connections between the generators and the bus bars, safety interrupters in said connections, sectioning interrupters in said bus bars, solenoids controlling said sectioning interrupters, a battery common to all the sections, maximum current relays the contacts of which are controlled by the current passing through the connections between the generators and the bus bars and are adapted to automatically close the circuit of said battery and actuate said sectioning interrupters to section said bus bars in case of overload of a generator.

2. In an electric supply system, in combination with the generators, bus bars conducting current to the feeders, connections between the generators and the bus bars, safety interrupters in said connections, sectioning interrupters in said bus bars, solenoids controlling said sectioning interrupters, a battery common to all the sections, means controlled by the current passing in the connections between the generators and the bus bars to automatically close the circuit of said battery and open the sectioning interrupters in case of overload of a generator, locking contacts inserted in said battery circuit and operated by he safety interrupters so that the opening of one of the sectioning interrupters be allowed only when the safety interrupter of the corresponding generator is closed.

3. In an electric supply system, in combination with the generators, bus bars conducting current to the feeders, connections between the generators and the bus bars, safety interrupters in said connections, sectioning interrupters in said bus bars, solenoids controlling said sectioning interrupters, a battery common to all the sections, a

battery circuit in which said solenoids are inserted, locking keys in said battery circuit actuated by the interrupter of the exciting circuit of the generator to allow the opening of the corresponding sectioning interrupter when the interrupter of the exciting circuit is closed, means controlled by the current passing through the connections between the generators and the bus bars to automatically close said battery circuit and 10 open the sectioning interrupter when the corresponding locking key is closed.

In testimony whereof I atlix ni signature in presence of two Witnesses.

EDlVIN BRANDENBURG. Witnesses H. T. E. Knutratrnnr, CHAS. ROY NASMITH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents Washington, I). C.

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