US1007480A

US1007480A - Alternating-electric-current-distribution system.

Info

Publication number: US1007480A
Authority: US
Inventors: Gilbert North; John Sedgwick Peck
Original assignee: Westinghouse Electric Corp
Current assignee: Westinghouse Electric Corp
Priority date: 1909-04-12
Filing date: 1909-04-12
Publication date: 1911-10-31
Anticipated expiration: 1928-10-31

Description

G.'NORTH 'w. s. PEGK. ALTERNAT'ING ELEGTRIG CURRENT DISTRIBUTION SYSTEM.

APPLICATION FILED APE.12, 1909.

Patented 001131, 1011.

ZHSHEETS-SHEET 1.-

WITN ESSES Arno/M W G. NORTH & J. S. PEI/K. ALTERNATING ELECTRIC CURRENT DISTRIBUTION SYSTEM.

n OUT 2 1B 7B 3 w i mm h m as t .ATU P o 11 F 2 r 4 N 2 3 m 8 g 1 F 0 O 2 F. W

APPLICATION FILED APR. 12, 1909.

UNITED STAT as PigrENtr oFFIoE;

GILBERT NORTH AND JOHN SEDGWICK PECFL, OF MANCHESTER, ENGLAND, ASSIGNORS T WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ALTERNATING-ELECTRIC-CURRENT-DISTRIBUTION SYSTEM.

To all whom it may concern:

Be it known that We,.GILBER'r NORTH, a subject of the King of Great Britain, and JOHN SEDGWIUK PEoK, a citizen of the United States, both residents of Manchester, in the county of Lancaster, England, have invented a new and usefulImprovement in Alternating Electric-Current Distribution Systems, of which the followingis a specification.

' Our i 'ention relates. to electric systems of distribution in which alternating current transformers are employed and it has particular reference to such systems in which both main and auxiliary transformers are interposed between the supply and the distribution systems.

In systems of the above mentioned character the transformers may be arranged in parallel or in series connection across the circuit conductors. \Vith a parallel connection, the main transformer circuits are arranged to be open at light loads and to be closed only when the load reaches a predetermined value. With a series connection, the main and auxiliary transformers are connected in series across the circuit conductors and the Windings'of the auxiliary transformer are arranged to be short-circuited when the load reaches a predetermined value.

' According to the present invention, dis tribution systems of the character referred to above are provided, for the purpose of effecting the specified connections, with switches which are electro-magnetically actuated, the circuits of the operating coils of the switches being controlled by means of relays and the switches being so' arranged that the circuits which carry any consider-v able currents are, when necessary, broken through the contacts of the main switches and not at the relay contacts thus preventing injury to the latter.

The invention 'is illustrated in theaccompanying drawings, of which Figure 1 is a diagram of connections for a control system'embodying the invention in which the main and auxiliary transformers are connected in parallel with each other. Fig. 2 is a similar diagram of connections of a modification of the system shown in Fig. 1. Fig. 3 is a diagram of connections for a control system in which the main and auxiliary transformers are connected in series Specification of Letters Patent.

with each other, Fig. 4 being a similar diagram of connections of a modification of the system hown in Fig. 3. Figs. 5 and 6 show furthe. -modifications of the invention as applied to a three-wire distribution system, and Fig. 7 illustrates the type of switch which is preferably employed in connection therewith.

Referring now'to Fig. 1, the supply circuit conductors 1-2 are shown as connected to the distribution circuit conductors 3-4 through parallel-connected main and auxiliary transformers 5-6, respectively. The primary Winding 9 and the secondary Winding 10 of the auxiliary transformer 6 are respectively connected across the circuit conductors 1-2 and 3-4, while the primary winding 7 and the secondary winding 8 of the main transformer 5 are respectively connected to the circuit conductors through an electromagnetically actuated main switch 24 having stationary contact terminals 11-12 which are respectively connected in the circuits of the windings 7-8. The main switch 24 also comprises a movable member having two bridge pieces 13-14 which are respectively adapted to make contact with the. stationary contact terminals 1112, when the switch is in its closed position.

The operating mechanism of the switch 24 is preferably of the toggle type, as illustrated in Fig. 7, the movable member 15- being raised into its closed position by means of a closing coil 16, and lowered into itsopen position by means of an opening coil 17, the circuits of the

coils

16, 17 being controlled by means of a relay 18, comprising a pair of stationary contact terminals 19 connected in the circuit of. the closing coil Patented Oct. 31, 1911. Application filed April 12, 1909. Serial No. 489,254.

16 and another pair of stationary contact terminals 20 connected in the circuit of the v opening coil 17. The movable member 22 of the relay 18 piece 21 which normally engages the contact terminals 20 of the relay, but is adapted to be moved into engagement with the contact terminals 19 when the current through the operating coil 23 of the relay exceeds a predetermined value, the operating coil 23 being connected in circuit with one of the distribution circuit conductors 3. It will be seen that the closing coil 16 of the main switch 24 is connected across the contact terminals 12 in series with the contact terminals 19 is provided with a bridge f of the relay 18, while the opening coil 17 is connected between one of the contact terminals 12 of the switch 24 and the distribution circuit conductor 3 through the contact terminals 20 of the relay 18.

The operation of the apparatus is as follows :Assuming the main switch 24 and the relay 18 to be in the positions indicated in the drawing, the distribution circuit condurtors 3 4 will. be supplied with (.HGIg through the auxiliary transfi)ruier (3, the

.primary and secondary circuits 1 8 respectively of the main transformer 5 being broken at the contact terminals 11--12 of the main switch. If the load upon the distribution circuit be increased beyond the predetermined value at which the energizing coil 23 of the relay 18 is designed to operate, the movable men'iber 22 of the relay 18 will be raised so that its bridge piece 21. engages the relay contact terminal, 19. A circuit will. thus be completed from the circuit conductor 3 through the main transformer winding 8, one contact terminal 12 of the switch 24, the closing coil 16, the contact terminals 19 and the bridge piece 21 of the relay 18 and the other contact terminal 12 to the other circuit conductor 4. The closing coil 16 of the switch 24- being thus energized, the movable member 15 of the switch will be moved into its closed position and the

bridge pieces

13 and 14 will connect the primary and secondary windings 78 of the main transformer 5 to the supply and I the distribution circuit conductors, respec tively. The engagement of the bridge piece 14 of the main switch with the stationary contact terminals 12 will short-circuit the closing coil 16 which is, therefore, energized only during the actual movement of the switch into its closed position. If the load on the distribution circuit conductors decreases below the predetermined value, the movable member 22 of the relay 18 will resume its former position, and the bridge piece 21 will engage the contact terminals 20, thus completing a circuit from the circuit conductor 4 through the contact terminals 12, the bridge piece 14, the opening coil 17 and the contact terminals 20 of relay 18 to the other circuit conductor 8. The switch 24 will,'consequently, move to its open position in, which the circuit of the opening coil 17 is broken by the separation of the bridge piece 14 from the contact terminals 12.

It will be seenfrom the above description that the circuits of the opening and closing coils 16'-17 of the main switch 24 are broken at the main contacts 1112, the contacts 1920 of the relay 18 being merely required to complete the circuits of the opening and closing coils.

In some cases it may be found that the connections above described provide insufficient current to operate the closmg coil 16 of the switch 24, since the coil is traversed only by the magnetizing current taken by.

the main transformer winding 8, when the latter is unloaded. In such cases, the moditrated in which the main and auxiliary transformers 56 are connected in series with each other between the circuit conductors 1--2, and 3 4, the primary and secondary windings 9-10 of the auxiliary transfo mer (3 being arranged to be short-circuited by means of the electro-magnetically operated switch 24 when the load on the circuit conductors 34 exceeds a predetermined value. The opening coil 17 of the switch 24 is connected between the bridge. piece 14 of the switch and the circuit conductor 3, through the contact terminals 20 of the relay 18, the closing coil 16 being connected across the contact terminals 12 of the switch 24 through the relay contact terminals 19, as in the system of Fig. 1. The circuit of the opening coil 17 is thus broken at the bridge piece 14 and the contact terminals 12 of the switch 24, while the closing coil 16 is shortcircuited by the bridge piece 14 when the switch is in its closed position.

Referring now to Fig. 4, a modification, similar to that illustrated in Fig. 2 is illustrated in which the circuit of the closing coil 1.6 is arranged to be broken at the contact terminals of a special switch 25, which is open when the switch 24 is in its closed position, this arrangement being intended to be used for systems in which the arrangement to How through the closing coil 16, by reason of its connection in series with the main transformer winding 8.

Referring now to Fig. 5, in which the invention is illustrated as applied to a threewire distribution system having the main and auxiliary transformers connected in parallel with each other, the connections are seen to be very similar to those of Fig. 1 except that the switch 24 is provided wit-h an additional bridge piece 26 which when the switch is closed, connects the middle point of the main transformer secondary winding to the neutral or balancing conductor 27 of the distribution system.

Fig. 6 illustrates the invention as applied to a three-Wire distribution system in which connected in series with each other, the

110 of Fig. 3 would not allow suificient current I bridge piece 26 of the switch 24 being connected to the neutral or balancing conductor of the distribution system, and the closure of the switch serving to short-circuit the secondary winding of the auxiliary transformer.

It will be noted that the primary winding of the main transformer comprises two

portions

28 and 29, between which the primary winding 30 of the auxiliary transformer is connected when the'switch 242' is open. It will also be noted that the-secondary winding of the main transformer comprises two

portions

28 and 29 between which is connected the secondary windingBO of the auxiliary transfornnr and that the common terminals of the three windings are connected to the stationary contact terminals of the switch 24 that are engaged by the member 26 when the switch is 'closcd. hen the switch 24 is open, the middle point of the series-connected secondary windings is connected. to the neutral conductor 27 by the conductor 31 and when the switch is closed the windi snort circuited and the adjacent tenainals of the windings 28 and 2t are connected together by the'switch and to the neutral conductor 27 by the conductor 26*.

The invention, which is applicable to single or polyphase distribution systems, is evidently capable of wide variation, as regards the manner of carrying out the same, and is not to be regarded as limited, except by the restrictions imposed by the state of the art.

We claim as our invention:

1. In an alternating current. distribution system, main and auxiliary transformers, a

switch forcontrolling the connection of one.

of the transformers, a relay comprising contact terminals for governlng the operation of the switch, C1ICl11tS.Wl1lCh include contact terminals of the switch and a single .system, main and auxiliary transformers connected between the supply and distribution circuits, a switch for controlling the connections of one of said transformers, an opening coil and a closing coil for said switch, a relay comprising contact terminals for making and breaking the circuit connections of said coils, relay circuits which include the contact terminals of the switch and a single actuating coil in the main distributing circuit.

4. In an alternating current distribution system, main and auxiliary transformers connected between the supply and distribution circuits, an electro-magnetically oper- 'ated switch for controlling the connections of one of thetransformers, opening and closing coils for directly actuating the switch and a relay for connecting the opening and closing coils to the circuit conductors through contact terminals of the switch, said relay having a single actuating coil in the main distributing circuit.

5. In an alternating current distribution system, main 4 and auxiliary transformers connected between the supply and distribution circuits, an electro-magnetically operated switch for controlling the connections of one of thetransformers, opening and closing coils for the switch, and a relay for one of the coils being opened at the contact terminals of the main switch.

6. Inan alternating current distribution system; main and auxiliary transformers connected between the supply and distribution circuits, a switch for controlling the connections of one of the transformers, opening and closing coils for a switch, and a relay for closing the circuits of both coils, the circuit of one of the coils being opened and the other coil being short-circuited at the contact terminals of the switch.

7 In an alternating current distribution system, main and auxiliary transformers connected between the supply and distribution circuits, a switch for controlling the connections of one of the transformers, a closing coil for said switch, relay contactterminals interposed between said closing coil and the contact terminals of said switch, an opening coil for the switch and relay contact terminals interposed between said opening coil and the distribution circuit conductors.

8. In an alternating current, distribution system, main and auxiliary transformers connected to the supply and distribution circuits, a switch for controlling the connections of one of the transformers, a closing .coil for said switch, relay contact terminals interposed between said closing coil and the contact terminals of the main switch, an opening coil for the switch, and relay contact terminals interposed between said opening coil and the distribution circuit conductors and-connected to contact terminals of the main switch.

""9. In an alternating currentdistribution for opening and closing a short-circuit conclosing the circuits of both of said coils,

nection across the terminals of the auxiliary transformer, and a relay for governing the one of the relay circuits including the .con

tact terminals of the switch.

11. In an alternating current distribution system, main and auxiliary transformers connected between the supply and distribution circuits, an electro-magnctically operated switch for controlling the connections of one of the transformers, a; relay, an opening coil for the switch connected through relay contact terminals and through the switch contactterminals to the'distribution circuit conductors, a closing coil for the switch and means for connecting the opening coil through relay contact terminals to the distribution circuit only when the switch is in closed position.

12. In an alternating current distribution system, main and auxiliary transformers, an electro-magnetically operated switch for controlling the connections of one of the trans formers, an opening coil for the switch con nected between the movable member of the switch and one of the contact terminals of the distribution circuit and a closing coil for the switch.

13. In an alternating current distribution system, main and auxiliary transformers connected to a three-wire distributing circuit, a switch for controlling the connections of one of the transformers, a relay for governing the operation of the switch, antrelay circuits including the contact terminals of the switch.

14:. in an alternatingcurrent diiti'ibution system, main and auxiliary transformers connected between the supply and distribution circuits, an electro-magnetically operated toggle switch for controlling the con nections of one of the transformers, opening and closing coils for operating the switch and a single relay for connecting the opening and closing coils to the distribution circuit conductors tl'irough the contact terminals of the switch.

In testimony whereof we have hereunto subscribed our names this Q-lth day of March, 1909.

Gll llllllt'l. NORTH. JOHN SEDGOVICK PECK. lvitness cs G. lV. PINNAR, J. Memos.