US1731966A - Automatic reclosing circuit-breaker system - Google Patents

Description

Oct. 15, 1929. A. E. ANDERSON AUTOMATIC RECLOSING CIRCUIT BREAKER SYSTEM Filed June 27, 1927 IIVI lnvenbor 1 Arvid B. Anderson,

Hi5 Attorney.

Patented a. 15, 1929 UNITED STATES laarlamr OFFICE ABVID E. ANDERSON, OI SCbTIA, NEW YORK, A SSIGNOB TO GENERAL ELECTRIC COM-.

PANY, A CORPORATION, OE NEW YORK AUTOMATIC RECLOSING CIRCUIT-BREAKER SYSTEM Application filed June 27,

My invention relates to automatic reclosing circuit breaker systems and particularly to such a system for controlling a circuit breaker between two alternating current circuits which are adapted to be energized by sources which may or may not be in synchronism, and its object is to provide an improved arrangement for reclosing such a circuit breaker in accordance with the various relative volt-age and phase conditions of the two circuits.

My invention will be better understood from the following description taken in connection with'the accompanying drawing and its scope will be pointed out in the appended claims. l 1

' Referrin to the accompanying drawing, which is a iagram of connections of an automatic reclosing circuit breaker system embodying my invention, land 2 represent two alternatin current circuits which are arranged to e connected to ether by a circuit breaker 3 which may be 0 any suitable type, examples of which are well known in the art.

In order to simplify the disclosure I have shown my invention in connection with single phase circuits, but it is obvious that it is applicable to polyphase circuits and in practice will be used principally with such circuits.

In the drawing the circuit breaker 3 is" shbwn as a latched-in circuit breaker and is provided with'a closing coil 4 and a trip coil 5. The circuit of the closing coil 4 is cons trolled by a control relay 6 of the well known hesitating t pe so as to insure that the coil 4 is energize long enough to effect the complete closin of the circuit breaker. The trip coil 5 may arranged in an suitable manner so that it is energized w en a predeter-v mined abnormal condition occurs on one'of the circuits. Preferably the trip coil 5 is arranged to be energized in accordance with the amount of current flowing from one circuit to the other when the circuit breaker 3 is closed. As shown in the drawing this result is obtained by connecting the tripcoil 5 to I the secondary of a current transformer 7 the primarypf which is connected in series with the. two circuits 1 and 2 when the circuit breaker 3 is closed.

When the circuit breaker 3 is opened by the above a predetermined value. dev1ce 8, which 1s well known in 1927. Serial No. 201,673

operation of the trip coil 5,;it isdesirable not I energized at that time. The timing device 8' effects the operation of a control relay 9 which in turn effects the immediate energization of the hesitating control relay 6 if the voltage of either circuit is below a predetermined value and the voltage of the other circuit is The timing the art as a motor operated timer,'is also arranged to effect the reclosing of the circuit breaker a predetermined number of times with predetermined time intervals between successive re'closures if the circuit breaker fails to remain closed after it has been reclosed. If the circuitbreaker fails toremain closed after said predetermined number of reclosures, the timing device is also arranged to be locked out so that further reclosing of the circuit breaker is prevented.

, If the voltage conditions of both of the Circuits'l and 2 are normal when the control relay 9 is energized in response to the opera- I tion of the timing device'8, this relay renders the timing device 8 temporarily inoperative and renders a synchronizing check device 10 and an automatic synchronizing device 11 operative to control the closing of the circuit breaker in accordance with predetermined phase relations of the voltages of the circuits 1 and 2. I

The synchronizing check device 10 may be of any suitable type. examples of which are well nown in the art, whereby it closes its contacts 12 if the phase difference between the voltages of the two circuits 1 and 2 does not exceed a predetermined value for a predetermined relatively long length of time, such for example as thirty seconds. This device functions to control the closing of the circuit breaker 3 when both of the circuits 1 I and 2 are energized by the same source or different sources which are connected together at some other point so that they are in syn chronism. Due to the diiferent lengths of the two circuits 1 and 2 and to the difierent loads that may be connected thereto, the voltages of the two circuits at the point where the circuit breaker 3 connects them together may be out of phase although supplied from the same source so that an excessive circulatingcurrent would flow through the circuits 1f the circuit breaker were closed under certain phase conditions. The synchronizing check device 10 functionsto, check this phase difference and to permit the circuit breaker to be closed only when the phase difference is such that an excessive circulating current will not flow when the circuit breaker is closed.

The particular type of synchronizing check device 10 shown in the drawing comprisesan' induction disk 13, shaded pole elements 14;

and 15 arranged to exert opposing torques thereon, and suitable means such as a drag magnet 16 for exerting a retarding force on the disk 13 soas to obtain'the desired time.

delay action in the movement thereof.

Movement of the disk 13 in a direction to carry itscircuit controlling member 17, which is carried by the disk 13, away'from the conta'cts 12 is limited by any suitable means such.

as a stop 18. Motor element 14 is arranged to be energized by the windings 19 and 20 "which are arranged to exert a torque on the disk 13 in accordance with the sum of the in stantaneousvoltages of the two circuits 1 and 2 and in a direction to move the circuit controlling member 17 towards thecontacts 12.

Motor element 15 is arranged to be energized by the windings 21 and 22 which are arranged to exert a torque on the disk 13 in'accordance with the difierence between the instantaneous voltages of the two circuits 1 and 2 and in a direction to move the circuit controlling member 17 away from thecontacts 12. The motor elements 14 and 15 are constructedso that the; torque exerted by the motor element 14 ex-- ceeds that exerted by the motor element 15 only when the phase difference between the voltages of the two circuits is less than a predetermined value. Due to the relatively long time delay that is produced by the drag magnet 16'it will be observed that the synchronizing check device operates to close itscontacts only when the two circuits 1 and 2 areenergized by a common source or synchronous sources, since if there were a difference in the frequencies of the two circuits, their voltages mlght not ordinarily remain'within the operating range of the synchronizing check device long enough to permit it to close-its contacts.

The synchronizing device 11 ma suitable typle, exam les-o whic are well known in t e art, w ereby it closes its contacts 23 when the two circuits 1. and 2 are supplied by sources which are not in synchro' be of any.

nism and the frequency difi'erence between the twocircuitsandthe phase'difl'erence between their instantaneous voltage are less than predetermined values. Preferably the synchronizing device 11 is also arranged to start the closing operation of the circuit breaker at atime. prior to phase coincidence of the. voltages of the two circuits so that when the circuit breaker is closed the voltages are substantially infphase coincidence. Since synchronizing devicesof the above mentioned type are well known in the art and the particular construction thereof is immaterial so far as my invention is concerned, Thave shown the synchronizing device in a conventional manner as comprlsing contacts..23 and coils 24 and 25 arranged respectively tobe connected so as to be energized by the voltages The closing of either the contacts 12 of the synchronizing check relay 10 or the contacts 23 of the synchronizing device 11 completes a circuit for the hesitating control relay 6 if both of the circuits 1 and 2 and the control relay 9 are energized." 27 is a voltage relay whichis arranged to be energized in response to the voltage of whichever circuitis energized when the circuit breaker 3is open and only one of the circuits 1 and 2 is energized. When both of the circuits 1 and 2 are energized the voltage relay 27 is energized from whichever circuit was the first to be energized. The function of the relay 27 is to permit the closing circuit of the-circuit breaker to be closed only in case the voltage of at least one of thecircuits Land 2 is suflicient to'permit proper reclosing action.

Relay 28 is a voltage relay which is arrangedto'be connected so that it is energized from the electric circuit on which the'fault occurred that caused the circuit breaker 3 to open, or which is not energized when only one of the electricfcircuits is energized. The

relay 28 is arranged to effect the reclo sing of the circuit breaker 3 as soon as the relay 9 is energized when only one of the'main circuits 1 and 2 is energized.

In order selectively to control the connections of the voltage relays 27 and 28 so-that they are properly connected in accordance wit-h the voltages of'the circuits 1 and 2 and so that the various control devices may be ener ized from whichever circuit is energize .when only one is energized any suit- 32 is a manually controlled controlswitch s the ungrounded secondary terminal of the transformer 33 the primary of which is confor rendering the automatic reclosing equipment inoperative.

The operation of the arrangement shown is as follows: It will'be assumed first that the circuit breaker 3 is open and that both of the circuits 1 and 2 are energized from the same source when the control switch 32 is closed. Before the switch 32- is closed, the relay 28 is energized so that its contacts 29 are open. 'The circuit of the relay 28 is from nected across the circuit 1.conductor 34, conta cts 35 of relay 30,.conductor 36, coil of relay 28 to ground. When the switch32 is closed a circuit is also completed for thecoil of re lay across the secondary of the transformer 33; This circuit also includes contacts 37 of relay 31. A circuit is also completed-for the coil of relay 31 across the secondary of the potential transformer 38, the primary of which is connected across the circuit 2. The

circuit of the coil of relay 31 also includes contacts 39 of the relay '30. Whichever of these two relays 30 and 31 operates first, opens the circuit of the other so that the latter becomes deenergized under the conditions assumed. It will be assumed for the urpose of this descriptifin -tha-t relay 30. is t e first to become energized. The relay 30 by opening its contacts 39 opens the circuit of relay'31 and by opening its contacts and closing its contacts 40 transfers the connection of the relay 28 from the secondary of the transformer 33 to the secondary of the transformer 38. Since, however, the voltage. of the circuit 2 is assumed to be normal the-contacts 29 of relay 28 are still held open.

The relay 30 by closing its contacts 41 connects the conductor 42 to the ungrounded ter minal of the secondary of the transformer 33 through contacts 37 of relay 31, thereby completing a circuit through the contacts 43 of the relay 9 to the driving motor 44' of the timer-8. Another-circuit is completed from conductor 42 through auxiliary contacts 45 on the circuit breaker 3 to the-release coil 46' of the timer 8 and to the voltage relay 27. Since both the release coil 46 and the driving motor 44 are energized the timer 8'starts to that the relay remains energized when the timer subsequently opens these contacts 47.

When the timer subsequently closes its contacts 52 a-circuitis completed for the control ,tion for a certain the closing coil 4 relay 9. This circuit is from conductor 42, through. auxiliary contacts 45 on' the circuit breaker 3, conductor 49, coil of relay 9, contacts 52 of the timer 8, contacts 51 of relay 48 toground. The rela 9 by clo'sin its contacts 53 completes a loc ing circuit or itself which is independent of the timer- 8 'and its associated relay 48. The control relay 9 by closing its contacts 54 completes the circuits of the windings 19 and 21 of the synchronizing check relay 10 and the winding 25 of the synchronizing relay 11 across the secondary 'of the transformer 33, and by closin its contacts 55' completes the'circuits of t e windings 20 and 22 of the synchronizing check relay 10 and the winding 24 of the synchronizing relay 11 across the secondarybf the trans former 38. r h

Since the two'c-ircuits 1 and 2 are assumed to be' energized from .the same source, there is no difference in frequency between the two circuits andtherefore the synchronizing device'll cannot effect the closing of its con-' tacts 23. The synchronizing check relay 10 however is operative to close its contacts 12 after the voltages of-the two circuits have remained within a re'determined phase relae'ngth of time. .When the relay 10 closes its contacts, 12 a-circuit is completed for the hesitatin control relay 6 from conductor 42 throu h the auxiliary contacts 45 on circuit breafier 3, conductor "49, coil of relay 6, conductor 57, contacts 12 of. relaylO, conductor 58, contacts 59 of relay 27, contacts 60 of relay 9 to ground. The relay 6 by closing) its contacts 62 connects etween conductor 42 and ground so that the circuit breaker 3 closes and connects together the circuits 1 and 2.

The circuit breaker 3 by 0 enin its contacts 45 effects the-deenergization o the relay 9 which by closing its contacts 43 reenergizesthe motor 44 so that the timer 8 is restored to its normal position.

The operation is the same as above described when the relay 31 is. energized be-- fore relay 30 except that theconductor 42 is connected to the ungrounded terminal of the transformer 38 through contacts 61 of relay 31 and contacts 39 of relay 3O lnstead of being energized from the transformer 33 and therefore the various control devices receive their control current from the transformer 38 instead of from the transformer 33.

The operation is the same as above described when the control switch 32 is closed at a time when the two circuits 1 and 2 are energized from separate sources which are not in synchronism except that thecircuit of the control relay 6 iscompleted by the synchronizing relay 11 when the frequency difference between the two circuits and the phase difference between their instantaneous voltages are less than predetermined values.

In case the switch 32 is closed at a time 1o ClI'CllltlS from conductor 42, through auxil- 1, phase difi'erence 1s varying at a predetersecondary of the transformer associated-with.

when only one of the circuits 1 and 2 is en- 'ergized the conductor 42 is connected to the whichever circuit is energized and the relay 28 is connected to the secondary transformer associated with the circuit which is notenergized. Therefore, when the relay 9 becomes energized a circuit is completed immediately for the control relay 6 through contacts 29 of the relay 28 which is not energized. -This iary contacts 45 on the circuit breaker 3, conductor49, coil of relay 6, conductor 57, contacts 29 of relay 28, conductor 58, contacts 59 of relay 27, contacts 60 of relay 9 to ground.

Therefore, itwill be seen that after the timer 8 has operated for a certain'period of time before effecting the energization of the 1 relay 9, the energization of the control relay 6 is effected immediately if the voltage of either of the circuits 1 and 2 is below a predetel-mined value, is effected by the scynchronizing check rela 10 if the two circuits 1 and 2 'are energized y synchronous sources and the phase difference between the voltages thereof remains less thanxa predetermined value for 'a predetermined length of time, and is effected by the synchronizing relay 11 if the circuits 1 and 2 are bothenergized by separate sources which are not in synchronism, but whose mined rate which will permit proper closing operation.

If the circuit breaker 3 is opened by an overload after it has been reclosed and before the timer 8 is restored to its normal position, the subsequent closing of the contacts 47 and 52 of the timer again completes in the .manner heretofore described the cir-- cuit of the relay 9' which becomes energized and effects the reclosing of the circuit breaker in accordance with the voltage and phase conditions then existing on the circuits 1 and 2. If the circuit breaker 3 is open when the timer 8 reaches its lockout position, a projection ($3.0m the timer engages-the release.

magnet 46 which is energized and prevents further rotation of the timer so that all of the reclosing means are rendered inoperative until the timer is released manually. I

\Vhile I have in accordancewith the patent statutes shown and described my invention as applied to a particular system and as embodying various devices diagrammatically indicated, changes and modifications will be obsaid circuit breaker. means forefiecting the reclosing of said circuit breaker after it has been open a predetermined length of time and the voltage of either of said circuits is ate a predetermined relation of the phases of the voltages of said circuits when both of .saidcircuits are energized.

2. In combination, two alternating current circuits, a circuit breaker for connecting said circuits together, means for opening said circuit breaker, timing means responsive to the opening of said circuit breaker for effecting the reclosing of said circuit break'erafter it has been open a predetermined length of time and a predetermined abnormal conditionexists on one of said circuits, and means responsive to the operation of said timing means for controlling the reclosing ofsaid circuit breaker in response to the phase relation of the voltages ofsaid circuits when both of said circuits are energized.

3. In combination, two alternating current circuits, a circuit breaker for connecting said circuits together, means for openlng said c1rcuit breaker, means arranged when the frequencies of the two circuits are the same to effect the reclosing of said circuit breaker in response to a predetermined phase difi'erence between the voltages of said circuits, and means arranged when the frequencies of the two circuits are different to effect the reclosing of said circuit breaker in response to a predetermined frequency difference and a predetermined phase difierence between the voltages of said circuits. I "4. In combination, two alternating current circuits, a circuit breaker for connecting said circuits together, means for opening said circuit breaker, and means arranged to effect the reclosing of said circuit breaker in response to a predetermined phase relation of the voltages of said circuits when the frequencies of the circuits are the same and in response to a different phase relation of the voltages of said circuits when the frequencies of the circuits are different.

5. In combination, two electric circuits, a circuit breaker for connecting said circuits together, means responsive to predetermined conditions of said circuits when said circuit breaker is open for effecting the reclosing of said circuit breaker, means responsive to other predetermined conditions of said circuits when said circuit breaker is open for effecting the reclosing of said circuit breaker, and means operative when said circuit breaker has been opened a predetermined numberof times for rendering both of said 6. In combination, two electric circuits, a

cuits are energized for effecting the reclosing of said circuit breaker, and means operative when said circuit breaker has been opened a predetermined number of timesfor rendering both of said reclosing means ino erative to effect the reclosing of said circuit reaker.

7. In combination, two alternating current circuits, a circuit breaker for connecting said circuits together, means for opening said circuit breaker, means responsive to a predetermined voltage on one of said circuits when said circuit breaker .is open and only one of said circuits is energized at substantially normal value for effecting the reclosing of said circuit breaker, means responsive to a predetermined relation between the phases \of the goltages of the two circuits when said circuit breaker is open and both circuits are en rgized for effecting the reclosing of said ci cuit breaker, and timing means responsive ti the opening of said circuit breaker for r ndering both of said reclosing means operive to effect the reclosing of said circuit bfreaker after said circuit breaker has been open a predetermined length of time and for rendering both of said reclosing means inoperative to effect the reclosing of said circuit breaker if said circuit breaker is in its open position at the expiration of a predetermined time interval after the first opening thereof.

8. In combination, two alternating current circuits, a circuit breaker for connecting said circuits together, means for opening said circuit breaker, means arranged to effect the reclosing of said circuit breaker in response to a predetermined phase relation of the voltages of said circuits when the frequencies of the circuits are the same and in response to a different phase relation of the voltages of said circuits when the frequencies of the circuits are different, andrtiming means responsive to the opening of said circuit breaker for rendering said reclosing1 means operative after said circuit breaker as been open a predetermined length of time.

9. In combination, two alternating current circuits, a circuit breaker forconnecting said circuits together, means for opening the circuit breaker, and means for reclosing the cirs cuit breaker comprising control means for effecting the closing of said circuit breaker when the potential of one of said circuits is below a predetermined value and the other of saidcircuits is energized, control means for effecting the reclosing of said circuit breaker in response to predetermined phase.

relationship between the voltages of said circuits when both of said circuits are energized, and timin means operative in response to the opening 0% said circuit breaker 'for rendering one of said control means operative after said circuit breaker has been open a predetermined length of time.

10. In combination, two electric circuits, a circuit breaker for connecting said circuits together, means for openin said circuit breaker, means for effecting the reclosing of said circuit breaker a predetermined number of times and means controlled by the voltages of said circuits when said circuit breaker is open and either of said circuits is energized and the other is deenergized for effecting the operation of said reclosing means from the energized circuit to reclose said circuit breaker a predetermined number of times while a fault exists on the deenergized circuit.

11. In combination, two electric circuits, a circuit breaker for connecting said circuits together, means for opening said circuit breaker, a motor operated timer adapted to effect the reclosing of said circuit breaker a predetermined number of times with predetermined time intervals between successive reclosures, and means controlled by the voltages of said circuits for effecting the opera tion of said timer in response to the opening of said circuit breaker when the voltage of either circuit is substantially normal and the voltage of the other circuit is subnormal.

12. In combination, two alternating cur-' rent circuits, a circuit breaker for connecting said circuits together, a closing coil for said circuit breaker, a, timing device adapted to effect the completion of the circuit of said closing coil a predetermined number of times with predetermined time intervals between successive completions thereof, a motor for driving said timing device, means for selectively controlling the connections of said m0- tor so that it is connected to whichever circuit is energized when said circuit breaker is open and only one of said circuits is energized.

13. In combination, two electric circuits, a switch for connecting said circuits together, means responsive to the current through said switch for opening said switch, and means for closing said switch including an electroresponsive device which when energized effects the closing of said switch, an energizing circuit for saiddevice, a timing device adapted to effect the completion of said energizing circuit after a predetermined time interval, means responsive to the position of said switch for controlling the operation of said timin device, means responsive to the volt- .age 0 one of said circuits, and means controlled by said voltage responsive means for controlling said energizing circuit independently of said timing device so that it is completed by the operation of said timing device 46 sive to the voltage of the other circuit, and

only when the voltage of said one of said circuits is below a predetermined value; 14. In combination, two electric circuits, a switch for connecting said circuits together, means responsive to the current through said switch for opening said-switch, and means for closing said switch including an electroresponsive device which when energized' ef- 'fects the closing of said switch, an energizing circuit for said. device, contacts in said energizing circuit, timing means arranged when' operated throughapredetermined range of movement to effect the closing of said 'contacts a plurality of times with predetermined time intervals between successive closures, means responsive to the position .of said switch for controlling the operation of said.

timing means, other contacts in said energiz-' responsive idevicewhich when energized ettects the closing of said switch, anenergizing circuit for said device, timing device timing means, means responsive to'the voltage of one of said circuits for controlling certain of said contacts so that said energizing circuit cannot be completed when the voltage of said one of said circuits is above a predetermined value, and means res onsive to the voltage of the other circuit or controlling certain of said contacts so that said energizing circuit cannot be completed when the voltage of said other. circuit is below a predeterminedvalue.

In witness whereof I have hereunto set my hand this 25th dayof June, 1927. ARVID E. ANDERSON.

adapted to effect the completion of said energizing circuit after a predetermined time interval, means responsive to the position of said switch for controlling the operation of said timing device, means responsive to the voltage of one of said circuits, means responmeans controlled by said timing device and said voltage responsive means for controlling said energizing circuit so that it is completed by the operation of said timing device only when the voltage of said one of said circuits is below a redetermined value and the voltage of sai other circuit isabove a predetermined value.

16. In combination, two electric circuits, 2. switch for connecting said circuits together means responsive to the current through sai switch for opening said switch, and means for closing sald SWltCh'lllCllldlIlg an electrorespons ve device WhlCh when energized effectsithe closing of said switch, an energizing circuit for said device, a plurality of series connected contacts in said energizing circuit, timing means arranged when opertted through a predetermined range of movement to effect the closing of certain .of said contacts a plurality of times'with predetermined time intervals between successive closures, means responsive-t0 the position of said switch for controlling the operationof said

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