US2519225A - Circuit breaker control system - Google Patents

Description

INVENTOR G. L. CLA YBOURN CIRCUIT BREAKER CONTROL SYSTEM 2 SheetsSheet l ATTOR Y Glen L C/aybourn.

Aug. 15, 1950 Filed May 5, 194a WITNESSES:

1950 x 4 G. 1.. CLAYBOURN 2,519,225

- cmcurr BREAKER CONTROL SYSTEM Filed May 5, 1948 2 Sheets-Sheet 2 .l r55, z l 1'. i

I 200 &

WITNESSES: INVENTOR x24 F1 15 6/60 L. C/aybour 9 U gy/L Patented Aug. 15, 195

UNITED STATES PATENT OFFICE CIRCUIT BREAKER CONTROL SYSTEM Glen L. Claybourn, iittsburgh, Pa., assignor to Westinghouse Electric Lorporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application May 5, 1948, Serial No. 25,237

4 Claims. 1

My invention relates, generally, to control systems and it has reference, in particular, to a circuit breaker control system for controlling the operation of a pair of feeder breakers and a feeder tie breaker, or the like.

Generally stated, it is an object of my inven tion to provide a circuit breaker control system that is simple and inexpensive to manufacture, and is reliable and effective in operation.

More specifically, it is an object of my invention to provide an automatic control system for selectively operating a pair of feeder breakers and a tie breaker connecting the feeders, so as to insure the maximum continuity of service for the feeders.

It is also an object of my invention to provide, in an automatic circuit breaker control system, for selectively operating a pair of feeder breakers and a tie breaker which connects the feeders so as to permit closing the tie breaker only when one of the feeder breakers is open.

Another object of my invention is to provide, in a feeder and ti circuit breaker control system, for preventing closure of the tie breaker to connect the feeders in the event that the reclosing means of either of the feeder breakers fails to effect reclosure of its feed breaker.

Yet another object of my invention is to provide, in a feeder and tie circuit breaker control system, for making the tie breaker the master element in determining whether or not the feeder breakers may be operated either manually or automatically.

It is animportant object of my invention to provide, in a circuit breaker control system, for using auxiliary control relays of the mechanically-latched electrically-reset type for controlling the operations of a pair of feeder breakers connecting feeders to separate sources of electrical energy, and also controlling the operation of a tie breaker connecting the feeders.

Another important object of my invention is to provide, in a circuit breaker control system, for delayed operation of a tie breaker disposed to connect two feeders, in order that it may be first determined whether a change in the operating position of either feeder breaker is only momentary or lasts for greater than a predetermined time.

Still another object of invention is to provide, in an automatic feeder and tie circuit breaker control system, for tripping the tie breaker whenever both feeders are separately energized from their respective sources, and also when neither feeder is energized from its separate source.

Yet a further object of my invention is to provide, in a feeder and tie circuit breaker control system, for selectively operating the tie and.

feeder breakers so as to provide the maximum;

2 continuity of service to both feeders without requiring synchronizing of the separate feeder sources.

Other objects will, in part, be obvious, and will, in part, be explained hereinafter.

In practicing my invention in one of its forms, each of two feeders is connected to a separate source by a feeder breaker which is disposed to be operated either manually or automatically. The feeders are connected by a tie breaker, and voltage responsive control means are utilized so that the tie breaker can only be closed when the voltage of one or the other of the sources fails. The control circuits of the feeder and tie breakers are so interlocked that if one or the other of the feeder breakers opens in response to a fault condition and is locked out after a predetermined number of reclosing operations, the tie breaker is prevented from reclosing and connecting the source of the other feeder to the faulty feeder. The closing circuits of the feeder breakers can only be completed when the tie breaker is opened, thus preventing connection of the separate sources, which are not synchronized.

For a more complete understanding of the nature and scope of my invention, reference may be made to the following detailed description which may be read in connection with the aocompanying drawings in which:

Figures 1A and 113, when placed side by side, provide a diagrammatic view of an automatic circuit breaker control system embodying the invention in one of its forms.

Referring generally to the drawings, the reference numerals 1e and I2 may denote generally a pair of feeder breakers for connecting feeder conductors l4. and i5 to separate sources of alternating current power represented by the conductors H and i8, respectively. A tie breaker 2?) may be provided for connecting feeder conductors l4 and 15, which may be connected to suitable load circuits (not shown). The breakers may be of any suitable type, being for example, of the well-known drawout type, wherein the breaker is normally positioned in a metal housing or cell, (not shown) and from which it may be withdrawn to isolate 'it from its power circuit for test purposes.

The control apparatus for the feeder breaker If} is, for the purposes of convenience, represented as contained within an enclosure 2i designated by a dot and dash line. The control apparatus for the circuit breaker I2 is represented as contained within an enclosure 22. Since the control apparatus for the other feeder breaker I2 is substantially identical with that of the feeder breaker in, it has not been illustrated in detail, inas much as it is believed that this would unduly complicate the drawings. The control apparatus for the tie breaker 26 is represented as contained 3 within an enclosure 23. Common control equipment for the feeder and tie breakers is shown below theenclosures.

Referring to' Fig. 1A, it will be seen that the feeder breaker Hi may comprise an armature 243 having an operating winding 25 which may be connected to a source of electrical energy through a cutout switch 25 by means of a 'closingrelay 2'! having an operating winding 28,..and. anauXiliary or cutoff relay 2.) havingan operating winding 35!. The closing relay Elmay loo-connected to the source of electrical energy through the cutout switch 26, either by a '"manual control switch 3 l, which may be of the drum type, or by an automatic recloser 32. Trip means comprising an armature 33. having. an. operating wind- Ming 3.4.for actuatingthearmature. 3.3 to-release the armature 24, may be provided for...trip.ping ithe feedenbreaker l9, either inresponse to the operation of acurrent responsive protectiv relay. 35, in response to. operation of .the..m-anual control switch .3I., or in-response to. operation of a'voltage relay 3.6 whichmay be responsive to the .voltage. of, the, conductors ll. .KAn... interlock 1 .switch' lllAlm'ay be provided.for..completing a:

controlcircuit whenthe breaker iswithdrawn from its cell or housing.

The automaticreclos'e'r. 32 maybe ofanylsuit- [able and Wellek-nown typesuch as are commonly employed to effect. a predeterminednumber of re.--;

,--.clsures of acircuit. breakenwhich has been opened inresponse toe-faultcondition. In..this M instanceit is. illustrated .asiamotor-driven switch .typercomprising, a .switchingelement fildriven bya synchronouslmotor 38..-FIhe switchingcele-lhment 31. comprises a plurality ofv cams39, cc; 4! 1. and. 42, for ..actuating.mcvable contact members 3%,.4011, M a andAZaJntoand-out of engagement with associatedastationary. contact members 391),

.4073, Mb and 42b,.respectively. .The recloser may be disposed to..-effect:periodicireclosures of the feeder breaker ill elf-acting; for example, an in- -stantaneous, reclosure, and two .subsequentreclosures at predeterminedr-intervals of time. A reclosingrelay '33 having an operating winding 45 ==may be energized.:through theimoving and-sta- ,.tionary..-members l! wand .4 lb to effect energiza tion of the closing relay Zhfopclosing thefeeder breaker. gent-auxiliary.reclosing relay 45 having i.- anloperating:winding lfi may be'u-til-ized in .coni junction' withthe reclosingrelay 4.3 to provide an energizing circuitfore-the closing relay 21.

i Referring to Fig-.113, it ..Will .be .seenthatthetie breaker- Zdmay comprise an armature it? having an operating winding 48.. Trip means comprising an armature 49 having anoperatingwinding 50, A 'may be. providedfortripping.the tiewbreaker. .lqOperation ofithe tiebreakeranay beefiected by means of a-closing relay 4! havinganoperating winding ,52; and .which'is' operative tolprovide an -energizing circuit-.fontheoperating-winding 45 of .the tie breaker. A cutofi relay 53 having anioperating winding 54 may be provided fordeenergiz- 1 inglthelclosingrelay Mas-soon asthetielbreaker acloses. A manual control switch 5.5 of-thet drum type-may be .-provided-.-f-or manuallyclosing or tripping the tie brea-ken. rln-terlock-switches- 28A, 252B and-womay be provided inaeonnectionwith the tiebreaker zil to provide for-completingdiiierrent control circuits when-the breaker iswithdrawn :fromits-cell for testrpurposes.

. A manual control .switchfilwhich may be of :the drdm. type,-;.-may be provided for-simultaneously'connecting the controlzequiprnen-t of the circuit-.blteakere Hi, l2 and Zll ioreithe ama u or automatic operation. Automatic operation of the feeder breakers l9 and I2 may be provided by utilizing, inconnection with: each of the breakers -aszshown inFig; 1A, the voltage responsive relay 35 in connection with an auxiliary relay "2 52 for tripping the feeder breaker iii in response to failure of voltage at the source conductors l1 and closing it in response to restoration of voltage, Thevoltage'responsiye relay 35 may, for 0 example, be of the induction type so as to provide :apredetermined time delay for its moving contact member 36a to swing from the normal voltage contacts'35b to engage the under voltage contacts 360. The auxiliary relay 52 may be of the mechanically latched, electrically-resetl-typeicomprising, for example, an armature 63 having anoperating Winding 64 whichmay be disposed to be energized through the under voltage contacts tfic. of 1 the relay 3%. Latch means 55 may be'provided-for "maintaining the armature 63 in'the operated p0- sition', anda reset winding 56 may be provided for I releasing the latch means to-rcstore the armature to the-reset position; Byutili-zingthe auxiliary relay 32 to trip the feeder breaker 5G in response to a voltage failure or low voltage condition on -thesourcseconductors L7,.and-toprovide an energizing circuit forethe closing'relay 5| of thetie breaker Ze -transfer of the feeder conductors I4 from the source conductors l! to.-the-.source con ductors l8 may be efifected;- By utilizing auxiliary pontact members of thefeederbreakerslll and [2 toprovide energizing cire-uits for the trip means of the tie breaker 28, wheneverbo-th of the feeder breakers areeither-o-pened or :closed, interconnection of the conductors -l."= and 8-may be prevented e under such conditions. I

In order to provide areliablefsource of control voltage ioroperating the*contro1.equipment of the tiebrea'ker 2! control transfo-rmers E7 and 68 wmay be provided in connection with the source conductors l? and IS; =-respectively. Control .--means,' such as the transferrelay 69; having an operating-winding 10 be: providedxfor con- 5 nesting the cutoff switch l-l'which supplied electrical energy to the control equipment for the tie breaker 25, to either theconductors 72 and Won the secondary side of the control transformer 61, or to'conductors i5 and 1e on the secondary side =30 of .the control transformer. 68, depending .on

. iwhether or not the conductors H. are energized.

Inorder to make the tie breaker 2!] the master element in. the controlsystem; and'prevent either one of. thefeeder breakers so or I! from being closed when the other is.close.d andthe tiebreaker is also closed, auxiliarycontact' members 28d and Bile of the tie breaker Ell-,whichare' normally closed when the tie breaker is open, may be .coni nected in the closing circuits of the. feeder break- (io; ersl5! and I2; Interlock switches 28A--and 25B, --Which'are :closed when the circuit breaker 23 is withdrawn from its cell so as to be incapable of connectinglthe feeder conductors l4 and H5,- may be utilized to shunt contact members Zlld and 25c, respectively, so that the feeder-breakers-may be closedwhen the tie breaker is'closed in the test position.-.= The limit switch IGA of the feeder *breaker ill may be utilized to permit closing the g tiebreaker when the feeder breaker is withdrawn fromits cell andcontact members I09 are not efiective. 7

With a view to preventing operation of the tie breaker 28 to connect the feederv conductors I 4 -and I5. in the event thateitherone of the feeder 7-? breakers 1001' I2 is locked out afterfailure ofits recloser to reclose it, means such as the lookout relay 82 may be provided, having an operating winding 83. The operating winding 83 may be connected for energization through contact members 42a and 42b of the recloser 32, which may be disposed in engagement whenever the breaker is locked open. The relay 82 may be disposed to interrupt the closing circuit for the tie breaker 20 by opening contact members 82a which may be connected therein whenever the recloser stops in the lockout position.

With the system in the deener'gized position, as shown, the cutoff switch 26 of the feeder breaker I9 may be closed to connect the control equipment to the conductors I'I through control transformer 67. The voltage responsive relay 3% thereupon operates, so that the moving contact member 39a. disengages contact members 360 and engages contact members 36b, so as to provide for operating the auxiliary relay 62 to the reset position in which it is shown.

With voltage on the conductors H, the transfer relay 99 will operate to connect the cutout switch 'II of the tie breaker 29 to conductors I2 and I9. Since the feeder breaker IE] is in the open position, an energizing circuit will be provided for the cutoff relay 29, extending from the cutout switch 26 through conductor 85, contact member 3Ib, conductor 86, contact member [9b,

resistor 88, operating winding 39 and conductor 89, back to the other side of the cutout switch. The cutoff relay thereupon operates to the energized position. The feeder breaker I9 may now he closed by operating the manual control switch 3| to the close position, whereupon the slip contact member 3Ie closes.

Upon return of the switch to the off position, contact member 3| e remains in the closed position, and an energizing circuit is provided for the reclosing relay 43, extending from one side of the cutout switch 29 through conductor 89, conductor 99, resistor 9!, contact member Iilf, operating winding 44, contact member 45a, conductor 92, moving contact member Ma, stationary contact member Mb, conductor 93, conductor 94, slip contact member 3Ie, contact member 3511, conductor 95, contact member 620, conductor 95, contact member 51b, conductor 91, contact member 29c, conductor 98 and conductors E92 and 85, back to the other side of the cutout switch. At the same time, an energizing circuit is provided for recloser motor 38, extending from conductor 94, through contact member 19d, conductor I2I and contact members 39a and 39b, through motor 38 and back to conductor 89 through conductor 88.

The reclosing relay 43 operates and provides an energizing circuit for the auxiliary reclosing relay 49 through contact member 43. A circuit is now completed for the closing relay 21', extending from conductor 39, through contact member 29b, operating winding 28, conductor 99, contact member 45b, contact member 43a, conductor I99, conductor 92, contact member Ma, contact member Mb, conductor 93, conductor 94, slip contact member Sic, contact member 3Id, conductor 95, contact member 62c, conductor 96, contact member 51b, conductor 9?, contact member 29c, conductor 93 and conductor I35, back to the ther side of the cutout switch.

The closing relay 2'! operates to the energized position. and provides an energizing circuit for the operating winding 25 of the feeder breaker I9, extending from the conductor 85 through conductor I92, conductor I03, contact member 21b,

' 6 operating winding 25, conductor I05, and conductor 89, back t the other side of the cutout switch.

When the feeder breaker I0 closes, the cutoff relay 29 is shunted down through contact member I 00 of the breaker, thus providing for interrupting the energizing circuit of the operating winding 28 of the closing relay 2'!. The recloser 32 operates to interrupt the energizing circuits for the reclosing and auxiliary reclosing relays 43 and 65, and finally stops in the reset position, as shown. The operation of the control equipment for the feeder breaker I2 will be similar, so that normally the feeder breakers l0 and I2 connect the feeders I4 and I5 to the separate source conductors I1 and I8, respectively.

Should voltage fail on the conductors I1, the voltage responsive relay 3S responds by slowly moving the contact member 39a in a clockwise direction, After a predetermined time interval, contact member 99a engages contact member 350 and an obvious energizing circuit is provided for the operating winding 64 of the auxiliary relay 62. The auxiliary relay 62 operates, and provides a trip circuit for the trip winding 34, of the feeder breaker I9, extending from negative through contact member I911, trip Winding 34, conductor I91. contact member 621), conductor I 68, and contact member 51a to positive. The feeder breaker I9 is thereby released to the open position. Since the reclosing circuit originally traced passed through contact member 620 of the auxiliary relay which is now in the open position, the recloser 32 cannot operate to reclose the feeder breaker.

When the auxiliary relay -62 operates, an energizing circuit is thereupon provided for energizing the closing relay 5! of the tie breaker 29. This circuit extends from the upper terminal of the cutout switch lI through conductor I in, contact member 53?) of the cutoff relay, operating winding 52, conductor III conductor H2, contact member 32a, contact member 199, conductor H3, contact member 62d, conductor H4, contact member sic and conductor I I5, to the lower terminal of the cutout switch H.

The cutout switch H is now energized from the control transformer 98, since upon failure of voltage at the source conductors H, the transfer relay 69 returns'to the deenergized position as shown. When theclosing relay 5! operates, it provides an energizing circuit for the operating winding A3 f the tie breaker 29 through contact member 56b, The tie breaker closes, connects the feeder I 4 to the source conductors I8. Upon closure of the tie breaker 29. the cutoff relay 53 is shunted down by contact member 29c, and interrupts the energizing circuit for the closing relay 5I.

Upon the return of voltage to the source conductors I1, the transfer relay 69 operates to the energized position, and transfers the connection of the cut out switch H back to the source conductors it, After a, predetermined interval of time the moving contact 38a of the voltage responsive relay 39 engages stationary contact members 361), so that an obvious energiring circuit is provided for the reset winding 66. The auxiliary relay 92 thereupon returns to the reset position as shown. This provides an energizing circuit for the trip winding 59 or the tie breaker 20, extending from negative through contact member 22a, trip winding conductor closed contact member of the auxiliary relay of feeder breaker I2, which corresponds to the auxiliary relay 62 of breaker I9, conductor H9,

' :aaregess contact' "member GZe; co'n'ductor*l 2 B; contact zxmember-"5ld; to "spo's'itiveil The tie breaker 29 -'opens;"and a closing circuit isprovided for the *feeder breaker if! as described heieinbefore. The feederbreaker ill thereuponcloses, and reconfnectsthe feeder conductors M to the source con- -=rrductors ll.

Should a fault occur on .either of the feeders, for example the feeder conductors Hi, the cur- "rentfrespon'sive relay'eiiioperates and provides ""antobvious'lenergizing'icircui't for the trip windingi 34 of. feeder breakerzi. H] through contact i membe'r 35a. As'soo'n as the feeder breaker iii r'opensganenergizing-circuit is provided for the reclosing relayx43vthrough the circuit 'herein-= beforetra-ced through"contact member ltf of the fceder breakeri At the same time, anenergizing circuit is prori'ded'fonthei motor- 38 of the recloser', 'exteridin'g-bfrom' the cutout switch 26 through:conductonv 69', conductor Gil; conductor 8?;rhotor 38, c'ontacnmer'nber 3%, contact member'fifia; conductor-12!, contact member and r-conductor-fldphack' to theconductcr 85 through :;.rtheacircuitfpreviously trained for' the reclosing 'trelay 43. Operation of the reclosing relay is in conjunc= ""T'blOll with the auxiliary r'eclosing relay 45 provides ean energizing. circuit for' the closing relay whiclfeifects energization of the operating wind FillgfZEiOf the feeder "breaker ll Upon closure Ofllhe' feeder "breaker; the' cutoff relay 29 is "shunted downand interrupts the energizing cir "-a'"c'uit-"for heic'l'os-ing relay. Should the feeder breaker ill remain in the closed'position, the recloserrmotorfit" continues to run until it is restored tdthapositio'n" shown upon'the' opening of'contact-member 16a; whereupon it is reset for a subsequent-- reclosingoperation.

Shoul'd' the'feeder breaker i9 fail to remain ""closed after thefirst' r'eclosure, a second reclosure takes place upon'actuation or the contact ---1nernber did by the next projection on the cam M. Should the "breakerstill fail to stay closed,

athird reclosurewill be effected, whereupon the operating circuit for'the reclosure tor will "be" interrupted'witnthe contact member 2 in engagementwith the stationary member' lZb. b'lhis'providcsan obvious operating circuit for 'the lockout' relay 82', which thereupon operates i to -the'energizedposition, thus interrupting the closing circuit for the tie breaker 2s. The tie breaker is therebyprevented' from connecting the faultyfeederconductors i i to the source conductors l8. Upon" removal of the fault on the "conductors i l, th'e'feed'er breaker is may here- 'for these feeder breakers must pass through con-i tact -i embers Bile and Zed, respectively, which are only closed when the tie breaker is opened. Thus, neither manual or automatic operation of f the-feeder breakers to the closed position may be effected when the tie breaker is closed. Should fith tie breaker 2% be removed from its cell, contact members 23d and Ziie will be shuntedby iothe cell interlock contact members ZGA and 263, thus perm'ittingclosing of the feeder breakers When-the tie breaker is closed, but-is in the test position; in:which it isznemoved fromz itsz'cel'loand is, therefore, ineffective torconne'ct-the; conductors M, and I5.

"From the :above descriptionssandi the accompanying drawings it will. be apparent that: Ig-have provided in asimpleand 'effective mz'mneriifor t insnringizthe maximum :continuity of" service to feeder rcircuitsrc-whichr are; normally energized from non synchronized alternating -current p'ower sources; Thetie breaker isutilized; as aemaster control device for determining Whether-the "feeder breakers may be manually Orr-automati- "cally closed; The feeder breakers are-zautomatically: opened and-thetieibreaker is closedrupon loss of or'reduction in voltage to thevrespective feeders from their separate 'sources.-l,,-=The" con- '--tinuity ofscrvice toscither feeder is protected in the event of. afault occurring onqthe othernfeeder, since theitiefbreaker ispreventedfroml cl'osing in the"eventcthateither feeder breaker is locked out.

Sincecertainichanges may be' made in the abovc-descr'beclf construction and different em- 'bodlments of the invention may be made without departing'from the spirit "and scope thereof, it is intended that" all the matter contained in the i abovedescription and shown in the accompanying drawings, shall-be considered a's'illustrative and not in a limitings'ense.

I claim as invention:

1; A transfer controlsysteih" for a pair of feeders: disposed to supplyelectricalenergy to load 'circuitsand a tie breaker operable to connect the load circuits comprising, 'a feeder breaker position upon failure to stayreclosed within the predetermined number of" reclosures, control "means operable in response to closing of the tie breaker to render the recloslng means inoperative, and relay means operable in espouse to failure of one of said feeder breakers to stay reclosed within the predetermined number of reclosures to prevent operation of the tie breaker.

2; A circuit breaker system for controlling the supply of electrical energy to a pair of feeders comprising, a circuit breaker disposed to connect each feeder to a separate source of electrical energy, control means associated with each feeder reaker operable to trip said breaker upon failure of voltage of the associated source, a normally open tie breaker disposed to connect the feeders together, circuit means controlled by said control means connected to normally'provide a closing circuit for the tie breaker, and fault means responsive to tripping of a feeder breaker in response to a fault, condition operable torender the circuit means ineffective to complete; said closing circuit.

3. A circuit breaker 'systemcomprising, a pair of feeder circuit breakers each disposed to normally connect a feeder to a source ofalternating current, current responsive means operable to trip the breakers in response to current in excess of a predetermined value, reclosing means connec ed to normally provide a reclosing circuit for reclosing each feeder. breaker a predetermined nu nbcr of times, a tie breaker disposed to connect the feeders together, controlmeans responsive to the. voltagev of one of thersources-to provide for selectively tripping the associated feeder breaker or rendering its reclosing means operable, said control means being also effective to selectively provide a closing circuit or a trip circuit for the tie breaker, and lockout means responsive to failure of the feeder breaker to remain closed after the predetermined number of reclosures by the reclosing means, said lockout means being effective to prevent completion of the closing circuit of the tie breaker.

4. In a control system, a pair of feeder circuit breakers disposed normally to connect feeder conductors to separate sources of alternating current, a closing relay for each of the feeder breakers, automatic reclosing means operable to provide an operating circuit for the closing relay and effect a predetermined number of reclosures of one of the feeder breakers in response to tripping 0f the breaker in response to a feeder fault, manual control means operable to provide an operating circuit for the closing relay, transfer means operable to render only one of the automatic reclosing or manual control means effective, a tie breaker disposed to connect the feeders to- 10 gether, circuit means responsive to closing of the tie breaker to render both the automatic reclosing and manual control means ineffective, relay means responsive to the voltage of one of the sources operable to provide for selectively tripping or closing its associated feeder breaker in response to loss of voltage at said one source or restoration thereof and selectively closing or tripping the tie breaker, and lockout means responsive to failure of a feeder breaker to reolose in the predetermined number of reclosures operable to render said relay means ineffective to close the tie breaker.

GLEN L. CLAYBOURN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,793,384 Anderson Feb. 17, 1931 2,065,360 Anderson Dec. 22, 1936

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