US3441800A - Electric circuit breaker comprising parallel-connected interrupters - Google Patents

Electric circuit breaker comprising parallel-connected interrupters Download PDF

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Publication number
US3441800A
US3441800A US608899A US3441800DA US3441800A US 3441800 A US3441800 A US 3441800A US 608899 A US608899 A US 608899A US 3441800D A US3441800D A US 3441800DA US 3441800 A US3441800 A US 3441800A
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United States
Prior art keywords
current
interrupters
circuit
contacts
circuit breaker
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US608899A
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English (en)
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Thomas H Lee
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General Electric Co
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General Electric Co
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/04—Means for extinguishing or preventing arc between current-carrying parts
    • H01H33/14—Multiple main contacts for the purpose of dividing the current through, or potential drop along, the arc
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
    • H01H33/66—Vacuum switches
    • H01H33/666—Operating arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H75/00—Protective overload circuit-breaking switches in which excess current opens the contacts by automatic release of mechanical energy stored by previous operation of power reset mechanism
    • H01H75/02—Details
    • H01H75/04—Reset mechanisms for automatically reclosing a limited number of times
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
    • H01H9/54—Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere
    • H01H9/56—Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere for ensuring operation of the switch at a predetermined point in the ac cycle

Definitions

  • An object of the present invention is to assure that arcs will be consistently established in all the parallel-connected interrupters during a circuit breaker-opening operation despite imperfect synchronization of the instants of contact part.
  • I provide a circuit breaker which comprises parallel-connected inter- 3,441,800 Patented Apr. 29, 1969 rupters and opening means for parting the contacts of the interrupters substantially simultaneously during an opening operation. I also provide means for sensing the current flowing through the circuit breaker and means controlled by the sensing means for preventing the opening means from operating to part the contacts so near current zero in the alternating current through the circuit breaker that contact partings will take place on opposite sides of the current zero.
  • the opening means is forced to part the sets of contacts during the period extending from shortly after current zero to the instant of peak current. Parting during this interval enables gaps of relatively great length to be established between the contatcs of all sets by the time current zero is reached, thereby reducing the likelihood of a reignition across any of the gaps at current zero.
  • I can establish substantially the full gap length by the time current zero is reached, assuming that a high speed-opening-operator is used for the interrupters.
  • interrupters do not properly share the interrupting current during an opening operation and one interrupter carries current exceeding its interrupting capabilities, then I immediately reclose all the interrupters and repeat the opening operation, thus offering the interrupters another opportunity to share the interrupting current.
  • This feature can be used either with or without the trip-timing feature of the two immediately preceding paragraphs.
  • FIG. 1 is a schematic view of one embodiment of the Invention.
  • FIG. 1a is a graphic representation showing the intervals during a current wave when the contacts are permitted to part.
  • FIG. 2 is a schematic view of another embodiment of the invention.
  • FIG. 3 is a schematic view of still another embodiment of the invention.
  • FIG. 4 is a schematic view of still another embodiment of the invention.
  • FIG. 1 there is shown an electric circuit breaker 10 that comprises two circuit interrupting devices 12 and 14 electrically connected in parallel in an alternating current power circuit 15.
  • Each of the circuit interrupting devices is preferably a vacuum-type circuit interrupter.
  • the vacuum-type circuit interrupters can be of a conventional design and are therefore shown only in schematic form.
  • Each of the illustrated vacuum type circuit interrupters comprises a highly evacuated insulating housing 16 and a pair of relatively movable contacts 18 and 20 located within the housing. The contacts are shown in a closed and engaged position.
  • the lower contact 20 is a movable contact which is fixed to the upper end of a vertically movable conductive operating rod 22.
  • a flexible metallic bellows 23 provides a seal around rod 22 that permits vertical movement thereof without impairing the vacuum inside envelope 16.
  • U. S. Patent 3,089,936, Smith, assigned to the assignee of the present invention, can be referred to for a more detailed disclosure of such a vacuum-type circuit interrupter.
  • the conductive operating rods 22 of the two interrupters are connected together by a cross bar 24 which causes the rods 22 to move in unison.
  • the cross bar 24 is biased in a downward opening direction by a suitable opening spring 25.
  • a trip latch schematically shown at 26 holds the contacts closed against the downward bias of the opening spring. When the trip latch 26 is released, the opening spring 25 responds by rapidly driving the cross bar 24 and the two operating rods 22 in a downward-opening direction.
  • the mechanical coupling between the two operating rods 22 assures that the contacts 18, 20 in the two interrupters will part substantially simultaneously. I have shown the operating mechanism 22-26 in a simplified schematic form to facilitate an understanding of the invention.
  • this operating mechanism is considerably more sophisticated and can include features such as a flux-shifting trip latch to provide for the desired high speed operation. See, for example, US. Patents 2,188,803, Boehne, and 2,740,859, Beatty et al., for examples of such mechanisms.
  • a normally open trip circuit 30 is provided for tripping the illustrated latch 26, a normally open trip circuit 30 is provided.
  • a normally open high-speed closing switch 32 which may, for example, be a silicon controlled rectifier, is provided for completing the trip circuit 30, when a predetermined pulse signal is delivered to the usual gate 3. of the controlled rectifier.
  • the latch 26 releases the opening spring and causes the contacts of the two interrupters to separate at the expiration of a predetermined fixed period following delivery of the pulse signal to gate 34, e.g., two milliseconds.
  • This timing of the pulse signal can be accomplished by conventional means such as shown for example in US. Patent 3,265,933, Perry et al., or 3,243,656, Baude, where circuits are disclosed that will supply an output pulse at a desired point on the current wave. Since the details of the pulse-forming and timing circuit are not a part of my invention, I have shown the circuit in block form at 40.
  • a suitable current transformer 42 coupled to power circuit 15 supplies input information to the pulse-forming and timing circuit 40 through an input circuit 43.
  • the output pulse signal is applied to a trip-initiating device (such as my silicon controlled rectifier 32) at such an instant that the contacts of the controlled circuit breaker will part precisely at current zero.
  • a trip-initiating device such as my silicon controlled rectifier 32
  • I use an entirely ditferent approach, setting the circuit 40 so that the signal pulse is applied at such an instant that contact-part occurs during a period considerably ahead of the first current zero following contactpart.
  • An important part of my invention is to prevent contact-part from occurring during the period immediately prior to current zero, and such timing of the pulse assures that this objective will be attained.
  • This relay 50 has normally open contacts 54 and an operating coil 53 connected across the secondary winding of a current transformer 52 coupled to the power line 15. When the current through power line 15 exceeds a predetermined value, relay 50 picks up to close its normally open contacts 54. Thereafter, the next pulse developed by the control circuit 40 is supplied to gate 34 to turn on the controlled rectifier 32 to cause circuit breaker opening.
  • vacuum type interrupters such as illustrated, are used with an operating mechanism of moderately high speed, substantially the full gap length can be established by the time current zero is reached at G.
  • the contacts of the vacuum interrupters are parted sufliciently early between instants B and C that a gap of inch or longer is attained in both interrupters by the time current zero is reached at G.
  • the present circuit breaker control system requires some precision in controlling the instant of contact part, the requirements for precision are not nearly as stringent as they are in those circuit breaker systems that attempt to force the contacts to part precisely a current zero. In comparison to such systems, the present system can tolerate contact-part over a very wide range. It is only during the period just prior to current zer'o that it is important with the present system to prevent contact-part.
  • Vacuum-type circuit interrupters lend themselves especially Well to parallel operation since vacuum arcs have a positive arc voltage-to-current relationship which forces a substantially equal distribution of current between the parallel vacuum arcs.
  • the present invention is not limited to circuit breakers that comprise vacuum-type circuit interrupters. It can also be used, for example, in circuit breakers that comprise fluid-blast type circuit interterupters.
  • inductors can be connected in series with each interrupter in its parallel branch to force substantially equal current distribution between the parallel branches. Such inductors are usually desirable even when vacuum-type interrupters are used, but they can be of a considerably smaller size than the inductors needed for nonvacuum type interrupters.
  • FIG. 2 illustrates one way of applying the invention to a polyphase circuit breaker, shown for simplicity as a two-phase circuit breaker.
  • the timing circuit 40 for each phase allows the circuit breaker assembly for that particular phase to part its contacts only during a period considerably ahead of current zero in that phase.
  • the overcurrent responsive relays 50 in the respective phases are shown mechanically coupled together so that the contacts 54 associated with all the phases close whenever any one of the overcurrent relays 50 picks up.
  • FIG. 3 where the reclosing device is shown as a high-speed fluid motor 70.
  • This motor 70 which may be of a conventional form, comprises a cylinder 71 and a vertically movable piston 72 shown in FIG. 3 in its lowermost or reset position.
  • a suitable 3-way control valve 73 controls the operation of piston 72.
  • This control valve normally vents the space heneath piston 72, but, upon operation, closes its vent and admits pressurized fluid to the space beneath piston 72 to drive the piston upward. Assuming that the circuit breaker is then open, this drives its operating mechanism 24 upwardly to reengage the contacts and reclose the circuit breaker.
  • I provide a current-balance relay 75 which is sensitive to the difference between the currents carried by the two interrupters. If this difference is greater than a predetermined value, the current-balance relay 75 (operating through components 93, 94) completes a closure-initiating circuit 80 after a short time that is, however, made long enough for the circuit breaker to reach its fully open position and have an adequate opportunity to interrupt, e.g., one cycle. If at the expiration of this short period, one of the interrupters is still carrying an excessive share of this high current, then relay 75 completes closure-initiating circuit 80, operating valve 73, and
  • reclosing device 70 to immediately reclose the circuit breaker.
  • a suitable b switch 82 is provided in the closure-initiating circuit 80.
  • the switch 82 closes; and the circuit 80 can thereafter be completed by the current-balance relay 75 should one of the interrupters be carrying an excessive share of a high current.
  • a reclosing operation results in the contacts of both interrupters reengaging, and immediately thereafter, a second opening operation is initiated by the operation of trip latch 26.
  • This second opening operation provides another opportunity for the interrupters to share the total interrupting current. If this current is properly shared, then the interruption will be successfully completed, and no further reclosings will occur.
  • the current-balance relay 7-5 will again sense whether the current is properly shared, and if it is, will not again pick up to reinitiate another closing operation.
  • the reclosing device will again reclose the circuit breaker. Thereafter, further opening operations are prevented by a suitably controlled lock-in switch 83 that permanently opens the trip-controlling circuit 34 until deliberately reset.
  • the lock-in switch 83 is opened by a suitable counting device (shown in block form at 85) that responds to closely successive operations of the circuit breaker to open switch 83 after a predetermined number of such closely successive sive operations. If fewer operations occur in close succession, the counting device 85 will reset to its normal condition and will not open trip-controlling circuit 34.
  • Patent 3,114,079, Sofianek et al., assigned to the assignee of the present invention may be referred to for an example of a suitable counting or sequencing device usable for this purpose.
  • the current-balance relay can be of a conventional type and has been shown in schematic form as comprising a core 89 linked to each of the parallel branches through a pair of windings 90. These windings 90 are wound to produce flux in opposite directions in the core 89. When the currents through windings 90 are equal, no net flux is conducted around the core 89. But when the currents are unequal, flux proportional to the difference in current is developed in core 89. A second winding 92 is coupled to core 89 and develops a voltage across its output terminals proportional to the flux developed. This voltage is used for energizing the operating coil 93 of a relay, which responds to voltage above a predetermined value to close its normally open contacts 94 after a suitable short time delay.
  • FIG. 4 A modification of the circuit breaker of FIG. 3 is shown in FIG. 4.
  • reclosing is initiated by overcurrent relays 96 and '97 which respond to the magnitude of the current through either interrupter, rather than the difference in currents. If the interrupting current through either interrupter exceeds a predetermined value and the interrupter is open, the closure-initiating circuit will be completed through [2 switch 82 and the contacts 94 of the appropriate overcurrent relay to initiate a circuit breaker reclosing operation.
  • the relays 96 and 97 are coupled to the respective parallel branches of the power circuit by means of current transformers 98 and 99.
  • the reclosing arrangements of FIG. 3 or 4 can be used either with the trip-timing arrangement of FIG. 1 or with a conventional tripping arrangement that trips at any point on the current wave.
  • An alternating current electric circuit breaker comprising:
  • each circuit interrupter comprising a pair of contacts relatively movable between an engaged closed position and a disengaged open position
  • An alternating current electric circuit breaker comprising:
  • each circuit interrupter comprising a pair of contacts relatively movable between an engaged closed position and a disengaged open position
  • circuit breaker of claim 2 in which said circuit interrupters are vacuum type circuit interrupters.
  • circuit interrupters are fluid blast type circuit interrupters.
  • circuit breaker of claim 2 in which operation of said opening means is consistently initiated at a time which results in both pairs of contacts parting during the approximately A cycle period extending from shortly after a current zero to the instant of peak current.
  • circuit interrupters are vacuum-type interrupters
  • operation of said opening means is consistently initiated at a time which results in both pairs of contacts parting sufficiently ahead of current zero to produce gaps of inch or longer by the time the first current zero is reached following contact-part.
  • circuit breaker of claim 6 in which substantially the full gap length is established at both contact pairs by the time the first current zero is reached.
  • An alternating current electric circuit breaker comprising:
  • each circuit interrupter comprising a pair of contacts relatively movable between an engaged closed position and a disengaged open position
  • opening means operable in response to an overcurrent in said one phase for parting the contacts of said pair of interrupters substantially simultaneously
  • closing control means for sensing whether said interrupters have properly shared said overcurrent during an attempted high current interruption and for developing a predetermined closing signal in response to improper sharing of the high current
  • reclosing means operable in response to said clos ing signal for immediately returning the contacts of said pair of interrupters to their engaged position upon receiving said closing signal, thereby permitting another opening operation in the event said overcurrent condition still prevails.
  • circuit breaker of claim 8 in combination with lock-in means for preventing further opening operations in the event of a predetermined number of closely successive circuit breaker operations.
  • said opening means is operable in response to an overcurrent in said one phase
  • closing control means is provided for sensing whether said interrupters have properly shared said overcurrent during an attempted high current interruption and for developing a predetermined closing signal in response to improper sharing of the high current

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
  • Keying Circuit Devices (AREA)
  • Breakers (AREA)
  • High-Tension Arc-Extinguishing Switches Without Spraying Means (AREA)
US608899A 1967-01-12 1967-01-12 Electric circuit breaker comprising parallel-connected interrupters Expired - Lifetime US3441800A (en)

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Application Number Priority Date Filing Date Title
US60889967A 1967-01-12 1967-01-12

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US (1) US3441800A (de)
JP (1) JPS4535700B1 (de)
DE (1) DE1640277B2 (de)
FR (1) FR1566251A (de)
GB (1) GB1143889A (de)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3592988A (en) * 1968-04-01 1971-07-13 Asea Ab Gas blast circuit breaker for high alternating voltages
US3970810A (en) * 1975-03-06 1976-07-20 General Electric Company Electric circuit breaker comprising parallel-connected vacuum interrupters
US3970809A (en) * 1975-02-10 1976-07-20 General Electric Company Electric circuit breaker comprising parallel-connected vacuum interrupters
US4000445A (en) * 1975-12-05 1976-12-28 General Electric Company Trip circuit for an electric circuit breaker
US20090173719A1 (en) * 2008-01-07 2009-07-09 Masato Kobayashi Vacuum switchgear
US20090250436A1 (en) * 2008-04-02 2009-10-08 Japan Ae Power Systems Corporation Large-capacity vacuum circuit breaker
US20100006544A1 (en) * 2006-08-21 2010-01-14 Arcoline Ltd. Medium-voltage circuit-breaker
US20170301494A1 (en) * 2014-12-05 2017-10-19 Omron Corporation Electromagnetic relay
US10134551B2 (en) * 2016-09-21 2018-11-20 Astronics Advanced Electronic Systems Corp. Galvanically isolated hybrid contactor
US10170260B2 (en) 2014-12-05 2019-01-01 Omron Corporation Electromagnetic relay
US10269519B2 (en) 2014-12-05 2019-04-23 Omron Corporation Electromagnetic relay
CN110050318B (zh) * 2016-12-15 2022-08-12 通用电器技术有限公司 开关设备

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4110806A (en) * 1976-01-08 1978-08-29 Tokyo Shibaura Denki Kabushiki Kaisha Circuit interrupting apparatus for use in direct current circuits
DE3705719A1 (de) * 1987-02-23 1988-09-01 Bbc Brown Boveri & Cie Hochstromschalter
DE3833166A1 (de) * 1988-09-27 1990-03-29 Siemens Ag Verfahren zum betrieb eines leistungsschalters

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3237030A (en) * 1962-09-28 1966-02-22 Dynamics Controls Corp Radio noise-free switch
US3265933A (en) * 1963-10-24 1966-08-09 Allis Chalmers Mfg Co Control circuit for operating circuit interrupter at a zero current point in system wave form
US3293496A (en) * 1962-02-14 1966-12-20 Bbc Brown Boveri & Cie Switching device for interruption of alternating current
US3390305A (en) * 1965-12-14 1968-06-25 Gen Electric Circuit interrupting means for a high voltage d-c circuit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3293496A (en) * 1962-02-14 1966-12-20 Bbc Brown Boveri & Cie Switching device for interruption of alternating current
US3237030A (en) * 1962-09-28 1966-02-22 Dynamics Controls Corp Radio noise-free switch
US3265933A (en) * 1963-10-24 1966-08-09 Allis Chalmers Mfg Co Control circuit for operating circuit interrupter at a zero current point in system wave form
US3390305A (en) * 1965-12-14 1968-06-25 Gen Electric Circuit interrupting means for a high voltage d-c circuit

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3592988A (en) * 1968-04-01 1971-07-13 Asea Ab Gas blast circuit breaker for high alternating voltages
US3970809A (en) * 1975-02-10 1976-07-20 General Electric Company Electric circuit breaker comprising parallel-connected vacuum interrupters
US3970810A (en) * 1975-03-06 1976-07-20 General Electric Company Electric circuit breaker comprising parallel-connected vacuum interrupters
US4000445A (en) * 1975-12-05 1976-12-28 General Electric Company Trip circuit for an electric circuit breaker
US20100006544A1 (en) * 2006-08-21 2010-01-14 Arcoline Ltd. Medium-voltage circuit-breaker
US8138440B2 (en) * 2006-08-21 2012-03-20 Arcoline Ltd. Medium-voltage circuit-breaker
US8168909B2 (en) * 2008-01-07 2012-05-01 Hitachi, Ltd. Vacuum switchgear
US20090173719A1 (en) * 2008-01-07 2009-07-09 Masato Kobayashi Vacuum switchgear
US20090250436A1 (en) * 2008-04-02 2009-10-08 Japan Ae Power Systems Corporation Large-capacity vacuum circuit breaker
US8269586B2 (en) * 2008-04-02 2012-09-18 Japan Ae Power Systems Corporation Large-capacity vacuum circuit breaker
US20170301494A1 (en) * 2014-12-05 2017-10-19 Omron Corporation Electromagnetic relay
US10170260B2 (en) 2014-12-05 2019-01-01 Omron Corporation Electromagnetic relay
US10176952B2 (en) * 2014-12-05 2019-01-08 Omron Corporation Electromagnetic relay
US20190096616A1 (en) * 2014-12-05 2019-03-28 Omron Corporation Electromagnetic relay
US10269519B2 (en) 2014-12-05 2019-04-23 Omron Corporation Electromagnetic relay
US10312044B2 (en) 2014-12-05 2019-06-04 Omron Corporation Electromagnetic relay
US10943753B2 (en) * 2014-12-05 2021-03-09 Omron Corporation Electromagnetic relay
US10134551B2 (en) * 2016-09-21 2018-11-20 Astronics Advanced Electronic Systems Corp. Galvanically isolated hybrid contactor
CN110050318B (zh) * 2016-12-15 2022-08-12 通用电器技术有限公司 开关设备

Also Published As

Publication number Publication date
GB1143889A (de)
DE1640277B2 (de) 1976-07-29
JPS4535700B1 (de) 1970-11-14
DE1640277A1 (de) 1971-02-04
FR1566251A (de) 1969-05-09

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