US3679909A - Hydraulic drive for electric switches - Google Patents

Hydraulic drive for electric switches Download PDF

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Publication number
US3679909A
US3679909A US110923A US3679909DA US3679909A US 3679909 A US3679909 A US 3679909A US 110923 A US110923 A US 110923A US 3679909D A US3679909D A US 3679909DA US 3679909 A US3679909 A US 3679909A
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US
United States
Prior art keywords
coil
circuit
valve
voltage
closing
Prior art date
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
Application number
US110923A
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English (en)
Inventor
Karl-Heinz Picard
Joachim Beierer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Siemens Corp
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Siemens Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Siemens Corp filed Critical Siemens Corp
Application granted granted Critical
Publication of US3679909A publication Critical patent/US3679909A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • H01H33/28—Power arrangements internal to the switch for operating the driving mechanism
    • H01H33/30—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator
    • H01H33/34—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator hydraulic
    • 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
    • H01H33/28—Power arrangements internal to the switch for operating the driving mechanism
    • H01H33/30—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/02—Details
    • H02H3/021—Details concerning the disconnection itself, e.g. at a particular instant, particularly at zero value of current, disconnection in a predetermined order

Definitions

  • the invention relates to a hydraulic drive for electric switches. Such drives are now being used with increasing frequency, particularly for actuating high voltage switches.
  • a piston is charged in a cylinder, usually through the control of a valve which is electrically actuated.
  • the valve is equipped with an excitation coil which pulls up an armature for opening the valve, as soon as the voltage is applied to the coil, the voltage being applied with a control switch provided for issuing commands.
  • the object of the invention is to obtain an adequate opening time for the electrically controlled valve of an electric switch, independent on the duration of the command, with simple electrical components.
  • the excitation coil of the valve is provided with a short circuit which delays the deactivation ofthe valve.
  • the shunt circuit for the excitation winding is preferably provided with a rectifier, which is inserted thereinto since the latter constitutes the desired short circuit only when the voltage is produced by the self-induction of the coil, after the control voltage is switched off.
  • a rectifier for the direct voltage which is customarily used for the control of the valve, said rectifier represents a virtually infinitely high resistance.
  • the rectifier may be provided with a resistance for limiting the current, in the event the rectifier fails.
  • Another embodiment for shunting constitutes the use of a relay which is connected to voltage by a wiping contact of the switch to be actuated.
  • the relay effects the short-circuiting of the excitation coil with an operating current contact, namely, at the time when the switch has already travelled a certain part of the switching movement, under the action of the hydraulic drive.
  • voltage is again removed from the relay by the wiping contact, so that the short-circuit is lifted. In this case, too, the short-circuit is being used only to prolong the opening period of the valve.
  • a preferred embodiment of the invention is characterized by a winding inductively coupled with the excitation coil and having an adjustable load resistance.
  • This winding is always present and defines with its mutual inductance, a means for delaying the pull-up time of the valve. This makes it possible to influence the opening time of the valve, within a certain framework.
  • the adjustment load resistance represents a very simple possibility for adjusting the actuating time of hydraulically operated switches.
  • valve that is provided for the control of the hydraulic operation of an electrical switch, more particularly a high voltage power breaker, is shown schematically in the drawing with its excitation coil 1.
  • the drive which is energized via the valve, from a hydraulic storer or accummulator and has a cylinder as well as a piston which acts on the movable circuit member of the switch for switching on the latter is omitted from the drawing as is the device which issues the electric command.
  • the coil 1 is situated in a current path whose terminal 2 is connected to the positive pole of the control voltage.
  • the current path contains a contact 3 of the switch to be actuated, which insures that the valve may be activated by coil 1, only if the switch is disconnected.
  • Another contact 4 is subordinated to a relay 5 which is connected into a circuit 6, not shown in detail.
  • the circuit 6 receives voltage when a switch-off command is issued, so that it is electrically safeguarded that the switch-on command will be cancelled, when a switch-off command is issued.
  • the negative pole of the control voltage is connected to terminal 10.
  • the excitation coil 1 of the valve is short circuited through a parallel-connected circuit, having a rectifier 8 connected with a resistance 9, in order to limit the current.
  • the forward direction of the rectifier 8 is between the terminals 2 and 10, in opposition to the control voltage which prevails at theexcitation coil.
  • the short circuit caused by the rectifier 8 is effective only for the self-induction voltage which occurs when the control voltage is disconnected.
  • the self-induction voltage then causes a current to flow through the rectifier, against the action of the control voltage.
  • the excitation coil I is inductively coupled with a winding l2 whose ends are closed, through a regulating resistance 13. Winding l2 and resistance 13 define a mutual inductance with an adjustable load, for the excitation coil 1.
  • a direct voltage of e.g. 60 V is applied to the terminals 2 and 10 by closing a control switch, in order to switch on the high voltage power breaker.
  • this control voltage is connected to the excitation coil 1, in order to effect a hydraulic actuation of the power breaker.
  • Coil l actuates an armature, so that the valve 22 opens.
  • a pull-up time delay is obtained via the winding 12, with regulating resistance 13.
  • the relay 5 with its contact 4 insures that a switch-off command can always be issued, independent on the position ofthe control switch and of the excitation of coil 1, of the valve 22. As soon as a switch-off command is used, each circuit with coil 1, is interrupted, even the one through rectifier 8.
  • the direct voltages between terminals 2 and 10 are again provided for the actuation of the excitation coil 1; the winding 12 with control resistance 13, provides the pull-up delay which may be utilized to adjust the opening time of the valve 22.
  • the relay 5 which is connected into the circuit 6 of the switch off command, can interrupt the excitation of the coil 1 with its contact 4, at any time.
  • Contact 3 of the power breaker to be actuated cancels the excitation of the coil I (even when the switch on command is of long duration), at the latest when the power breaker assumes the switch on position.
  • the embodiment according to FIG. 2 uses in place of the rectifier 8, a contact 15 of a relay 16, which short circuits the excitation coil 1.
  • the relay is excited by the DC control voltage at terminals [7 and 18, via a wiping contact 20 of the power breaker to be actuated. This results in the following mode of operation:
  • the power breaker When a switch-on command is issued, the power breaker is set into motion as soon as the hydraulic fluid which is controlled by the valve, charges the piston of the power breaker, following the excitation of the coil 1. As a result, the wiper contact 20 is closed, following a specific length of travel. This excites the relay coil 16 and the relay coil closes the operating contact 15. This produces a short circuit for the excitation coil 1, via resistor 9, which maintains the excitation of the valve for such time until the power breaker is reliably switched on.
  • FIG. 2A shows, that the relay [6 may also be equipped with a steady current contact (opener) 21, which is connected in series with the excitation coil 1 and its short circuit relay.
  • a steady current contact opener
  • resistor 9 which only functions as a current limiter
  • said shunt circuit comprising a resistor in serial connection with said rectifier for limiting the current in said shunt circuit 4.
  • the hydraulic drive includes a movable piston for opening and closing the electric switch and wherein said circuit comprises a relay having a set of relay contacts serially connected in said shunt circuit for closing and opening the same, ancillary voltage supply means, and a wiper contact movable with said piston to momentarily connect said ancillary voltage supply means to said relay to energize the latter for closing said relay contacts thereby momentarily closing said shunt circuit.

Landscapes

  • Arc-Extinguishing Devices That Are Switches (AREA)
  • Control Of Eletrric Generators (AREA)
  • Magnetically Actuated Valves (AREA)
US110923A 1970-01-30 1971-01-29 Hydraulic drive for electric switches Expired - Lifetime US3679909A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19702005027 DE2005027B2 (de) 1970-01-30 1970-01-30 Hydraulischer antrieb fuer elektrische schalter

Publications (1)

Publication Number Publication Date
US3679909A true US3679909A (en) 1972-07-25

Family

ID=5761403

Family Applications (1)

Application Number Title Priority Date Filing Date
US110923A Expired - Lifetime US3679909A (en) 1970-01-30 1971-01-29 Hydraulic drive for electric switches

Country Status (3)

Country Link
US (1) US3679909A (enExample)
JP (1) JPS5411505B1 (enExample)
DE (1) DE2005027B2 (enExample)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2900578A (en) * 1957-02-25 1959-08-18 Westinghouse Electric Corp Series capacitor protective device
US3168681A (en) * 1962-09-04 1965-02-02 Gen Electric Protective arrangement for an electric circuit breaker

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2900578A (en) * 1957-02-25 1959-08-18 Westinghouse Electric Corp Series capacitor protective device
US3168681A (en) * 1962-09-04 1965-02-02 Gen Electric Protective arrangement for an electric circuit breaker

Also Published As

Publication number Publication date
DE2005027A1 (de) 1971-08-05
JPS5411505B1 (enExample) 1979-05-15
DE2005027B2 (de) 1973-02-15

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