US1925469A - Selective relay for alternating current networks which is dependent on resistance - Google Patents

Selective relay for alternating current networks which is dependent on resistance Download PDF

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Publication number
US1925469A
US1925469A US299192A US29919228A US1925469A US 1925469 A US1925469 A US 1925469A US 299192 A US299192 A US 299192A US 29919228 A US29919228 A US 29919228A US 1925469 A US1925469 A US 1925469A
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United States
Prior art keywords
circuit
voltage
impedance
responsive
dependent
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Expired - Lifetime
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US299192A
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English (en)
Inventor
Stoecklin Josef
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BBC Brown Boveri AG Germany
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Bbc Brown Boveri & Cie
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • H02H7/30—Staggered disconnection
    • 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
    • H02H3/40—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 responsive to ratio of voltage and current

Definitions

  • the short circuit current will flow in two phases only, while only one voltage, that between the two phases affected by the short circuit will form a measure of the distance of the point of disturbance.
  • the second relay receives the short circuit current, but it receives a line voltage which is only slightly influenced by the disturbance, while the third relay carries no short circuit current at all and has a high voltage and will therefore not be responsive.
  • the response of the second relay carrying a short circuit current and a relatively high voltage is uncertain and depends on the kind of short circuit or on the magnitude of the current and on the selected responsive impedance of the relay. It would not be necessary to take into account the responsiveness of the second relay, if it were possible to arrange the relay in such amanner that its time of operation would be greater than that of the first relay. Since the voltage of this second relay in all circumstances is greater than that of the first relay, it would be possible, by suitably selecting the phase position between the current and the voltage system of the second system which regulates the period of operation and is dependent on resistance, to delay the operation of the second relay.
  • phase position referred to is already determined by the desired character of the member which is dependent on resistance, that is to say, by its being constructed in the form of a pure ohmmeter or of a reactance meter.
  • the uncertainty in the behaviour of the second relay may be overcome by preventing the responsive member, which is dependent on the impedance, from responding when the voltage which is connected to the relay exceeds a certain amount.
  • This locking may for instance be effected by the responsive impedance of the responsive member being reduced to such an extent for instance by interposing a saturated iron choke in its voltage circuit that upon a certain voltage being exceeded (of for instance of the normal net work voltage), the response above this limiting voltage is prevented. It is also possible to obtain the desired effect by mechanically locking the responsive member which is dependent on the impedance above the limiting voltage by means of a voltage magnet.
  • Figure 1 shows diagrammatically one embodiment of the invention, and Fig. 2 a modification thereof.
  • A is the impedance dependent member comprising a magnet 2 which is fed by the current transformer 1, and a magnet 4 which is fed by the voltage transformer 3.
  • the armatures 5 and 6 of these magnets are fixed to the axis 9 at diiferent angles respectively, and when the current increases in the exciting winding 7 or the voltage decreases in the exciting winding 8, they try to turn in the direction of the arrow 5' shown on armature 5.
  • the circuits of the impedance responsive device are so arranged that the action of magnet 8 is stronger than that of magne 7 and shaft 9, therefore, tends to rotate in the direction of the arrow 6 of armature 6.
  • impedance dependent member A comprises, as in Fig. 1, magnet 2 fed by current translormer 1 and magnet 4 fed by voltage transformer 3 and mounted on a shaft 9 under different angles respectively, said magnets trying to turn in'the direction of arrow 5' when the current increases in exciting winding 7 or decreases in exciting winding 8.
  • the axis 9 is prevented from turning by the latch 11 against which pushes the lever 10 fixed to the axis 9.
  • the electro-magnet 13 releases its armature 14 and therewith the latch 11
  • the axis 9 is free to turn.
  • it operates the time element B by means of the lever 12 and the fork 15, which time element after its expiration disconnects the endangered net part in the same manner as described in connection with Fig. 1.
  • an impedance-responsive element comprising a voltage coil, the said element being operative responsive to impedance of the said network below a predetermined value to initiate operation of the said device, and means comprising a reactance connected in series with the said coil and having an iron core which is saturated at a voltage above a predetermined fraction of the normal operating value of the said network voltage to prevent operation of the said element when the said network voltage exceeds a predetermined fraction of its normal operating value, the said element being responsive to a value of impedance which value diminishes in proportion as the said network voltage exceeds a predetermined fraction of its normal operating value.
  • an alternating current line divided into sections, a switch operative to establish and interrupt connections of sections of said line, a time delay device operative to actuate said switch.
  • an alternating current line divided into sections, a switch operative to establish and interrupt connections of sections of said line, a
  • time delay device operative to actuate said switch, an element operative responsive to and in dependence upon the impedance of said line only when reduced to a predetermined fraction of its normal value for initiating actuation of said device, the said element comprising a coil energized responsive to and in dependence upon the value of current flowing in said line, and a coil energized responsive to and in dependence upon the value of the potential of said line, and a reactance coil connected in series circuit with the second said coil operative to control the extent of energization thereof to thereby permit operation of said element when the potential of said line is reduced to a predetermined fraction of its normal value, the said device being operative to effect actuation of the said switch in a predetermined time independently of the value of the impedance of said line.
  • a protective system in combination with an alternating current circuit, and apparatus to be operated in dependence upon impedance conditions of said circuit, of an element operable only in response to a reduction in the impedance of said circuit below a predetermined value, electromagnetic means responsive to the potential of said circuit operable to permit operation of said element only upon reduction of the potential of said circuit to a predetermined fraction of its normal operating value, a time-delay device operable to cause operation of said switch a predetermined time after initiation of operation of said device, and means actuated responsive to operation of said element for initiating operation of said device substantially simultaneously with said reduction of the impedance and said reduction of the potential of said circuit to thereby effect operation of said apparatus a predetermined time thereafter independently of subsequent variation of the impedance of said circuit and independently of subsequent variation of the potential thereof.
  • a protective system in combination with an alternating current circuit divided into sections, and a switch operable to establish and interrupt the connection of sections of said circuit, of an element operable only in response to a reduction in the impedance of said circuit below a predetermined value, means responsive to the potential of said circuit operable to permit operation of said element only upon reduction of the potential of said circuit to a predetermined fraction of its normal operating value, a time-delay device operable to cause operation of said switch a predetermined time after initiation of operation of said device, and means actuated responsive to operation of said element for initiating operation of said device substantially simultaneously with said reduction of the impedance and said reduction of the potential of said circuit to thereby effect operation of said switch to interrupt connection of said sections of said circuit a predetermined time thereafter independently of subsequent variation of the impedance and potential of said circuit.
  • a protective system in combination with an alternating current circuit divided into sections, and a switch operable to establish and interrupt the connection of sections of said circuit, of an element operable only in response to a reduction in the impedance of said circuit below a predetermined value, an electromagnet responsive to the potential of said circuit operable to permit operation of said element only upon reduction of the potential of said circuit to a preimpedance and said reduction of the potential of said circuit to thereby effect operation of said switch to interrupt connection of said sections of said circuit a predetermined time thereafter independently of subsequent variation of the impedance and potential of said circuit.

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  • Relay Circuits (AREA)
  • Emergency Protection Circuit Devices (AREA)
US299192A 1927-08-15 1928-08-13 Selective relay for alternating current networks which is dependent on resistance Expired - Lifetime US1925469A (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DE29919228X 1927-08-15
DE122846X 1927-08-15
DE134762X 1927-08-15
DE661682X 1927-08-15
DEA51761D DE542407C (de) 1927-08-15 1927-08-16 Widerstandsabhaengiges Selektivrelais fuer Wechselstromnetze

Publications (1)

Publication Number Publication Date
US1925469A true US1925469A (en) 1933-09-05

Family

ID=66099959

Family Applications (1)

Application Number Title Priority Date Filing Date
US299192A Expired - Lifetime US1925469A (en) 1927-08-15 1928-08-13 Selective relay for alternating current networks which is dependent on resistance

Country Status (5)

Country Link
US (1) US1925469A (de)
AT (1) AT122846B (de)
CH (1) CH134762A (de)
DE (1) DE542407C (de)
FR (1) FR661682A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2513957A (en) * 1945-06-26 1950-07-04 Landis & Gyr Ag Protective system for condensers

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009076290A2 (en) * 2007-12-06 2009-06-18 Ventus Medical, Inc. Delayed resistance nasal devices and methods of use

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2513957A (en) * 1945-06-26 1950-07-04 Landis & Gyr Ag Protective system for condensers

Also Published As

Publication number Publication date
CH134762A (de) 1929-08-15
AT122846B (de) 1931-05-11
FR661682A (fr) 1929-07-29
DE542407C (de) 1932-01-23

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