WO1994007254A1 - A memory or signature circuit for switchgear - Google Patents

A memory or signature circuit for switchgear Download PDF

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Publication number
WO1994007254A1
WO1994007254A1 PCT/AU1993/000472 AU9300472W WO9407254A1 WO 1994007254 A1 WO1994007254 A1 WO 1994007254A1 AU 9300472 W AU9300472 W AU 9300472W WO 9407254 A1 WO9407254 A1 WO 9407254A1
Authority
WO
WIPO (PCT)
Prior art keywords
memory
circuit
switchgear
data
circuit breaker
Prior art date
Application number
PCT/AU1993/000472
Other languages
French (fr)
Inventor
David Russell Murray
Peter Robert Lambert
Original Assignee
Nu-Lec Pty Ltd
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 Nu-Lec Pty Ltd filed Critical Nu-Lec Pty Ltd
Priority to AU48103/93A priority Critical patent/AU4810393A/en
Publication of WO1994007254A1 publication Critical patent/WO1994007254A1/en

Links

Classifications

    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/0015—Means for testing or for inspecting contacts, e.g. wear indicator
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1/00—Details of emergency protective circuit arrangements
    • H02H1/0038—Details of emergency protective circuit arrangements concerning the connection of the detecting means, e.g. for reducing their number
    • H02H1/0053—Means for storing the measured quantities during a predetermined time

Definitions

  • This invention relates to a memory or signature circuit for use with electrical switchgear.
  • Pole mounted circuit breakers for medium voltage applications typically have vacuum interrupters contained within a sealed enclosure or housing.
  • a pole mounted control cubicle which is normally mounted low on the pole for ease of access, houses an operator control panel and associated micro-electronics. This cubicle provides the protection functions and controls and monitors the operation of the circuit breaker and may provide remote control.
  • the cubicle is connected to the circuit breaker by an unpluggable umbilical cable.
  • the circuit breaker and the cubicle together comprise a remotely controlled and monitored pole mounted circuit breaker or recloser. Either the cubicle contains all of the control circuitry necessary for its proper function with the circuit breaker or alternatively some of the cirtcuitry normally contained in the cubicle may be contained in the circuit breaker housing or associated with the circuit breaker rather than directly with the cubicle.
  • the circuit breaker includes a vacuum interrupter with contacts for each phase supplied to the breaker.
  • the breaker has a closing solenoid which operates a mechanism plate for moving a contact push rod for closing the contacts.
  • a trip coil or solenoid is present for opening the contacts.
  • the trip coil moves a trip armature for this purpose.
  • an unpluggable cable links the communications cubicle to the breaker. That cable can be connected to a switch cable entry module in the breaker housing which enables remote control and monitoring of the breaker.
  • the invention provides a circuit breaker or other switchgear and coupled to a control cubicle via a cable, the circuit breaker or other switchgear including in combination a memory or signature circuit associated with a housing of the circuit breaker or other switchgear, the memory circuit storing data and information unique to the circuit breaker or other switchgear to which it is connected such as number of circuit breaker or other switchgear operations, serial number, quality assurance information, calibration data and its voltage screens, date of manufacture, switchgear type, I T data and other information, the memory circuit including a non-volatile memory for the storing data and information whereby the data and information in the memory circuit may be retained and made available to a control circuit or an adjacent cubicle should the switchgear be disconnected from the control circuit or cubicle to which it was previously connected.
  • the circuit breaker or other switchgear including in combination a memory or signature circuit associated with a housing of the circuit breaker or other switchgear, the memory circuit storing data and information unique to the circuit breaker or other switchgear to which it is connected
  • a memory or signature circuit for storing data and information unique to a circuit breaker or other switchgear with which the circuit is associated such as number of circuit breaker or switchgear operations, serial number, quality assurance information, calibration data and its voltage screens, date of manufacture, switchgear type, I T data and other information
  • the circuit including a non-volatile memory for storing data and to which data and information may supplied locally and remotely and which may be interrogated from a remote location.
  • the non-volatile memory may comprise a RAM memory device provided with battery back-up.
  • the memory device may consist of a programmable memory device such as an E PROM device which requires no battery back-up.
  • the inputs to control the memory device and to input data and select the locations from which data is outputted may be controlled by a single input line divided into separate lines of different time constant paths.
  • One way in which this may be achieved is to employ Schmitt trigger circuits coupled to the clock, data and select pins of the memory device.
  • the clock signal is secured from one of the separate lines and has the shortest time constant path for the signal which achieves the clock pulse signal while the data and the select inputs are secured from separate lines having progressively longer time constant paths. In this way it is possible to use a single line from which all signals for the memory device may be secured. DESCRIPTION OF PREFERRED EMBODIMENTS
  • resistor RIO resistor RIO
  • capacitor Cl capacitor Cl
  • transistor Q4 parallel connected capacitors C4 and C5
  • the line identified by the word PRESS+ enables inputs to be applied to the memory Ul.
  • Resistors Rll and R12 together with zener diode Zl condition the input to the memory as does Schmidt trigger U2:A.
  • Memory Ul in this embodiment is an E PROM device although any other non-volatile memory may be used.
  • a RAM memory device with battery back-up may be used.
  • the output from the memory device is coupled to a pull down resistor R15.
  • Series connected Schmidt trigger devices U2:E and U2:F condition the output from the memory device Ul.
  • Resistor R16 is a bias resistor for transistor Q5.
  • Zener diode Z2 is connected across the collector emitter electrodes of the transistor Q5 and protects that transistor from high level voltages.
  • Current limiting resistor R17 is connected in series with the collector electrode of transistor Q5.
  • Metal oxide varistor SA10 limits the magnitude of the voltage which may be impressed across the collector emitter electrodes of the transistor Q5. An output from the memory is available at terminal SU2.
  • the memory device Ul has a clock input provided at pin 2 via Schmitt trigger U2:B.
  • the pulse provided by the Schmidt trigger is of relatively short duration and clocking occurs on the negative transition of that short duration pulse.
  • This clock pulse arrives at the memory device Ul before signals at pins 3 and 1 of the memory device.
  • the time constant represented by R13 and C2 is longer than the duration of the clock pulse applied to pin 2 and shorter than the time constant represented by resistor R14 and capacitor C3. By choosing the relative time constant duration it is possible to employ only one line for clocking the memory, inputting data to the memory and selecting information to be read from the memory and made available at output pin 4.
  • the memory device store data and information representative of information including the following:
  • Some of the data may be added to the memory device before initial service while other data is added as a consequence of the service life and history of operation of the circuit breaker.
  • Information peculiar to a circuit breaker is then contained in a memory or signature circuit associated with that circuit breaker such that if the umbilical cable is disconnected from one circuit breaker and connected to another circuit breaker the data and information peculiar to the circuit breaker is not lost.
  • the circuit breaker from which the connection has been removed still has a memory or signature circuit associated with it and information unique to it is not lost and can still be retrieved or interrogated once a connection with any communications cubicle is re-established.
  • control circuitry is replaced the information peculiar to the circuit breaker is not lost and is made available to replacement control circuitry.

Abstract

A memory circuit associated with the housing for a circuit breaker or other switchgear is disclosed. The circuit has a non-volatile memory or a memory with battery back-up and a single input line divided into separate lines of different time constant. By choosing the relative time constant duration it is possible to control the memory, input data to the memory and select memory locations from which data is to be read and made available at the output using this single line. The memory stores information peculiar to a particular circuit breaker or other switchgear, as well as other data added as a consequence of the service life and history of operation of the circuit breaker.

Description

TITLE AMEMORYORSIGNATURECIRCUITFOR SWITCHGEAR
FILED OF THE INVENTION This invention relates to a memory or signature circuit for use with electrical switchgear.
BACKGROUND OF THE INVENTION The invention will be described by way of example with reference to medium voltage pole mounted circuit breakers and it should be appreciated that the invention may also be used with other types of circuit breakers and switchgear.
Pole mounted circuit breakers for medium voltage applications typically have vacuum interrupters contained within a sealed enclosure or housing. A pole mounted control cubicle, which is normally mounted low on the pole for ease of access, houses an operator control panel and associated micro-electronics. This cubicle provides the protection functions and controls and monitors the operation of the circuit breaker and may provide remote control. The cubicle is connected to the circuit breaker by an unpluggable umbilical cable. The circuit breaker and the cubicle together comprise a remotely controlled and monitored pole mounted circuit breaker or recloser. Either the cubicle contains all of the control circuitry necessary for its proper function with the circuit breaker or alternatively some of the cirtcuitry normally contained in the cubicle may be contained in the circuit breaker housing or associated with the circuit breaker rather than directly with the cubicle.
The circuit breaker includes a vacuum interrupter with contacts for each phase supplied to the breaker. The breaker has a closing solenoid which operates a mechanism plate for moving a contact push rod for closing the contacts. A trip coil or solenoid is present for opening the contacts. The trip coil moves a trip armature for this purpose. It is usual for the closing solenoid to be energised by a capacitor and likewise a charged capacitor is used to energise the trip solenoid. As mentioned, an unpluggable cable links the communications cubicle to the breaker. That cable can be connected to a switch cable entry module in the breaker housing which enables remote control and monitoring of the breaker. It is not uncommon for several circuit breakers to be present at the same location or substation and sometimes it is desirable or necessary to disconnect the cable from one breaker and couple it to an adjacent circuit breaker. When this is done it becomes difficult to determine from a remote location just exactly which circuit breaker is in service and what its service and operation history has been. It is particularly important to accurately know the service history of each circuit breaker so that regular maintenance and servicing can be carried out. In this way the proper operation of each circuit breaker can be assured.
There is currently no convenient way in which the characteristics and service history can be remotely or locally determined and this difficulty is compounded by the fact that sometimes the cable extending from one communications cubicle is disconnected from its usual circuit breaker and coupled to an adjacent circuit breaker.
OBJECT OF THE INVENTION It is an object of the present invention to provide a memory or signature circuit which at least minimises the disadvantages referred to above. SUMMARY OF THE INVENTION
According to one aspect, the invention provides a circuit breaker or other switchgear and coupled to a control cubicle via a cable, the circuit breaker or other switchgear including in combination a memory or signature circuit associated with a housing of the circuit breaker or other switchgear, the memory circuit storing data and information unique to the circuit breaker or other switchgear to which it is connected such as number of circuit breaker or other switchgear operations, serial number, quality assurance information, calibration data and its voltage screens, date of manufacture, switchgear type, I T data and other information, the memory circuit including a non-volatile memory for the storing data and information whereby the data and information in the memory circuit may be retained and made available to a control circuit or an adjacent cubicle should the switchgear be disconnected from the control circuit or cubicle to which it was previously connected.
According to another aspect of the invention there is provided a memory or signature circuit for storing data and information unique to a circuit breaker or other switchgear with which the circuit is associated such as number of circuit breaker or switchgear operations, serial number, quality assurance information, calibration data and its voltage screens, date of manufacture, switchgear type, I T data and other information, the circuit including a non-volatile memory for storing data and to which data and information may supplied locally and remotely and which may be interrogated from a remote location.
The non-volatile memory may comprise a RAM memory device provided with battery back-up. Alternatively, the memory device may consist of a programmable memory device such as an E PROM device which requires no battery back-up. The inputs to control the memory device and to input data and select the locations from which data is outputted may be controlled by a single input line divided into separate lines of different time constant paths. One way in which this may be achieved is to employ Schmitt trigger circuits coupled to the clock, data and select pins of the memory device. The clock signal is secured from one of the separate lines and has the shortest time constant path for the signal which achieves the clock pulse signal while the data and the select inputs are secured from separate lines having progressively longer time constant paths. In this way it is possible to use a single line from which all signals for the memory device may be secured. DESCRIPTION OF PREFERRED EMBODIMENTS
A particular preferred embodiment of the invention will now be described with reference to the only drawing which shows a detailed circuit diagram of the circuit of an embodiment of the invention. In the drawing, resistor RIO, capacitor Cl, transistor Q4 and parallel connected capacitors C4 and C5 provide a regulated power supply for the memory Ul. The line identified by the word PRESS+ enables inputs to be applied to the memory Ul. Resistors Rll and R12 together with zener diode Zl condition the input to the memory as does Schmidt trigger U2:A.
Memory Ul in this embodiment is an E PROM device although any other non-volatile memory may be used. For example, a RAM memory device with battery back-up may be used. The output from the memory device is coupled to a pull down resistor R15. Series connected Schmidt trigger devices U2:E and U2:F condition the output from the memory device Ul. Resistor R16 is a bias resistor for transistor Q5. Zener diode Z2 is connected across the collector emitter electrodes of the transistor Q5 and protects that transistor from high level voltages. Current limiting resistor R17 is connected in series with the collector electrode of transistor Q5. Metal oxide varistor SA10 limits the magnitude of the voltage which may be impressed across the collector emitter electrodes of the transistor Q5. An output from the memory is available at terminal SU2.
The memory device Ul has a clock input provided at pin 2 via Schmitt trigger U2:B. The pulse provided by the Schmidt trigger is of relatively short duration and clocking occurs on the negative transition of that short duration pulse. This clock pulse arrives at the memory device Ul before signals at pins 3 and 1 of the memory device. The time constant represented by R13 and C2 is longer than the duration of the clock pulse applied to pin 2 and shorter than the time constant represented by resistor R14 and capacitor C3. By choosing the relative time constant duration it is possible to employ only one line for clocking the memory, inputting data to the memory and selecting information to be read from the memory and made available at output pin 4. The memory device store data and information representative of information including the following:
-serial number
-calibration data of the current transformers
-quality assurance information -number of switchgear operations
-calibration date of voltage screens
-IT data indicative of a measure of arcing and hence contact wear
-date of manufacture -switchgear type (CB or load break switch)
-etc
Some of the data may be added to the memory device before initial service while other data is added as a consequence of the service life and history of operation of the circuit breaker. Information peculiar to a circuit breaker is then contained in a memory or signature circuit associated with that circuit breaker such that if the umbilical cable is disconnected from one circuit breaker and connected to another circuit breaker the data and information peculiar to the circuit breaker is not lost. The circuit breaker from which the connection has been removed still has a memory or signature circuit associated with it and information unique to it is not lost and can still be retrieved or interrogated once a connection with any communications cubicle is re-established. Likewise when control circuitry is replaced the information peculiar to the circuit breaker is not lost and is made available to replacement control circuitry.

Claims

CLAIMS :
1. A circuit breaker or other switchgear and coupled to a control cubicle via a cable, the circuit breaker or other switchgear including in combination a memory or signature circuit associated with a housing of the circuit breaker or other switchgear, the memory circuit storing data and information unique to the circuit breaker or other switchgear to which it is connected such as number of circuit breaker or other switchgear operations, serial number, quality assurance information, calibration data and its voltage screens, date of manufacture, switchgear type, I T data and other information, the memory circuit including a non-volatile memory for the storing data and information whereby the data and information in the memory circuit may be retained and made available to a control circuit or an adjacent cubicle should the switchgear be disconnected from the control circuit or cubicle to which it was previously connected.
2. A memory or signature circuit for storing data and information unique to a circuit breaker or other switchgear with which the circuit is associated such as number of circuit breaker or switchgear operations, serial number, quality assurance information, calibration data and its voltage screens, date of manufacture, switchgear type, I2T data and other information, the circuit including a non-volatile memory for storing data and to which data and information may supplied locally and remotely and which may be interrogated from a remote location.
3. A circuit breaker or other switchgear of Claim 1 wherein the memory is either RAM memory with battery back-up or an E PROM memory device.
4. The circuit breaker or other switchgear of Claim 1 wherein inputs to control the memory and to input data to the memory and to select locations from which data is outputted are controlled by a single input line divided into separate lines of different time constant paths.
5. The circuit breaker or other switchgear of Claim 4 wherein the different time constant paths are provided by connecting Schmitt trigger circuits in the separate lines and securing a clock signal from the separate line having the shortest time constant path while the data and the select inputs are secured from the separate lines having progressively longer time constant paths.
6. The circuit breaker or switchgear of Claim 5 including a power supply for supplying power to the memory and Schmitt trigger circuits.
7. The circuit of Claim 2 wherein the memory is either RAM memory with battery back-up or an E PROM memory device.
8. The circuit of Claim 2 wherein inputs to control the memory and to input data to the memory and to select locations from which data is outputted are controlled by a single input line divided into separate lines of different time constant paths.
9. The circuit of Claim 8 wherein the different time constant paths are provided by connecting Schmitt trigger circuits in separate lines and securing a clock signal from the separate line having the shortest time constant path while the data and the select inputs are secured from the separate lines having progressively longer time constant paths.
10. The circuit of Claim 9 including a power supply for supplying power to the memory and Schmitt trigger circuits.
PCT/AU1993/000472 1992-09-14 1993-09-14 A memory or signature circuit for switchgear WO1994007254A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU48103/93A AU4810393A (en) 1992-09-14 1993-09-14 A memory or signature circuit for switchgear

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPL465592 1992-09-14
AUPL4655 1992-09-14

Publications (1)

Publication Number Publication Date
WO1994007254A1 true WO1994007254A1 (en) 1994-03-31

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1993/000472 WO1994007254A1 (en) 1992-09-14 1993-09-14 A memory or signature circuit for switchgear

Country Status (2)

Country Link
CN (1) CN1088022A (en)
WO (1) WO1994007254A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001078100A1 (en) * 2000-04-05 2001-10-18 Nu-Lec Industries Pty Limited Isolating circuit breaker and circuit protection arrangement
AU768686B2 (en) * 2000-04-05 2003-12-18 Nu-Lec Industries Pty Limited Isolating circuit breaker and circuit protection arrangement

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4476511A (en) * 1980-04-15 1984-10-09 Westinghouse Electric Corp. Circuit interrupter with front panel numeric display
GB2162004A (en) * 1984-05-31 1986-01-22 Mc Graw Edison Co Current responsive recloser control with independent memory
DE3505818A1 (en) * 1985-02-20 1986-08-21 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt MONITORING AND CONTROL DEVICE FOR SWITCHGEAR
US4668878A (en) * 1983-09-22 1987-05-26 Hugo Wyss Electric power switch containing selfprogrammed control timer with continuously refreshed cycle of on/off sequences
US4672501A (en) * 1984-06-29 1987-06-09 General Electric Company Circuit breaker and protective relay unit
US4751605A (en) * 1986-01-03 1988-06-14 Merlin Gerin Reader for a digital trip device associated with a current breaking device
US4780786A (en) * 1986-08-08 1988-10-25 Merlin Gerin Solid-state trip unit of an electrical circuit breaker with contact wear indicator
US4958252A (en) * 1990-01-16 1990-09-18 Westinghouse Electric Corp. Circuit breaker with rating plug having memory
EP0432054A2 (en) * 1989-11-16 1991-06-12 Merlin Gerin Electronic circuit breaker of which the front panel is constituted as a flat panel display
GB2243493A (en) * 1990-04-26 1991-10-30 Mitsubishi Electric Corp Electrostatic protection of portable semiconductor memory device
WO1992007342A1 (en) * 1990-10-11 1992-04-30 Intellikey Corporation Electronic lock and key system
US5196831A (en) * 1991-07-19 1993-03-23 General Electric Company Electric switchgear equipment with detection of unauthorized changes to the setpoints

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4476511A (en) * 1980-04-15 1984-10-09 Westinghouse Electric Corp. Circuit interrupter with front panel numeric display
US4668878A (en) * 1983-09-22 1987-05-26 Hugo Wyss Electric power switch containing selfprogrammed control timer with continuously refreshed cycle of on/off sequences
GB2162004A (en) * 1984-05-31 1986-01-22 Mc Graw Edison Co Current responsive recloser control with independent memory
US4672501A (en) * 1984-06-29 1987-06-09 General Electric Company Circuit breaker and protective relay unit
DE3505818A1 (en) * 1985-02-20 1986-08-21 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt MONITORING AND CONTROL DEVICE FOR SWITCHGEAR
US4751605A (en) * 1986-01-03 1988-06-14 Merlin Gerin Reader for a digital trip device associated with a current breaking device
US4780786A (en) * 1986-08-08 1988-10-25 Merlin Gerin Solid-state trip unit of an electrical circuit breaker with contact wear indicator
EP0432054A2 (en) * 1989-11-16 1991-06-12 Merlin Gerin Electronic circuit breaker of which the front panel is constituted as a flat panel display
US4958252A (en) * 1990-01-16 1990-09-18 Westinghouse Electric Corp. Circuit breaker with rating plug having memory
GB2243493A (en) * 1990-04-26 1991-10-30 Mitsubishi Electric Corp Electrostatic protection of portable semiconductor memory device
WO1992007342A1 (en) * 1990-10-11 1992-04-30 Intellikey Corporation Electronic lock and key system
US5196831A (en) * 1991-07-19 1993-03-23 General Electric Company Electric switchgear equipment with detection of unauthorized changes to the setpoints

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001078100A1 (en) * 2000-04-05 2001-10-18 Nu-Lec Industries Pty Limited Isolating circuit breaker and circuit protection arrangement
GB2365627A (en) * 2000-04-05 2002-02-20 Nu Lec Ind Pty Ltd Isolating circuit breaker and circuit protection arrangement
GB2365627B (en) * 2000-04-05 2003-06-11 Nu Lec Ind Pty Ltd Isolating circuit breaker and circuit protection arrangement
AU768686B2 (en) * 2000-04-05 2003-12-18 Nu-Lec Industries Pty Limited Isolating circuit breaker and circuit protection arrangement
US6687110B2 (en) 2000-04-05 2004-02-03 Nu-Lec Industries Pty Limited Isolating circuit breaker and circuit protection arrangement

Also Published As

Publication number Publication date
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