GB2290180A - Electronic trip unit - Google Patents

Electronic trip unit Download PDF

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Publication number
GB2290180A
GB2290180A GB9510382A GB9510382A GB2290180A GB 2290180 A GB2290180 A GB 2290180A GB 9510382 A GB9510382 A GB 9510382A GB 9510382 A GB9510382 A GB 9510382A GB 2290180 A GB2290180 A GB 2290180A
Authority
GB
United Kingdom
Prior art keywords
battery
trip unit
microprocessor
electronic trip
current
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.)
Granted
Application number
GB9510382A
Other versions
GB2290180B (en
GB9510382D0 (en
Inventor
Esteban Santos
Hanns P Sailer
Donald Mcgrath
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.)
General Electric Co
Original Assignee
General Electric Co
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
Priority claimed from GB9411684A external-priority patent/GB9411684D0/en
Application filed by General Electric Co filed Critical General Electric Co
Priority to GB9510382A priority Critical patent/GB2290180B/en
Publication of GB9510382D0 publication Critical patent/GB9510382D0/en
Publication of GB2290180A publication Critical patent/GB2290180A/en
Application granted granted Critical
Publication of GB2290180B publication Critical patent/GB2290180B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1/00—Details of emergency protective circuit arrangements
    • H02H1/06—Arrangements for supplying operative power
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0069—Charging or discharging for charge maintenance, battery initiation or rejuvenation
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • H02J9/061—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for DC powered loads

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

An electronic trip unit with an auxiliary battery power supply 3 has a microprocessor 1 which periodically provides a pulsed load to the battery 3 to prolong battery operational life. The trip unit may include ROM and RAM memory and current transformers for sensing overcurrents and supplying power to the microprocessor. <IMAGE>

Description

ELECTRONIC TRIP UNIT This invention relates to electronic trip units An electronic trip unit typically comprises a microprocessor, RAM, ROM, and associated circuitry. The current transformers used for monitoring the circuit current are also connected to provide operating power to the microprocessor and related circuit components. In the event that a fault condition is detected, the circuit breaker is tripped and the current flow is interrupted thus the trip unit loses power. An auxiliary battery power supply then provides the energy to the trip unit electronics thus providing the user with a valuable fault information even when main power is not present.
An electronic trip unit according to the present invention includes an auxiliary battery power supply and means arranged to apply, periodically, a pulsed load to the batteries.
The battery pulsing "exercises" the batteries during normal operation and improves the auxiliary battery supply power up response and longevity.
A preferred arrangement of the means for pulsing the battery power supply comprises ROM memory containing stored operational information; RAM memory containing stored data for overcurrent determination; a microprocessor connecting with said ROM and RAM for overcurrent determination and circuit interruption; current sensing transformers connecting with an electric circuit providing circuit current information and operating power to said microprocessor; and a battery connecting with said current transformers through a switch, said microprocessor providing pulsed currents to said battery promoting extended battery life to said battery although other means may be utilized within the scope of the present invention.
The electronic trip unit may further include a transistor switch connecting the battery to ground through a load resistor and, in this case, the microprocessor may connect with a gate to the transistor switch for providing the pulsed current to the battery.
According to a further aspect of the present invention, a method for extending battery life to a battery connected with a circuit breaker electronic trip unit comprises the steps of applying, periodically, a pulsed load to the battery.
In a particularly preferred embodiment the method comprises the steps of connecting said battery to an input to a microprocessor contained within said circuit breaker trip unit; connecting said battery to ground through a load resistor and a transistor switch; connecting an output from said microprocessor to a gate on said transistor switch; and applying gating current to said transistor switch in pulse current increments to connect said battery to ground for corresponding short time increments.
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a schematic diagram of an embodiment of the present invention; Figure 2 is a flow chart of the associated software algorithm used by the embodiment of Figure 1; and Figure 3 is a schematic diagram of a trip unit employing a microprocessor and battery according to the present invention.
Referring to Figure 1, an electronic trip unit includes a microprocessor 1 which is arranged to be powered by an auxiliary battery power supply 3 when the circuit breaker with which it is employed trips and the auxiliary battery supply 3 is coupled to power the electronic trip unit via the latch 7 which is closed when the circuit breaker trips.
As will be explained in more detail below, the microprocessor determines whether the electronic trip unit is being powered by a primary 5-volt supply 6 or the auxiliary battery supply 3. In this embodiment of the invention the source of the power for the electronic trip unit is determined from a secondary of the latching relay 7.
If the microprocessor 1 determines that the power is coming from the primary 5-volt supply 6 then the microprocessor 1 will take action to provide a momentary load to the latched auxiliary battery supply 3.
In the embodiment of Figure 1 this is achieved by applying a PULSE~BAT signal on line 2 to the gate of a MOSFET 4 which connects the auxiliary battery power supply 3 to ground via a load resistor 5.
The microprocessor is arranged in this- embodiment to provide such momentary loading to the auxiliary power battery supply 3 at 30-second intervals whilst the electronic trip unit is being powered by the 5-volt supply 6.
When the electronic trip unit is being powered by the battery 3, then no periodic momentary loading of the battery auxiliary power supply is effected by the microprocessor 1.
The length of time the load is applied to the battery and the frequency of doing so can be varied according to the particular design of the invention employed in a given electronic trip unit with preferred parameters being selected by simply trial and error experimentation or from knowledge of a particular battery's characteristics.
Referring now to Figure 2 there is shown a flow-chart showing the pulse software routine employed by the electronic trip unit of Figure 1.
The microprocessor enters the battery pulse routine step S1 and determines whether the electronic trip unit is under battery power as indicated by step S2. If the microprocessor determines that the electronic unit is indeed under battery power, then the pulse battery software routine is exited as indicated by the 'YES' exit from the step S2 leading to-the exit routine step S3.
If the microprocessor 1 determines that the electronic trip unit is not under battery power at the step S2, then the routine moves to step S4 and determines whether 30 seconds has elapsed since the last pulse has been applied to the auxiliary battery supply 3.
If 30 seconds has not yet elapsed then the microprocessor increments an internal 30-second timer as indicated at step S5 after which the pulse battery software routine moves to the exit routine S3.
If, however, the microprocessor 1 determines that 30 seconds has elapsed at step 54 then the routine moves on to step S6 wherein the battery is pulsed, moves on then to step S7 where the internal 30-second timer is reset, whereupon the microprocessor 1 moves on to the -exit routine S3. This software routine is repeated at intervals sufficient to ensure that the required pulsing of the auxiliary battery power supply at approximately 30-second intervals is achieved.
It will be appreciated that in the particular embodiment described a microprocessor is programmed to carry out the required pulsing of the auxiliary battery power supply. However, it will be appreciated by those skilled in the art that this particular embodiment is a matter of convenience and that other arrangements, either hardware or software can be employed to provide the required battery pulsing according to the present invention.
Referring now to Figure 3 an electronic trip unit comprises inputs 11 to 17 for monitoring various currents and voltages which are input via buffers 18 and 19 to sample and hold amplifiers 21 and 22 before multiplexing via multiplexer 20.
The output from multiplexer 20 is passed to an A/D converter 24 as indicated by the output line 23. The control circuitry of the electronic trip unit is known in the prior art and comprises a bus 25 interconnecting a RAM memory 28, ROM 29, and unvolatile memory 31, a microprocessor 30, a display 57, a transceiver 27 and an output control 26.
The electronic trip circuit further includes an interface circuit 34 connected via line 33 to the auxiliary power supply 3, which components are as described with respect to Figure 1 and arranged to effect the software routine as described with respect to Figure 2.

Claims (6)

CLAIMS:
1. An electronic trip unit for circuit breakers comprising: ROM memory containing stored operational information; RAM memory containing stored data for overcurrent determination; a microprocessor connecting with said ROM and RAM for overcurrent determination and circuit interruption; current sensing transformers connecting with an electric circuit providing circuit current information and operating power to said microprocessor; and a battery connecting with said current transformers through a switch, said microprocessor providing pulsed currents to said battery promoting extended battery life to said battery.
2. The electronic trip unit of claim 1 further including a transistor switch connecting said battery to ground through a load resistor.
3. The electronic trip unit of claim 2 wherein said microprocessor connects with a gate to said transistor switch for providing said pulsed current to said battery.
4. A method for extending battery life to a battery connected with a circuit breaker electronic trip unit compriseing the steps of: connecting said battery to an input to a microprocessor contained within said circuit breaker trip unit; connecting said battery to ground through a load resistor and a transistor switch; connecting an output from said microprocessor to a gate on said transistor switch; and applying gating current to said transistor switch in pulse current increments to connect said battery to ground for corresponding short time increments.
5. An electronic trip unit substantially as hereinbefore described with reference to the accompanying drawings.
6. A method for extending battery life to a battery connected with a circuit breaker electronic trip unit substantially as hereinbefore described with reference to the accompanying drawings.
GB9510382A 1994-06-10 1995-05-23 Electronic trip unit Expired - Fee Related GB2290180B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9510382A GB2290180B (en) 1994-06-10 1995-05-23 Electronic trip unit

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9411684A GB9411684D0 (en) 1994-06-10 1994-06-10 Electronic trip unit with battery refreshing circuit
GB9510382A GB2290180B (en) 1994-06-10 1995-05-23 Electronic trip unit

Publications (3)

Publication Number Publication Date
GB9510382D0 GB9510382D0 (en) 1995-07-19
GB2290180A true GB2290180A (en) 1995-12-13
GB2290180B GB2290180B (en) 1998-07-29

Family

ID=26305053

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9510382A Expired - Fee Related GB2290180B (en) 1994-06-10 1995-05-23 Electronic trip unit

Country Status (1)

Country Link
GB (1) GB2290180B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012054337A1 (en) * 2010-10-20 2012-04-26 Schneider Electric USA, Inc. Circuit breaker with fault indication and secondary power supply
WO2012054363A1 (en) * 2010-10-20 2012-04-26 Schneider Electric USA, Inc. Electronic circuit breaker with alternate mode of operation using auxiliary power source
CN103155326B (en) * 2010-10-20 2016-11-30 施耐德电气美国股份有限公司 There is indicating fault and the electronic circuit breaker of auxiliary charger
US11152800B2 (en) 2019-04-29 2021-10-19 Caterpillar Inc. Systems and methods for charging a battery

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2241396A (en) * 1990-01-23 1991-08-28 Cooper Power Syst Multimode CT-fed power supply for recloser

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2241396A (en) * 1990-01-23 1991-08-28 Cooper Power Syst Multimode CT-fed power supply for recloser

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012054337A1 (en) * 2010-10-20 2012-04-26 Schneider Electric USA, Inc. Circuit breaker with fault indication and secondary power supply
WO2012054363A1 (en) * 2010-10-20 2012-04-26 Schneider Electric USA, Inc. Electronic circuit breaker with alternate mode of operation using auxiliary power source
CN103155327A (en) * 2010-10-20 2013-06-12 施耐德电气美国股份有限公司 Electronic circuit breaker with alternate mode of operation using auxiliary power source
CN103155326A (en) * 2010-10-20 2013-06-12 施耐德电气美国股份有限公司 Electronic circuit breaker with fault indication and secondary power supply
US8503148B2 (en) 2010-10-20 2013-08-06 Schneider Electric USA, Inc. Circuit breaker with fault indication and secondary power supply
US8675325B2 (en) 2010-10-20 2014-03-18 Schneider Electric USA, Inc. Electronic circuit breaker with alternate mode of operation using auxiliary power source
RU2553669C2 (en) * 2010-10-20 2015-06-20 ШНЕЙДЕР ЭЛЕКТРИК ЮЭсЭй, ИНК. Automatic circuit breaker with fault indication and secondary power supply source
EP2887481A1 (en) * 2010-10-20 2015-06-24 Schneider Electric USA, Inc. Electronic circuit breaker with alternate mode of operation using auxiliary power source
CN103155327B (en) * 2010-10-20 2016-01-20 施耐德电气美国股份有限公司 Use the electronic circuit breaker with alternate operating mode of accessory power supply
RU2578679C2 (en) * 2010-10-20 2016-03-27 ШНЕЙДЕР ЭЛЕКТРИК ЮЭсЭй, ИНК. Electronic automatic circuit breaker with alternative operation mode using auxiliary power supply source
CN103155326B (en) * 2010-10-20 2016-11-30 施耐德电气美国股份有限公司 There is indicating fault and the electronic circuit breaker of auxiliary charger
US11152800B2 (en) 2019-04-29 2021-10-19 Caterpillar Inc. Systems and methods for charging a battery

Also Published As

Publication number Publication date
GB2290180B (en) 1998-07-29
GB9510382D0 (en) 1995-07-19

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Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20040523