EP1817826A1 - Method and circuit for amplifying the input signals of an electronic overcurrent release of low-voltage circuit breakers with a selectable amplification factor - Google Patents

Method and circuit for amplifying the input signals of an electronic overcurrent release of low-voltage circuit breakers with a selectable amplification factor

Info

Publication number
EP1817826A1
EP1817826A1 EP05810924A EP05810924A EP1817826A1 EP 1817826 A1 EP1817826 A1 EP 1817826A1 EP 05810924 A EP05810924 A EP 05810924A EP 05810924 A EP05810924 A EP 05810924A EP 1817826 A1 EP1817826 A1 EP 1817826A1
Authority
EP
European Patent Office
Prior art keywords
overcurrent release
microprocessor
amplifying
input signals
low
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.)
Withdrawn
Application number
EP05810924A
Other languages
German (de)
French (fr)
Inventor
Andreas Krauss
Andreas Pancke
Wolfgang Röhl
Manfred Schiller
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
Original Assignee
Siemens AG
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 AG filed Critical Siemens AG
Publication of EP1817826A1 publication Critical patent/EP1817826A1/en
Withdrawn legal-status Critical Current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
    • H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
    • 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
    • H02H3/006—Calibration or setting of parameters

Definitions

  • the invention relates to a method and a circuit ⁇ arrangement for amplifying the input signals of an electronic overcurrent release of low-voltage circuit breakers with selectable gain, the electro ⁇ nische overcurrent release on the input side has at least one integrating capacitor and at least one preamplifier and a microprocessor.
  • Electronic overcurrent releases are used to monitor the current in a single- or multi-phase network with regard to the occurrence of overcurrents and short-circuit currents.
  • the overcurrent release Depending on the level of an impermissibly high current measured via the current transformer, the overcurrent release causes a delayed or instantaneous tripping of the low-voltage circuit breaker.
  • the input signals for the electronic release are taken from the current transformers.
  • Rogowski coils for example, which have an undamped transmission behavior, but whose output signals have only a low power, so that they must be amplified before the transfer to a trigger circuit, which is usually realized by a microprocessor with upstream A / D converter ,
  • the measured current signal after A / D conversion is set in relation to a reference voltage, so that at the output of elek ⁇ tronic overcurrent release, for example, to the nominal Power of a protected system is normalized value available.
  • the amplification of the input signals of the electronic trigger takes place via an operational amplifier.
  • the gain setting in this preamplifier has hitherto been carried out by means of analog switch connected feedback resistors, such as DE 198 25 384 Al or DE 199 59 787 Al show.
  • the invention has for its object to provide a way with which the setting of the gain of a preamplifier in electronic overcurrent releases is fast, easy and inexpensive.
  • a resistor is connected with a switch in series and the switch is pulse-width modulated via the microprocessor.
  • the effective resistance value of the inserted resistors can be inversely proportional to the touch resistance. Ratio can be increased and thus an extremely wide rule ⁇ area can be achieved.
  • Another advantage of this circuit is the reduced EMC sensitivity compared to the previous switching device of the feedback resistors of the operational amplifiers.
  • only one resistor is required for different gain factors. In the event that resistance tolerances of the resistors interfere in the individual phases, a common resistor four distri ⁇ can strengthen paths existing phases are used for all three respectively.
  • Figure 1 shows a circuit according to the invention with three amplifiers ⁇ kern, in each case an amplifier for a current phase and
  • FIG. 2 shows a variant of the circuit according to FIG. 1 with a common resistance for all current phases.
  • FIG. 1 shows a circuit according to the invention for an overcurrent release of a three-phase circuit breaker.
  • current sensors are used in the form of Rogowski coils L1 ... L3.
  • the signal from each Rogowski coil Ll ... L3 is guided in each case via a resistor Rl ... R3 and a parallel-arranged ⁇ integrating capacitor Cl ... C3 to a preamplifier Vl ... V3.
  • the outputs of the preamplifiers Vl ... V3 are connected to a microprocessor ⁇ P.
  • the microprocessor ⁇ P evaluates the current signal in the three phases in cycles and, in the event of overcurrent, decides that the circuit breaker should be switched off by a signal sent to a tripping solenoid.
  • Vl ... V3 resistors R4 ... R6 are provided, which are arranged in parallel with the integrating capacitors Cl ... C3 together with Schal ⁇ tern Sl ... S3.
  • the switches Sl ... S3 are pulse-width modulated by the microprocessor ⁇ P.
  • the resistance value of the resistors R4 ... R6 may be returned to ⁇ proportional to the duty cycle and thus the height change of the input signal for the preamplifier Vl ... V3.
  • FIG. 2 shows a variant of the circuit.
  • the micro ⁇ processor uP anyway only one of the pre-amplifier Vl ... V3 is always effective and therefore currently still only one of the switches S ... must be keyed S3, currency ⁇ rend the other two in OFF position, it is possible to provide a common resistor R7 for all phases.
  • the switches Sl ... S3 are in this case connected to one side in each case to the common resistor R7 and this then to ground.

Landscapes

  • Emergency Protection Circuit Devices (AREA)
  • Measurement Of Current Or Voltage (AREA)

Abstract

The invention relates to a method and a circuit for amplifying the input signals of an electronic overcurrent release of low-voltage circuit breakers with a selectable amplification factor, said electronic overcurrent release comprising at least one integrating condenser on the input side, and at least one pre-amplifier and a microprocessor. According to the invention, a resistance is coupled to a switch in series, parallel to an integrating condenser, and the switch is switched by means of the microprocessor in a pulsewidth-modulated manner. In this way, the effectively active resistance value of the inserted resistances is inversely increased proportionally to the pulsewidth repetition rate, thus obtaining an extremely wide regulating range.

Description

Beschreibungdescription
Verfahren und Schaltungsanordnung zur Verstärkung der Eingangssignale eines elektronischen Überstromauslösers von Niederspannungs-Leistungsschaltern mit wählbarem VerstärkungsgradMethod and circuit arrangement for amplifying the input signals of an electronic overcurrent release of selectable gain low-voltage circuit breakers
Die Erfindung betrifft ein Verfahren und eine Schaltungs¬ anordnung zur Verstärkung der Eingangssignale eines elektro- nischen Überstromauslösers von Niederspannungs-Leistungs- schaltern mit wählbarem Verstärkungsgrad, wobei der elektro¬ nische Überstromauslöser eingangsseitig mindestens einen Integrierkondensator aufweist sowie mindestens einen Vorverstärker und einen Mikroprozessor.The invention relates to a method and a circuit ¬ arrangement for amplifying the input signals of an electronic overcurrent release of low-voltage circuit breakers with selectable gain, the electro ¬ nische overcurrent release on the input side has at least one integrating capacitor and at least one preamplifier and a microprocessor.
Elektronische Überstromauslöser dienen zur Überwachung des Stromes in einem ein- oder mehrphasigen Netz hinsichtlich des Auftretens von Überströmen und Kurzschlussströmen. Je nach der Höhe eines unzulässig hohen, über Stromwandler gemessenen Stromes bewirkt der Überstromauslöser eine verzögerte oder unverzögerte Auslösung des Niederspannungs-Leistungsschal- ters . Die Eingangssignale für den elektronischen Auslöser werden den Stromwandlern entnommen. Als Stromwandler dienen beispielsweise Rogowskispulen, die zwar ein ungedämpftes Übertragungsverhalten aufweisen, deren Ausgangssignale aber nur eine geringe Leistung haben, so dass sie vor der Übergabe an eine Auslöseschaltung, die üblicherweise durch einen Mikroprozessor mit vorgeschaltetem A/D-Wandler realisiert wird, verstärkt werden müssen. Im Mikroprozessor wird das ge- messene Stromsignal nach A/D-Wandlung zu einer Referenzspannung ins Verhältnis gesetzt, so dass am Ausgang des elek¬ tronischen Überstromauslösers ein zum Beispiel auf den Nenn- Strom einer zu schützenden Anlage normierter Wert zur Verfügung steht.Electronic overcurrent releases are used to monitor the current in a single- or multi-phase network with regard to the occurrence of overcurrents and short-circuit currents. Depending on the level of an impermissibly high current measured via the current transformer, the overcurrent release causes a delayed or instantaneous tripping of the low-voltage circuit breaker. The input signals for the electronic release are taken from the current transformers. Rogowski coils, for example, which have an undamped transmission behavior, but whose output signals have only a low power, so that they must be amplified before the transfer to a trigger circuit, which is usually realized by a microprocessor with upstream A / D converter , In the microprocessor, the measured current signal after A / D conversion is set in relation to a reference voltage, so that at the output of elek ¬ tronic overcurrent release, for example, to the nominal Power of a protected system is normalized value available.
Die Verstärkung der Eingangssignale des elektronischen Aus- lösers erfolgt über einen Operationsverstärker. Die Verstärkungseinstellung in diesem Vorverstärker erfolgt bisher über durch Analogschalter geschaltete Rückkopplungswiderstände, wie beispielsweise DE 198 25 384 Al oder DE 199 59 787 Al zeigen.The amplification of the input signals of the electronic trigger takes place via an operational amplifier. The gain setting in this preamplifier has hitherto been carried out by means of analog switch connected feedback resistors, such as DE 198 25 384 Al or DE 199 59 787 Al show.
Es ist auch eine Lösung bekannt, nach der mehrere mit Opera¬ tionsverstärkern aufgebaute Verstärker eingangsseitig paral¬ lel geschaltet sind. Die Operationsverstärker besitzen unterschiedliche Verstärkungsfaktoren und werden je nach der Höhe des Eingangspegels von dem Mikroprozessor über den Verstärkern nachgeordnete Schalter als Signalquellen ausgesucht. Nachteilig hierbei sind die hohen Kosten für den Mehrfachaufbau.There is also known a solution according to which a plurality of Opera tion amplifier constructed ¬ amplifiers input side paral lel ¬ are connected. The operational amplifiers have different gain factors and depending on the level of the input level are selected by the microprocessor via the amplifiers downstream switches as signal sources. The disadvantage here is the high cost of the multiple structure.
Der Erfindung liegt die Aufgabe zugrunde, eine Möglichkeit anzugeben, mit der die Einstellung der Verstärkung eines Vorverstärkers in elektronischen Überstromauslösern schnell, einfach und preiswert erfolgt.The invention has for its object to provide a way with which the setting of the gain of a preamplifier in electronic overcurrent releases is fast, easy and inexpensive.
Erfindungsgemäß wird die Aufgabe gelöst durch die Merkmale der Ansprüche 1 und 2. Eine zweckmäßige Ausgestaltung ist Gegenstand des Unteranspruchs.According to the invention the object is achieved by the features of claims 1 and 2. An expedient embodiment is the subject of the subclaim.
Danach wird parallel zu einem Integrierkondensator ein Wider- stand mit in Reihe liegendem Schalter geschaltet und der Schalter über den Mikroprozessor pulsweitenmoduliert getastet. Hierdurch kann der effektiv wirkende Widerstandswert der eingefügten Widerstände umgekehrt proportional zum Tast- Verhältnis erhöht werden und somit ein extrem weiter Regel¬ bereich erzielt werden. Dadurch, dass die Anbindung direkt an den Integrierkondensatoren erfolgt, kann der Störeinfluss auf das Analogsignal verschwindend klein gehalten werden. Vorteil dieser Schaltung ist weiter die verringerte EMV-Empfindlich- keit gegenüber der bisherigen Umschalteinrichtung der Rückkopplungswiderstände der Operationsverstärker. Außerdem ist nur ein Widerstand für unterschiedliche Verstärkungsfaktoren erforderlich. Für den Fall, dass Widerstandtoleranzen der Widerstände in den einzelnen Phasen stören, kann auch ein gemeinsamer Widerstand für alle drei beziehungsweise vier Ver¬ stärkungspfade der vorhandenen Phasen verwendet werden.Thereafter, in parallel with an integrating capacitor, a resistor is connected with a switch in series and the switch is pulse-width modulated via the microprocessor. As a result, the effective resistance value of the inserted resistors can be inversely proportional to the touch resistance. Ratio can be increased and thus an extremely wide rule ¬ area can be achieved. The fact that the connection is made directly to the integrating capacitors, the interference on the analog signal can be kept very small. Another advantage of this circuit is the reduced EMC sensitivity compared to the previous switching device of the feedback resistors of the operational amplifiers. In addition, only one resistor is required for different gain factors. In the event that resistance tolerances of the resistors interfere in the individual phases, a common resistor four distri ¬ can strengthen paths existing phases are used for all three respectively.
Die Erfindung soll nachstehend anhand von Ausführungsbeispie- len näher erläutert werden. In den zugehörigen Zeichnungen zeigen:The invention will be explained in more detail below with reference to exemplary embodiments. In the accompanying drawings show:
Figur 1 eine erfindungsgemäße Schaltung mit drei Verstär¬ kern, jeweils ein Verstärker für eine Stromphase undFigure 1 shows a circuit according to the invention with three amplifiers ¬ kern, in each case an amplifier for a current phase and
Figur 2 eine Variante der Schaltung gemäß Figur 1 mit einem gemeinsamen Widerstand für alle Stromphasen.FIG. 2 shows a variant of the circuit according to FIG. 1 with a common resistance for all current phases.
Figur 1 zeigt eine erfindungsgemäße Schaltung für einen Über- stromauslöser eines dreiphasigen Leistungsschalters. Zur Stromerfassung in einem durch den Leistungsschalter überwachten Netz dienen Stromsensoren in Form von Rogowskispulen Ll...L3. Das Signal jeder Rogowskispule Ll...L3 wird über je- weils einen Widerstand Rl...R3 und über einen parallel ange¬ ordneten Integrierkondensator Cl...C3 an einen Vorverstärker Vl...V3 geführt. Die Ausgänge der Vorverstärker Vl...V3 sind auf einen Mikroprozessor μP geschaltet. Der Mikroprozessor μP bewertet taktweise das Stromsignal in den drei Phasen und entscheidet im Überstromfall über eine Ausschaltung des Leistungsschalters durch ein Signal an einen Auslösemagneten.FIG. 1 shows a circuit according to the invention for an overcurrent release of a three-phase circuit breaker. For current detection in a network monitored by the circuit breaker, current sensors are used in the form of Rogowski coils L1 ... L3. The signal from each Rogowski coil Ll ... L3 is guided in each case via a resistor Rl ... R3 and a parallel-arranged ¬ integrating capacitor Cl ... C3 to a preamplifier Vl ... V3. The outputs of the preamplifiers Vl ... V3 are connected to a microprocessor μP. The microprocessor μP evaluates the current signal in the three phases in cycles and, in the event of overcurrent, decides that the circuit breaker should be switched off by a signal sent to a tripping solenoid.
Zur Einstellung der Verstärkung der Vorverstärker Vl...V3 sind Widerstände R4...R6 vorgesehen, die gemeinsam mit Schal¬ tern Sl...S3 parallel zu den Integrierkondensatoren Cl...C3 angeordnet sind.For adjusting the gain of the preamplifier Vl ... V3 resistors R4 ... R6 are provided, which are arranged in parallel with the integrating capacitors Cl ... C3 together with Schal ¬ tern Sl ... S3.
Die Schalter Sl... S3 werden von dem Mikroprozessor μP puls- weitenmoduliert getastet. Durch Veränderung des Tastverhält¬ nisses kann der Widerstandswert der Widerstände R4...R6 um¬ gekehrt proportional zum Tastverhältnis und damit die Höhe des Eingangssignals für die Vorverstärker Vl...V3 geändert werden.The switches Sl ... S3 are pulse-width modulated by the microprocessor μP. By changing the Tastverhält ¬ Nisses the resistance value of the resistors R4 ... R6 may be returned to ¬ proportional to the duty cycle and thus the height change of the input signal for the preamplifier Vl ... V3.
Figur 2 zeigt eine Variante der Schaltung. Da für den Mikro¬ prozessor μP ohnehin immer nur jeweils einer der Vorverstärker Vl...V3 wirksam ist und somit auch aktuell immer nur je- weils einer der Schalter Sl...S3 getastet werden muss, wäh¬ rend die anderen beiden sich in AUS-Stellung befinden können, ist es möglich, für alle Phasen einen gemeinsamen Widerstand R7 vorzusehen. Die Schalter Sl...S3 werden hierbei mit einer Seite jeweils an den gemeinsamen Widerstand R7 und dieser dann gegen Masse geschaltet. FIG. 2 shows a variant of the circuit. As for the micro ¬ processor uP anyway only one of the pre-amplifier Vl ... V3 is always effective and therefore currently still only one of the switches S ... must be keyed S3, currency ¬ rend the other two in OFF position, it is possible to provide a common resistor R7 for all phases. The switches Sl ... S3 are in this case connected to one side in each case to the common resistor R7 and this then to ground.
Bezugs zei chenli steReference numeral
Ll.. •L3 RogowskispulenLl .. • L3 Rogowski coils
Rl.. .R3 WiderstandRl .. .R3 resistance
Cl.. •C3 IntegrierkondensatorCl .. • C3 integrating capacitor
Vl.. •V3 Vorverstärker μP MikroprozessorVl .. • V3 preamplifier μP microprocessor
R4.. .R6 WiderstandR4 .. .R6 resistance
Sl.. •S3 SchalterSl .. • S3 switch
R7 Widerstand R7 resistance

Claims

Patentansprüche claims
1. Verfahren zur Verstärkung der Eingangssignale eines elektronischen Überstromauslösers von Niederspannungs-Leistungs- Schaltern mit wählbarem Verstärkungsgrad, wobei der elektro¬ nische Überstromauslöser eingangsseitig mindestens einen In¬ tegrierkondensator aufweist sowie mindestens einen Vorverstärker und einen Mikroprozessor, d a d u r c h g e k e n n z e i c h n e t , dass parallel zu einem Integrierkondensator ein Widerstand mit in Reihe liegendem Schalter geschaltet und der Schalter über den Mikroprozessor pulsweitenmoduliert getastet wird.1. A method for amplifying the input signals of an electronic overcurrent release of low-voltage power switches with selectable gain, the electro ¬ nische overcurrent release on the input side at least one In ¬ tegrierkondensator and at least one preamplifier and a microprocessor, characterized in that parallel to an integrating capacitor, a resistor connected in series with a switch and the switch is pulse-width modulated via the microprocessor.
2. Schaltungsanordnung zur Verstärkung der Eingangssignale eines elektronischen Überstromauslösers von Niederspannungs-2. Circuit arrangement for amplifying the input signals of an electronic overcurrent release of low-voltage
Leistungsschaltern mit wählbarem Verstärkungsgrad, wobei der elektronische Überstromauslöser eingangsseitig mindestens einen Integrierkondensator aufweist sowie mindestens einen Vorverstärker und einen Mikroprozessor zur Durchführung des Verfahrens nach Anspruch 1, d a d u r c h g e k e n n z e i c h n e t , dass parallel zu einem Integrierkondensator ein Widerstand und ein zu dem Widerstand in Reihe liegender, über den Mikroprozessor pulsweitenmoduliert getasteter Schalter geschaltet ist.Circuit breakers with selectable gain, wherein the electronic overcurrent release on the input side has at least one integrating capacitor and at least one preamplifier and a microprocessor for carrying out the method according to claim 1, characterized in that parallel to an integrating capacitor, a resistor and a resistor lying in series, via the microprocessor pulse width modulated keyed switch is connected.
3. Schaltungsanordnung nach Anspruch 2, d a d u r c h g e k e n n z e i c h n e t , dass jeweils ein Pol der Schalter über einen gemeinsamen Widerstand gegen Masse geschaltet ist. 3. A circuit arrangement as claimed in claim 2, wherein a pole of the switches is connected to ground via a common resistor, in each case.
EP05810924A 2004-11-30 2005-11-10 Method and circuit for amplifying the input signals of an electronic overcurrent release of low-voltage circuit breakers with a selectable amplification factor Withdrawn EP1817826A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102004058763A DE102004058763A1 (en) 2004-11-30 2004-11-30 Method and circuit arrangement for amplifying the input signals of an electronic overcurrent release of selectable gain low-voltage circuit breakers
PCT/EP2005/055880 WO2006058823A1 (en) 2004-11-30 2005-11-10 Method and circuit for amplifying the input signals of an electronic overcurrent release of low-voltage circuit breakers with a selectable amplification factor

Publications (1)

Publication Number Publication Date
EP1817826A1 true EP1817826A1 (en) 2007-08-15

Family

ID=35564708

Family Applications (1)

Application Number Title Priority Date Filing Date
EP05810924A Withdrawn EP1817826A1 (en) 2004-11-30 2005-11-10 Method and circuit for amplifying the input signals of an electronic overcurrent release of low-voltage circuit breakers with a selectable amplification factor

Country Status (5)

Country Link
US (1) US20080123237A1 (en)
EP (1) EP1817826A1 (en)
CN (1) CN101048924A (en)
DE (1) DE102004058763A1 (en)
WO (1) WO2006058823A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014218831B4 (en) * 2014-09-18 2020-08-20 Siemens Aktiengesellschaft Circuit breaker
NL2021408B1 (en) * 2018-07-27 2020-01-31 Tryst B V Monitoring system of a medium-voltage electric power network, and method thereto

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2924752A (en) * 1957-07-12 1960-02-09 Ite Circuit Breaker Ltd Combined circuit breaker and short circuiter
US5606249A (en) * 1995-01-27 1997-02-25 Eaton Corporation Electrical apparatus with wide dynamic range for monitoring and protecting electric power systems
DE59702865D1 (en) * 1996-10-14 2001-02-08 Siemens Ag METHOD AND ARRANGEMENT FOR MEASURING CURRENT
DE19825384A1 (en) * 1998-05-28 1999-12-02 Siemens Ag Electronic trip unit for a circuit breaker
EP1177453B8 (en) * 1999-04-12 2008-07-16 CHK Wireless Technologies Australia Pty Limited Apparatus and method for electrical measurements on conductors
DE19959789A1 (en) * 1999-12-07 2001-06-13 Siemens Ag Integrator circuit for trigger circuit of power switch with Rogowski coil
DE19959787A1 (en) * 1999-12-07 2001-06-13 Siemens Ag Electronic over-current release of power switch with Rogowski coil
DE10148815A1 (en) * 2001-10-02 2003-04-10 Abb Patent Gmbh Method and device for current value determination using a current transformer which works in the area of core saturation
US7099130B2 (en) * 2003-01-17 2006-08-29 Ericson Manufacturing Company Voltage monitor for ground fault circuit interrupter
DE102004011023A1 (en) * 2004-03-04 2005-09-15 Siemens Ag Three or four-pole low-voltage circuit breaker, has output signals from Rogowski coils fed via low-pass filters to measuring amplifier and via resistances to integrating capacitor
WO2007000062A1 (en) * 2005-06-29 2007-01-04 Abb Research Ltd. Apparatus for the detection of a current and method for operating such an apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2006058823A1 *

Also Published As

Publication number Publication date
WO2006058823A1 (en) 2006-06-08
CN101048924A (en) 2007-10-03
DE102004058763A1 (en) 2006-06-08
US20080123237A1 (en) 2008-05-29

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