EP2384083A1 - Agencement de commutation pour un appareil de cuisson à induction, procédé de fonctionnement d'un agencement de commutation et appareil de cuisson à induction - Google Patents

Agencement de commutation pour un appareil de cuisson à induction, procédé de fonctionnement d'un agencement de commutation et appareil de cuisson à induction Download PDF

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Publication number
EP2384083A1
EP2384083A1 EP11405248A EP11405248A EP2384083A1 EP 2384083 A1 EP2384083 A1 EP 2384083A1 EP 11405248 A EP11405248 A EP 11405248A EP 11405248 A EP11405248 A EP 11405248A EP 2384083 A1 EP2384083 A1 EP 2384083A1
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EP
European Patent Office
Prior art keywords
circuit
induction
circuit arrangement
arrangement according
resonant
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Withdrawn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
EP11405248A
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German (de)
English (en)
Inventor
Albert Thomann
Christian Fuchs
Martin Behle
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.)
Inducs AG
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Inducs AG
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Filing date
Publication date
Application filed by Inducs AG filed Critical Inducs AG
Publication of EP2384083A1 publication Critical patent/EP2384083A1/fr
Withdrawn legal-status Critical Current

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/06—Control, e.g. of temperature, of power
    • H05B6/062—Control, e.g. of temperature, of power for cooking plates or the like

Definitions

  • the invention is in the field of induction devices for the catering industry and, in particular, relates to an improved control of induction cooking appliances, which takes into account different inductances of cookware materials and is especially suitable for multi-hob appliances.
  • the problem is that the magnetic fields of the individual, operated at different frequencies, induction coils of cooktops, influence or interfere with each other. This influence, in particular unwanted noise, can be prevented by operating all hobs at the same frequency.
  • this in turn has the disadvantage that only one frequency is available.
  • the inductance resonant circuit no longer operates at a desired or optimum frequency (resonant frequency).
  • you can not easily work with independent power level.
  • the variation of the resonant frequency may cause, depending on the switching frequency, individual switches of the power stage to be switched on under voltage, and / or that a short circuit over the power stage occurs for a short time until a corresponding freewheeling diode blocks. This leads to circuit losses.
  • a solution to this problem is that an external protection circuit of the power stage switches is made (snubber circuit). Although such an external circuit can not prevent unsuitable operating points, at least higher inrush currents can be absorbed. However, this still leads to switching losses. Such a circuit is also quite complex and correspondingly expensive.
  • the object is achieved by the circuit arrangement, the method for driving the circuit arrangement and the induction cooking appliance, as described in the independent claims.
  • the inventive circuit arrangement for an induction cooking appliance has a resonant circuit with at least one induction coil for inductive heating of an induction cookware and at least one capacity.
  • the resonant circuit includes a variable circuit element for varying the inductance and / or the capacitance of the resonant circuit.
  • the variable circuit element is preferably by at least one controllable throttle formed, wherein this at least one controllable throttle, for example, controlled by DC (transductor).
  • a switching frequency which corresponds to a drive frequency of the power stage of the circuit arrangement should always be greater than a resonance frequency of the resonant circuit. If a switching frequency is less than or equal to the resonance frequency, resonance operation is practically uncontrollable. In addition, smaller frequencies cause unwanted audible noise.
  • a reduction in the output power is achieved by reducing the resonant frequency of the oscillatory circuit by means of variation of the variable circuit element.
  • a further reduction of the output power is achieved by a reduction of a modulation level of a feeding alternating voltage.
  • variable circuit element By varying the variable circuit element, it is ensured that a switch of a bridge circuit for supplying the resonant circuit is in each case switched on without current.
  • a transistor is turned on without power, preferably only when an associated freewheeling diode is energized.
  • no corresponding protective circuit is required, and their switching losses omitted.
  • short circuits can be prevented via the power supply.
  • the circuit arrangement is preferably constructed in such a way that when a current-conducting transistor of a bridge branch is switched off when driving the circuit, the current is then applied to a freewheeling diode of an opposite one Bridge branches commuted. A transistor of this opposite bridge branch is turned on, during which the freewheeling diode is still in the conducting state. A transistor is thus switched on only in de-energized state.
  • the described solution does not subsequently influence inappropriate states for a resonant circuit or a power stage, but completely or almost completely prevents them. Thus, the sometimes massive circuit losses can be prevented.
  • variable circuit element is preferably connected in series with the at least one induction coil. If now a cookware with a certain inductance and capacity brought into the sphere of action of the induction coil of the cooking appliance, this will affect the resonant frequency of the resonant circuit. With an increase in the inductance, a resonant frequency of the resonant circuit is reduced. A variation of the resonant frequency is also possible by means of the variable circuit element, wherein with increasing deviation of the resonant frequency from the switching frequency of the power stage, a power output to the resonant circuit and the cooking appliance decreases. For a stepless variation, in particular reduction of the power output is possible, for example, by reducing the resonant frequency at a constant switching frequency.
  • a modulation level (or duty cycle) of the power stage is reduced, then a device with very low power can be operated. Due to the reduced resonant frequency can be ensured that - compared with a control which varies only the duty cycle - at high duty cycles, a switch or transistor turns off power.
  • variable circuit element influences of different inductances or capacities of cookware materials on the inductance and possibly also the capacitance of the resonant circuit and thus its resonant frequency are compensated by the variable circuit element.
  • a caused by an induction cookware frequency change of the resonant circuit can be compensated by a variation of the controllable circuit element again.
  • a control is preferably carried out automatically, in which is set to a predetermined, preferably constant frequency.
  • a variable circuit element in an optimal state which corresponds for example to a very good induction cookware, not driven.
  • an induction cooker equipped with such an improved circuit also has the advantage that the cooking appliance and cookware do not have to be matched or even offered together. With a simple and favorable change, it is also possible to improve existing induction devices and induction devices with multiple induction coils.
  • the circuit arrangement according to the invention is preferably operated at a constant switching frequency of a feeding power stage.
  • This offers the additional advantage that several induction coils can be arranged next to one another in a device with a multi-hob, as is common in gastronomy and commercial kitchens.
  • these devices have a contiguous cooking plate, such as a ceramic plate, which includes several cooktops.
  • Each cooktop is preferably associated with one or at least one induction coil, eg, 2.3 or 4 induction coils.
  • a control parameter is now introduced directly in the resonant circuit itself.
  • the plurality of feeding power stages of the plurality of induction coils are fed by a common DC power supply.
  • variable circuit elements which, for example, can cover a wider range of induction / capacitance.
  • FIG. 1 a circuit arrangement is shown, as it can be found in conventional induction devices.
  • the arrangement has an induction coil 1, capacitances 2 and a power stage 3 connected to a control 4.
  • Switches of the power stage are electronic circuit breakers like bsw. Power transistors of various types.
  • Schematically drawn is also a cookware 5, which on a hotplate 6, z. B. ceramic plate, provided interacts with the inductance of the induction coil.
  • the influence on the induction coil different, but manifests itself in a change in the inductance and / or capacity of the resonant circuit and thus its frequency.
  • the frequency or switching frequency used in the power stage control circuit 3 is typically varied between 20-40kHz. With a frequency variation of the switching frequency can be achieved that the resonant circuit is operated in the vicinity of its resonance frequency and an optimum operating point for the resonant circuit and / or the power stage 3 is produced.
  • the less optimal or matched to the resonant circuit of the induction device is the material of a cookware, the more energy is applied for the unwanted heating of other circuit components, in particular for circuit losses in the power stage 3. This can lead to a malfunction of an induction device.
  • FIG. 2 an embodiment of the inventive circuit arrangement is shown.
  • the basic arrangement corresponds to that FIG. 1 , wherein like elements are provided with the same reference numerals.
  • a controllable throttle 7 is arranged, which is preferably driven by direct current.
  • the device is preferably set so that the default value of the operation of the device is set with a 'good', so ideal, good ferromagnetic cookware.
  • a bridge branch in each case includes a transistor T1, T2 and a freewheeling diode D1, D2 associated therewith. Not shown is a DC voltage source, typically a rectifier circuit, which feeds the bridge circuit.
  • a choke has an inductance range of typically 0-200 ⁇ H, e.g. 0-20 ⁇ H, 0-50 ⁇ H or 0-100 ⁇ H.
  • a throttle has the advantage that it is a relatively cheap and less error-prone circuit element with limited space requirements.
  • a very wide induction / capacitance range can be covered by one or more chokes.
  • the circuit arrangement shown can be operated with a variable frequency. Then, an optimization of the resonant circuit via the two control parameters frequency and variable switching element can be made.
  • the circuit is operated at a constant frequency of, for example, 20kHz. Any frequency change in the resonant circuit caused by the operation of an induction device can then be compensated (to a degree) solely by control of the choke.
  • a power output to the resonant circuit or the cooking appliance can be controlled by means of the throttle.
  • variable circuit elements there are also other variable circuit elements conceivable with which directly the inductive and / or capacitive properties of the resonant circuit can be controlled.
  • a throttle instead of a DC-controlled throttle, a throttle with variably insertable core can be used. Since an influence of a cookware for the most part causes inductance changes, a controllable switching element which directly effects a compensation in the inductance is preferred.
  • there are also controlled capacities which can be introduced into the circuit in the form of stepless controllable capacitors or as connected capacitor stages.
  • FIGS. 3a to 3c are the voltage applied at the bridge center and thus at the resonant circuit voltage V1, V2, V3 and the coil current I1, I2, I3, according to the circuit according to FIG. 2 , represented as it is in different modes.
  • the switching frequency is the same for all three operating modes.
  • the arrows with the labels T1, T2, D1, D2 describe through which component the current flows at the appropriate time.
  • FIG. 3a a maximum power output is achieved in which the switching frequency is in the vicinity of the resonant frequency of the resonant circuit and a complete modulation (maximum duty cycle) is present.
  • the control throttle 7 is deactivated.
  • the current curve I1 is on the whole symmetrical. While the upper transistor T1 is conducting, the current flows through the upper bridge branch 8. In the falling phase of the current (about 876 ⁇ s), the upper transistor T1 is turned off. This is done with a certain safety margin to the zero crossing of the current, since the zero crossing is not known precisely due to the variability of the resonant circuit, and since later the lower transistor T2 is to be turned off.
  • the current commutates to the lower freewheeling diode D2.
  • the switching point S1 at which the transistor T2 of the second, lower bridge branch 9 is turned on, is at 0ampere or shortly before, the transistor is thus turned off and de-energized.
  • the transistor T2 can be switched on substantially without voltage and current. After the lower transistor T2 has taken over the current, the current can also flow in the opposite direction to the lower freewheeling diode D2 through the lower bridge branch 9.
  • the current will swing back again, and the current will be commutated to the upper freewheeling diode D1 of the upper bridge branch 8 by switching off the lower transistor T2 and then, as long as D1 is conducting, the upper transistor T1 will be switched on.
  • FIG. 3b shows the coil current I2 at a medium power, but also full modulation.
  • the choke is activated and the resonance frequency is thereby reduced and thus further away from the constant switching frequency of the power stage than at full power output as in FIG. 3a , This can be continuously reduced to a complete saturation of the throttle a power output.
  • the control of the transistors T1, T2 is analogous to that at full power.
  • the switching point S3 in which the transistor of the second bridge branch is turned on, in contrast to the operation at full modulation time shifted forward, just before the zero crossing of the current. This avoids that current already flows in the 'wrong direction' and the transistor can not be switched on without power.
  • variable circuit element is thus used in series with an induction coil in combination with a variable duty cycle of a power stage, in particular an IGBT drive.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Induction Heating Cooking Devices (AREA)
  • Cookers (AREA)
  • Inverter Devices (AREA)
EP11405248A 2010-04-30 2011-04-27 Agencement de commutation pour un appareil de cuisson à induction, procédé de fonctionnement d'un agencement de commutation et appareil de cuisson à induction Withdrawn EP2384083A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH00652/10A CH703021B1 (de) 2010-04-30 2010-04-30 Schaltungsanordnung für ein Induktionskochgerät, Verfahren zum Betreiben der Schaltungsanordnung für ein Induktionskochgerät.

Publications (1)

Publication Number Publication Date
EP2384083A1 true EP2384083A1 (fr) 2011-11-02

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EP11405248A Withdrawn EP2384083A1 (fr) 2010-04-30 2011-04-27 Agencement de commutation pour un appareil de cuisson à induction, procédé de fonctionnement d'un agencement de commutation et appareil de cuisson à induction

Country Status (3)

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US (1) US20120024842A1 (fr)
EP (1) EP2384083A1 (fr)
CH (1) CH703021B1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024046629A1 (fr) * 2022-08-30 2024-03-07 BSH Hausgeräte GmbH Appareil de cuisson

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITTO20120896A1 (it) 2012-10-15 2014-04-16 Indesit Co Spa Piano cottura a induzione
US10605464B2 (en) 2012-10-15 2020-03-31 Whirlpool Corporation Induction cooktop
EP3432682A1 (fr) 2017-07-18 2019-01-23 Whirlpool Corporation Procédé de fonctionnement d'une plaque de cuisson par induction et plaque de cuisson faisant appel à un tel procédé
US10993292B2 (en) 2017-10-23 2021-04-27 Whirlpool Corporation System and method for tuning an induction circuit
US11140751B2 (en) 2018-04-23 2021-10-05 Whirlpool Corporation System and method for controlling quasi-resonant induction heating devices

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2442566A1 (fr) * 1978-11-24 1980-06-20 Electricite De France Modulation de puissance pour circuit de chauffage a induction
FR2486345A1 (fr) * 1980-07-01 1982-01-08 Fonderie Soc Gen De Generateur de chauffage a induction a circuit oscillant alimente par le secteur redresse non filtre echantillonne a haute frequence
US5705923A (en) * 1992-03-13 1998-01-06 Bha Group, Inc. Variable inductance current limiting reactor control system for electrostatic precipitator
WO1998032310A1 (fr) * 1997-01-20 1998-07-23 Induced Energy Ltd. Appareil de chauffage par induction

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB255162A (en) * 1925-04-18 1926-07-19 Cecil Reginald Burch Improvements in or relating to high frequency heating apparatus
DE1438401A1 (de) * 1962-07-23 1968-10-31 Allg Elek Citaets Ges Aeg Tele Schaltungsanordnung zur symmet?chen Lastverteilung eines Drehstromnetzes bei Anschluss eines einphasigen Verbrauchers,insbesondere einer Induktionsspule einer Induktions-Erwaermungsanlage od.dgl.
US3814888A (en) * 1971-11-19 1974-06-04 Gen Electric Solid state induction cooking appliance
GB1387470A (en) * 1972-04-10 1975-03-19 Matsushita Electric Ind Co Ltd Induction heating equipment
US4426564A (en) * 1979-12-26 1984-01-17 General Electric Company Parallel resonant induction cooking surface unit
JPH0349561A (ja) * 1989-07-14 1991-03-04 Mitsubishi Heavy Ind Ltd 合金化用誘導加熱における電源制御装置
US5648008A (en) * 1994-11-23 1997-07-15 Maytag Corporation Inductive cooking range and cooktop
IT1281843B1 (it) * 1995-01-25 1998-03-03 Meneghetti Ampelio & C S N C Dispositivo di controllo particolarmente per fornelli ad induzione multipiastra
US6211498B1 (en) * 1999-03-01 2001-04-03 Powell Power Electronics, Inc. Induction heating apparatus and transformer
JP2005056781A (ja) * 2003-08-07 2005-03-03 Matsushita Electric Ind Co Ltd 高周波加熱装置
KR100529925B1 (ko) * 2003-10-27 2005-11-22 엘지전자 주식회사 유도가열 전기밥솥 및 그 동작방법
JP4868952B2 (ja) * 2006-06-16 2012-02-01 三菱電機株式会社 誘導加熱調理器
EP2175690B1 (fr) * 2008-10-08 2017-03-08 Whirlpool Corporation Procédé de contrôle d'une unité de conversion de puissance statique et système de chauffage par induction pour appareils de cuisson utilisant ledit procédé
DE102009048490A1 (de) * 2009-09-24 2011-04-07 E.G.O. Elektro-Gerätebau GmbH Verfahren zum Einstellen einer Heizleistungsabgabe einer Induktionsheizeinrichtung sowie zugehörige Induktionsheizeinrichtung

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2442566A1 (fr) * 1978-11-24 1980-06-20 Electricite De France Modulation de puissance pour circuit de chauffage a induction
FR2486345A1 (fr) * 1980-07-01 1982-01-08 Fonderie Soc Gen De Generateur de chauffage a induction a circuit oscillant alimente par le secteur redresse non filtre echantillonne a haute frequence
US5705923A (en) * 1992-03-13 1998-01-06 Bha Group, Inc. Variable inductance current limiting reactor control system for electrostatic precipitator
WO1998032310A1 (fr) * 1997-01-20 1998-07-23 Induced Energy Ltd. Appareil de chauffage par induction

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024046629A1 (fr) * 2022-08-30 2024-03-07 BSH Hausgeräte GmbH Appareil de cuisson

Also Published As

Publication number Publication date
CH703021A1 (de) 2011-10-31
CH703021B1 (de) 2014-11-14
US20120024842A1 (en) 2012-02-02

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