EP0561206B1 - Plaque de cuisson à induction - Google Patents

Plaque de cuisson à induction Download PDF

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Publication number
EP0561206B1
EP0561206B1 EP93103272A EP93103272A EP0561206B1 EP 0561206 B1 EP0561206 B1 EP 0561206B1 EP 93103272 A EP93103272 A EP 93103272A EP 93103272 A EP93103272 A EP 93103272A EP 0561206 B1 EP0561206 B1 EP 0561206B1
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EP
European Patent Office
Prior art keywords
heating system
power
control
cooking point
point heating
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.)
Expired - Lifetime
Application number
EP93103272A
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German (de)
English (en)
Other versions
EP0561206A2 (fr
EP0561206A3 (en
Inventor
Günter Fettig
Jürgen HORN
Franz Bogdanski
Willi Essig
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.)
EGO Elektro Geratebau GmbH
Original Assignee
EGO Elektro Gerate Blanc und Fischer GmbH
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Publication of EP0561206A2 publication Critical patent/EP0561206A2/fr
Publication of EP0561206A3 publication Critical patent/EP0561206A3/de
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Publication of EP0561206B1 publication Critical patent/EP0561206B1/fr
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Classifications

    • 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
    • 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
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H05B6/12—Cooking devices
    • H05B6/1209—Cooking devices induction cooking plates or the like and devices to be used in combination with them
    • H05B6/1245—Cooking devices induction cooking plates or the like and devices to be used in combination with them with special coil arrangements
    • H05B6/1263—Cooking devices induction cooking plates or the like and devices to be used in combination with them with special coil arrangements using coil cooling arrangements
    • 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
    • H05B2213/00—Aspects relating both to resistive heating and to induction heating, covered by H05B3/00 and H05B6/00
    • H05B2213/07—Heating plates with temperature control means

Definitions

  • the invention relates to an inductive hotplate heater for cooking vessels or the like.
  • Induction heating has the advantage of very low-inertia heat generation directly in the cooking vessel, namely in the bottom of the saucepan.
  • the cooking appliance itself remains largely cold.
  • Their disadvantage is the relatively high construction costs and the difficult controllability. Since electronic components are required for the necessary high-frequency generation and its control and, on the other hand, due to the heat loss in the electronics and the induction coil, the induction generating means nevertheless heat up more, it was necessary to arrange the conversion and control electronics separately from the hotplate. This hampered installation in normal cookers or hobs and induction hobs were therefore mostly installed in special appliances.
  • the object of the invention is to provide a low-loss and therefore low-self-heating, easily controllable or adjustable hotplate heating in a hotplate heating.
  • the vibration packet control according to the invention has no direct voltage component and is therefore practically without mains feedback.
  • the formation of harmonics is largely eliminated, so that radio interference suppression is also simplified.
  • the high-frequency inverter is designed to be free-swinging, d. H. its frequency changes depending on current and damping.
  • PLL phase-controlled loop circuit
  • the electronic switches also switch at zero crossing.
  • the converter Due to the control principle of full half-wave control, the converter always works at the point of maximum efficiency. It therefore has a high level of continued cooking (partial power) efficiency. As a result, the power components can also be correspondingly smaller and consist of commercially available elements.
  • the control principle is optimized with regard to network feedback. The influence on pacemakers is also minimized.
  • US-A-4 112 287 describes an induction heater in which the power supplied to the four induction coils is switched by four triacs switched at the mains frequency, which are connected between the power oscillator and one induction coil each. In order to excite the corresponding induction coil, the triacs switch only at the zero point of the envelope of the modulated high frequency.
  • the setting range is also slightly non-linear over the setting path (toggle position) so that it can be ergonomically optimized. Smaller outputs can be more finely adjustable.
  • the free-floating converter results in low switching losses. It is therefore not necessary to oversize the electronic circuit breakers (IGBTs). There is also no constant frequency, rather frequency modulation occurs due to saturation effects.
  • a novel optical measuring device is used to measure the temperature of the plate. It contains an infrared sensor, for example a silicon photodiode, which carries out a temperature measurement using Planck's law of radiation. With increasing temperature of the glass ceramic plate, the maximum of the frequency of the emitted photons also increases (Vienna's law of displacement). Above a certain temperature, the energy corresponds to that emitted Photons of the spectral sensitivity of the sensor, so that an evaluable signal is generated, which is used to switch off or reduce the heating power.
  • an infrared sensor for example a silicon photodiode
  • the temperature limitation should have a locking function, i. H. After the temperature limiting circuit has responded, the hotplate should remain switched off until it is switched off manually and then switched on again. This can easily be provided by the control electronics, for example a microcomputer.
  • FIG. 1 to 3 show a component 11 for two induction hotplates 10. It is provided for arrangement under a plate 12, for example a glass ceramic plate.
  • the component forms a compact, relatively flat, manageable unit which, with the exception of the mains connection and an adjusting and regulating member 27 with adjusting knob 26, which can also include a power control device which contains all the elements necessary for operation.
  • the component can be pressed against the plate 12 from below, for example, by spring elements, not shown.
  • This arrangement and the inclusion of all essential components mean that the induction heating can also be arranged in a glass ceramic cooktop instead of and in addition to conventional radiation hotplates.
  • the component contains in a sheet metal shell 23 a heat sink 15, preferably an aluminum molded part with a largely closed surface at the top, and cooling fins 18 on the underside, which form cooling channels 19 between them. They run approximately along an axis 9 connecting the two hotplates 10.
  • the heat sink has recesses 29 in which induction generating means 14 are arranged, each of which is assigned to a hotplate 10.
  • a circuit board 16 is provided on the underside of the heat sink, for example screwed to the outer cooling fins, so that the cooling channels 19 and further larger spaces 28, which also serve as cooling channels, enclose on the underside of the heat sink 15.
  • Electronic power control elements 21 are arranged therein, preferably in a heat-conducting connection with the heat sink 15.
  • the circuit board also carries electronic components, but mainly those used for control, with relatively small currents and therefore less heating elements. The whole thing fits in a sheet metal bowl.
  • the board could also form the lower cover itself.
  • ventilation openings 25 are provided, through which a fan 37 arranged in a recess of the cooling body 15 sucks in air or blows it out after flowing through the cooling channels 19, 28.
  • a fan arranged centrally on the heat sink with an air outlet on two or more sides is also possible.
  • the induction generating means 14 consist of an induction coil 30 in the form of a flat, disk-shaped or ring-shaped plate, magnetic return means 31 arranged underneath and thermal insulation 32 on the side facing the plate, in the area of which a shield 33 can be provided.
  • the induction coil 30 contains strands 38 wound as a spiral and / or spiral, which are made up of individual conductors 39 (see FIG. 12).
  • the strand 38 is made up of a plurality of, preferably five to nine, in the present case seven card wires 40 which are stranded together and in turn contain a number between five and nine, in the present case seven individual wires stranded together.
  • the individual conductors are electrically insulated from one another in the usual way, for example by a heat-resistant lacquer layer.
  • the individual conductors 39 made of copper have a diameter d between 0.1 and 0.4 mm, preferably 0.2 mm. This value applies to the preferred frequency of the current supplied to the induction coil between 20 and 30 kHz, preferably approximately 25 kHz.
  • the electrical conductivity ⁇ of the single-conductor material is in A / V ⁇ m, the permeability ⁇ is to be used in V ⁇ s / A ⁇ m and the frequency f in 1 / s.
  • the wire thickness d preferably used is preferably between a quarter and three quarters of the base value D calculated according to this formula. It has surprisingly been found that the power loss in the induction coil 30 could be significantly reduced with these small diameters of the individual conductors.
  • the coil losses should decrease with a reduction in diameter d up to a value equal to the base value D according to the above formula, but hardly afterwards.
  • the theoretical knowledge previously considered to be reliable, was based on the skin effect of a single conductor and determined an optimal size for the above-mentioned diameter D, because then the entire diameter was flowed through evenly despite the current being displaced towards the surface.
  • the basic value D corresponds to the penetration depth of the current into a conductor surface, with the round wire shape resulting in penetration from all sides at the same time and thus a uniform current occupancy over the cross section.
  • the consideration based on this theory was, however, surprisingly refuted by experiments. Even a diameter of less than 0.2 mm, ie less than half of the base value D, would be preferred, but the mechanical possibilities of processing a diameter reduction put an end at some point.
  • the magnetic yoke means 31 Under the coil, also as a flat, annular layer with a central opening 35, is the magnetic yoke means 31, which is made up of ferrite segments. It closes the magnetic field created on the underside of the induction coil with a low magnetic resistance but a high electrical resistance, so that the eddy current losses remain low there as well. Therefore, no significant induction field arises on the underside of the induction generating means 14.
  • the magnetic yoke means 31 also form a thermal bridge between the induction coil 30 and the heat sink, on which they rest, so that the coil loss heat is dissipated directly into the heat sink.
  • the thermal insulation 32 is in the form of a plate covering the induction coil 30 with a central opening 35 between it and the glass ceramic plate 12. It consists of a very good heat-insulating and, if possible, also electrically insulating material, for example a pyrogenic silica airgel, which presses into a plate is.
  • the induction coil generates so little heat, particularly in the case of the low-loss coil structure mentioned above, that heat bridge to the consumer tends to extract heat rather than supply it to the consumer.
  • Thermal insulation keeps the induction coil at a lower temperature level, which has advantages for coil design and isolation.
  • the thermal insulation 32 advantageously also forms an electrical insulation against the glass ceramic plate 12, which becomes electrically conductive at an elevated temperature.
  • an optical sensor 36 is arranged, which receives the radiation coming from the glass ceramic plate. It thus indirectly monitors the temperature of the cooking vessel that could become dangerous to the glass ceramic plate by means of non-contact measurement, which would otherwise be difficult to carry out in the magnetic field of an induction hob. It is therefore a measurement of the cause of the temperature hazard of the glass ceramic plate, since this is only heated by the cooking vessel.
  • the glass ceramic largely allows the radiation to pass through and can therefore hardly be measured without contact. With other plate materials, these can themselves be the radiation source.
  • the optical sensor is an infrared detector, whose spectral sensitivity is in the infrared range. As the temperature of the cooking vessel rises, the maximum of the frequency of the emitted photons increases according to Vienna's law of displacement. Above a predetermined temperature, the energy of the emitted photons corresponds to the spectral sensitivity of the IR detector, so that an evaluable signal is produced which is then used to switch off or reduce the power of the induction heating.
  • the optical sensors 36 of each induction hotplate act on a microcomputer 42 via comparators 41 (FIG. 4), one of which is provided for the control and regulation of an induction hotplate. It can be adjusted to a specific temperature or power level in each case by means of the setting element with the setting button 26.
  • the optical sensors 36 can be silicon diodes.
  • measuring resistors could also be applied to the plate, e.g. B. between insulation and plate in the coil area if the measuring resistances are not or only slightly influenced by the magnetic field and an influence is compensated for by circuitry or in the measuring program.
  • the shield 33 is provided between the induction coil 30 and the glass ceramic plate 12. It can lie on the bottom or top of the thermal insulation 32 or can advantageously be embedded in it.
  • the shielding consists of a wire or ribbon structure, for example shown in FIGS. 4 and 6, which is designed with low eddy currents. On the one hand, this means that the thickness of the individual structural elements 45 (wires, strips or the like) is less than the current penetration depth at the frequency used, and on the other hand the structures are in no way electrically closed. 6 there is therefore an open ring conductor 46 with inwardly projecting branches 45 which are of different lengths, so that the entire area is evenly occupied.
  • the ring 46 is connected to an earth 34, for example by connection to the earthed sheet metal shell 23 of the component 11 (FIG. 1).
  • FIG. 7 shows a structure in which branches with conductor structures 45 extend outwards from a center point at which the grounding acts, which are also branched in such a way that they shield the hob as evenly as possible.
  • the shield By this shielding, without causing significant losses, the electrical field formed around the induction coil is shielded from above and thus the electrical interference. Leakage currents from the cooking vessel can also be reduced.
  • the shield could also be formed by a grounded layer of a resistance material. It is essential that the material is non-magnetic and, in order to avoid eddy current losses, has a relatively high electrical resistance compared to metallic conductors.
  • FIG. 4 shows that the alternating current coming from the mains connection 22 via a radio interference suppression 50 and rectifier 51 is fed to a common intermediate circuit 52, from which both converters 53, which could also be referred to as high-frequency generators, are supplied for each induction coil 30 .
  • the intermediate circuit and converter are controlled by a controller 54, which in turn receives signals from the microcomputers (MC) 42.
  • MC microcomputers
  • FIG. 5 shows the circuit of an induction coil 30 in greater detail, the control, converter 53 and induction coil 30 of a second hotplate, which is also connected to the intermediate circuit 52, not shown for the sake of clarity.
  • the intermediate circuit 52 not shown for the sake of clarity.
  • Each induction coil 30 is in an oscillating circuit with a half-bridge circuit, ie two branches 55, 56 are provided, in each of which a capacitor 57, 58 and an electronic switch 60, 61 are located.
  • These can be IGBT components, ie electronic semiconductor components, which contain several transistor functions and, controlled by the controller 62, can switch extremely quickly.
  • a free-wheeling diode 63, 64 and a resistor 65, 66 are connected in parallel with each of these circuit breakers 60, 61.
  • These elements form the converter 53 designed as an oscillating circuit, to which the intermediate circuit 52 and the rectifier 51 are connected upstream.
  • a rectifier bridge generates a pulsating DC voltage, in which sine half-waves of the same polarity are strung together by rectifying the mains alternating current.
  • the outputs of the rectifier bridge 51 are connected to the two branches 55, 56.
  • In the intermediate circuit there is a common capacitor 67 between the two branches and a resistor 68 connected by an electronic switch 69.
  • the switch 69 can be a MOS-FET which, in cooperation with the resistor, prevents cracking noises when the converter is switched on. It discharges the DC link.
  • a control unit 80 which contains a galvanic isolation between the low voltage part 54 and the power side, for example by optocouplers. Furthermore, the switches are supplied with the control energy. This is supplied via supply units 81 which are located in the branches of the resistors 65, 66 and which each contain a Zener diode 82 and a diode 83 and a capacitor 84.
  • the Zener dione limits the voltage to the control voltage required for the switches 60, 61 and the diode and capacitor act as rectification. This creates a simple “power supply unit” for the switch drive energy, which draws its energy from the resistance branch, ie from an energy source that is available in any case. As a result, the resistances have lower energy losses generate and still the other conditions are not affected, z. B. the current value at point 70.
  • the resonant circuit shown in the symmetrical circuit structure could also be replaced by an asymmetrical structure in which only one is provided instead of the two resonant circuit capacitors 57, 58.
  • the resonant circuit then only absorbs energy from the network on one side. In particular, in cases where it is not important to adhere to certain radio interference suppression values, this simpler circuit design could be advantageous.
  • a switching control 71 for the converter 53 which contains a sample and hold element 72, a limit value memory 73, a comparator 74 and a yes / no memory 75.
  • This switching control is intended to switch off the induction heating immediately if there is no decrease in power, for example when the cooking vessel 13 is removed from the hotplate, and to switch it on again only when a cooking vessel is present. For this purpose, a check is carried out at relatively short intervals as to whether a customer is present. This is done by measuring the damping of the induction coil 30.
  • the resonant circuit is always switched on at the zero crossing of the mains voltage, specifically according to a specific scheme that is specified by the microcomputer 42 and will be explained in the following.
  • the resonant circuit is over the electronic circuit breaker 60, 61 controlled, namely from the controller 62. Before each half-wave of the generated high-frequency voltage, which is of the order of 25 kHz, there is a switchover between the circuit breakers 60, 61 at the zero crossing. This creates a completely free-running converter or inverter 53 which has low switching losses.
  • no phase gating control which would result in a forced oscillation, is used for power setting or control.
  • the frequency is not constant and can be adjusted by frequency modulation according to the saturation effects. As a result, no oversizing of the electrical circuit breakers 60, 61 is necessary and there is also a small harmonic generation.
  • the power setting is done by a vibration package control.
  • the converter is always switched on for a full line half-wave in normal operation.
  • the basis of the power setting is that different power levels are determined by switch-on patterns, which consist of a sequence or combination of the same or different, in themselves symmetrical basic patterns of wave packets. The complete symmetry minimizes network interference.
  • FIGS. 8 and 9 show an example of a sample layout plan for such a vibration package control:
  • a total time interval Z of 2.1 seconds is divided into 35 subintervals T of 60 milliseconds each, ie six network half-waves at a frequency of 50 Hz.
  • Fig. 8 a shows a partial interval T with the designation " ⁇ ", in which all six network half-waves are present. So it's a "full power" interval.
  • Fig. 8 c contains only two network half-waves, namely the first as positive and the fourth as negative.
  • This subinterval T with the designation "Y" therefore has a power share of one third.
  • Fig. 8 d shows the zero power, d. H. no power is released during this partial power interval "0".
  • FIG. 9 now shows the occupancy plans using the total of 35 subintervals T, which together form the time interval Z of 2.1 seconds duration. Only various power levels are shown there, for example, corresponding to the toggle position of the adjusting knob 44, to which the most varied combinations of the basic patterns according to FIG. 8, in each case in a row, are assigned. It can be seen from the percentages of power release given below that the power characteristic curve in a power-controlled induction hob can be adapted to practical requirements in this way. For example, the performance is in the lower Adjustment levels can be regulated much more precisely than in the upper ones, which corresponds to practical requirements. Since each basic pattern "Y" according to FIG.
  • Fig. 8 shows positive and negative network half-waves as they exist before the rectification in order to demonstrate the absence of feedback on the power network.
  • Mains half-waves are present in the oscillating circuit in the form of rectified alternating current.
  • the basic patterns are mixed as desired under the control of the microcomputer and thus produce a control or control that is DC-free on the network side Control in relatively short pulses, but each containing an entire network half-wave.
  • the setting can be purely performance-dependent via the setting elements 43, as shown in FIG. 9, but control influences from temperature sensors or the like can also act on the microcomputer, so that a control circuit is created.
  • the start of the resonant circuit for generating the high frequency feeding the induction coil 30 therefore basically begins at the zero crossing of the mains voltage and the amplitude and frequency in the resonant circuit change with the rise and fall of current and voltage over the individual mains half-waves.
  • the frequency is therefore higher at the beginning of each half-wave and decreases in the area of its maximum because the converter oscillates freely.
  • the frequency changes not only with the current, but also with the pot material because, for example, the inductance is not constant due to magnetic saturation in the bottom of the pot. If the inductance of the overall arrangement becomes smaller, a higher frequency results.
  • This arrangement also has advantages in terms of radio interference suppression because broadband interferers are easier to suppress. In addition, fewer harmonics are generated because phase control is not necessary.
  • the current in the resonant circuit rises sharply because the damping decreases.
  • the current in the converter is tapped at point 70 and detected by the sample and hold element 72. If it exceeds a limit value stored in the limit value memory 73, the converter is switched off via the controller 62 in that the circuit breakers 60, 61 are closed or are no longer opened. This can also happen within a network half-wave.
  • the energy then present in the resonant circuit is fed back into the intermediate circuit 52 via the freewheeling diodes 63, 64. Depending on the current in the resonant circuit, the shutdown works extremely quickly and without loss.
  • a phase-controlled loop circuit (PLL "phase locked loop") specifies the control clock frequency for the circuit breakers 60, 61.
  • PLL phase locked loop
  • the loop circuit releases a half-oscillation when one of the two power switches 60 or 61 is triggered by the microcomputer.
  • the tapping point 70 was charged to a certain voltage via the resistors 65, 66 and thus a certain energy was present in the resonant circuit.
  • current therefore flows for a high-frequency half-wave.
  • the sampling cold element e.g. B. a peak detector, which also contains a current transformer to convert the actually flowing currents into measuring currents, measures the current during this oscillation and stores the result. It corresponds to the value i max in FIG. 10.
  • the amplitude then decays according to the energy consumption due to the damping according to a specific function (corresponding to an e-function). If this decay is too slow, the damping is too low and the conditions for power on are not met. This is demonstrated, for example, in FIG. 10, where a decaying oscillation is shown and the limit values G1, G2, G3 and G4 indicate, for example, the values that could be stored in the limit value memory 73. If they are exceeded, this means "insufficient damping" and it a signal is given to the microcomputer: "no activation".
  • the pan detection therefore works on the principle of damping measurement, with the test only working with one half of the converter, so that the power oscillating circuit does not start, for which purpose an alternate activation of the two power switches 60, 61 would be necessary.
  • the test procedure takes place in such a way that the current value is measured from the first oscillation when one of the power transistors 60 or 61 is switched on for a very short period of time E, for example 20 microseconds (approximately one half oscillation in idle frequency), held by the sample-and-hold element 72 and the subsequent limit values, z. B. G1 to G5 can be derived.
  • the loop circuit PLL Under the control of the microcomputer, the loop circuit PLL then pauses P in the same order of magnitude and then switches on the power transistor again. From the current drop in the next oscillation (see FIG. 11 a) it can now be determined by comparison with the limit values, which is done via the comparator 74, whether the current exceeded these limit values (here G2 and G3). The result of this check is temporarily stored in the memory 75.
  • a second activation then takes place, where the limit values G4 and G5 are used for comparison.
  • this second measurement is carried out in order to prevent falsification by strong frequency deviation, e.g. B. to avoid errors with an aluminum or copper object instead of a cooking vessel. If this measurement also does not result in the limit values being exceeded, the damping is sufficient and the resonant circuit is switched on by the controller 62. Since the entire measurement took place in the microsecond range, the energy in the resonant circuit decayed because it could not be replaced during this time by the high-resistance voltage dividers 65, 66 connected in parallel with the circuit breakers 60, 61.
  • the resonant circuit is again supplied with the corresponding test voltage via this voltage divider and a new test can begin if the limit values are exceeded and thus "too little damping" was detected and the resonant circuit was not switched to power mode.
  • the test can take place with a very low test current, for example with a tenth of the nominal current during power operation.
  • the resonance circuit in test mode is only about 1 / 100,000th of the total time in operation due to the very short switch-on times of, for example, 20 microseconds within the test cycle of 2 seconds, the total power release during the test is only a completely insignificant fraction of the total power of the hotplate and can be neglected both energetically and in terms of influencing the environment. It is, for example, a 2,000 W hotplate of the order of 1 to 4 mW.
  • the test only works with one half of the converter, so the resonant circuit does not start during the test phase. If during the two successive measurements (second and third switch-on of the PLL) the values stored in the memory 75 both show "damping sufficient" (limit values not exceeded), the oscillating circuit is switched on in the controller 72 by the PLL loop circuit being switched on, by alternately switching on the circuit breaker 60, 61 started at full power. The power release itself then takes place in accordance with the power scheme explained with reference to FIGS. 8 and 9 until either the hotplate is switched off via the setting element 43 or self-protection is accessed by removing the pot and the power is switched off so that it goes back into the test phase .

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Claims (9)

  1. Chauffage par induction d'emplacements de cuisson, comprenant des moyens de production d'une induction (14) et une commande électronique destinée à ceux-ci, caractérisé par une commande symétrique par paquets d'oscillations comprenant une commande à phase symétrique des paquets d'oscillations, constitués par des demi-ondes complètes du réseau sur un faible nombre de périodes de la tension du réseau.
  2. Chauffage d'emplacements de cuisson selon la revendication 1, caractérisé par un changeur de fréquence à haute fréquence à oscillations libres (53) dont la fréquence de sortie varie et dont la mise en circuit et hors circuit ont lieu à chaque fois lors du passage par le zéro de la tension du réseau.
  3. Chauffage d'emplacements de cuisson selon l'une des revendications précédentes, caractérisé par un circuit oscillant comprenant deux branches séparées (55, 56) qui contiennent chacune un moyen de production d'une induction (14) et qui comprennent chacune un commutateur électronique de puis sance (60, 61), et de préférence un IGBT, lequel met alternativement en circuit et hors circuit une branche (55, 56) pour chaque demi-onde de haute fréquence.
  4. Chauffage d'emplacements de cuisson selon l'une des revendications précédentes, caractérisé par un circuit intermédiaire commun (52) destiné à plusieurs changeurs de fréquence à haute fréquence (53), et de préférence à deux, qui amènent à celui-ci la tension du réseau redressée.
  5. Chauffage d'emplacements de cuisson selon l'une des revendications précédentes, caractérisé par le fait que des niveaux de puissance différents sont déterminés par des modèles de commutation qui sont constitués à partir d'une succession ou, respectivement, d'une combinaison de modèles de base identiques ou différents, et symétriques par eux-mêmes, de demi-ondes de la tension du réseau, de préférence à l'intérieur d'un intervalle de temps (Z) qui est constant et déterminé.
  6. Chauffage d'emplacements de cuisson selon l'une des revendications précédentes, caractérisé par le fait que la commande électronique (62) contient des moyens de commande du circuit oscillant comprenant un circuit en boucle à verrouillage de phase (PLL) qui commande des commutateurs électroniques de puissance (60, 61) et qui travaille de préférence avec une fréquence d'horloge de commande de marche à vide lorsque le circuit oscillant ne travaille pas en fonctionnement en puissance et qui reprend la fréquence de celui-ci après sa mise en marche.
  7. Chauffage par induction d'emplacements de cuisson selon l'une des revendications précédentes, caractérisé par un dispositif de mesure optique (36, 41) pour mesurer la température d'une plaque (12) sous laquelle le chauffage est disposé, ce dispositif de mesure travaillant de préférence sans contact et comprenant un capteur (36) qui est efficace dans la région du champ magnétique d'un moyen de production d'une induction (14), et en particulier en son milieu, mais qui est toutefois disposé éventuellement à l'extérieur de cette région, cependant que le capteur (36) présente le cas échéant une gamme de sensibilité spectrale déterminée qui est située de préférence dans la région du rayonnement infrarouge.
  8. Chauffage d'emplacements de cuisson selon la revendication 7, caractérisé par le fait que le dispositif de mesure est prévu pour protéger la plaque (12) des surchauffes, et qu'il agit sur le chauffage inductif en diminuant la puissance ou en la coupant, respectivement, et par le fait que le chauffage de l'emplacement de cuisson est pourvu d'un blocage de la remise en circuit.
  9. Chauffage d'emplacements de cuisson selon l'une des revendications 3 à 8, caractérisé par le fait que les commutateurs de puissance (60, 61) sont excités chacun par l'intermédiaire d'une unité d'excitation (80) qui comprend une séparation électrique, le cas échéant, et qui est alimentée de préférence, par l'intermédiaire d'une unité d'alimentation (81), en une énergie de commande dérivée d'une partie de circuit (65, 66), celle-ci amenant au circuit oscillant une énergie de départ bien définie.
EP93103272A 1992-03-14 1993-03-02 Plaque de cuisson à induction Expired - Lifetime EP0561206B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4208252A DE4208252A1 (de) 1992-03-14 1992-03-14 Induktive kochstellenbeheizung
DE4208252 1992-03-14

Publications (3)

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EP0561206A2 EP0561206A2 (fr) 1993-09-22
EP0561206A3 EP0561206A3 (en) 1993-10-13
EP0561206B1 true EP0561206B1 (fr) 1996-08-28

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EP93103272A Expired - Lifetime EP0561206B1 (fr) 1992-03-14 1993-03-02 Plaque de cuisson à induction

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US (1) US5488214A (fr)
EP (1) EP0561206B1 (fr)
DE (2) DE4208252A1 (fr)
ES (1) ES2091505T3 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012102575B4 (de) 2012-03-26 2024-04-18 Hupfer Metallwerke Gmbh & Co. Kg Verfahren und Induktionsgerätemodul zum Erwärmen von Lebensmitteln

Families Citing this family (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5914066A (en) * 1994-03-09 1999-06-22 Aktiebolaget Electrolux Circuit for the control of energy supply in a resonance converter
FR2726704B1 (fr) * 1994-11-07 1997-01-31 Breda Jean Pierre Generateur haute frequence a resonance pour un appareil de chauffage a induction
DE19613572A1 (de) * 1996-04-04 1997-10-09 Innovat Ges Fuer Sondermaschin Generator zum Erwärmen von Speisen, insbesondere in Speisetablett-Transportwagen oder -Ständern
DE19856140A1 (de) * 1998-12-04 2000-06-08 Bsh Bosch Siemens Hausgeraete Sensorgesteuertes Kochfeld mit unterhalb der Kochfeldplatte angeordneter Sensoreinheit
FR2792157B1 (fr) * 1999-04-09 2001-07-27 Jaeger Regulation Table de cuisson par induction comportant des foyers a induction alimentes par des generateurs
US6111228A (en) * 1999-08-11 2000-08-29 General Electric Company Method and apparatus for sensing properties of glass-ceramic cooktop
US6133552A (en) * 1999-08-11 2000-10-17 General Electric Company Sensor assembly for glass-ceramic cooktop appliance and method of calibrating
US6534753B1 (en) 2000-06-15 2003-03-18 Wilmington Research And Development Corporation Backup power supply charged by induction driven power supply for circuits accompanying portable heated container
US6452136B1 (en) 2000-12-13 2002-09-17 General Electric Company Monitoring and control system and method for sensing of a vessel and other properties of a cooktop
WO2003063552A1 (fr) 2002-01-25 2003-07-31 Matsushita Electric Industrial Co., Ltd. Appareil chauffant a induction
DE60332821D1 (de) * 2002-03-19 2010-07-15 Panasonic Corp Induktionsheizeinrichtung
DE10314690A1 (de) * 2003-03-27 2004-10-07 E.G.O. Elektro-Gerätebau GmbH Heizungseinrichtung für eine flächige Beheizung mit Induktions-Heizelementen
ES2246640B1 (es) † 2003-05-15 2006-11-01 Bsh Electrodomesticos España, S.A. Regulacion de la temperatura para un elemento calentador de calentamiento inducido.
FR2863039B1 (fr) * 2003-11-27 2006-02-17 Brandt Ind Procede de chauffage d'un recipient pose sur une table de cuisson a moyens de chauffage associe a des inducteurs
WO2006032292A1 (fr) * 2004-09-23 2006-03-30 E.G.O. Elektro-Gerätebau GmbH Dispositif de chauffage pour un chauffage plan, pourvu d'elements chauffants a induction
DE102005005527A1 (de) * 2005-01-31 2006-08-03 E.G.O. Elektro-Gerätebau GmbH Induktionsheizeinrichtung und Kochfeldmulde mit einer solchen Induktionsheizeinrichtung
ES2289872B1 (es) * 2005-06-08 2008-09-16 Bsh Electrodomesticos España, S.A. Dispositivo para calentamiento inductivo de un elemento calentador.
DE102006047121A1 (de) * 2006-09-26 2008-04-03 E.G.O. Elektro-Gerätebau GmbH Induktionsheizeinrichtung für ein Induktionskochfeld und Induktionskochfeld
DE102007006280A1 (de) * 2007-01-31 2008-08-07 E.G.O. Elektro-Gerätebau GmbH Verfahren zum Aufbau eines Induktionskochfeldes und Induktionskochfeld
US8853599B2 (en) * 2008-05-27 2014-10-07 Panasonic Corporation Induction heating cooking apparatus
WO2010106769A1 (fr) * 2009-03-19 2010-09-23 パナソニック株式会社 Cuiseur à chauffage par induction
EP2473001B1 (fr) * 2009-10-23 2019-12-04 Panasonic Corporation Dispositif de chauffage par induction
DE102009047185B4 (de) * 2009-11-26 2012-10-31 E.G.O. Elektro-Gerätebau GmbH Verfahren und Induktionsheizeinrichtung zum Ermitteln einer Temperatur eines mittels einer Induktionsheizspule erwärmten Kochgefäßbodens
DE102011083386A1 (de) * 2011-09-26 2013-03-28 E.G.O. Elektro-Gerätebau GmbH Verfahren zum Beheizen eines Kochgefäßes mittels einer Induktionsheizeinrichtung und Induktionsheizeinrichtung
DE102012210851B4 (de) * 2012-06-26 2024-07-11 BSH Hausgeräte GmbH Induktionskochgerät mit IR-Sensor
ES2537830B1 (es) * 2013-09-30 2016-04-12 Manin Company Construcciones En Acero Inoxidable, S.L.U. Sistema de cocción
EP3177108B1 (fr) * 2015-12-02 2020-04-01 Electrolux Appliances Aktiebolag Table de cuisson a induction
US11665790B2 (en) * 2016-12-22 2023-05-30 Whirlpool Corporation Induction burner element having a plurality of single piece frames
KR102052704B1 (ko) * 2017-06-26 2019-12-05 엘지전자 주식회사 유도 가열 장치
WO2021104849A1 (fr) * 2019-11-27 2021-06-03 BSH Hausgeräte GmbH Système d'appareil électroménager

Family Cites Families (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE216830C (fr) *
DE1801404B2 (de) * 1968-10-05 1972-02-10 Hartmann & Braun Ag, 6000 Frankfurt Schaltungsanordnung zur kontaktlosen steuerung der leistung von wechselspannungsverbrauchern
US3569656A (en) * 1969-07-24 1971-03-09 Bowmar Tic Inc Automatic cooking cycle control system for microwave ovens
US4151387A (en) * 1971-04-06 1979-04-24 Environment/One Corporation Metal base cookware induction heating apparatus having improved power control circuit for insuring safe operation
US3719789A (en) * 1971-12-29 1973-03-06 Gen Electric Induction cooking appliance including temperature sensing of inductively heated cooking vessel by"modulated"light
US3886342A (en) * 1973-04-26 1975-05-27 Environment One Corp Induction cooking unit having all pan safe operation, wide range power control and low start-up and shut-down transients
US3921092A (en) * 1974-05-22 1975-11-18 Applied Materials Inc Resonant load power supply with phase locked loop
US3925633A (en) * 1974-09-06 1975-12-09 Donald F Partridge Circuit for controlling power flow from a high frequency energy source to a plurality of high frequency loads
JPS5193450A (fr) * 1975-02-14 1976-08-16
JPS51103333A (fr) * 1975-03-07 1976-09-11 Matsushita Electric Ind Co Ltd
JPS5820226B2 (ja) * 1976-01-14 1983-04-22 松下電器産業株式会社 静止電力変換装置
FR2357141A1 (fr) * 1976-07-02 1978-01-27 Electricite De France Dispositif de chauffage par induction
US4112287A (en) * 1976-11-04 1978-09-05 White-Westinghouse Corporation Central oscillator for induction range using triac burner controls
GB1529114A (en) * 1977-03-31 1978-10-18 Diamond Controls Ltd H Power supply circuits
US4191875A (en) * 1977-11-10 1980-03-04 Cunningham Ronald J Fan speed control used in induction cooking apparatus
JPS592802B2 (ja) * 1978-09-25 1984-01-20 シャープ株式会社 加熱調理器
DE2843092A1 (de) * 1978-09-29 1980-04-10 Siemens Ag Schaltungsanordnung nach dem prinzip der schwingungspaket-steuerung oder -regelung
US4438311A (en) * 1979-07-05 1984-03-20 Sanyo Electric Co., Ltd. Induction heating cooking apparatus
US4352000A (en) * 1979-08-10 1982-09-28 Sanyo Electric Co., Ltd. Induction heating cooking apparatus
US4426564A (en) * 1979-12-26 1984-01-17 General Electric Company Parallel resonant induction cooking surface unit
SU1001511A1 (ru) * 1981-10-05 1983-02-28 Предприятие П/Я Р-6930 Методическа индукционна нагревательна установка
US4507531A (en) * 1981-10-30 1985-03-26 Raytheon Company Regulated microwave oven and method, using uniformly spaced, integral cycle control
JPS5878386A (ja) * 1981-11-04 1983-05-11 松下電器産業株式会社 誘導加熱用インバ−タ装置
GB2108786B (en) * 1981-11-05 1985-12-11 Sanyo Electric Co Induction heating apparatus
SU1094162A2 (ru) * 1983-02-25 1984-05-23 Предприятие П/Я А-1067 Устройство дл регулировани мощности индукционной плиты
DD216830A1 (de) * 1983-07-11 1984-12-19 Stoeckel Hans J Schaltungsanordnung zur leistungssteuerung von wechsel- und drehstromverbrauchern
JPS635196Y2 (fr) * 1984-11-27 1988-02-12
US4885447A (en) * 1985-01-23 1989-12-05 Balay, S.A. System for the induction heating of the electric plates of a cooker
US4686340A (en) * 1985-04-17 1987-08-11 Sanyo Electric Co., Ltd. Induction heating apparatus with unsuitable load detecting circuit
DE3712242A1 (de) * 1987-04-10 1988-10-27 Thomson Brandt Gmbh Schaltung zur stromversorgung einer induktiven kochstelle
US5134265A (en) * 1990-02-16 1992-07-28 Metcal, Inc. Rapid heating, uniform, highly efficient griddle
KR920007540B1 (ko) * 1990-07-31 1992-09-05 주식회사 금성사 전자 조리 장치에서의 서어지 발생 방지 회로

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012102575B4 (de) 2012-03-26 2024-04-18 Hupfer Metallwerke Gmbh & Co. Kg Verfahren und Induktionsgerätemodul zum Erwärmen von Lebensmitteln

Also Published As

Publication number Publication date
DE59303529D1 (de) 1996-10-02
ES2091505T3 (es) 1996-11-01
US5488214A (en) 1996-01-30
EP0561206A2 (fr) 1993-09-22
DE4208252A1 (de) 1993-09-16
EP0561206A3 (en) 1993-10-13

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