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EP-3481147-B1 - INDUCTION HEATING DEVICE AND METHOD FOR DETERMINING LOADED-OBJECT ON THE INDUCTION HEATING DEVICE

EP3481147B1EP 3481147 B1EP3481147 B1EP 3481147B1EP-3481147-B1

Inventors

  • YOON, Bada
  • KANG, JOHN
  • PARK, Wongyu

Dates

Publication Date
20260506
Application Date
20181022

Claims (15)

  1. An induction heating device, comprising: a working coil (210); an inverter (208) configured to apply current to the working coil (210) based on a switching operation of the inverter (208); an inverter driving unit (24) configured to apply a switching signal to the inverter (208) to enable the inverter (208) to perform the switching operation, the switching signal having a first operation frequency and a second operation frequency; a control unit (20) that is configured to generate a control signal, that is configured to apply the control signal to the inverter driving unit (24), and that is configured to cause the inverter driving unit (24) to generate the switching signal based on the control signal; and a determination unit (22) configured to determine a type of an object disposed on the induction heating device based on (i) a first resonant current value (30, 32, 34) that is measured from the working coil (210) in response to operation of the inverter (208) by the switching signal having the first operation frequency and (ii) a second resonant current value (50, 52, 54) that is measured from the working coil (210) in response to operation of the inverter (208) by the switching signal having the second operation frequency, wherein the determination unit (22) is further configured to: determine whether the object on the induction heating device has an inductive-heating property based on the first resonant current value (30, 32, 34); characterized in that in response to a determination that the object has the inductive-heating property based on the first resonant current value (30, 32, 34), determine whether the object on the induction heating device has an inductive-heating property based on a difference between the first resonant current value (30, 32, 34) and the second resonant current value (50, 52, 54).
  2. The induction heating device of claim 1, wherein the determination unit (22) is further configured to: compare the first resonant current value (30, 32, 34) to a first reference value (302); and based on a comparison result, determine presence of the object on the induction heating device or absence of the object from the induction heating device; and/or, wherein the determination unit (22) is further configured to: compare the first resonant current value (30, 32, 34) to a second reference value (304); and based on a comparison result, determine whether the object on the induction heating device has an inductive-heating property.
  3. The induction heating device of claim 2, wherein the determination unit (22) is further configured to, in response to a determination that the object has the inductive-heating property based on the first resonant current value (30, 32, 34), compare a difference between the first resonant current value (30, 32, 34) and the second resonant current value (50, 52, 54) to a third reference value; and/or, wherein the control unit (20) is further configured to, based on the determination unit (22) determining absence of the object from the induction heating device, stop supplying the control signal to the inverter driving unit (24).
  4. The induction heating device of claim 2 or 3, wherein the control unit (20) is further configured to, based on the determination unit (22) determining that the object on the induction heating device does not have the inductive-heating property, stop supplying the control signal to the inverter driving unit (24).
  5. The induction heating device of claim 3 or 4, wherein the determination unit (22) is further configured to determine that the object has the inductive-heating property based on the difference between the first resonant current value (30, 32, 34) and the second resonant current value (50, 52, 54) being less than the third reference value.
  6. The induction heating device of any one of claims 1 to 5, further comprising a sensor (D) connected to the determination unit (22) and configured to measure a resonant current from the working coil (210) based on operation of the inverter driving unit (24).
  7. A method for detecting and identifying an object disposed on an induction heating device, the method comprising: operating (602, 604) an inverter (208) of the induction heating device at a first operation frequency; measuring (606) a first resonant current value (30, 32, 34) from a working coil (210) based on operation of the inverter (208) at the first operation frequency; based on the first resonant current value (30, 32, 34), determining (608, 612) at least one of presence of the object on the induction heating device, absence of the object from the induction heating device, or a type of the object on the induction heating device; operating (614, 616) the inverter (208) of the induction heating device at a second operation frequency; measuring (618) a second resonant current value (50, 52, 54) from the working coil (210) based on operation of the inverter (208) at the second operation frequency; and determining the type of the object based on the second resonant current value (50, 52, 54), wherein determining at least one of presence of the object, absence of the object, or the type of the object comprises: determining whether the object on the induction heating device has an inductive-heating property based on the first resonant current value (30, 32, 34), characterized in that determining the type of the object based on the second resonant current value (50, 52, 54) comprises: in response to a determination that the object has the inductive-heating property based on the first resonant current value (30, 32, 34), determining whether the object on the induction heating device has an inductive-heating property based on a difference between the first resonant current value (30, 32, 34) and the second resonant current value (50, 52, 54).
  8. The method of claim 7, wherein determining at least one of presence of the object, absence of the object, or the type of the object comprises: comparing (608) the first resonant current value (30, 32, 34) to a first reference value (302); and based on a comparison result, determining presence of the object on the induction heating device or absence of the object from the induction heating device; and/or, wherein determining at least one of presence of the object, absence of the object, or the type of the object comprises: comparing (612) the first resonant current value (30, 32, 34) to a second reference value (304); and based on a comparison result, determining whether the object on the induction heating device has an inductive-heating property.
  9. The method of claim 7 or 8, wherein determining the type of the object based on the second resonant current value (50, 52, 54) comprises: based on the first resonant current value (30, 32, 34), determining that the object on the induction heating device has an inductive-heating property; and in response to a determination that the object has the inductive-heating property based on the first resonant current value (30, 32, 34), confirming whether the object has the inductive-heating property based on the difference between the first resonant current value (30, 32, 34) and the second resonant current value (50, 52, 54).
  10. The method of claim 9, wherein confirming whether the object has the inductive-heating property based on the second resonant current value (50, 52, 54) comprises (620) comparing a difference between the first resonant current value (30, 32, 34) and the second resonant current value (50, 52, 54) to a third reference value.
  11. The method of any one of claims 8 to 10, wherein determining presence or absence of the object on the induction heating device comprises: determining presence of the object based on the first resonant current value (30, 32, 34) being greater than or equal to the first reference value (302); determining (610) absence of the object based on the first resonant current value (30, 32, 34) being less than the first reference value (302); and based on the first resonant current being between the first reference value (302) and the second reference value (304), determining that the object is present on the induction heating device and that the object has the inductive-heating property, wherein the second reference value (304) is greater than the first reference value (302).
  12. The method of any one of claims 8 to 11, wherein operating the inverter (208) of the induction heating device at the second operation frequency comprises operating the inverter (208) of the induction heating device at the second operation frequency in response to a determination that the first resonant current value (30, 32, 34) being less than the second reference value (304).
  13. The method of any one of claims 9 to 12, further comprising operating the inverter (208) of the induction heating device based on a confirmation that the object has the inductive-heating property; and/or, further comprising restricting operation of the inverter (208) based on a determination that the object on the induction heating device does not have the inductive-heating property.
  14. The method of any one of claims 10 to 13, further comprising determining (620) that the object has the inductive-heating property based on the difference between the first resonant current value (30, 32, 34) and the second resonant current value (50, 52, 54) being less than the third reference value.
  15. The method of any one of claims 7 to 14, further comprising restricting operation of the inverter (208) based on a determination of absence of the object from the induction heating device.

Description

The present disclosure relates to an induction heating device and a method for detecting an object on the induction heating device. A cooking device may use various heating methods to heat food. For example, gas ranges uses gas as fuel. In some examples, a cooking device uses electricity to heat a cooking vessel such as a pot. A method for heating an object using electricity may be divided into a resistive heating type and an inductive heating type. In the electrical resistive heating method, heat is generated when current flows through a metal resistance wire or a non-metallic heating element such as silicon carbide, and transmitted to the loaded object through radiation or conduction, thereby heating the loaded object. In the inductive heating method, when a high-frequency power of a predetermined magnitude is applied to the working coil, an eddy current is generated in the loaded object made of a metal by using a magnetic field generated around the working coil so that the loaded object itself is heated. In some examples of induction heating, based on power being applied to the induction heating device, a high-frequency voltage of a predetermined magnitude is applied to the working coil. As a result, an inductive magnetic field is generated around the working coil disposed in the induction heating device. When the flux of the generated inductive magnetic field passes through a bottom of the loaded object containing the metal as loaded on the induction heating device, an eddy current is generated inside the bottom of the loaded object. When the resulting eddy current flows in the bottom of the loaded object, the loaded object itself is heated. In some cases, there is a restriction in a type of the loaded object on the induction heating device. For example, the object in which eddy current is generated when high-frequency power is supplied to the coil of the induction heating device may be used on the induction heating device. That is, loaded-objects with magnetic properties may be used on a cooker for induction heating. In some cases, it is difficult for the user to determine solely from the appearance of the loaded-object whether or not the loaded-object is a loaded-object working on the inductively-heated device. Further, the user may load an object that does not work on the induction heating device and apply power to the induction heating device, which causes unnecessary power consumption. EP 2 533 605 A2 relates to an induction heating apparatus capable of detecting a vessel and correspondingly controlling power to the induction heating coil. EP 2 645 814 A1 relates to an induction-heating cooking system which is operable to instantly determine material and standing situation of the heated-subject and capable to provide the heating coils with high-frequency current of optimal drive frequency, and a controlling process thereof. The present disclosure provides an induction heating device capable of more accurately determining a type of a loaded-object placed on the induction heating device, and a method for determining the type of the loaded-object by the induction heating device. The purposes of the present disclosure are not limited to the above-mentioned purposes. Other purposes and advantages of the present disclosure, as not mentioned above, may be understood from the following descriptions and more clearly understood from the implementations of the present disclosure. Further, it will be readily appreciated that the objects and advantages of the present disclosure may be realized by features and combinations thereof as disclosed in the claims. An induction heating device according to the invention is presented in claim 1. A method for detecting and identifying an object disposed on an induction heating device according to the invention is presented in claim 7. Embodiments of the invention are presented in the dependent claims. According to one aspect of the subject matter described in this application, an induction heating device includes a working coil, an inverter configured to apply current to the working coil based on a switching operation of the inverter, an inverter driving unit configured to apply a switching signal to the inverter to enable the inverter to perform the switching operation, the switching signal having a first operation frequency and a second operation frequency, a control unit that is configured to generate a control signal, that is configured to apply the control signal to the inverter driving unit, and that is configured to cause the inverter driving unit to generate the switching signal based on the control signal, and a determination unit configured to determine a type of an object disposed on the induction heating device based on (i) a first resonant current value that is measured from the working coil in response to operation of the inverter by the switching signal having the first operation frequency and (ii) a second resonant current value that is measured from the w