INDUCTION HOB

Abstract

The invention relates to an induction-based cooking appliance comprising multiple heating power transferring elements (3a, 3b) and multiple heating power energy units (5a, 5b) for powering said heating power transferring elements (3a, 3b), each heating power energy unit (5a, 5b) comprising one or more power switching devices, in particular power transistors, for providing electrical power to the heating power transferring elements (3a, 3b), wherein: —said power switching devices, in particular power transistors, included in said multiple heating power energy units (5a, 5b) are wide bandgap power switching devices, in particular wide bandgap transistors, comprising more in particular semiconductor materials with a bandgap greater than 2 eV, and/or are configured to be operated in a first frequency range (FR1) and in a second frequency range (FR2) different or at least essentially identical, in particular identical, to the first frequency range (FR1); or—a first heating power transferring element (3a) is powered by a heating power energy unit (5a) comprising a first type (T1) of power switching device, in particular power transistor, adapted to be operated in a first frequency range (FR1) and a second heating power transferring element (3b) is powered by a heating power energy unit (5b) comprising a second type (T2) of power switching device, in particular power transistor, adapted to be operated in a second frequency range (FR2) different or at least essentially identical, in particular identical, to the first frequency range (FR1).

Claims

1. Induction-based cooking appliance comprising multiple heating power transferring elements and multiple heating power energy units for powering said heating power transferring elements, each heating power energy unit comprising one or more power switching devices, in particular power transistors, for providing electrical power to the heating power transferring elements, wherein: said power switching devices, in particular power transistors, included in said multiple heating power energy units are wide bandgap power switching devices, in particular wide bandgap transistors, comprising more in particular semiconductor materials with a bandgap greater than 2 eV, and/or are configured to be operated in a first frequency range and/or in a second frequency range different or at least essentially identical, in particular identical, to the first frequency range; or a first heating power transferring element is powered by a heating power energy unit comprising a first type of power switching device, in particular power transistor, adapted to be operated in a first frequency range and a second heating power transferring element is powered by a heating power energy unit comprising a second type of power switching device, in particular power transistor, adapted to be operated in a second frequency range different or at least essentially identical, in particular identical, to the first frequency range.

2. Induction-based cooking appliance according to claim 1, wherein said power switching devices are insulated gate bipolar transistors, IGBTs, bipolar junction transistors, BJTs, field-effect transistors, metal-oxide-silicon transistors, metal-oxide-semiconductor field-effect transistors, MOSFETs, power diodes and/or thyristors.

3. Induction-based cooking appliance according to claim 1, wherein said wide bandgap transistors are transistors based on silicon carbide, gallium nitride or boron nitride.

4. Induction-based cooking appliance according to claim 1, wherein the first type or second type of power switching device or power transistor is a transistor having a material with a bandgap lower than 2 eV, specifically a silicon-based insulated-gate bipolar transistor.

5. Induction-based cooking appliance to claim 1, wherein the second type or first type of power switching device or power transistor is a wide bandgap transistor, specifically a transistor including silicon carbide, gallium nitride or boron nitride.

6. Induction-based cooking appliance according to claim 1, wherein the first frequency range and the second frequency range are separated from each other by a frequency gap of at least 10 kHz.

7. Induction-based cooking appliance according to claim 1, wherein the power switching device(s), in particular the first type and/or second type of power switching device or power transistor, is/are configured to be powered in a frequency range of 20 kHz to 50 kHz.

8. Induction-based cooking appliance according to claim 1, wherein the power switching device(s), in particular the second type and/or first type of power switching device or power transistor, is/are configured to be powered in a frequency range of 60 kHz to 90 kHz.

9. Induction-based cooking appliance according to claim 1, wherein the first heating power transferring element is arranged next to the second heating power transferring element, specifically directly next to the second heating power transferring element.

10. Induction-based cooking appliance according to claim 1, wherein said wide bandgap transistors are configured to be operated in a frequency range from 20 kHz to 90 kHz.

11. Method for operating an induction-based cooking appliance, the cooking appliance comprising multiple heating power transferring elements and multiple heating power energy units for powering said heating power transferring elements, wherein: said multiple heating power energy units comprise power switching devices, in particular power transistors which are wide bandgap transistors, more in particular comprising semiconductor materials with a bandgap greater than 2 eV, wherein at least one of said power switching devices, in particular power transistors is operated in a first frequency range and another one of said power switching devices, in particular power transistors, is operated in a second frequency range different or at least essentially identical, in particular identical, to the first frequency range; or a first heating power energy unit comprises a first type of power switching device, in particular power transistor, and a second heating power energy unit comprises a second type of power switching device, in particular power transistor, and the first type of power switching device, in particular power transistor, included in the first heating power energy unit is operated in a first frequency range and the second type of power switching device, in particular power transistor, included in the second heating power energy unit is operated in the second frequency range, said second frequency range in particular being a frequency range having no overlap with the first frequency range or being at least essentially identical, more in particular identical to the first frequency range.

12. Method according to claim 11, wherein said wide bandgap transistors are transistors based on silicon carbide, gallium nitride or boron nitride.

13. Method according to claim 11, wherein the first type of power transistor is a transistor having a material with a bandgap lower than 2 eV, specifically a silicon-based insulated-gate bipolar transistor.

14. Method according to claim 11, wherein the second type of power switching device, in particular power transistor, is a wide bandgap transistor, specifically a transistor including silicon carbide, gallium nitride or boron nitride.

15. Method according to claim 11, wherein the first type and/or second type of power switching device, in particular power transistor, is powered in a frequency range of 20 kHz to 50 kHz and/or the second type of power transistor is powered in a frequency range of 60 kHz to 90 kHz.

16. Method according to claim 11, wherein said power switching devices, in particular wide bandgap transistors, are configured to be operated in a frequency range from 20 kHz to 90 kHz and/or wherein said power switching devices are insulated gate bipolar transistors, IGBTs, bipolar junction transistors, BJTs, field-effect transistors, metal-oxide-silicon transistors, metal-oxide-semiconductor field-effect transistors, MOSFETs, power diodes and/or thyristors.

17. An induction-based cooking appliance comprising: a first induction coil; a second induction coil; a first wide bandgap transistor configured to operate in a first frequency range and to selectively provide electrical power to the first induction coil; and a second wide bandgap transistor configured to operate in a second frequency range and to selectively provide electrical power to the second induction coil, wherein at least the first wide bandgap transistor or the second wide bandgap transistor has a bandgap greater than 2 eV, wherein the first frequency range is 20 kHz to 50 kHz, wherein the second frequency range is 60 kHz to 90 kHz, and wherein the first induction coil is physically arranged directly next to the second induction coil within the induction-based cooking appliance.

18. The induction-based cooking appliance, wherein the first wide bandgap transistor and the second wide bandgap transistor are each selected from the group consisting of: an insulated gate bipolar transistor, a bipolar junction transistors, a field-effect transistor, a metal-oxide-silicon transistor, a metal-oxide-semiconductor field-effect transistors, a power diode, or a thyristors.

19. Induction-based cooking appliance according to claim 1, wherein the first wide bandgap transistor and the second wide bandgap transistor are based on silicon carbide, gallium nitride or boron nitride.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:

[0075] FIG. 1 shows an example top view on a cooking appliance comprising multiple heating zones; and

[0076] FIG. 2 shows a frequency diagram comprising a first and a second frequency range.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0077] The present invention will now be described more fully with reference to the accompanying drawings, in which example embodiments are shown. The embodiments in the figures may relate to preferred embodiments, while all elements and features described in connection with embodiments may be used, as far as appropriate, in combination with any other embodiment and feature as discussed herein, in particular related to any other embodiment discussed further above. However, this invention should not be construed as limited to the embodiments set forth herein. Throughout the following description similar reference numerals have been used to denote similar elements, parts, items or features, when applicable.

[0078] The features of the present invention disclosed in the specification, the claims, examples and/or the figures may both separately and in any combination thereof be material for realizing the invention in various forms thereof.

[0079] FIG. 1 illustrates a schematic diagram of an electric induction hob 1.

[0080] The induction hob 1 comprises multiple heating zones 2. Each heating zone 2 may be, for example, associated with one or more heating power transferring elements 3a, 3b, specifically, one or more induction coils. In the present embodiment, each heating zone 2 is associated with a single heating power transferring element 3a, 3b. However, according to other embodiments, a heating zone 2 may be associated with multiple heating power transferring elements.

[0081] In addition, the cooking appliance 1 comprises a user interface 4, based on which a user may control the induction hob 1. For example, based on the user interface 4, the user may control the power level of the heating zones 2.

[0082] For powering the heating power transferring elements 3a, 3b, two or more heating power energy units 5a, 5b are provided. For example, a first heating power energy unit 5a may be electrically coupled with a first heating power transferring element 3a in order to provide electrical power to said first heating power transferring element 3a. Similarly, a second heating power energy unit 5b may be electrically coupled with a second heating power transferring element 3b in order to provide electrical power to said second heating power transferring element 3b.

[0083] In order to generate a pulsed electrical signal based on which a resonant circuit, in which the respective heating power transferring elements 3a, 3b are included, is excited, the heating power energy units 5a, 5b comprise switching devices, in particular power switching devices, in particular power transistors.

[0084] In a first embodiment, the heating power energy units 5a, 5b comprise different types of switching devices, in particular power transistors. More in detail, the first heating power energy unit 5a comprises a first type T1 of switching device, in particular power transistor, whereas the second heating power energy unit 5b comprises a second type T2 of switching device, in particular power transistor.

[0085] The power transistor of first type T1 is configured to be operated in a first frequency range FR1. In contrary thereto, the power transistor of second type T2 is configured to be operated in a second frequency range FR2 which is different to the first frequency range FR1. Preferably, said first frequency range FR1 covers a frequency band which is totally different to frequency band covered by the second frequency range FR2. So, in other words, the first and second frequency ranges FR1, FR2 do not overlap, as shown in FIG. 2.

[0086] In an embodiment, a first heating power transferring element 3a is powered by a heating power energy unit 5a comprising a first type T1 of power switching device, in particular power transistor, adapted to be operated in a first frequency range FR1 and a second heating power transferring element 3b is powered by a heating power energy unit 5b comprising a second type T2 of power switching device, in particular power transistor, adapted to be operated in a second frequency range FR2 different or at least essentially identical, in particular identical, to the first frequency range FR1.

[0087] In an embodiment, the first frequency range FR1 is at least essentially identical to the second frequency range FR2.

[0088] According to an embodiment, the first type T1 of power transistor may be an insulated gate bipolar transistor (IGBT). Preferably, a silicon-based insulated gate bipolar transistor may be used. The insulated gate bipolar transistor may be, for example, configured to be operated in a first frequency range FR1 which covers the frequency band between 20 KHz and 50 KHz. Such silicon-based power transistors are preferable for cost reasons.

[0089] Furthermore, the second type T2 of power transistor may be a metal-oxide-semiconductor field-effect transistor (MOSFET). Said power transistor may comprise a wide bandgap semiconductor material, for example selected from the list of silicon carbide, gallium nitride and boron nitride. Preferably, a silicon-carbide metal-oxide-semiconductor field-effect transistor may be used. The metal-oxide-semiconductor field-effect transistor may be, for example, configured to be operated in a second frequency range FR2 which comprise higher frequencies than the first frequency range FR1. Preferably, the second frequency range FR2 covers the frequency band between 60 KHz and 90 KHz.

[0090] Said switching devices, in particular power switching devices, may be insulated gate bipolar transistors, IGBTs, bipolar junction transistors, BJTs, field-effect transistors, metal-oxide-silicon transistors, metal-oxide-semiconductor field-effect transistors, MOSFETs, power diodes and/or thyristors.

[0091] By using different types of transistors, it is possible to define separate frequency windows for adjacent heating power transferring elements 3a, 3b and thereby spread the frequencies at which the heating power transferring elements 3a, 3b are operated. Thereby, acoustic interference noise can be avoided or at least mitigated.

[0092] Within the respective frequency range FR1, FR2, the operation frequency at which the respective heating power transferring element 3a, 3b is driven, can be chosen according to the respective operation conditions.

[0093] According to another embodiment, both heating power energy units 5a, 5b arranged next to each other comprise wide bandgap power transistors. Wide bandgap power transistors are capable to be operated in a broad frequency range specifically in a range from 20 kHz to 90 kHz. Using wide bandgap power transistors in both heating power energy units 5a, 5b arranged next to each other may be disadvantageous in view of costs. However, such configuration provides a greater flexibility regarding switching frequency.

[0094] In an embodiment, said switching devices, in particular power switching devices, more in particular power transistors, included in said multiple heating power energy units 5a, 5b are wide bandgap power switching devices, in particular wide bandgap transistors, comprising more in particular semiconductor materials with a bandgap greater than 2 eV.

[0095] Said switching devices, in particular power switching devices, may be insulated gate bipolar transistors, IGBTs, bipolar junction transistors, BJTs, field-effect transistors, metal-oxide-silicon transistors, metal-oxide-semiconductor field-effect transistors, MOSFETs, power diodes and/or thyristors.

[0096] In an embodiment, said power switching devices, in particular power transistors, are configured to be operated in a first frequency range FR1 and in a second frequency range FR2 different or at least essentially identical, in particular identical, to the first frequency range FR1.

[0097] In an embodiment, the first frequency range FR1 is at least essentially identical to the second frequency range FR2.

[0098] In an embodiment, the first frequency range FR1 is identical to the second frequency range FR2.

[0099] In an embodiment, said switching devices, in particular power switching devices, in particular power transistors, are configured to be operated in a second frequency range FR2.

[0100] In an embodiment, said switching devices are wide bandgap switching devices and/or based on wide band gap material that work on high frequency range and/or provide switching operation in a broad frequency band, specifically in a frequency band of 50 kHz or higher, specifically 60 kHz, 70 kHz, 80 kHz, 90 kHz or 100 kHz.

[0101] In an embodiment, said switching devices, in particular power switching devices, in particular power transistors, are configured to be operated in a first frequency range FR1.

[0102] It should be noted that the description and drawings merely illustrate the principles of the proposed invention. Those skilled in the art will be able to implement various arrangements that, although not explicitly described or shown herein, embody the principles of the invention.

LIST OF REFERENCE NUMERALS

[0103] 1 induction hob [0104] 2 heating zone [0105] 3a, 3b heating power transferring element [0106] 4 user interface [0107] 5a, 5b heating power energy unit [0108] FR1 first frequency range [0109] FR2 second frequency range [0110] T1 first type of switching device, in particular power transistor [0111] T2 second type of switching device, in particular power transistor