COOKING APPLIANCE

Abstract

A cooking appliance device includes a control and/or regulating unit provided to repetitively control a first induction target with a first heating current frequency in a periodic continuous heating operating state, which is allocated an operating period, to supply the first induction target with energy, and to operate the first induction target in a switched-on interval of the operating period with a heating power. The control and/or regulating unit is provided to select in the continuous heating operating state a sum of all switched-on intervals of the operating period as a multiple of a reciprocal value of the first heating current frequency.

Claims

1-12. (canceled)

13. A cooking appliance device, comprising a control and/or regulating unit provided to repetitively control a first induction target with a first heating current frequency in a periodic continuous heating operating state, which is allocated an operating period, to supply the first induction target with energy, and to operate the first induction target in a switched-on interval of the operating period with a heating power, wherein the control and/or regulating unit is provided to select in the continuous heating operating state a sum of all switched-on intervals of the operating period as a multiple of a reciprocal value of the first heating current frequency.

14. The cooking appliance device of claim 13, constructed in the form of an induction hob device.

15. The cooking appliance device of claim 13, wherein the sum of all switched-on intervals of the operating period corresponds to maximum half of a period duration of an alternating voltage supply.

16. The cooking appliance device of claim 13, wherein the operating period corresponds to maximum half of a period duration of an alternating voltage supply.

17. The cooking appliance device of claim 13, wherein the operating period corresponds to an integer factor of half of a period duration of an alternating voltage supply.

18. The cooking appliance device of claim 13, wherein the control and/or regulating unit is provided to operate the first induction target in the continuous heating operating state in at least one further switched-on interval of the operating period with a heating power.

19. The cooking appliance device of claim 13, wherein the control and/or regulating unit is provided to continuously operate in the continuous heating operating state a second induction target during the operating period.

20. The cooking appliance device of claim 13, further comprising an inverter operably connected to the first induction target, said control and/or regulating unit operating the inverter in the continuous heating operating state.

21. The cooking appliance device of claim 13, wherein the control and/or regulating unit is provided to measure in the continuous heating operating state the heating power of the first induction target at least twice within half of a period duration of an alternating voltage supply.

22. The cooking appliance device of claim 13, wherein the control and/or regulating unit is provided to repetitively control in the continuous heating operating state a second induction target with a second heating current frequency, to supply the second induction target with energy, and to operate the second induction target in a second switched-on interval of the operating period with a heating power, wherein the second heating current frequency either essentially equals the first heating current frequency or differs from the first heating current frequency by at least 16 kHz, said control and/or regulating unit being provided to select in the continuous heating operating state a sum of all second switched-on intervals of the operating period as a multiple of a reciprocal value of the second heating current frequency.

23. The cooking appliance device of claim 13, wherein the control and/or regulating unit is provided to divide in the continuous heating operating state the switched-on interval of the first induction target in the operating period into at least two switched-on part intervals that are separated by at least one switched-off interval in which the first induction target is operated with a power deficit with respect to a desired heating power.

24. A cooking appliance, comprising a cooking appliance device, said cooking appliance device comprising a control and/or regulating unit provided to repetitively control an induction target with a heating current frequency in a periodic continuous heating operating state, which is allocated an operating period, to supply the induction target with energy, and to operate the induction target in a switched-on interval of the operating period with a heating power, wherein the control and/or regulating unit is provided to select in the continuous heating operating state a sum of all switched-on intervals of the operating period as a multiple of a reciprocal value of the heating current frequency.

25. The cooking appliance of claim 24, constructed in the form of a hob.

26. A method for operating a cooking appliance device, in particular an induction hob device, said method comprising: repetitively controlling in a periodic continuous heating operating state, which is allocated at least one operating period, a first induction target with a first heating current frequency; supplying the first induction target with energy; operating the first induction target with a heating power in a switched-on interval of the operating period; and selecting in the continuous heating operating state a sum of all switched-on intervals of the operating period as a multiple of a reciprocal value of the first heating current frequency.

27. The method of claim 26, further comprising operating the first induction target in the continuous heating operating state in a further switched-on interval of the operating period with a heating power.

28. The method of claim 26, further comprising continuously operating in the continuous heating operating state a second induction target during the operating period.

29. The method of claim 26, further comprising operating an inverter for the first induction target in the continuous heating operating state.

30. The method of claim 26, further comprising measuring in the continuous heating operating state the heating power of the first induction target at least twice within half of a period duration of an alternating voltage supply.

31. The method of claim 26, further comprising: repetitively controlling in the continuous heating operating state a second induction target with a second heating current frequency which either essentially equals the first heating current frequency or differs from the first heating current frequency by at least 16 kHz; supply the second induction target with energy; operating the second induction target in a second switched-on interval of the operating period with a heating power; and selecting in the continuous heating operating state a sum of all second switched-on intervals of the operating period as a multiple of a reciprocal value of the second heating current frequency.

32. The method of claim 26, further comprising dividing in the continuous heating operating state the switched-on interval of the first induction target in the operating period into at least two switched-on part intervals that are separated by at least one switched-off interval in which the first induction target is operated with a power deficit with respect to a desired heating power.

Description

[0043] In the drawings:

[0044] FIG. 1 shows a hob having a cooking appliance device and in an exemplary manner items of cookware that are placed thereon,

[0045] FIG. 2 shows the cooking appliance device having four induction targets that are defined by a control and/or regulating unit,

[0046] FIG. 3 shows a schematic illustration of a control for one of the induction targets,

[0047] FIG. 4 shows a schematic illustration of a control for three of the induction targets,

[0048] FIG. 5 shows a schematic illustration of a further control for three of the induction targets and

[0049] FIG. 6 shows a schematic illustration of a method for operating the cooking appliance device.

[0050] In the figures, in part only one instance of the objects that are provided multiple times is provided with a reference character.

[0051] FIG. 1 illustrates a cooking appliance 20 that is embodied as a hob 12, in particular as an induction hob, and three items of cookware 14, 14′, 14″ that are placed on said induction hob.

[0052] The cooking appliance 20 has a resting plate 16. The resting plate 16 is provided for the placement of items of cookware 14, 14′, 14″. The resting plate 16 is embodied as a hob plate. In the illustrated exemplary embodiment, the cooking appliance 20 has four classic cooking zones 18. It is however alternatively also feasible that the cooking appliance 20 is embodied as a matrix hob. In each case an item of cookware 14, 14′, 14″ is arranged on three of the four cooking zones 18.

[0053] The cooking appliance 20 has a cooking appliance device 10 that is embodied as an induction hob device.

[0054] The cooking appliance device 10 has a plurality of inductors 22, 22′, 22″, 22′″. FIG. 2 illustrates in an exemplary manner a cooking appliance device 10 having in each case one inductor 22, 22′, 22″, 22′″ per cooking zone 18 or item of cookware 14, 14′, 14″, 14′. An inductor 22, 22′, 22″, 22′″ is allocated precisely to one cooking zone 18. It is conceivable that in the case of a matrix hob, the inductors 22, 22′, 22″, 22′″ are arranged in the manner of a matrix below the resting plate 16 in order to embody a uniform cooking zone 18. It is likewise conceivable that in the case of a matrix hob, multiple inductors 22, 22′, 22″, 22′ are arranged in individual regions of the resting plate 16 in order to embody various cooking zones such as for example rapid cooking zones, wherein it is furthermore possible by virtue of the matrix hob to utilize the full surface of the resting plate 16 for cooking. In the current example, the cooking appliance device 10 has four inductors 22, 22′, 22″, 22′.

[0055] The inductors 22, 22′, 22″, 22′″ are arranged in the installed state below the resting plate 16, in particular within the cooking appliance device 10. The inductors 22, 22′, 22″, 22′ are in each case in particular provided so as in a periodic continuous heating operating state 50 to heat, in particular in an inductive manner, an item of cookware 14, 14′, 14″, 14′″ that is arranged on the resting plate 16 and is placed over the inductors 22, 22′, 22″, 22′″.

[0056] The cooking appliance device 10 has a control panel 24 for inputting and/or selecting operating parameters by an operator. For example, an operating parameter can be embodied as a desired heating power 30, 30′, 30″ and/or a cooking duration, wherein the operating parameter can be set in particular as a discrete and/or abstract value for example in quantized intervals or from a pool of an essentially continuous value range. The control panel 24 is embodied as a display 28, in particular a touchscreen display. The control panel 24 is provided so as to output the at least one operating parameter to the operator.

[0057] The cooking appliance device 10 has a control and/or regulating unit 26. The control and/or regulating unit 26 is in particular provided so as to implement programs, actions and/or algorithms and/or so as to change settings of the cooking appliance device 10 in dependence upon the operating parameters that are input by an operator, such as the desired heating power 30, 30′, 30″ or a cooking duration.

[0058] Based on the item of cookware 14, 14′, 14″, 14′″ that is placed on the resting plate 16, the control and/or regulating unit 26 defines in this case for example multiple induction targets 32, 32′, 32″, 32″″. In FIG. 1, two induction targets 32, 32′ are defined by the control and/or regulating unit 26 based on the items of cookware 14, 14′ that are placed on the resting plate 16 and the inductors 22, 22′ that are arranged below the resting plate 16. In FIG. 2, four induction targets 32, 32′, 32″, 32′″ are defined by the control and/or regulating unit 26. One induction target 32, 32′, 32″, 32′″ has precisely one inductor 22, 22′, 22″, 22′″. One induction target 32, 32′, 32″, 32′″ has at least one item of cookware 14, 14′, 14″, 14′″. The control and/or regulating unit 26 can define a plurality of induction targets 32, 32′, 32″, 32′″ in particular in dependence upon the embodiment of the hob 12 and the items of cookware 14, 14′, 14″, 14′″ that are located on said hob.

[0059] The control and/or regulating unit 26 heats an item of cookware 14, 14′, 14″, 14′″ by applying a heating current frequency 36 to the respective inductor 22, 22′, 22″, 22′″. An output power 34 that is achieved in particular for a moment of one of each induction target 32, 32′, 32″, 32′″ is largely dependent upon the heating current frequency 36 that is applied at the induction target 32, 32′, 32″, 32′″. In a ZVS mode, the output heating power 34 of an induction target 32, 32′, 32″, 32′″ increases with decreasing heating current frequency 36. In a ZCS mode, the output heating power 34 of an induction target 32, 32′, 32″, 32′″ decreases with decreasing heating current frequency 36. The control and/or regulating unit 26 operates the cooking appliance device 10 in an exemplary manner in the ZVS mode.

[0060] In the continuous heating operating state 50, an energy source supplies the induction targets 32, 32′, 32″, 32′″ with electrical energy. The energy source is an electrical current phase of a current supply network. The cooking appliance device 10 comprises at least one inverter unit 38 for providing at least one heating current frequency 36 for the respective induction target 32, 32′, 32″, 32′″ (cf. FIG. 2).

[0061] FIG. 2 illustrates the cooking appliance device 10 with four of the induction targets 32, 32′, 32″, 32′″ that are defined by the control and/or regulating unit 26 of the cooking appliance device 10. The cooking appliance device 10 has four resonant inverter units 38. The inverter units 38 provide the heating current frequency 36 for the induction targets 32, 32′, 32″, 32′″. The inverter units 38 supply the induction targets 32, 32′, 32″, 32′″ with electrical energy independent of one another. Each inverter unit 38 is in each case allocated to one of the induction targets 32, 32′, 32″, 32′″. Each inverter unit 38 comprises an inverter 64 in FIG. 2 in an exemplary manner.

[0062] The control and/or regulating unit 26 is provided so as in the periodic continuous heating operating state 50, which is allocated an operating period 42, to repetitively control and supply energy to the at least one induction target 32, 32′, in particular from the energy source. The control and/or regulating unit 26 is provided in the continuous heating operating state 50 so as to periodically control and supply energy to the induction targets 32, 32′. The control and/or regulating unit 26 is in particular provided so as to operate the induction target 32, 32′, 32″, 32′″ in a switched-on interval 40 of the operating period 42 with a heating power, in particular a desired heating power 30, 30′, 30″ or an excess power with respect to the desired heating power 30, 30′, 30″. The control and/or regulating unit 26 in the continuous heating operating state 50 repetitively cycles through the operating period 42 for at least one induction target 32, 32′, 32″, 32′″ in particular in the absence of an amended desired heating power 30, 30′, 30″ that is set by an operator.

[0063] The cooking appliance device 10 has one electromechanical switch element 60 per induction target 32, 32′, 32″, 32′″. The switch element 60 is embodied as a relay 62. The induction targets 32, 32′, 32″, 32′″ can be connected by the relay 62 to the electrical energy supply. The cooking appliance device 10 has in each case one resonance capacitor unit 44 per induction target 32, 32′, 32″, 32′″. Each induction target 32, 32′, 32″, 32′ can be controlled individually at a respective heating current frequency 36.

[0064] FIG. 3 illustrates a ZVS mode control of the control and/or regulating unit 26 for the case that an operator has input a desired heating power 30, 30′, 30″ for a single induction target 32, 32′, 32″, 32′″. In the case of the control of an individual induction target 32, 32′, 32″, 32′″, the control and/or regulating unit 26 in the continuous heating operating state 50 determines the target frequency for the induction target 32, 32′, 32″, 32′″, in particular from the desired heating power 30, 30′, 30″ that is set by the operator. In the case of the control of an individual induction target 32, 32′, 32″, 32′″, in the continuous heating operating state 50 the control and/or regulating unit 26 matches the target frequency with a maximum possible frequency, in particular a maximum frequency, of the at least one induction target 32, 32′, 32″, 32′″. FIGS. 3a and 3b in each case illustrate a diagram that illustrates the temporal curve of the heating power of an induction target 32, 32′, 32″, 32′ over an operating period 42 of different continuous heating operating states 50. The time in seconds is plotted on the abscissa 70 and the power in watts is plotted on the ordinate 72 (cf. FIGS. 3a and 3b). The time in seconds is plotted on the abscissa 70 in the FIGS. 3a and 3b. The power in watts is plotted on the ordinate 72 in the FIGS. 3a and 3b.

[0065] FIG. 3a illustrates the case that the maximum frequency is higher than the determined target frequency for the induction target 32, 32′, 32″, 32′. If the maximum frequency is higher than the determined target frequency, the control and/or regulating unit 26 in the continuous heating operating state 50 selects the switched-on interval 40 as identical to the operating period 42 in order to provide the desired heating power 30, 30′, 30″ that is set in each operating period 42. If the maximum frequency is higher than the determined target frequency, the control and/or regulating unit 26 in the continuous heating operating state 50 selects the switched-on interval 40 as a multiple of the reciprocal value of the heating current frequency 36 that is applied, in particular of the target frequency of the induction target 32, 32′, 32″, 32′ that is controlled.

[0066] FIG. 3b illustrates the case that the maximum frequency is lower than the determined target frequency for the induction target 32, 32′, 32″, 32′″. If the maximum frequency is lower than the determined target frequency, the control and/or regulating unit 26 in the continuous heating operating state 50 operates the induction target 32, 32′, 32″, 32′″ in the switched-on interval 40, t.sub.on of an operating period 42 at the maximum frequency of said induction target. If the maximum frequency is lower than the determined target frequency, the control and/or regulating unit 26 in the continuous heating operating state 50 operates the induction target 32, 32′, 32″, 32′″ without a frequency in a switched-off interval 46, t.sub.off, in particular of the same operating period 42, in order to achieve the desired heating power 30, 30′, 30″ in the middle during the operating period 42. If the maximum frequency is lower than the determined target frequency, the control and/or regulating unit 26 in the continuous heating operating state 50 selects the switched-on interval 40 as a multiple of the reciprocal value of the heating current frequency 36, in particular of the maximum frequency of the induction target 32, 32′, 32″, 32′″ that is controlled. FIG. 3b illustrates that the selected switched-off interval 46 and the selected switched-on interval 40 have the same duration, in particular half of the duration of the operating period 42. Depending upon the form of the maximum frequency of an induction target 32, 32′, 32″, 32′″ and the desired heating power 30, 30′, 30″ that is set and also the selected duration of the operating period 42, the control and/or regulating unit 26 varies the duration of the switched-on and switched-off intervals 40, 46 with respect to one another, in particular in order to achieve the requested desired heating power 30, 30′, 30″ during each operating period of the continuous heating operating state 50.

[0067] FIGS. 3a and 3b illustrate that the control and/or regulating unit 26 in the continuous heating operating state 50 selects the operating period 42 precisely as half of a period duration of an alternating voltage supply 48, T.sub.HNETZ. In both, in particular in the cases illustrated by the FIGS. 3a and 3b, the sum of all the switched-on intervals 40 corresponds to maximum half of the period duration of the alternating voltage supply 48, T.sub.HNETZ, in particular mains alternating voltage. In both, in particular in the cases that are illustrated in the FIGS. 3a and 3b, the operating period 42 corresponds to maximum half of the period duration of the alternating voltage supply 48, T.sub.HNETZ, in particular mains alternating voltage. It is conceivable in both cases that the operating period 42 corresponds to an integer factor of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ. In both cases, the control and/or regulating unit 26 selects each switched-on interval 40 in each operating period 42 of the continuous heating operating state 50 as a multiple of the reciprocal value of the heating current 36 that is applied at the respective induction target 32, 32′, 32″, 32′″, in particular a multiple of 10 μs to 50 μs. In both cases, the control and/or regulating unit 26 selects each time interval, in particular switched-on interval 40, 40′ and/or switched-off interval 46 in each operating period 42 as a multiple of the reciprocal value of the heating current frequency 36 that is applied, in particular a multiple of 10 μs to 50 μs. A conformity to flicker standards is checked after each half of the period duration of the alternating voltage supply 48, T.sub.HNETZ. A flicker is permitted in a controlled manner by the control and/or regulating unit 26 by the formation of the operating period 42 as an integer factor of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ. It is possible to avoid a maximum power requirement of over 4.25 kW, preferably of over 3.7 kW, over a time limit of one of the halves of the period duration of the alternating voltage supply 48, T.sub.HNETZ by the formation of the operating period 42 as an integer factor of the half of the period duration of the alternating voltage supply 48.

[0068] FIG. 4 illustrates a ZVS mode control for induction targets 32, 32′, 32″, 32′″ by the control and/or regulating unit 26 for the case that an operator has input a desired heating power 30, 30′, 30″ for three induction targets 32, 32′, 32″. The time in milliseconds is plotted on the abscissa 74 in the FIGS. 4a to 4d. The voltage in volts is plotted on the ordinate 76 in FIG. 4a. The current strength in amps is plotted on the ordinate 78 in the FIGS. 4b to 4d.

[0069] FIG. 4a illustrates the rectified temporal curve of the alternating voltage supply. The time in milliseconds is plotted on the abscissa 74 and the voltage in volts is plotted on the ordinate 76. The FIGS. 4b to 4c illustrate the temporal curve of the prevailing current at the inductors of the respective controlled induction targets 32, 32′, 32″. The time in milliseconds is plotted on the abscissa 74 and the current strength in amps is plotted on the ordinate 78.

[0070] The FIGS. 4 a to 4d illustrate the case that the control and/or regulating unit 26 in the continuous heating operating state 50 operates three of the induction targets 32, 32′, 32″, 32′″ while avoiding intermodulation interfering signals. The control and/or regulating unit 26 is in particular provided so as in the continuous heating operating state 50 to measure a heating power, in particular output heating power 34, of the induction target 32, 32′, 32″ at least twice within the half of the period duration of the alternating voltage supply 48. The control and/or regulating unit 26 is in particular provided so as in the continuous heating operating state 50 to repetitively control at least one second induction target 32′ with a second heating current frequency 36′ and so as to supply said second induction target with energy. The control and/or regulating unit 26 is in particular provided so as in the continuous heating operating state 50 to operate the first induction target 32 in the switched-on interval 40, t.sub.on1 of the operating period 42 with a heating power, in particular the desired heating power 30, P.sub.SOLL. The control and/or regulating unit 26 is in particular provided so as in the continuous heating operating state 50 to operate the second and third induction target 32′, 32″ in at least one second, in particular one third, switched-on interval 66, tong, t.sub.on2, t.sub.on3 of the operating period 42 with a heating power, in particular an excess power with respect to the desired heating power 30′, 30″, P.sub.SOLL. The second heating current frequency 36′ matches either essentially the heating current frequency 36 or differs from the heating current frequency 36 by at least 16 kHz, in particular by at least 20 kHz. In the illustrated example, the control and/or regulating unit 26 operates all three induction targets 32, 32′, 32″ with the same heating current frequency 36 of 55 kHz. The control and/or regulating unit 26 is in particular provided so as in the continuous heating operating state 50 to select a sum of all the second switched-on intervals 66 of the operating period 42 as a multiple of a reciprocal value of the second heating current frequency 36′.

[0071] In order to avoid intermodulation interfering signals, the control and/or regulating unit 26 determines the target frequencies for each induction target 32, 32′, 32″ that is to be controlled.

[0072] The first induction target 32 has for example a target frequency of 55 kHz. The target frequencies of the second and third induction target 32′, 32″ differ by less than 16 kHz, in particular less than 20 kHz, from the target frequency of the first induction target 32.

[0073] The control and/or regulating unit 26 in the continuous heating operating state 50 operates the three induction targets 32, 32′, 32″, whose target frequencies differ from one another by less than 16 kHz, in particular less than 20 kHz, with the same heating current frequency 36, wherein the heating current frequency 36 corresponds in particular to the lowest target frequency of all the, in particular three, induction targets 32, 32′, 32″ that are controlled together. The control and/or regulating unit 26 controls all the induction targets 32, 32′, 32″ with the same heating current frequency 36, in this example 55 kHz, in particular in order to avoid intermodulation interfering signals.

[0074] The control and/or regulating unit 26 in the continuous heating operating state 50 operates the three induction targets 32, 32′, 32″ periodically in each case over an entire cooking duration. The cooking duration is divided into operating periods 42. In the continuous heating operating state 50, the control and/or regulating unit 26 sets output powers of the three induction targets 32, 32′, 32″ over the respective heating current frequency 36. The operating period 42 has three switched-on intervals 40, t.sub.on1, t.sub.on2, t.sub.on3 (cf. FIGS. 4b, 4c, 4d).

[0075] The control and/or regulating unit 26 in the continuous heating operating state 50 operates the first induction target 32 in all the switched-on intervals 40, t.sub.on1, t.sub.on2, t.sub.on3 of the operating period 42 with the desired heating power 30, P.sub.SOLL of the first induction target 32 (cf. FIG. 4b), in particular above the target frequency of for example 55 kHz.

[0076] The control and/or regulating unit 26 in the continuous heating operating state 50 operates the second induction target 32′ in a first time interval t.sub.off1, in particular the switched-off interval 46, of the operating period 42 with a power deficit, in particular with a zero heating power (cf. FIG. 4c). The control and/or regulating unit 26 operates the second induction target 32′ in a second time interval t.sub.on2 of the operating period 42 with an excess power with respect to the desired heating power 30′, P.sub.SOLL of the second induction target 32′. The control and/or regulating unit 26 operates the second induction target 32′ in a third time interval t.sub.on3, in particular the switched-off interval 46, of the operating period 42 with a power deficit, in particular a zero heating power, with respect to the desired heating power 30′ P.sub.SOLL of the second induction target 32′. The control and/or regulating unit 26 operates the second induction target 32′ in precisely one time interval t.sub.on with an excess power with respect to the desired heating power 30′, P.sub.SOLL that is in particular requested by the operator. The control and/or regulating unit 26 operates the second induction target 32′ in two time intervals t.sub.off1, t.sub.off2 with a zero heating power, in other words without an applied heating current frequency 36 that is different from 0, in particular with a zero heating power.

[0077] The control and/or regulating unit 26 in the continuous heating operating state 50 operates the third induction target 32″ in a first time interval t.sub.off3, in particular the switched-off interval 46, of the operating period 42 with a power deficit, in particular with a zero heating power, in other words operated without a heating current frequency 36 that is different from 0 (cf. FIG. 4d). The control and/or regulating unit 26 operates the third induction target 32″ in a second time interval t.sub.on3 of the operating period 42 with an excess power with respect to the desired heating power 30″, P.sub.SOLL of the second induction target 32″, in particular at the determined target frequency of the first induction target 32. The control and/or regulating unit 26 operates the third induction target 32′ in a third time interval t.sub.off4 of the operating period 42 with a power deficit, in particular a zero heating power, with respect to the desired heating power 30″, P.sub.SOLL of the third induction target 32″. The control and/or regulating unit 26 operates the third induction target 32″ in precisely one time interval t.sub.on3 with an excess power with respect to the desired heating power 30″, P.sub.SOLL that is in particular requested by the operator. The control and/or regulating unit 26 operates the second induction target 32′ in two time intervals t.sub.off3, t.sub.off4 with a zero heating power, in other words without an applied heating current frequency 36 that is different from 0, in particular with a zero heating power.

[0078] The control of the three induction targets 32, 32′, 32″ provides the desired heating power 30, 30′, 30″ at each induction target 32, 32′, 32″ for each induction target 32, 32′, 32″ averaged over the operating period 42. The operating period 42 corresponds to maximum half of the period duration of an alternating voltage supply 48, T.sub.HNETZ, in particular mains alternating voltage. The operating period 42 is identical in this example to half of the period duration of the alternating voltage supply 48, T.sub.HNETZ. Half of the period duration of the alternating voltage supply 48, T.sub.HNETZ is illustrated in an exemplary manner in FIG. 4a. The control and/or regulating unit 26 is in particular provided so as in the continuous heating operating state 50 to select a sum of all the switched-on intervals 40 of the operating period 42, in particular for the three induction targets 32, 32′, 32″ as a multiple of a reciprocal value of the heating current frequency 36, in particular that is respectively applied and in this example identical for all the induction targets.

[0079] The sum of all the switched-on intervals 40, in particular of a single induction target 32, 32′, 32″, of the operating period 42 corresponds to maximum half of a period duration of an alternating voltage supply 48, T.sub.HNETZ, in particular to mains alternating voltage.

[0080] It is conceivable that the operating period 42 corresponds to an integer factor of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ.

[0081] It is also conceivable that each induction target 32, 32′, 32″, 32′″ is to be and/or must be controlled in the continuous heating operating state 50 with another heating current frequency 36. In particular in that case, the control and/or regulating unit 26 is provided so as in the continuous heating operating state 50 to operate at least one inverter 64 per induction target 32, 32′, 32″, 32′″.

[0082] A flicker is checked by the control and/or regulating unit 26 by the formation of the operating period 42 as an integer factor of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ and by the formation of switched-off intervals 46 at the beginning and end of each operating period 42. In particular, a flicker is checked by the control and/or regulating unit 26 because the same power level is achieved at each beginning and end of an operating period 42, in particular summed over all the induction targets. It is possible by the formation of the operating period 42 as an integer factor of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ to avoid a maximum power requirement of above 4.25 kW, in particular of above 3.7 kW, at the start and/or end of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ.

[0083] FIG. 5 illustrates the case that the control and/or regulating unit 26 in the continuous heating operating state 50 operates three of the induction targets 32, 32′, 32″, 32′″ while avoiding intermodulation interfering signals. In FIGS. 5a to 5d, the time in milliseconds is plotted on the abscissa 74. In FIG. 5a, the voltage in volts is plotted on the ordinate 76. In the FIGS. 5b to 5d, the current strength in amps is plotted on the ordinate 78.

[0084] The rectified temporal curve of the alternating voltage supply is illustrated in FIG. 5a. The time in milliseconds is plotted on the abscissa 74 and the voltage in volts is plotted on the ordinate 76. The FIGS. 5b to 5c illustrate the temporal curve of the current that is applied to the inductors of the respectively controlled induction targets 32, 32′, 32″. The time in milliseconds is plotted on the abscissa 74 and the current strength in amps is plotted on the ordinate 78.

[0085] In order to avoid intermodulation interfering signals, the control and/or regulating unit 26 determines the target frequencies for each of the three induction targets 32, 32′, 32″ that are to be controlled.

[0086] The first induction target 32 for example has a target frequency of 50 kHz. The target frequency of the second induction target 32′ differs from the target frequency of the first induction target 32 by less than 16 kHz, in particular less than 20 kHz. The target frequency of the third induction target 32″ differs from the target frequency of the first induction target 32 by at least 20 kHz. The target frequency of the second induction target 32′ is lower than the target frequency of the third induction target 32″.

[0087] The control and/or regulating unit 26 in the continuous heating operating state 50 operates two of the three induction targets 32, 32′, whose target frequencies differ from one another by less than 16 kHz, in particular less than 20 kHz, with the same heating current frequency 36, wherein the heating current frequency 36 corresponds in particular to the lowest target frequency of all the, in particular of the two, induction targets 32, 32′ that are controlled together. The control and/or regulating unit 26 controls two of the three induction targets 32, 32′ with the same heating current frequency 36, in this example 50 kHz, and the third induction target 32″ with another heating current frequency 36, in this example 70 kHz, in particular in order to avoid intermodulation interfering signals.

[0088] The control and/or regulating unit 26 in the continuous heating operating state 50 operates the three induction targets 32, 32′, 32″ in each case periodically over an entire cooking duration. The cooking duration is divided into, in particular repeating, operating periods 42. In the continuous heating operating state 50, the control and/or regulating unit 26 sets output powers of the three induction targets 32, 32′, 32″ above a respective heating current frequency 36. The operating period 42 has different time intervals t.sub.on12, t.sub.on13, t.sub.on14, t.sub.on15, t.sub.on16, t.sub.off1l, t.sub.off12, t.sub.off13, t.sub.off14, t.sub.off15, t.sub.off16, in particular the switched-on intervals 40, 40′ and switched-off intervals 46 and/or switched-on part intervals 68 (cf. FIGS. 5b-d).

[0089] The control and/or regulating unit 26 in the continuous heating operating state 50 operates the first induction target 32 in the time interval t.sub.on11 of the operating period 42 with the desired heating power 30, P.sub.SOLL, in particular target frequency, of the first induction target 32 (cf. FIG. 5b).

[0090] The control and/or regulating unit 26 in the continuous heating operating state 50 operates the second induction target 32′ in a first time interval t.sub.off11, in particular switched-off interval 46, of the operating period 42 with a power deficit, in particular with a zero heating power (cf. FIG. 5c). The control and/or regulating unit 26 operates the second induction target 32′ in a second time interval t.sub.on12, of the operating period 42 with an excess power with respect to the desired heating power 30′, P.sub.SOLL of the second induction target 32′. The control and/or regulating unit 26 operates the second induction target 32′ in a third time interval t.sub.off12 of the operating period 42 with a power deficit, in particular a zero heating power, with respect to the desired heating power 30′, P.sub.SOLL of the second induction target 32′. The control and/or regulating unit 26 is in particular provided so as in the continuous heating operating state 50 to operate the induction target 32′ in at least one further switched-on interval 40′, t.sub.on13, t.sub.on14, t.sub.on15, t.sub.on16 of the operating period 42, T.sub.BP with a heating power, in particular a desired heating power 30′ or an excess power with respect to the desired heating power 30′, P.sub.SOLL. The control and/or regulating unit 26 in the continuous heating operating state 50 operates the second induction target 32′ in the switched-on interval 40, t.sub.on12, t.sub.on13, t.sub.on14, t.sub.on15, t.sub.on16 of the operating period 42, T.sub.BP with a heating power, in particular a desired heating power 30′ or an excess power with respect to a desired heating power 30′, P.sub.SOLL. The control and/or regulating unit 26 operates the second induction target 32′ in precisely five time intervals t.sub.on12, t.sub.on13, t.sub.on14, t.sub.on15, t.sub.on16 with an excess power. The control and/or regulating unit 26 operates the second induction target 32′ in six time intervals t.sub.off11, t.sub.off12, t.sub.off13, t.sub.off14, t.sub.off15, t.sub.off16 with a zero heating power, in other words without an applied heating power 36 that is different from 0, in particular with a zero heating power. Alternatively, the control and/or regulating unit 26 can operate the second induction target 32′ in a similar manner to the exemplary embodiment in accordance with FIG. 4 in only one time interval with a heating power, in particular the desired heating power 30′ or an excess power with respect to the desired heating power 30′, P.sub.SOLL. The control and/or regulating unit 26 is provided in this exemplary embodiment in particular so as in the continuous heating operating state 50 to divide the switched-on interval 40 of the second induction target 32′ into at least one of the at least one operating periods 42, in particular in at least half of the period duration of the alternating voltage supply 48, in particular mains alternating voltage, into at least two switched-on part intervals 68, 68′ that are separated by at least one switched-off interval 46 in which the corresponding induction target 32′ is operated with a power deficit with respect to a desired heating power 30′, in particular without power. The control and/or regulating unit 26 achieves an advantageous conformity to EMC standards by virtue of the distribution of the switched-on intervals 40, 40′ of the second induction target 32′ over the entire operating period 42 (cf. FIG. 5c).

[0091] The control and/or regulating unit 26 is in particular provided so as in the continuous heating operating state 50 to continuously operate at least one further induction target 32, 32′, 32″ during the operating period 42. The control and/or regulating unit 26 in the continuous heating operating state 50 continuously operates the third induction target 32″ in the switched-on interval t.sub.on11 of the operating period 42 in order to achieve the desired heating power 30″, P.sub.SOLL of the third induction target 32 (cf. FIG. 5b).

[0092] Averaged over the operating period 42, the control of the three induction targets 32, 32′, 32″ for each induction target 32, 32′, 32″ provides the requested desired heating power 30, 30′, 30″ to each induction target 32, 32′, 32″ while avoiding intermodulation interfering noise. The operating period 42 corresponds to maximum half of the period duration of the alternating voltage supply 48, T.sub.HNETZ, in particular mains alternating voltage. The operating period 42 in this example equals half of the period duration of the alternating voltage supply 48, T.sub.HNETZ. Half of the period duration of the alternating voltage supply 48, T.sub.HNETZ is illustrated in an exemplary manner in FIG. 5a. The control and/or regulating unit 26 is in particular provided so as in the continuous heating operating state 50 to select a sum of all the switched-on intervals 40, t.sub.on11, t.sub.on12, t.sub.on13, t.sub.on14, t.sub.on15, tones of the operating period 42, in particular for each of the three induction targets 32, 32′, 32″ separately as a multiple of a reciprocal value of the heating current frequency 36.

[0093] The sum of all the switched-on intervals 40, in particular of an individual induction target 32, 32′, 32″ of the operating period 42 corresponds to maximum half of the period duration of the alternating voltage supply 48, T.sub.HNETZ, in particular mains alternating voltage.

[0094] At the start and at the end of each operating period 42 an identical heating power is achieved by the control and/or regulating unit 26 in sum over all the induction targets 32, 32′, 32″ that are controlled.

[0095] It is conceivable that the operating period 42 corresponds to an integer factor of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ.

[0096] It is also conceivable that each induction target 32, 32′, 32″, 32′″ is controlled and/or must be controlled with another heating current frequency 36. In particular in that case, the control and/or regulating unit 26 is provided so as in the continuous heating operating state 50 to operate at least one inverter 64 per induction target 32, 32′, 32″, 32′″. A flicker is checked by the control and/or regulating unit 26 by the formation of the operating period 42 as an integer factor of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ. It is possible by the formation of the operating period 42 as an integer factor of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ to avoid a maximum power requirement of above 4.25 kW, preferably of above 3.7 kW, over a temporal limit of half of the period duration of the alternating voltage supply 48, T.sub.HNETZ.

[0097] In each case, each induction target 32, 32′, 32″, 32′″ has a minimum frequency with which it is possible to control said induction target. In each case, each induction target 32, 32′, 32″, 32′″ has a maximum frequency with which it is possible to control said induction target.

[0098] In each case, each induction target 32, 32′, 32″, 32′″ can be controlled in such a manner that the same power is achieved at the beginning and end of each operating period 42, in particular over all the induction targets 32, 32′, 32″, 32′″ that are operated. In particular, it is possible to switch off a modulation for each induction target 32, 32′, 32″, 32′″, in particular a control, with the heating current frequency 36 within the operating period 42, in particular within the half of the period duration of the alternating voltage supply 48.

[0099] It is conceivable that the switched-on intervals 40 are embodied as distributed over the half of the period duration of the alternating voltage supply 48 by the control and/or regulating unit 26 for at least one induction target 32, 32′, 32″, 32′″. It is conceivable that the switched-on intervals 40 are embodied as distributed over the half of the period duration of the alternating voltage supply 48 by the control and/or regulating unit 26 for at least one induction target 32, 32′, 32″, 32′″, wherein these high frequency variations do not destabilize the mains supply voltage. It is conceivable that the switched-off intervals 36 are embodied as distributed over the half of the period duration of the alternating voltage supply 48, in particular over the operating period 42, by the control and/or regulating unit 26 for at least one induction target 32, 32′, 32″, 32′″, in particular in order to meet EMC standards. It is conceivable that the switched-off intervals 36 are embodied as distributed over half of the period duration of the alternating voltage supply 48, in particular over the operating period 42, by the control and/or regulating unit 26 for at least one induction target 32, 32′, 32″, 32′″, wherein a maximum power requirement of above 4.25 kW, preferably of above 3.7 kW or equivalent 16 A.sub.rms, is avoided at the beginning or at the end of the half of the period duration of the alternating voltage supply 48.

[0100] It is conceivable that in an operating period 42 of a maximum 10 ms, a maximum 750 cycles of the heating current frequency 36 are applied to an induction target, in the case of a maximum heating current frequency 36 of 75 kHz. It is conceivable that in one operating period 42 of maximum 10 ms, minimum 300 cycles of the heating current frequency 36 are applied to an induction target, in the case of a minimum heating current frequency 36 of 30 kHz. In the prior art, in one operating period 42 of 2 s, between 200 and 240 cycles of the heating current frequency 36 are applied to an induction target.

[0101] FIG. 6 illustrates schematically a method for operating a cooking appliance device 10, in particular an induction hob device.

[0102] In at least one periodic continuous heating operating state 50, which is allocated at least one operating period 42, at least one induction target 32, 32′, 32″, 32′″ is repetitively controlled with a heating current frequency 36 and is supplied with energy.

[0103] In the at least one continuous heating operating state 50, the induction target 32, 32′, 32″, 32′″ is operated in at least one switched-on interval 40 of the operating period 42 with a heating power, in particular a desired heating power 30, 30′, 30″ or an excess power with respect to a desired heating power 30, 30′, 30″.

[0104] In the at least one continuous heating operating state 50, a sum of all the switched-on intervals 40 of the operating period 42 is selected as a multiple of a reciprocal value of the heating current frequency 36.

[0105] The at least one continuous heating operating state 50 comprises at least four part states, in particular at least one input state 52, at least one determining state 54, at least one control state 56 and at least one heating state 58. In the at least one input state 52, a desired heating power 30, 30′, 30″, P.sub.SOLL is input by an operator for at least one induction target 32, 32′, 32″, 32′″.

[0106] In the at least one input state 52, the target frequency for the induction target 32, 32′, 32″, 32′″ is calculated, in particular from a desired heating power 30, 30′, 30″, P.sub.SOLL that is set by the operator.

[0107] In the at least one determining state 54, in particular that adjoins the at least one input state 52, the target frequency of each induction target 32, 32′, 32″, 32′″ is matched with a maximum possible frequency, in particular a maximum frequency, of the at least one induction target 32, 32′, 32″, 32′″. In the at least one determining state 54, the target frequency of each induction target 32, 32′, 32″, 32′″ is matched with the target frequencies of each further induction target 32, 32′, 32″, 32′″ in order to avoid intermodulation interfering noise. In the at least one determining state 54, the heating current frequency 36 of each induction target 32, 32′, 32″, 32′″ is selected within the limits as approximate to the maximum frequency, in particular in order to avoid intermodulation interfering noise.

[0108] In the at least one control state 56, the switched-on intervals 40 and switched-off intervals 46 are selected for each induction target 32, 32′, 32″, 32′″ that is to output a desired heating power 30, 30′, 30″ in an operating period 42. In the at least one control state 56, the at least one switched-on interval 40 of each induction target 32, 32′, 32″, 32′″ are selected as a multiple of the reciprocal value of the heating current frequency 36, in particular of the maximum frequency of the induction target 32, 32′, 32″, 32′″ that is controlled. In the at least one control state 56, the sum of the switched-on interval 40 is selected for each induction target 32, 32′, 32″, 32′″ as a multiple of the reciprocal value of the heating current frequency 36, in particular the maximum frequency of the induction target 32, 32′, 32″, 32′″ that is controlled. It is conceivable that in the at least one control state 56, at least one switched-off interval 46, in particular a sum of the switched-off intervals 46, of an induction target 32, 32′, 32″, 32′″ is selected as a multiple of the reciprocal value of the heating current frequency 36, in particular the maximum frequency of the induction target 32, 32′, 32″, 32′″ that is controlled.

[0109] If a heating current frequency 36 that is selected for an induction target 32, 32′, 32″, 32′″ is lower than the target frequency that is determined for the respective induction target 32, 32′, 32″, 32′″, in the at least one control state 56, a switched-on interval 40 is selected for the respective induction target 32, 32′, 32″, 32′″ and said switched-on interval is shorter than the operating period 42.

[0110] If a heating current frequency 36 that is selected for an induction target 32, 32′, 32″, 32′″ is identical to the target frequency that is determined for the respective induction target 32, 32′, 32″, 32′″, in the at least one control state 56, the at least one switched-on interval 40 that is identical to the operating period 42 is selected for the respective induction target 32, 32′, 32″, 32′″.

[0111] In the at least one heating state 58, each induction target 32, 32′, 32″, 32′″ is operated over at least one operating period 42 with the selected switched-on and/or switched-off intervals 46 in order to provide the desired heating power 30, 30′, 30″, P.sub.SOLL that is set.

[0112] In the at least one continuous heating operating state 50, the part states are repetitively cycled through, wherein parameters that are selected/calculated and/or determined in the part states are maintained in the absence of a desired heating power 30, 30′, 30″, P.sub.SOLL that is changed by an operator for at least one induction target 32, 32′, 32″, 32′″.

LIST OF REFERENCE CHARACTERS

[0113] 10 Cooking appliance device [0114] 12 Hob [0115] 14 Item of cookware [0116] 16 Resting plate [0117] 18 Cooking zone [0118] 20 Cooking appliance [0119] 22 Inductor [0120] 24 Control panel [0121] 26 Control and/or regulating unit [0122] 28 Display [0123] 30 Desired heating power [0124] 32 Induction target [0125] 34 Output heating power [0126] 36 Heating current frequency [0127] 38 Inverter unit [0128] 40 Switched-on interval [0129] 42 Operating period [0130] 44 Resonance capacitor unit [0131] 46 Switched-off interval [0132] 48 Half of a period duration of an alternating voltage supply [0133] 50 Continuous heating operating state [0134] 52 Input state [0135] 54 Determining state [0136] 56 Control state [0137] 58 Heating state [0138] 60 Switch element [0139] 62 Relay [0140] 64 Inverter [0141] 66 Switched-on interval [0142] 68 Switched-on part interval [0143] 70 Abscissa [0144] 72 Ordinate [0145] 74 Abscissa [0146] 76 Ordinate [0147] 78 Ordinate