INDUCTION DEVICE

Abstract

An induction device includes a plurality of induction areas which can be controlled independently from one another, and a control unit configured to control the plurality of induction areas within a control period from a first control interval and a second control interval repetitively with an alternating current frequency and to supply the plurality of induction areas with energy. The control unit operates in the first control interval at least two of the plurality of induction areas with a first phase shift to minimize interference.

Claims

1-13. (canceled)

14. An induction device, comprising: a plurality of induction areas which are controllable independently from one another; and a control unit configured to control the plurality of induction areas within a control period from a first control interval and a second control interval repetitively with an alternating current frequency and to supply the plurality of induction areas with energy, said control unit operating in the first control interval at least two of the plurality of induction areas with a first phase shift to minimize interference.

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

16. The induction device of claim 14, wherein the control unit operates in the second control interval the at least two of the plurality of induction areas with a second phase shift which differs from the first phase shift.

17. The induction device of claim 14, wherein the control unit operates in the first control interval at least a further one of the plurality of induction areas with a further first phase shift.

18. The induction device of claim 16, wherein the control unit operates in the second control interval at least a further one of the plurality of induction areas with a further second phase shift.

19. The induction device of claim 14, wherein at least one of the first and second control intervals has a duration which is shorter than half a cycle time of a mains alternating voltage.

20. The induction device of claim 14, wherein the control period has a duration which is shorter than half a cycle time of a mains alternating voltage.

21. The induction device of claim 14, wherein the control unit controls in at least one of the first and second control intervals at least one of the plurality of induction areas with the alternating current frequency and at least a further one of the plurality of induction areas with a further alternating current frequency which differs from the alternating current frequency.

22. The induction device of claim 21, wherein the further alternating current frequency is an integral multiple of the alternating current frequency.

23. The induction device of claim 14, wherein the control unit controls in at least one of the first and second control intervals at least two of the plurality of induction areas with a same alternating current frequency.

24. The induction device of claim 14, wherein the control unit controls in at least one of the first and second control intervals the at least two of the plurality of induction areas with a same alternating current frequency.

25. The induction device of claim 14, wherein the control unit controls in the first control interval at least two of the induction areas with a same alternating current frequency.

26. The induction device of claim 14, wherein the control unit controls in the first control interval the at least two of the induction areas with a same alternating current frequency.

27. The induction device of claim 14, wherein the control unit calculates a phase angle of the first phase shift from a quotient from 180° and a number of the plurality of induction areas to be operated simultaneously within the first control interval.

28. The induction device of claim 14, wherein based on a number of the plurality of induction areas to be operated simultaneously within the first control interval, the control unit selects a phase angle for the first phase shift from a catalog of phase angles.

29. An induction cooking appliance, comprising an induction device, said induction device comprising a plurality of induction areas which are controllable independently from one another, and a control unit configured to control the plurality of induction areas within a control period from a first control interval and a second control interval repetitively with an alternating current frequency and to supply the plurality of induction areas with energy, said control unit operating in the first control interval at least two of the plurality of induction areas with a first phase shift to minimize interference.

30. The induction cooking appliance of claim 27, constructed in the form of an induction hob

31. A method for operating an induction device, comprising: controlling a plurality of induction areas independently of one another within a control period from a first and second consecutive control intervals repetitively with an alternating current frequency and to supply the plurality of induction areas with energy; and operating at least two of the plurality of induction areas with a first phase shift to minimize interference influence in at least one of the first and second consecutive control intervals.

32. The method of claim 31, further comprising operating the at least two of the plurality of induction areas in the second control interval with a second phase shift which differs from the first phase shift.

33. The method of claim 31, further comprising calculating a phase angle of the first phase shift from a quotient from 180° and a number of the plurality of induction areas to be operated simultaneously within the first control interval.

Description

[0029] FIG. 1 shows a schematic diagram of an induction appliance with an induction device, which has a plurality of induction areas and a control unit,

[0030] FIG. 2 shows a circuit diagram of the induction device in a schematic representation,

[0031] FIG. 3 shows the induction device in a schematic representation with a connection to a mains voltage source,

[0032] FIG. 4 shows a schematic diagram of a control period of the induction device,

[0033] FIG. 5 shows a schematic diagram of a method for operating the induction device,

[0034] FIG. 6 shows a schematic diagram of a control period of an induction device of an alternative exemplary embodiment and

[0035] FIG. 7 shows a circuit diagram of a further alternative exemplary embodiment of an induction device in a schematic representation.

[0036] FIG. 1 shows an induction appliance 100a with an induction device 10a. The induction appliance 100a is embodied as an induction cooking appliance, namely as an induction hob. The induction device 10a is embodied as an induction cooking appliance device. The induction device 10a has a plurality of induction areas 12a, 14a, 16a, 18a. The induction device 10a has a control unit 20a. The induction areas 12a, 14a, 16a, 18a can be controlled independently by the control unit 20a. The control unit 20a is provided to control the induction areas 12a, 14a, 16a, 18a within a control period 22a (cf. FIG. 4) repetitively with at least one alternating current frequency 24a and to supply the same with energy. The control unit 20a has a computing unit 92a and a storage unit 94a.

[0037] FIG. 2 shows a circuit diagram of the induction device 10a in a schematic representation. An inverter 38a is assigned to each of the induction areas 12a in each case. Each of the inverter units 38a has a first switching element 40a and a second switching element 42a. The first switching element 40a and the second switching element 42a are embodied in each case as transistors, namely as bipolar transistors with insulated gate electrodes. In one operating state, the control unit 20a controls the respective induction areas 12a, 14a, 16a, 18a repetitively by way of the inverter units 38a assigned to the respective induction areas 12a, 14a, 16a, 18a with the alternating current frequency 24a.

[0038] FIG. 3 shows the induction device 10a in a schematic representation. The induction device 10a is connected to a mains alternating voltage source 70a. The mains alternating voltage source 70a provides a mains alternating voltage 72a or a mains alternating current 74a. The induction device 10a has a filter unit 76a and a rectifier unit 78a. The rectifier unit 78a converts the mains alternating voltage 72a into a direct voltage 80a. The direct voltage 80a has a cycle time 84a, which corresponds to a cycle time of the mains alternating voltage 72a. A duration 88a of the control period 22a is shorter than half a cycle time 86a of the mains alternating voltage 72a. The control period 22a consists of a number of control intervals 26a, 28a, 30a. The duration of all control intervals 26a, 28a and 30a adds up to the duration of the control period 22a (cf. FIG. 4). Hence, a duration of all control intervals 26a, 28a, 30a is shorter than half the cycle time 86a of the mains alternating voltage 72a.

[0039] FIG. 4 shows an overview of a number of diagrams for representing the control period 22a of the control unit 20a in an exemplary operating state of the induction device 10a. A time is plotted on an X axis 46a of a first diagram. A total power provided inductively by the induction areas 12a, 14a, 16a, 18a is shown on a Y axis 44a of the first diagram. The control period 22a comprises a first control interval 26a, a second control interval 28a and two further control intervals 30a. A time is plotted on an X axis 50a of a second diagram. A power provided by the induction area 12a of the induction areas 12a, 14a, 16a, 18a is plotted on an Y axis 48a of the second diagram. A time is plotted on an X axis 54a of a third diagram. A power provided by the induction area 14a is plotted on a Y axis 52a of the third diagram. A time is plotted on an X axis 58a of a fourth diagram. A power provided by the induction area 16a is plotted on an Y axis 56a of the fourth diagram. A time is plotted on an X axis 62a of a fifth diagram. A power provided by the induction area 18a is plotted on an Y axis 60a of the fifth diagram. A time is plotted on an X axis 66a of a sixth diagram. A phase angle 36a of a phase shift is plotted on a Y axis 64a of the sixth diagram. In the first control interval 26a, the control unit 20a operates the first induction area 12a and the second induction area 14a with the same alternating current frequency 24a. In the first control interval 26a, in order to minimize interferences, the control unit 20a operates the induction area 14a with a first phase shift 32a with respect to the induction area 12a.

[0040] The computing unit 92a is used by the control unit 20a to compute the phase angle 36a of the first phase shift 32a from a quotient of 180° and a number of induction areas 12a, 14a, 16a, 18a to be operated simultaneously within the first control interval 26a. In the first control interval 26a, the induction area 12a and the induction area 14a are to be operated simultaneously by the control unit 20a, so that the number of induction areas 12a, 14a to be operated simultaneously is equal to two. The computing unit 92a of the control unit 20a computes therefrom the phase angle 36a from the quotient of 180° and two and determines an amount of 90° for the phase angle 36a of the first phase shift 32a in the first control interval 26a.

[0041] In the second control interval 28a, the control unit 20a operates the induction area 14a, the induction area 16a, and the induction area 18a simultaneously with the same alternating current frequency 24a in each case. In the second control interval 28a, the control unit 20a operates the induction area 16a with a second phase shift 34a with respect to the induction area 14a and the induction area 18a with the second phase shift 34a with respect to the induction area 14a. The second phase shift 34a differs from the first phase shift 32a.

[0042] FIG. 5 shows a schematic representation of a method for operating the induction device 10a with a plurality of induction areas 12a, 14a, 16a, 18a which can be controlled independently. In a first method step 102a, the control unit 20a determines a number of induction areas 12a, 14a, 16a, 18a to be operated simultaneously within the first control interval 26a. In a second method step 104a, within the control period 22a at least two of the induction areas 12a, 14a, 16a, 18a are controlled repetitively with the alternating current frequency 18a and supplied with energy. In order to minimize interferences, two of the induction areas 12a, 14a, 16a, 18a are operated with the first phase shift 32a in the first control interval 26a.

[0043] FIGS. 6 and 7 show further exemplary embodiments of the invention. The following descriptions are restricted essentially to the differences between the exemplary embodiments, wherein with regard to components, features and functions which remain the same, reference can be made to the description of the exemplary embodiment in FIGS. 1 to 5. In order to differentiate the exemplary embodiments, the letter a is replaced in the reference characters of the exemplary embodiment in FIGS. 1 to 5 by the letters b and c in the reference characters of the exemplary embodiment in FIGS. 6 and 7. Reference can basically also be made to the drawings and/or the description of the exemplary embodiment in FIGS. 1 to 5, in respect of components labeled the same, in particular in respect of components with identical reference characters.

[0044] FIG. 6 relates to a further exemplary embodiment of an induction device 10b. The induction device 10b is configured identically to the induction device 10a in respect of a structural design and only differs in respect of a programming of a control unit 20b. FIG. 6 shows an overview of a number of diagrams for representing a control period 22b of the control unit 20b in an exemplary operating state. The control period 22b comprises a first control interval 26b, a second control interval 28b and two further control intervals 30b. A time is plotted on an X axis 46b of a first diagram. A total power provided inductively by the induction areas 12b, 14b, 16b, 18b is shown on a Y axis 44b of the first diagram. A time is plotted on an X axis 50b of a second diagram. A power provided by the induction area 12b is plotted on a Y axis 48b of the second diagram. A time is plotted on an X axis 54b of a third diagram. A power provided by the induction area 14b is plotted on a Y axis 52b of the third diagram. A time is plotted on an X axis 58b of a fourth diagram. A power provided by the third induction area 16b is plotted on a Y axis 56b of the fourth diagram. A time is plotted on an X axis 62b of a fifth diagram. A power provided by the induction area 18b is plotted on a Y axis 60b of the fifth diagram. A time is plotted on an X axis 66b of a sixth diagram. A phase angle 36b of a phase shift is plotted on a Y axis 64b of the sixth diagram. In the first control interval 26b, the control unit 20b operates the induction areas 14b and 16b with an alternating current frequency 24b and the induction area 18b with a further alternating current frequency 90b. The further alternating current frequency 90b differs from the alternating current frequency 24b. The further alternating current frequency 90b is an integral multiple of the alternating current frequency 24b.

[0045] In the first control interval 26b, the control unit 20b operates the induction area 14b and the induction area 16b with a first phase shift 32b. From a catalog stored in a storage unit 94b of the control unit 20b, the control unit 20b determines a suitable phase angle 36b for the first phase shift 32b from a number of induction areas 12b, 14b, 16b, 18b to be operated simultaneously in the first control interval 26b.

[0046] In the first control interval 26b, the control unit 20b operates the further induction area 18b with a further first phase shift 96b. In the second control interval 28b, the control unit 20b operates the induction area 14b, the induction area 16b, and the induction area 18b with the same alternating current frequency 24b in each case. The control unit 20b operates the induction area 14b and the induction area 16b with a second phase shift 34b. The second phase shift 34b differs from the first phase shift 32b. In the second control interval 28b, the control unit 20b operates the further induction area 18b with a further second phase shift 98b with respect to the induction area 14b.

[0047] FIG. 7 shows a circuit diagram of an alternative induction device 10c in a schematic representation. The induction device 10c has four induction areas 12c, 14c, 16c, 18c. Each of the induction areas is supplied with electrical energy in a matrix multi-inverter topology. Each of the induction areas 12c, 14c, 16c, 18c has five inductors 106c in each case. An inverter unit 38ac is assigned to each of the induction areas 12c, 14c, 16c, 18c. Each of the inverter units 38c has a first switching element 40c and five second switching elements 42c in each case. Each of the switching elements 40a, 42c is embodied in each case as a transistor, namely as a bipolar transistor with an insulated gate electrode. Separate control of the individual inductors 106c of the respective induction areas 12c, 14c, 16c, 18c is enabled by means of the switching elements 42c.

REFERENCE CHARACTERS

[0048] 10 induction device [0049] 12 first induction area [0050] 14 second induction area [0051] 16 third induction area [0052] 18 fourth induction area [0053] 20 control unit [0054] 22 control period [0055] 24 alternating current frequency [0056] 26 first control interval [0057] 28 second control interval [0058] 30 further control interval [0059] 32 first phase shift [0060] 34 second phase shift [0061] 36 phase angle [0062] 38 inverter unit [0063] 40 first switching element [0064] 42 second switching element [0065] 44 Y axis [0066] 46 X axis [0067] 48 Y axis [0068] 50 X axis [0069] 52 Y axis [0070] 54 X axis [0071] 56 Y axis [0072] 58 X axis [0073] 60 Y axis [0074] 62 X axis [0075] 64 Y axis [0076] 66 X axis [0077] 70 mains alternating voltage source [0078] 72 mains alternating voltage [0079] 74 mains alternating current [0080] 76 filter unit [0081] 78 rectifier unit [0082] 80 direct voltage [0083] 84 cycle time [0084] 86 half cycle time [0085] 88 duration [0086] 90 further alternating current frequency [0087] 92 computing unit [0088] 94 storage unit [0089] 96 further first phase shift [0090] 98 further second phase shift [0091] 100 induction appliance [0092] 102 first method step [0093] 104 second method step [0094] 106 inductor