EP4074142A1

EP4074142A1 - Induction device

Info

Publication number: EP4074142A1
Application number: EP20816174.5A
Authority: EP
Inventors: Tomas Cabeza Gozalo; Alberto Dominguez Vicente; Jorge ESPAÑOL LEZA; Manuel Fernandez Martinez; Sergio Llorente Gil; Ramon Peinado Adiego; Jorge VILLA LOPEZ
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2019-12-13
Filing date: 2020-12-02
Publication date: 2022-10-19
Also published as: US20230009984A1; WO2021115871A1

Abstract

The invention relates to an induction device (10a; 10b; 10c), in particular an induction cooking device, comprising a plurality of independently controllable induction areas (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) and comprising at least one control unit (20a; 20b) which is provided to repetitively control the induction areas (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) within a control period (22a; 22b) formed by a first control interval (26a; 26b) and at least one second control interval (28a; 28b) with at least one AC frequency (24a; 24b) and to supply same with energy. In order to provide a generic device with improved characteristics in terms of safe and/or comfortable operation, in the first control interval (26a; 26b), the control unit (20a; 20b) operates at least two of the induction areas (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) with a first phase shift (32a; 32b) in order to minimise interferences.

Description

Induction device

The invention relates to an induction device according to the preamble of claim 1 and a method for operating an induction device according to the preamble of claim 13.

An induction cooking device device with at least one control and / or regulating unit is already known from the prior art, which is provided to control at least one induction target repetitively and to provide with energy in at least one periodic continuous heating operating state, which is assigned at least one operating period to operate the induction target in at least one switch-on interval of the operating period with a heating output, in particular a target heating output or a power surplus compared to a target heating output, the control and / or regulating unit being provided to set a heating current frequency for the induction target in the switch-on interval in the continuous heating operating state to vary the operating period in order to enable quiet operation.

Furthermore, an induction cooking appliance device with at least two induction heating elements and with at least one control unit which, in at least one operating state, the induction heating elements in at least a first time interval with a first phase shift and in at least one second time interval different from the first time interval with one of the first phase shift operates different second phase shift, so as to enable improved heat distribution.

The object of the invention is in particular, but not limited to, to provide a device of the generic type with improved properties with regard to safe and / or convenient operation. The object is achieved according to the invention by the features of claims 1 and 13, while advantageous Ausgestal lines and developments of the invention can be found in the subclaims.

The invention is based on an induction device, in particular an induction cooking appliance device, with a plurality of independently controllable induction targets and with at least one control unit, which is provided to control the induction targets within a control period of a first control interval and at least a second control interval repetitively with at least one alternating current frequency and to supply them with energy.

It is proposed that the control unit, in order to minimize interference, operate at least two of the induction targets with a first phase shift in the first control interval.

Due to the inventive design, a generic cooking device device with improved properties with regard to safe and / or comfortable operation, in particular low-noise operation and / or in particular with regard to compliance with EMC standards and / or flicker conformity, can be provided. In particular, interfering noises resulting from intermodulations can advantageously be minimized. This makes it possible in particular to avoid an unfavorable acoustic stress on an operator, which in particular makes it possible to achieve a high level of operating comfort and, in particular, a positive operating impression for the operator, in particular with regard to acoustic quality. Furthermore, an induction device with improved conformity with respect to statutory guidelines, in particular guidelines with regard to EMC conformity and / or flicker conformity, can advantageously be achieved with simple technical means. Another advantage is that stricter limit values planned for the future with regard to EMC conformity can already be complied with at this point in time.

An “induction device” should be understood to mean in particular at least a part, in particular a subassembly, of an induction device which has a main function in the form of energy transmission to at least one external unit.

The induction device could, for example, be designed as a part and / or a sub-assembly of an induction charger, wherein the external unit could have at least one receiving element, for example a secondary coil and, for example, as a handheld power tool, such as a drill and / or an electric screwdriver and / or a hammer drill and / or a saw, or could be designed as a mobile device such as a smartphone and / or tablet and / or laptop. Alternatively or additionally, the induction device could be designed as part of a transformer and in particular at least one primary coil of one Transformer include. The induction device is preferably designed as an Indukti onsgargerätvorrichtung, for example as an induction oven device or as an induction grill device, and particularly preferably as an Induktionskochfeldvor device and provided for heating the external unit, which can be designed in particular as a cookware.

An “induction target” is to be understood as meaning, in particular, an inductor or a plurality of inductors which is / are part of the induction device and which / which can be controlled jointly by the control unit. An “inductor” is to be understood here in particular as an element which has at least one induction coil and which is provided in at least one operating state to supply energy to at least one receiving element, in particular a receiving element of the external unit, in particular in the form of an alternating magnetic field to feed. In the case of an induction device designed as an induction cooking device, an induction target can in particular be provided to supply the receiving element with energy for the purpose of heating. In this case, the external unit could be designed, for example, as a cookware and have at least one secondary coil as a receiving element for receiving the energy provided by the inductor. Alternatively or additionally, the receiving element could also be designed as a metallic heating means, in particular as an at least partially ferromagnetic heating means, for example as a ferromagnetic base of a cooking utensil, in which eddy currents and / or magnetic reversal effects are caused in the operating state by the inductor Heat can be converted. In particular, the plurality of inductors can be arranged like a matrix, wherein the inductors arranged like a matrix can form a variable cooking surface. In particular, at least one inverter unit is assigned to each of the induction targets, which inverter unit can be embodied in particular as a resonance inverter and / or as a dual half-bridge inverter. In particular, the inverter unit comprises at least two switching elements which can be individually controlled by the control unit. A “switching element” is to be understood in particular as an element which is provided to establish and / or separate an electrically conductive connection between two points, in particular contacts of the switching element. The switching element preferably has at least one control contact via which it can be switched. In particular, the switching element is a semiconductor switching element, in particular as a transistor, for example as a metal-oxide-semiconductor field effect transistor (MOSFET) or organic field effect transistor (OFET), advantageously as a bipolar transistor with a preferably insulated gate electrode (IGBT). Alternatively, it is conceivable that the switching element is designed as a mechanical and / or electromechanical switching element, in particular as a relay.

A “control unit” is to be understood in particular as an electronic unit which is at least partially integrated in the induction device and which is provided in particular to control at least one of the inverter units. The control unit preferably comprises a computing unit and, in particular, in addition to the computing unit, a memory unit with at least one control program stored therein which is provided to be executed by the computing unit. A “control period” is to be understood in particular as a period of time in which the control unit repeatedly controls the induction targets using at least one control strategy. A “control strategy” is to be understood as meaning, in particular, a special control of a unit, in particular of at least two induction targets, and / or a special method and / or a special algorithm which is applied to the unit, in particular to the induction targets . The control strategy can in particular include at least one phase shift. A “control interval” is to be understood in particular as a sub-period of the control period in which the control unit controls the induction targets with exactly one specific control strategy and maintains this control strategy during this sub-period. During a control interval, in particular a number of the induction targets operated simultaneously by the control unit is constant. In connection with the tax interval, the terms “first / first”, “second / second”, “further / further” are to be understood as pure naming for a better differentiation of the respective tax intervals and do not imply a chronological order and / or ranking of the respective tax intervals. For example, the first control interval can be placed after the second control interval and / or further control intervals or vice versa. In particular, the first control interval can be longer or shorter than the second control interval and / or further control intervals, or all control intervals can each last the same length of time. An “alternating current frequency” should be understood to mean, in particular, a frequency of an electrical alternating current in a range from 20 kHz to 150 kHz, preferably from 30 kHz to 75 kHz, with which at least one inductor of an induction target is controlled to generate an alternating magnetic field.

Interfering influences can in particular be influences that are perceptible by a user and perceived as undesirable and / or influences that are prohibited by legal regulations. For example, interference could be designed as flicker. Alternatively or in addition, interference could be unwanted acoustic influences, in particular in a frequency range between 20 Hz and 20 kHz that is perceptible to an average human ear. Interference could be caused in particular by intermodulation and could be expressed in acoustically perceptible interfering noises. “Intermodulation” is to be understood as meaning, in particular, sum and / or difference products of individual alternating current frequencies or their nth harmonics, where n stands for an integer greater than zero. Furthermore, alternatively or additionally, interference can be caused by the occurrence of a ripple current, that is to say an alternating current of any frequency and curve shape, which is superimposed on a direct current and manifests itself in an undesirable hum. In this context, interference does not include any technical malfunctions, defects and / or other undesirable phenomena, such as, for example, an uneven distribution of heat.

A “phase shift” should be understood in particular to mean that an oscillation of a control signal of a first inverter unit, with which a first induction target is controlled, and an oscillation of a further control signal of a further inverter unit, with which a further induction target is controlled, zero crossings spaced from one another exhibit. In particular, the phase shift assumes an amount which corresponds to a distance between the zero crossings and is specified as a phase angle. The amount of the phase shift is to be considered in the following each based on the control signal, by means of which the control unit first controls a specific induction target and supplies it with energy in the relevant control interval. In connection with the term phase shift, the terms "first / first", "second / second", "further / further" are used as a pure name to better differentiate between phase shifts. To understand exercises that differ in terms of an amount and / or the relevant induction goals and / or the relevant control interval. Furthermore, the terms “first / first”, “second / second”, “further / further” in connection with a phase shift are used for an assignment to a respective control interval in which a specific phase shift is used. For example, a first phase shift and a further first phase shift are each used in a first control interval. In particular, the concept of the first phase shift does not necessarily imply the presence of a second and / or further phase shift.

“Provided” is to be understood in particular as specifically programmed, designed and / or equipped. The fact that an object is provided for a specific function is to be understood in particular to mean that the object fulfills and / or executes this specific function in at least one application and / or operating state.

It is further proposed that the control unit operates the at least two induction targets in the second control interval with a second phase shift different from the first phase shift. It would be conceivable, for example, that the control unit in the first control interval operates exactly two of the induction targets simultaneously with the first phase shift, for example offset by a phase angle of 90 ° to one another, and in the second control interval the two induction targets with the second phase shift, for example by offset from one another by a phase angle of 60 °. In this way, interfering influences in different operating situations, for example with different power output of the induction targets, can advantageously be minimized.

It is also proposed that the control unit drives at least one more of the induction targets with a further first phase shift in the first control interval. For example, it would be conceivable for the control unit to operate three induction targets simultaneously in the first control interval, namely a second induction target with the first phase shift from a first induction target and a further induction target with the further first phase shift from the first induction target. This can advantageously cause interference in different operating situations, for example, if there are different numbers of induction targets to be operated simultaneously.

It is also proposed that the control unit operates at least one further induction target with a further second phase shift in the second control interval. For example, it would be conceivable that the control unit would have exactly two induction targets simultaneously with the first phase shift in the first control interval and three induction targets simultaneously in the second control interval, namely a second induction target with the second phase shift compared to a first induction target and a further induction target with the other second phase shift with respect to the first induction target. In this way, interference in different operating situations, for example with a different number of simultaneously operated induction targets, can advantageously be minimized.

It is also proposed that a duration of at least one of the control intervals, in particular all of the control intervals, is in each case shorter than half a period of an AC mains voltage. This makes it possible to react advantageously, in particular very quickly and in particular automatically by the control unit, to a changed operating situation, for example switching individual induction targets on and / or off by a user, and at the same time minimizing interference. In addition, it is proposed that a duration of the control period is shorter than half a period of an AC mains voltage. In this way, flicker conformity can advantageously be improved.

It is also proposed that the control unit controls at least one of the induction targets with the alternating current frequency and at least one other of the induction targets with a further alternating current frequency different from the alternating current frequency in at least one of the control intervals. It is, for example, conceivable that the control unit controls the at least two induction targets with the alternating current frequency in the first control interval and one of the two same induction targets with the alternating current frequency and the other of the two same induction targets with the further alternating current frequency in the second control interval. Alternatively, it is conceivable that the control unit controls the at least two induction targets with the alternating current frequency in the first control interval and one of the same two induction targets with the alternating current frequency and another induction target in the second control interval The first control interval was not activated, activates with the further alternating current frequency. As a result, several induction targets can advantageously be operated at the same time with different output powers and interference can be minimized at the same time.

It would be conceivable, for example, that the alternating current frequency and the further alternating current frequency are spaced apart by a certain amount, in particular by an amount of at least 20 kHz, without the alternating current frequency and the further alternating current frequency having a common integer multiple. In order to advantageously enable a phase shift even in the case of two induction targets operated with a different alternating current frequency, it is proposed that the further alternating current frequency is an integral multiple of the alternating current frequency. For example, the alternating current frequency at which the first two induction targets are operated could be 35 kHz and the further alternating current frequency with which another induction target is operated could be 70 kHz. This advantageously minimizes interference, especially in those cases in which at least two induction targets of the induction device have to be operated with different alternating current frequencies for technical reasons, for example due to different output powers.

It is further proposed that the control unit drives at least two of the induction targets, in particular the at least two induction targets, with the same alternating current frequency in at least one of the control intervals, in particular the first control interval. With the same alternating current frequency, a phase shift can advantageously be implemented with, in particular, simple technical means and at the same time a minimization of interference can be achieved.

It is also proposed that the control unit calculate a phase angle of the first phase shift from a quotient of 180 ° and a number of induction targets to be operated simultaneously within the first control interval. In particular, the control unit calculates all phase angles of all phase shifts from 180 ° and a number of induction targets to be operated simultaneously within the first control interval. In order to calculate the phase angle, the control unit includes, in particular, a computing unit. For example, two induction targets could be operated simultaneously in one of the control intervals so that the arithmetic unit of the control unit calculates the phase angle, divided by 180 ° by two, to be 90 °. This allows for partial interference, which in particular can differ greatly depending on the number of induction targets operated simultaneously within a control interval, are minimized by the control unit, in particular automatically.

In an alternative embodiment, it is proposed that the control unit select at least one suitable phase angle for the first phase shift from a catalog of suitable phase angles based on a number of induction targets to be operated simultaneously within the first control interval. In particular, the control unit selects at least one suitable phase angle for the respective phase shift from a catalog of suitable phase angles based on a number of induction targets to be operated simultaneously within a respective control interval. In particular, the control unit comprises at least one memory unit in which the catalog is stored such that it can be called up by the control unit. The catalog can in particular contain a large number of suitable phase angles, in particular those determined experimentally through tests. In particular, it is conceivable that with the large number of phase angles stored in the catalog, in addition to the number of induction targets to be operated simultaneously, other factors, for example a number of inductors that are assigned to the respective induction targets and / or a diameter and / or a number of windings Coil of an inductor. In particular, it is conceivable that the phase angles contained in the catalog are adapted to a special application of the induction device, for example a specific operating mode. In particular, a first catalog of a first induction device, which is part of a first induction device, can differ from a second catalog of a second induction device, which is part of a second induction device that is different from the first, in particular with regard to a field of application. In particular, it is conceivable that the catalog can be expanded and / or adapted by further suitable phase angles, so that new empirical findings with regard to suitable phase angles can be supplemented, for example by means of a software update.

The invention is also based on a method for operating an Induktionsvorrich device, in particular an Induktionsgargerätvorrichtung, with a plurality of independently controllable induction targets, the induction targets within a control period from at least two consecutive control intervals repetitively controlled with at least one alternating current frequency and supplied with energy become. It is proposed that, in order to minimize interference, at least two of the induction targets are operated with a phase shift in at least one of the control intervals. In this way, particularly low-noise operation of the induction device can advantageously be achieved.

The induction device should not be restricted to the application and embodiment described above. In particular, the induction device can have a number of individual elements, components and units that differs from a number of individual elements, components and units mentioned herein in order to fulfill a mode of operation described herein.

Further advantages emerge from the following description of the drawings. In the drawing voltage, embodiments of the invention are shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into useful further combinations.

Show it:

Fig. 1 is a schematic representation of an induction device with an Indukti onsvorrichtung, which has a plurality of induction targets and a control unit,

Fig. 2 is a circuit diagram of the induction device in a schematic presen- tation,

3 shows the induction device in a schematic representation with a connection to a mains voltage source,

Fig. 4 is a schematic representation of a control period of the Induktionsvor direction,

5 shows a schematic representation of a method for operating the induction device,

Fig. 6 is a schematic representation of a control period of an Induktionsvor device of an alternative embodiment and

Fig. 7 is a circuit diagram of a further alternative embodiment of an induction device in a schematic representation.

FIG. 1 shows an induction device 100a with an induction device 10a. The induction device 100a is designed as an induction cooking device, specifically as an induction hob. forms. The induction device 10a is designed as an induction cooking appliance device. The induction device 10a has a plurality of induction targets 12a, 14a,

16a, 18a. The induction device 10a has a control unit 20a. The induction targets 12a, 14a, 16a, 18a can be controlled independently by the control unit 20a.

The control unit 20a is provided to control the induction targets 12a, 14a, 16a, 18a within a control period 22a (see FIG. 4) repetitively with at least one alternating current frequency 24a and to supply them with energy. The control unit 20a has a computing unit 92a and a memory unit 94a.

Figure 2 shows a circuit diagram of the induction device 10a in a schematic presen- tation. An inverter unit 38a is assigned to each of the induction targets 12a. 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 Schaltele element 42a are each designed as transistors, namely as bipolar transistors with an insulated gate electrode. In an operating state, the control unit 20a controls the respective induction targets 12a, 14a, 16a, 18a repetitively via the inverter units 38a assigned to the respective induction targets 12a, 14a, 16a, 18a at the alternating current frequency 24a.

Figure 3 shows the induction device 10a in a schematic representation. The induction device 10a is connected to a mains AC voltage source 70a. The AC line voltage source 70a provides an AC line voltage 72a or an AC line current 74a. The induction device 10a has a filter unit 76a and a rectifier unit 78a. The rectifier unit 78a converts the network alternating voltage 72a into a DC voltage 80a. The direct voltage 80a has a period 84a, which corresponds to a period of the mains alternating voltage 72a. A duration 88a of the control period 22a is shorter than half a period duration 86a of the AC mains voltage 72a. The control period 22a consists of several control intervals 26a, 28a, 30a. The duration of all control intervals 26a, 28a and 30a results in the sum total of the duration of the control period 22a (see FIG. 4). Consequently, a duration of all control intervals 26a, 28a, 30a is shorter than half the period duration 86a of the AC mains voltage 72a.

Figure 4 shows a synopsis of several diagrams to show the control period 22a of the control unit 20a in an exemplary operating state of the induction direction 10a. A time is plotted on an abscissa axis 46a of a first diagram. A total power inductively provided by the induction targets 12a, 14a, 16a, 18a is shown on an ordinate 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 abscissa axis 50a of a second diagram. A power provided by the induction target 12a of the induction targets 12a, 14a, 16a, 18a is plotted on an ordinate axis 48a of the second diagram. A time is plotted on an abscissa axis 54a of a third diagram. A power provided by the induction target 14a is plotted on an ordinate axis 52a of the third diagram. A time is plotted on an abscissa axis 58a of a fourth diagram. A power provided by the induction target 16a is plotted on an ordinate axis 56a of the fourth diagram. A time is plotted on an abscissa axis 62a of a fifth diagram. A power provided by the induction target 18a is plotted on an ordinate axis 60a of the fifth diagram. A time is plotted on an abscissa axis 66a of a sixth diagram. A phase angle 36a of a phase shift is plotted on an ordinate axis 64a of the sixth diagram. In the first control interval 26a, the control unit 20a operates the first induction target 12a and the second induction target 14a at the same AC frequency 24a. In the first control interval 26a, in order to minimize interference, the control unit 20a operates the induction target 14a with a first phase shift 32a with respect to the induction target 12a.

Using the computing unit 92a, the control unit 20a calculates the phase angle 36a of the first phase shift 32a from a quotient of 180 ° and a number of induction targets 12a, 14a, 16a, 18a to be operated simultaneously within the first control interval 26a. In the first control interval 26a, the induction target 12a and the induction target 14a are to be operated simultaneously by the control unit 20a, so that the number of the induction targets 12a, 14a to be operated simultaneously is two. The computing unit 92a of the control unit 20a calculates 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. In the second control interval 28a, the control unit 20a operates the induction target 14a, the induction target 16a, and the induction target 18a at the same time, each at the same AC frequency 24a. In the second control interval 28a, the control unit 20a operates the induction target 16a with a second phase shift 34a with respect to the induction target 14a and the induction target 18a with the second phase shift 34a with respect to the induction target 14a. The second phase shift 34a differs from the first phase shift 32a.

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

In FIGS. 6 and 7, further exemplary embodiments of the invention are shown. The following descriptions are essentially limited to the differences between the exemplary embodiments, reference being made to the description of the exemplary embodiment in FIGS. 1 to 5 with regard to components, features and functions that remain the same. To distinguish the exemplary embodiments, the letter a in the reference symbols of the exemplary embodiment in FIGS. 1 to 5 is replaced by the letters b and c in the reference symbols of the exemplary embodiment in FIGS. 6 and 7. With regard to components with the same designation, in particular with regard to components with the same reference symbols, reference can in principle also be made to the drawings and / or the description of the exemplary embodiment in FIGS. 1 to 5.

FIG. 6 relates to a further exemplary embodiment of an induction device 10b. The induction device 10b is designed identical to the induction device 10a with regard to a structural design and differs only with regard to the programming of a control unit 20b. FIG. 6 shows a synopsis of several diagrams to represent a control period 22b of the control unit 20b in an operating state, for example. 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 abs zissa axis 46b of a first diagram. A total power inductively provided by the induction targets 12b, 14b, 16b, 18b is shown on an ordinate axis 44b of the first diagram. A time is plotted on an abscissa axis 50b of a second diagram. A power provided by the induction target 12b is plotted on an ordinate axis 48b of the second diagram. A time is plotted on an abscissa axis 54b of a third diagram. A power provided by the induction target 14b is plotted on an ordinate axis 52b of the third diagram. A time is plotted on an abscissa axis 58b of a fourth diagram. A power provided by the third induction target 16b is plotted on an ordinate axis 56b of the fourth diagram. A time is plotted on an abscissa axis 62b of a fifth diagram. A power provided by the induction target 18b is plotted on an ordinate axis 60b of the fifth diagram. A time is plotted on an abscissa axis 66b of a sixth diagram. A phase angle 36b of a phase shift is plotted on an ordinate axis 64b of the sixth diagram. In the first control interval 26b, the control unit 20b operates the induction targets 14b and 16b at one AC frequency 24b and operates the induction target 18b at a further AC frequency 90b. The further alternating current frequency 90b is different from the alternating current frequency 24b. The further alternating current frequency 90b is an integral multiple of the alternating current frequency 24b.

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

The control unit 20b operates the further induction target 18b with a further first phase shift 96b in the first control interval 26b. In the second control interval 28b, the control unit 20b operates the induction target 14b, the induction target 16b, and the induction target 18b at the same AC frequency 24b, respectively. The control unit 20b operates the induction target 14b and the induction target 16b with a second phase Displacement 34b. The second phase shift 34b is different from the first phase shift 32b. In the second control interval 28b, the control unit 20b operates the further induction target 18b with a further second phase shift 98b with respect to the induction target 14b. Figure 7 shows a circuit diagram of an alternative induction device 10c in a schematic representation. The induction device 10c has four induction targets 12c, 14c, 16c, 18c. Each of the induction targets is supplied with electrical energy in a matrix multi-inverter topology. Each of the induction targets 12c, 14c, 16c, 18c each has five inductors 106c. An inverter unit 38ac is assigned to each of the induction targets 12c, 14c, 16c, 18c. Each of the inverter units 38c has a first switching element 40c and five second switching elements 42c. Each of the switching elements 40a, 42c is designed as a transistor, specifically as a bipolar transistor with an insulated gate electrode. The switching elements 42c enable the individual inductors 106c of the respective induction targets 12c, 14c, 16c, 18c to be controlled separately.

Reference number

10 induction device

12 first induction target

14 second induction target

16 third induction goal

18 fourth induction target

20 control unit

22 tax period

24 AC frequency

26 first tax interval

28 second tax interval

30 further control interval

32 first phase shift

34 second phase shift 36 phase angle

38 Inverter unit

40 first switching element

42 second switching element

44 ordinate axis

46 abscissa axis

48 axis of ordinate

50 axis of abscissa

52 ordinate axis

54 abscissa axis

56 ordinate axis

58 axis of abscissa

60 ordinate axis

62 abscissa axis

64 ordinate axis Abscissa axis AC line voltage source AC line voltage AC line current filter unit rectifier unit DC voltage period duration half period duration further alternating current frequency arithmetic unit storage unit further first phase shift further second phase shift induction device first method step second method step inductor

Claims

EXPECTATIONS

1. Induction device (10a; 10b; 10c), in particular Induktionsgargerätevorrich device, with a plurality of independently controllable induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) and with at least a control unit (20a; 20b) which is provided to control the induction targets (12a,

14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) within a control period (22a; 22b) consisting of a first control interval (26a; 26b) and at least one second control interval (28a; 28b) with at least one alternating current frequency (24a; 24b) to control and to be supplied with energy, characterized in that the control unit (20a; 20b), to a minimization of

Interferences, in the first control interval (26a; 26b) at least two of the induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) with a first phase shift (32a; 32b ) operates.

2. induction device (10a; 10b; 10c) according to claim 1, characterized in that the control unit (20a; 20b) the at least two induction targets (12a,

14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) operates in the second control interval (28a; 28b) with a second phase shift (34a; 34b) different from the first phase shift (32a; 32b).

3. induction device (10a; 10b; 10c) according to claim 1 or 2, characterized in that the control unit (20a; 20b) in the first control interval

(26a; 26b) operates at least one further of the induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) with a further first phase shift (96b).

4. induction device (10a; 10b; 10c) according to one of the preceding claims, characterized in that the control unit (20a; 20b) in the second control interval (28a; 28b) has at least one other of the induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) with a further second phase shift (98b).

5. Induction device (10a; 10b; 10c) according to one of the preceding claims, characterized in that a duration of at least one of the control intervals (26a, 28a, 30a; 26b, 28b, 30b), in particular all control intervals (26a, 28a, 30a; 26b, 28b, 30b), each shorter than half a period (86a) of an alternating mains voltage (72a).

6. induction device (10a; 10b; 10c) according to one of the preceding claims, characterized in that a duration (88a) of the control period (22a; 22b) is shorter than half a period (86a) of an AC mains voltage (72a).

7. induction device (10a; 10b; 10c) according to one of the preceding claims, characterized in that the control unit (20a; 20b) in at least one of the control intervals (26a, 28a, 30a; 26b, 28b, 30b), at least one of the Induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) with the alternating current frequency (24a; 24b) and at least one other of the induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) with a further alternating current frequency (90b) different from the alternating current frequency (24a; 24b).

8. induction device (10a; 10b; 10c) according to claim 7, characterized in that the further alternating current frequency (90b) is an integral multiple of the alternating current frequency (24a; 24b).

9. induction device (10a; 10b; 10c) according to one of claims 1 to 6, characterized in that the control unit in at least one of the control intervals (26a, 28a, 30a; 26b, 28b, 30b), in particular the first control interval ( 26a; 26b), at least two of the induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c), in particular the at least two induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c), operates with the same alternating current frequency (24a; 24b).

10. Induction device (10a; 10c) according to one of the preceding claims, characterized in that the control unit (20a) has a phase angle (36a) of the first phase shift (32a) from a quotient of 180 ° and a number of within the first control interval (26a ) simultaneously to be driven induction targets (12a; 14a, 16a, 18a; 12c, 14c, 16c, 18c) are calculated.

11. Induction device (10b; 10c) according to one of claims 1 to 9, characterized in that the control unit (20b) is based on a number of induction targets (12b,

14b, 16b, 18b; 12c; 14c, 16c, 18c) selects at least one suitable phase angle (36b) for the first phase shift (32b) from a catalog of suitable phase angles (36b).

12. Induktionsgargerät (100a), in particular induction hob, with an Indukti onsvorrichtung (10a; 10b; 10c) according to one of the preceding claims.

13. A method for operating an induction device (10a; 10b; 10c), in particular an induction cooking device device, in particular according to one of claims 1 to 11, with a plurality of independently controllable induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c), the induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c, 18c) within a

Control period (22a; 22b) from at least two successive control intervals (26a, 28a, 30a; 26b, 28b, 30b) are controlled repetitively with at least one alternating current frequency (24a; 24b) and supplied with energy, characterized in that to minimize of interference in at least one of the control intervals (26a, 28a, 30a; 26b, 28b, 30b), at least two of the induction targets (12a, 14a, 16a, 18a; 12b, 14b, 16b, 18b; 12c, 14c, 16c , 18c) can be operated with a phase shift (32a; 32b).