EP3001773B1 - Cooking device and method for operating a cooking appliance - Google Patents

Description

The invention relates to an induction hob apparatus according to the preamble of claim 1 and to a method for operating an induction hob apparatus according to the preamble of claim 13.
From the EP 1 951 003 B1 An induction hob is known which has at least two inverters and a control unit which is provided to jointly operate the at least two inverters in at least one time window of a continuous operating state and to divide the time window into two time intervals. A total output power of the at least two inverters is constant in the two time intervals, wherein a jump in the total output power occurs in a transition region.

The EP 2 469 972 A1 discloses another prior art induction hob apparatus. The object of the invention is, in particular, to provide a generic induction hob apparatus with improved power supply characteristics. The object is solved by the characterizing features of claims 1 and 13, while advantageous embodiments and modifications of the invention can be taken from the dependent claims.

The invention relates to an induction hob apparatus having at least two inverters which are each provided to operate at least one inductor, and to a control unit which is provided to operate the at least two inverters together in at least one time window of a continuous operating state and at least one To divide time windows into at least two time intervals.
It is proposed that the control unit is provided to design and / or form at least one of the at least two time intervals as a transitional time interval and to continuously vary a total output power of the at least two inverters in the transitional time interval.

According to the invention, the control unit is provided for operating the at least two inverters such that at least one of the time intervals is designed as a transitional time interval. According to the invention, the control unit is provided to operate the at least two inverters in such a way that the total output power of the at least two inverters changes continuously in the transitional time interval. Furthermore, the control unit can be provided in particular to divide the at least one time window into at least four time intervals, into at least five time intervals, into at least six time intervals and / or into another number of time intervals that appears appropriate to a person skilled in the art. A "cooking appliance device" is to be understood in particular as meaning at least one part, in particular a sub-assembly, of a cooking appliance, in particular a cooktop and preferably an induction cooktop. In particular, the cooking appliance device may also comprise the entire cooking appliance, in particular the entire hob and preferably the entire induction hob. The at least two inverters are intended to provide a high-frequency heating current for the inductors. For this purpose, the at least two inverters are operated in at least one operating state with a frequency, in particular switching frequency, of at least 1 kHz, advantageously of at least 10 kHz, preferably of at least 20 kHz and particularly preferably of not more than 100 kHz. In this case, the high-frequency heating current flows in at least one operating state through at least one of the inductors and is provided in particular for heating, in particular of cooking utensils, in particular by means of eddy current and / or magnetic reversal effects. A "control unit" should also be understood in particular to mean an electrical and / or electronic unit which is at least provided to control and / or regulate an operation of the at least two inverters and to provide at least one control signal for this purpose. Preferably, the control unit comprises a computing unit and in particular in addition to the arithmetic unit, a memory unit with a control and / or control program stored therein, which is in particular provided to be executed by the arithmetic unit. By "provided" is intended to be understood in particular specially programmed, designed and / or equipped. The fact that an object is intended for a specific function should in particular mean that the object fulfills and / or executes this specific function in at least one application and / or operating state. Furthermore, the use of the control unit is intended to provide the at least two inverters "in which at least one time window to operate together" in particular be understood that the control unit is designed to operate the at least two inverters in the at least one time window at least temporarily simultaneously and / or successively, in particular immediately one after the other and preferably alternately. In particular, the control unit is provided, in particular in the case of simultaneous operation of the at least two inverters, the at least two inverters with at least one at least 15 kHz, preferably at least 16 kHz and more preferably at least 17 kHz different frequency, in particular switching frequency, and / or the same frequency, in particular switching frequency to operate. By the notion that the control unit is intended to "operate" at least one of the inverters, it should be understood, in particular, that the at least one inverter has a finite output power, which is different in particular from zero. In particular, the at least one time window has a time duration between 100 ms and 5 s, preferably between 500 ms and 3 s and particularly preferably between 1 s and 2 s. A minimum time duration of the time window can be predetermined, in particular, by a flicker standard, wherein, in particular, the flicker standard is violated below this minimum time duration. Furthermore, a maximum time duration of the time window can be determined in particular by a thermal inertia of the cooking utensil. Preferably, the control unit is provided to repeat the at least one time window periodically. Preferably, the control unit is provided to subdivide the at least one time window into the at least two and preferably at least three time intervals in such a way that successive, preferably all, time intervals differ at least in one operating parameter. In this context, "successive time intervals" are to be understood as meaning, in particular, at least two time intervals, in particular the at least two time intervals of the at least one time window, which in particular directly adjoin one another. In this context, the term "immediately adjoining one another" should be understood to mean that two objects, in particular time windows and / or time intervals, in particular at least in terms of time, lie directly behind one another and in particular have at least one common time. The operating parameter may in particular be a frequency, in particular a switching frequency, a duty cycle and / or a phase, in particular of the at least one control signal, and / or a Output power, in particular at least one inverter, and / or a period of time, in particular at least one time interval act. A "duty cycle" is to be understood as meaning in particular a ratio of a time period in which a signal, preferably a periodic signal, assumes a switch-on value, in particular a high level, at a defined time range, preferably a period duration of the signal. A "phase" of a signal, preferably a periodic signal, is to be understood in particular as a phase angle of the signal. In particular, the phase of the at least one control signal defines a switching time of at least one of the at least two inverters. By a shift and / or change in the phase of the at least one control signal, a shift of a switching time of the at least two inverters can therefore take place against each other. Furthermore, a "transitional time interval" should be understood as meaning, in particular, a time interval which deviates from a time interval with an at least substantially constant total output power. In particular, a transitional time interval has a finite time duration, in particular of at least 1 ms, advantageously at least 10 ms, preferably at least 50 ms and particularly preferably at least 100 ms. An "at least substantially" constant total output power should be understood to mean in particular a total output power which has a relative fluctuation, in particular power fluctuation, of at most 5%, preferably of at most 3% and particularly preferably of not more than 1%. Furthermore, a "continuous operation state" should be understood to mean in particular an operating state which is in particular at least 100 ms, advantageously at least 500 ms, preferably at least 1 s and particularly preferably at least 5 s after starting the cooking device device and / or a selection of a heating power and / or a Selection of an operating and / or cooking program starts. In particular, the control unit is provided to operate the at least two inverters in the continuous operating state over a relatively long period of time, in particular at least 1 s, advantageously at least 5 s, preferably at least 10 s and particularly preferably at least 15 s, in particular jointly. In particular, the continuous operating state is different from a start operating state, in particular a detection of a cookware and / or a regulation of an output power of the at least two inverters. In this case, the continuous operating state preferably directly adjoins the starting operating state. In particular, an output power averaged over the at least one time window corresponds to the at least two inverters in the Continuous operating state at least substantially a desired by the control unit and preferably predetermined by an operator and / or a cooking program target performance. In this context, an "output power" of an inverter should be understood as meaning, in particular, a power which is provided at at least one output of the inverter in at least one operating state. In particular, the output power is supplied to at least one of the inductors. Furthermore, an "average output power" is to be understood in particular to mean a time-averaged output power, which corresponds in particular to an arithmetic mean of the output power in a defined time range, in particular the at least one time window and / or at least one of the time intervals. In this context, the phrase that the average output power "at least substantially" corresponds to a target power aimed at by the control unit is to be understood to mean that the two power values deviate from each other by at most 5%, preferably at most 3% and particularly preferably at most 1% , Furthermore, a "total output power" should be understood to mean, in particular, a total output power, in particular a sum of the output powers of the at least two inverters, in particular of all inverters, in particular at any desired time, in particular in the at least one time window. Furthermore, the phrase "steady" should be understood to mean, in particular, free of jumps. Preferably, the control unit is provided to change the total output power of the at least two inverters in the transitional time interval smooth, continuous, monotonically increasing and / or monotone decreasing. In this case, the control unit is preferably designed to change the total output power of the at least two inverters strictly monotonically increasing and / or decreasing in the transitional time interval. With this configuration, a generic Gargerätevorrichtung can be provided with improved properties in terms of a power supply. In particular, it is advantageously possible to increase the efficiency of the cooking device device and to increase operating safety. In addition, in particular flicker can be advantageously reduced, in particular because jumps in the total output power can be reduced and / or avoided altogether. Furthermore, an overall output power difference, in particular between two time intervals in which the at least two inverters have a constant total output power, can be increased, so that advantageously a thermal response time can be improved. In this context, a "total output power difference" should be understood to mean in particular a difference of a total output power between at least two, preferably exactly two, time intervals. In addition, the cooking appliance device can be advantageously adapted to different requirements, which in particular achieves a particularly uniform power output and, advantageously, a selected setpoint power can be provided as accurately as possible.

The control unit could be provided for continuously changing the total output power, in particular in the continuous operating state, in the transitional time interval in any manner, in particular at least essentially logarithmically and / or exponentially in time. Preferably, the control unit is provided to change the total output power, in particular in the continuous operating state, in the transitional time interval at least substantially linearly in time, in particular linearly increasing and / or decreasing. In particular, the control unit is provided to operate the at least two inverters such that the total output power of the at least two inverters changes linearly in the transitional time interval. In particular, the total output power of the at least two inverters in the transitional time interval has an at least substantially constant slope and / or first derivative. The fact that the total output power is "at least substantially" temporally linear and / or has a constant slope should in this context be understood in particular to mean that a linear regression curve, in particular the total output power, has a coefficient of determination of at least 0.9, preferably of at least zero , 95 and more preferably of at least 0.98. In particular, at least one form factor, in particular an analytical flicker form factor, in particular the total output power in the transitional time interval, has a value between 0 and 1, preferably between 0.2 and 0.8 and particularly preferably between 0.4 and 0.6, wherein a Jump point and / or a stage in particular a value of 1 and a straight line in particular has a value of 0. In this way, in particular a calculation of the total output power can be simplified, whereby in particular a selected target power can be provided as accurately as possible.

If the control unit is provided to change in the transitional time interval at least one switching frequency and / or at least one duty cycle and / or at least one phase, in particular of the at least one control signal of the control unit, in particular continuously, an advantageous flexibility can be achieved, in particular since a change the total output power can be adapted to different requirements.

Furthermore, it is proposed that the control unit, in particular in at least one operating state and / or in at least one application state, be provided for simultaneously operating the at least two inverters in the transitional time interval. As a result, an output power can be controlled individually, in particular during the transitional time interval.

In one embodiment of the invention, it is proposed that the control unit be provided to change both an output power of a first and an output power of a second of the at least two inverters simultaneously, in particular in each case continuously, in the transitional time interval. In particular, the control unit is provided to operate the at least two inverters in the transitional time interval such that both an output power of a first and an output power of a second of the at least two inverters changes simultaneously, in particular in each case continuously. In particular, this can further increase efficiency. Furthermore, possible flicker can be advantageously reduced and / or avoided.

The control unit, in particular in at least one further operating state and / or further application state, in particular different from the at least one operating state and / or application state, is preferably designed to operate exactly one of the at least two inverters in the transitional time interval. As a result, in particular a control algorithm can be simplified.

Furthermore, it is proposed that the control unit is provided to change at least one output power of the inverter in the transitional time interval with one, in particular momentarily and / or temporarily and / or preferably at the beginning of the transitional time interval, the highest output power, in particular continuously. In this way, in particular an overall output power can advantageously be changed simply and efficiently.

In a preferred embodiment of the invention it is proposed that the at least one time window comprises at least one time interval in which the at least two inverters have a finite, in particular non-zero, and at least substantially constant total output power and which at least one, preferably exactly one, common Having border time with the transition time interval. Preferably, the at least one time interval directly adjoins the transition time interval. In particular, the control unit may be provided in the at least one time interval to operate the at least two inverters simultaneously and / or exactly one of the inverters. In this way, in particular a simple control and / or an advantageous heating can be achieved.

It is further proposed that the total output power at the at least one, preferably exactly one, limit time point and / or in a transitional region between the at least one time interval and the transition time interval is continuous. In particular, the total output power at the at least one time limit is free from a discontinuity and / or a discontinuity. In this way, in particular flicker can be advantageously reduced, since jumps in the total output power can be advantageously reduced.

The at least one time window comprises at least one further time interval, in particular different from the at least one time interval, in which the at least two inverters have a finite, in particular non-zero, total output power and which at least one, preferably exactly one, in particular of the at least one limit time In particular, a control and / or a heating can be further improved in terms of temporally different, further time limit with the transition time interval. Preferably, the at least one further time interval directly adjoins the transition time interval. In particular, the control unit may be provided in the at least one further time interval to operate the at least two inverters simultaneously and / or exactly one of the inverters. Preferably, the at least two inverters have an at least substantially constant total output power in the at least one further time interval. Alternatively, it is conceivable that the at least one further time interval is designed as a further transitional time interval.

Fig. 1

ein als Induktionskochfeld ausgebildetes Gargerät mit einer Gargerätevorrichtung, welche zwei Wechselrichter umfasst,

Fig. 2

beispielhafte, nicht maßstabsgetreue Leistungs-Zeit-Kurven der zwei Wechselrichter,

Fig. 3

beispielhafte, nicht maßstabsgetreue Leistungs-Zeit-Kurven zweier Wechselrichter einer weiteren Gargerätevorrichtung,

Fig. 4

beispielhafte, nicht maßstabsgetreue Leistungs-Zeit-Kurven zweier Wechselrichter einer weiteren Gargerätevorrichtung,

Fig. 5

beispielhafte, nicht maßstabsgetreue Leistungs-Zeit-Kurven zweier Wechselrichter einer weiteren Gargerätevorrichtung,

Fig. 6

beispielhafte, nicht maßstabsgetreue Leistungs-Zeit-Kurven zweier Wechselrichter einer weiteren Gargerätevorrichtung,

Fig. 7

beispielhafte, nicht maßstabsgetreue Leistungs-Zeit-Kurven zweier Wechselrichter einer weiteren Gargerätevorrichtung und

Fig. 8

beispielhafte, nicht maßstabsgetreue Leistungs-Zeit-Kurven zweier Wechselrichter einer weiteren Gargerätevorrichtung.

In addition, it is proposed that the total output power at the at least one, preferably exactly one, further limit time point and / or in a transitional area between the at least one further time interval and the transition time interval is continuous. In particular, the total output power at the at least one further limit time is free from a discontinuity and / or a discontinuity. As a result, advantageously possible flicker can be further reduced.
Furthermore, a method for operating a cooking device device, in particular an induction hob device, proposed, with at least two inverters, which are each intended to operate at least one inductor, wherein the at least two inverters are operated together in at least one time window of a continuous operating state and the at least one Time window is divided into at least two time intervals.
It is proposed that at least one of the at least two time intervals is configured as a transitional time interval and an overall output power of the at least two inverters in the transitional time interval is changed continuously, in particular at least substantially linearly in time. As a result, a power supply, in particular an efficiency and / or a reliability, can be advantageously improved. In addition, in particular flicker can be advantageously reduced and a particularly uniform power output can be achieved.
Further advantages emerge from the following description of the drawing. In the drawing, seven embodiments of the invention are shown. The drawing, the description and the claims contain numerous features in combination.
Show it:

Fig. 1

a cooking appliance designed as an induction hob with a cooking appliance device comprising two inverters,

Fig. 2

exemplary, not to scale, power-time curves of the two inverters,

Fig. 3

exemplary, not true-to-scale power-time curves of two inverters of another cooking appliance device,

Fig. 4

exemplary, not true-to-scale power-time curves of two inverters of another cooking appliance device,

Fig. 5

exemplary, not true-to-scale power-time curves of two inverters of another cooking appliance device,

Fig. 6

exemplary, not true-to-scale power-time curves of two inverters of another cooking appliance device,

Fig. 7

exemplary, not to scale true-time curves of two inverters another cooking appliance device and

Fig. 8

exemplary, not to scale power-time curves of two inverters another cooking appliance device.

FIG. 1 shows an example designed as an induction hob cooking device 18a in a schematic plan view. The cooking appliance 18a comprises a cooking device device. The cooking appliance device has a hob plate with two heating zones 20a. Each heating zone 20a is intended to heat exactly one cooking utensil (not shown). For this purpose, the cooking appliance device comprises at least two inductors (not shown). In the present case, the cooking appliance device comprises exactly two inductors. The inductors are arranged below the hob plate. Each inductor is associated with one of the heating zones 20a. Furthermore, in the present case, the cooking appliance device comprises two inverters 10a, 12a. Each of the inverters 10a, 12a is associated with one of the inductors. In this case, the inverters 10a, 12a are provided to convert a pulsating rectified mains voltage of a power source into a high-frequency heating current for the inductors and in particular to supply one of the inductors, whereby in particular a cooking utensil placed on the cooking plate can be inductively heated. In addition, the cooking appliance device has an operating unit 22a. The operation unit 22a is for input and / or selection of a power level by a user. For controlling a heating power, the cooking appliance device further comprises a control unit 14a. The control unit 14a has an arithmetic unit, a memory unit and an operating program stored in the memory unit, which is intended to be executed by the arithmetic unit. The control unit 14a is provided to operate the inverters 10a, 12a. Further, the control unit 14a forms together with the inductors in a known manner a detection unit for detecting a cooking utensil.

In addition, it is conceivable for a cooking appliance device to have any other number of inverters, in particular at least three and / or at least four inverters, and / or any other number of inductors, in particular at least three, at least four and / or at least six inductors. In particular, a cooking appliance device can also be provided for a matrix cooking field. Furthermore, a cooking device device can also have an additional switching unit, which is in particular provided to interrupt a conduction path between inverters and inductors and / or to assign a plurality of inverters to an inductor. In this case, a control unit could be provided, in particular, for operating the inverters and / or the switching unit in a time-division multiplexing method in at least one operating mode in which a heating power is requested for a plurality of inductors. Furthermore, the cooking appliance device may comprise further units, in particular at least one filter unit, at least one rectifier unit, at least one voltage converter unit, at least one resonance unit and / or at least one detection unit.

In an operating state in which cooking utensil is to be heated, an operator selects a power level for at least one of the heating zones 20a by means of the operating unit 22a. Based on the selected value, the control unit 14a set a target power P _obj1 , P _obj2 for the inverters 10a, 12a. In the present case, the power level selected by the operator directly corresponds to the desired power P _obj1 , P _{obj2 of} the two inverters 10a, 12a. Furthermore, in a start operating state, the control unit 14a first checks whether cooking equipment suitable for inductive heating is placed on the heating zones 20a of the hob plate. If so, in a next step, the control unit 14a determines, in a known manner for different duty cycles, a power-frequency curve of a given inductor-cookware combination. In this case, the control unit 14a may use the inductors as inductive sensors for detecting the cooking utensils.

Subsequently, the control unit 14a distinguishes between at least three modes of operation. In a first operating state, in which only one of the inverters 10a, 12a is operated, the control unit 14a can be provided to continuously provide an output power, in particular in a continuous operating state. In a second operating state, in which the inverters 10a, 12a are common and are continuously operable with a switching frequency difference of at least 15 kHz, the control unit 14a is provided to continuously operate the inverters 10a, 12a, in particular in a continuous operation state. In a third operating state, in which the inverters 10a, 12a are to be operated together, and in particular are not continuously operable, the control unit 14a is provided to jointly operate the inverters 10a, 12a in at least one time window 16a, in particular a continuous operating state, and the at least one time window 16a in at least two time intervals t _a , t _b , t _c , t _{d to} divide.

In the following, the third operating mode will be described in more detail. FIG. 2 shows exemplary, not to scale, power-time curves of a first inverter 10a and a second inverter 12a. In this case, in each case one time is plotted on an abscissa axis 24a and an output power P ₁ , P _{2 of} the inverters 10a, 12a and an overall output power P _{T are} plotted on an ordinate axis 26a. A curve 28a shows the total output power P _{T of} the inverters 10a, 12a. A curve 30a shows the output power P _{1 of} the first inverter 10a. A curve 32a shows the output power P _{2 of} the second inverter 12a. The total output power P _T results from the sum of the output power P _{1 of} the first inverter 10a and the output power P _{2 of} the second inverter 12a.

The time window 16a has a fixed time duration of 2 s. The time window 16a is periodically formed. In the present case, the control unit 14a is provided to divide the time window 16a into four time intervals t _a , t _b , t _c , t _d . The control unit 14a is provided to divide the time slot 16a in such a way in the time intervals t _a, t _b, t _c, t _d that successive time intervals t _a, t _b, t _c, t _d within the time window 16a at least in a Distinguish operating parameters. In the present case, the time intervals t _a , t _b , t _c , t _d differ at least in one period of time, the output power P ₁ , P _{2 of} the inverters 10a, 12a and / or in the total output power P _{T of} the inverters 10a, 12a. Furthermore, the control unit 14a is provided to design two of the time intervals t _a , t _b , t _c , t _d as transitional time intervals t _trans1 , t _trans2 . In addition, in the present case, the control unit 14a is provided to operate the inverters 10a, 12a in the time window 16a in common, in particular alternately.

A first time interval t _a has a duration of about 600 ms. In this case, the inverters 10a, 12a in the first time interval t _{a have} a finite and constant Total output power P _T on. The total output power P _T is 2300 W in the first time interval t _a . In the present case, the control unit 14 a is provided to operate exactly one of the inverters 10 a, 12 a in the first time interval t _a . In this case, the control unit 14a is provided to operate the first inverter 10a. The first inverter 10a has a constant output power P ₁ and / or a constant frequency over a total period of the first time interval t _a . In the present case, the first inverter 10a has an output power P ₁ of 2300 W over the entire time duration of the first time interval t _a . The second inverter 12a has an output power P ₂ of 0 W over the entire duration of the first time interval t _a . Accordingly, in the first time interval t _a , the first inverter 10 _{a has} a higher output power P ₁ than the second inverter 12 a.

A second time interval t _b immediately adjoins the first time interval t _a . The second time interval t _b is _configured as a first transitional time interval t _trans1 . Accordingly, the first time interval t _{a has} a common limit time T _G1 with the first transition time interval t _trans1 . The first transitional time _interval t _trans1 has a duration of about 200 ms. In the present case, the control unit 14a is provided to continuously change a total output power P _{T of} the inverters 10a, 12a in the first transitional time _interval t _trans1 . The total output power P _{T is} temporally linear, in particular linearly decreasing, changed. A form factor is 0.5. Alternatively, it is also conceivable that a control unit is provided to change an overall output power exponentially. The total output power P _T falls in the first transitional time _interval t _trans1 from 2300 W to 1500 W. The total output _{power difference} corresponds to a maximum total output _{power difference} . Furthermore, the total output power P _T at the limit time T _{G1 is} continuous and in particular free of a jump. In addition, the total output power P _{T of} the inverters 10a, 12a at a beginning of the first transitional time interval t _{trans1 corresponds to} the total output power P _{T of} the inverters 10a, 12a at one end of the first time interval t _a .

In the present case, the control unit 14a is provided to operate exactly one of the inverters 10a, 12a in the first transitional time _interval t _trans1 . In this case, the control unit 14a is provided to operate the first inverter 10a. The output power P _{1 of} the first inverter 10a corresponds to a beginning of the first transition time interval t _{trans1 of} the output power P _{1 of} the first inverter 10a at one end of the first time interval t _a . Thus, the output power P _{1 of} the first inverter 10a at the beginning of the first transitional time _interval t _{trans1 is} 2300 ° W. Further, the output power P _{1 of} the first inverter 10a is steady at the limit timing T _G1 . Alternatively, at a time limit, a jump could occur in an output power of at least one inverter and / or in a total output power of the inverters. In the present case, the control unit 14a is provided to _change the output power P _{1 of} the first inverter 10a in the first transition time _interval t _trans1 linearly in time, in particular linearly decreasing. In this case, the control unit 14a is provided to change a switching frequency of the first inverter 10a. Furthermore, the control unit 14a is provided to keep a phase and / or a duty cycle of the first inverter 10a constant. Alternatively, it is also conceivable to change a duty cycle and / or a phase of at least one inverter and in particular to keep a switching frequency constant. Furthermore, a control unit could be provided to exponentially change an output power of an inverter. At one end of the first transition time _interval t _trans1 , the output power P _{1 of} the first inverter 10a is 1500 ° W. The second inverter 12a has an output power P ₂ of 0 W over the entire duration of the first transitional time _interval t _trans1 . Accordingly, the control unit 14a is provided to _change the output power P ₁ , P _{2 of} the inverter _{10 a, 12 a} with a highest and / or higher output power P ₁ , P ₂ in the first transitional time _interval t _trans1 .

A third time interval t _c immediately adjoins the first transitional time interval t _trans1 . Accordingly, the first transitional time interval t _{trans1 has} a further common limit time T _G2 with the third time interval t _c . The third time interval t _c has a duration of about 1 s. The inverters 10a, 12a have a finite and constant total output power P _T in the third time interval t _c . The total output power P _T in the third time interval t _c is lower than the total output power P _T in the first time interval t _a . The total output power P _T in the third time interval t _{c is} 1500 W. A total output power difference between the first time interval t _a and the third time interval t _c is thus 800 W. The total output power P _T is continuous at the further limit time T _G2 and in particular free from one discontinuity. The total output corresponds to this P _{T of} the inverters 10a, 12a at a beginning of the third time interval t _{c of} the total output power P _{T of} the inverters 10a, 12a at one end of the first transitional time interval t _trans1 .

In the present case, the control unit 14a is provided for in the third time interval t _c exactly one of the inverters 10a, 12a operate. In this case, the control unit 14a is provided to operate the second inverter 12a. The first inverter 10a has an output power P ₁ of 0 W over a total duration of the third time interval t _c . The second inverter 12a has a constant output power P ₂ and / or a constant switching frequency over the entire duration of the third time interval t _c . In the present case, the second inverter 12a has an output power P ₂ of 1500 W over the entire duration of the third time interval t _c . Accordingly, in the third time interval t _c , the second inverter 12 a has a higher output power P ₂ than the second inverter 10 a.

At the third time interval t _c immediately adjoins a fourth time interval t _d . The fourth time interval t _d is designed as a second transitional time interval t _trans2 . Accordingly, the third time interval t _{c has} a common limit time T _G3 with the second transition time interval t _trans2 . The second transitional time _interval t _trans2 is symmetrical to the first transitional time _interval t _trans1 . An operation in the second transition time _interval t _trans2 takes place corresponding to the first transition time _interval t _trans1 . In the second transition time _interval t _trans2 , _however , the total output power P _T is changed linearly increasing, in particular by changing the switching frequency and thus the output power P _{1 of} the first inverter 10a. The total output power P _T increases from 1500 W to 2300 W in the second transitional time _interval t _trans2 . Alternatively, it is also conceivable to asymmetrically change an overall output power in a second transitional time interval, for example exponentially, in particular exponentially increasing. Furthermore, it is conceivable to operate a second inverter and / or at least two inverters and / or all inverters in a first transitional time interval and / or in a second transitional time interval.

At one end of the fourth time interval t _d a period is completed. Accordingly, the fourth time interval t _d and / or the time window 16 a immediately adjoin another time window, which is identical in particular to the time window 16 a. A In this case, the output power P _ave1 , P _{ave2 of} the respective inverter 10a, 12a averaged over the time window 16a corresponds in each case to the desired power P _obj1 , P _obj2 assigned by the control unit 14a. Alternatively, however, it is also conceivable that an end of a fourth time interval and / or a time window is followed by a further time window different from the time window. In this case, the time window is aperiodic.

For operation, the control unit 14a is provided, depending on the selected target power P _obj1 , P _obj2 the inverter 10a, 12a suitable periods of time intervals t _a , t _b , t _c , t _d and / or frequencies, in particular switching frequencies of the inverter 10 a , 12a, to determine. For this purpose, the control unit 14a is provided to solve the following matrix equation: $$\mathrm{A}\cdot \mathrm{x}=\mathrm{b}$$

A matrix A is composed of the output powers P ₁ , P _{2 of} each inverter 10 a, 12 a (rows i) in the various time intervals t _a , t _b , t _c , t _d (columns j). This results in a value P _ij for each element of the matrix A. A number of the rows corresponds to a number N of operated inverters 10a, 12a. Further, a number of columns corresponds to a number M of time intervals t _a , t _b , t _c , t _d . In general, the matrix A thus corresponds to an N × M matrix. In a transitional time _interval t _trans1 , t _{trans2, the} following applies for a time-linear change in the output power: $${\mathrm{P}}_{\mathrm{xy}}=\left({\mathrm{P}}_{\mathrm{xy}-1}+{\mathrm{P}}_{\mathrm{xy}+1}\right)/2$$

In this case, P _xy corresponds to the output power of the inverter x in the transition time interval y, P _{xy-1 of} the output power of the inverter x in a time interval y-1 which is immediately before the transitional time interval y and P _{xy + 1 of} an output power of the inverter x in one Time interval y + 1, which is temporally immediately after the transition time interval y. Furthermore, an M × 1 vector x is composed of the time periods t _{j of} the time intervals t _a , t _b , t _c , t _d . Further, an N × 1 vector b is composed of the target power P _obj1 , P _{obj2 of} the inverters 10a, 12a.

Such a control program and / or maximum and / or minimum durations of the time intervals t _a , t _b , t _c , t _d and / or the time window 16 a are stored in the memory unit of the control unit 14 a.

In the FIG. 3 a further embodiment of the invention is shown. The following description and the drawings are essentially limited to the differences between the exemplary embodiments, with respect to identically named components, in particular with regard to components having the same reference numerals, in principle also to the drawing and / or the description of the other embodiment, in particular Figures 1 and 2 , can be referenced. To distinguish the embodiments of the letter a is the reference numerals of the embodiment in the Figures 1 and 2 readjusted. In the embodiment of FIG. 3 the letter a is replaced by the letter b.

FIG. 3 shows exemplary, not to scale true power-time curves of a first inverter 10b and a second inverter 12b of another cooking appliance device.

An operation of the inverters 10b, 12b takes place at least substantially analogously to an operation of the previous embodiment of the Figures 1 and 2 , In this case, a control unit 14b, however, is provided to the inverter 10b to operate simultaneously in a third time interval t _c 12b. In this case, the control unit 14b is provided to operate the inverters 10b, 12b in the third time interval _tc with a switching frequency difference of at least 15 kHz and / or the same switching frequency. In the present case, the control unit 14b is provided to operate the inverters 10b, 12b in the third time interval t _c with a switching frequency difference of 17 kHz. The first inverter 10b has a constant output power P ₁ and / or a constant switching frequency over the entire duration of the third time interval t _c . In this case, the first inverter 10b has an output power P ₁ of approximately 700 W over the entire duration of the third time interval t _c . The second inverter 12b has a constant output power P ₂ and / or a constant switching frequency over the entire duration of the third time interval t _c . In the present case, the second inverter 12a has an output power P ₂ of approximately 800 W over the entire duration of the third time interval t _c .

In the FIG. 4 a further embodiment of the invention is shown. The embodiment of FIG. 4 the letter c is adjusted.

FIG. 4 shows exemplary, not to scale true power-time curves of a first inverter 10c and a second inverter 12c of another cooking appliance device.

In this case, a control unit 14c is provided for simultaneously operating the inverters 10c, 12c in a time window 16c, in particular over a total time duration of the time window 16c. Thus, a control unit 14c is provided for simultaneously operating the inverters 10c, 12c in at least one transitional time _interval t _trans1 , t _trans2 . In this case, the control unit 14c is provided to simultaneously continuously change both an output power P _{1 of} the first and an output power P _{2 of} the second of the at least two inverters 10c, 12c in at least one of the transitional time _intervals t _trans1 , t _trans2 .

In a first time interval t _a , the control unit 14 c is provided to operate the inverters 10 c, 12 c with a switching frequency difference of at least 15 kHz. The first inverter 10c and the second inverter 12c each have a constant output power P ₁ , P ₂ and / or a constant switching frequency over the entire time duration of the first time interval t _a . In the present case, the first inverter 10c has a higher output power P ₁ in the first time interval t _a than the second inverter 12 c.

Further, the control unit 14c is provided to _change the output power P _{1 of} the first inverter 10c linearly decreasing in a first transition time _interval t _trans1 . In addition, the control unit 14c is provided to _change the output power P _{2 of} the second inverter 12c linearly decreasing in the first transitional time _interval t _trans1 . In this case, the control unit 14c is provided to change in each case a duty cycle of the first inverter 10c and the second inverter 12c. Furthermore, the control unit 14c is provided to keep a phase and / or a switching frequency of the inverters 10c, 12c constant. The switching frequency of the inverters 10c, 12c corresponds to the switching frequency of the inverters 10c, 12c in the first time interval t _a in the first transitional time interval t _trans1 . Thus, the control unit 14c is to provided to operate the inverters 10c, 12c in the first transitional time _interval t _trans1 with a switching frequency _difference of at least 15 kHz.

Furthermore, the control unit 14c is provided to operate the inverters 10c, 12c in a third time interval _tc with a same and / or an identical switching frequency. The first inverter 10c and the second inverter each have a constant output power P ₁ , P ₂ and / or a constant switching frequency over the entire time duration of the third time interval t _c . In the third time interval t _c , the second inverter 12 _c has a higher output power P ₂ than the first inverter 10 _c .

A second transition time _interval t _trans2 is symmetrical in the present case at the first transition time _interval t _trans1 . The control unit 14c is provided to _change the output power P _{1 of} the first inverter 10a in a linearly increasing manner in the second transitional time _interval t _trans2 . In addition, the control unit _{14 c is provided to change} the output power P _{2 of} the second inverter 12 a linearly increasing in the second transitional time _interval t _trans2 .

In the FIG. 5 a further embodiment of the invention is shown. The embodiment of FIG. 5 the letter d is added.

FIG. 5 shows exemplary, not to scale true power-time curves of a first inverter 10d and a second inverter 12d another cooking appliance device.

In this case, a control unit 14d is provided for shifting a phase, in particular of a control signal, of the first inverter 10d with respect to a phase, in particular of a further control signal, of the second inverter 12d. In this case, the control unit 14d is provided to operate the inverters 10d, 12d in a first time interval t _a , in a first transitional time interval t _trans1 and / or in a second transitional time interval t _trans2 with a mutually shifted phase. Alternatively, it is also conceivable that a control unit is provided to shift a phase of a first inverter and a second inverter, in particular against each other.

In addition, the control unit is provided to 14d, in the first time interval t _a the inverters 10d, 12d to operate with a same switching frequency. In the transitional time _intervals t _trans1 , t _trans2 , the control unit 14d is provided to change the switching frequency of the inverters 10d, 12d, in particular linearly in time. In a third time interval t _c, the control unit 14d is also intended, in particular only to operate the first inverter 10d, in the third time interval t _c particular, no phase shift occurs.

In the FIG. 6 a further embodiment of the invention is shown. The embodiment of FIG. 6 the letter e is readjusted.

FIG. 6 shows exemplary, not to scale, power-time curves of a first inverter 10e and a second inverter 12e of another cooking appliance device.

In the present case, a control unit 14e is provided to divide a time window 16e into six time intervals t _a , t _b , t _c , t _d , t _e, t _f . Furthermore, the control unit 14e is provided to design three of the time intervals t _a , t _b , t _c , t _d , t _e, t _f as transition time intervals t _trans1 , t _trans2 , t _trans3 . In the present case, the control unit 14e is provided for alternately operating the inverters 10e, 12e in the time window 16e. Alternatively, a control unit may also be provided to simultaneously operate inverters in at least one time interval.

In the present case, a first time interval t _a , a second time interval t _b and / or a first transition time interval t _trans1 and a third time interval t _c correspond at least essentially, in particular to corresponding time periods, a first time interval t _a , a second time interval t _b and a third time interval t _{c of} the first embodiment.

In the present case, a fourth time interval t _d and / or a second transition time interval t _trans2 to the first transitional time interval t _{trans1 is} asymmetrical and / or asymmetrical. In the second transitional time _interval t _trans2 , a total output power P _{T is changed to} decrease linearly, in particular by changing a switching frequency and thus an output power P _{1 of} the first inverter 10e. The total output power P _T drops from 1500 W to about 300 W in the second transition time _interval t _trans2 .

The second transition time interval t _trans2 immediately adjoins a fifth time interval t _e . In the present case, the control unit 14e is provided to operate none of the inverters 10e, 12e in the fifth time interval t _e . Accordingly, the total output power P _T , the output power P _{1 of} the first inverter 10e and the output power P _{2 of} the second inverter 12e in the fifth time interval t _e 0 W.

At the fifth time interval t _e immediately adjoins a sixth time interval t _f . The sixth time interval t _f is designed as a third transitional time interval t _trans3 . The control unit 14e is provided to change the total output power P _T linearly increasing in the third transitional time _interval t _trans3 , in particular by changing the switching frequency and thus the output power P _{1 of} the first inverter 10e. The total output power P _T increases from about 200 W to 2300 W in the third transitional time _interval t _trans3 .

In the FIG. 7 a further embodiment of the invention is shown. The embodiment of FIG. 7 the letter f is readjusted.

FIG. 7 shows exemplary, not to scale true power-time curves of a first inverter 10f and a second inverter 12f another cooking appliance device.

The embodiment of FIG. 7 differs from the previous embodiments, in particular the embodiment of Figures 1 and 2 by an arrangement of a first transition time _interval t _trans1 and / or a second transition time _interval t _trans2 .

In a first time interval t _a , a control unit 14 f is provided to operate exactly one of the inverters 10 f, 12 f, in particular the first inverter 10 f. The inverters 10f, 12f have a finite and constant total output power P _T in the first time interval t _a . The total output power P _T is 1800 W in the first time interval t _a .

The first time interval t _a directly adjoins the first transition time interval t _trans1 . In the first transitional time _interval t _trans1 , the control unit _{14 f} is provided to _supply exactly one of the inverters _{10 f, 12 f} , in particular the first inverter _{10 f} operate. Furthermore, the control unit 14f is provided to _change the total output power P _T linearly decreasing in the first transition time _interval t _trans1 , in particular by changing a switching frequency and thus an output power P _{1 of} the first inverter _{10 f} . At one end of the first transitional time _interval t _trans1 , the total output power P _T and / or the output power P ₁ corresponds to a power that can be achieved to a minimum, in particular when operating at least one of the inverters _{10 f, 12 f} . The total output power P _T drops from 1800 W to 200 W in the first transition time _interval t _trans1 .

A third time interval t _c immediately adjoins the first transitional time interval t _trans1 . The third time interval t _c is designed as a second transitional time interval t _trans2 . Accordingly, the first transition time _interval t _{trans1 has} a common limit time T _G2 with the second transition time _interval t _trans2 . The total output power P _T is continuous at the limit time T _G2 and in particular free from a jump. In the second transition time _interval t _trans2 , the control unit 14f is provided to operate exactly one of the inverters 10f, 12f, in particular the second inverter 12f. Furthermore, the control unit 14f is provided to _change the overall output power P _T linearly increasing in the second transitional time _interval t _trans2 , in particular by changing a switching frequency and thus an output power P _{2 of} the second inverter 12f. The total output power P _T thereby increases from 200 W to 1800 W in the second transitional time _interval t _trans2 .

The second transition time interval t _trans2 is directly _{adjoined by} a fourth time interval t _d . In the fourth time interval t _d , the control unit 14 f is provided to operate exactly one of the inverters 10 f, 12 f, in particular the second inverter 12 f. The inverters 10a, 12a have a finite and constant total output power P _T in the fourth time interval t _d . The total output power P _T in the fourth time interval t _d is identical to the total output power P _T in the first time interval t _a . The total output power P _T is 1800 W in the fourth time interval t _d .

The fourth time interval t _d is immediately followed by a fifth time interval t _e . The fifth time interval t _e is designed as a third transitional time interval t _trans3 . The third transitional time _interval t _trans3 is mirror-symmetrical to the second transitional time _interval t _trans2 . In the third transition time _interval t _trans3 , the control unit _{14 f} is provided to _decrease the total output power P _{T in a} linear decreasing manner change, in particular by changing a switching frequency and thus an output power P _{2 of} the second inverter 12f. The total output power P _T falls in the third transitional time _interval t _trans3 from 1800 W to 200 W.

The third transition time interval t _trans3 is immediately followed by a sixth time interval t _f . The sixth time interval t _f is _configured as the fourth transitional time interval t _trans4 . The fourth transitional time _interval t _trans4 is mirror-symmetrical to the first transitional time _interval t _trans1 . In the fourth transition time _interval t _trans4 , the control unit 14f is provided to change the overall output power P _{T in a} linearly increasing manner, in particular by changing a switching frequency and thus an output power P _{1 of} the first inverter 10 f. The total output power P _T thereby increases in the fourth transitional time _interval t _trans4 from 200 W to 1800 W.

In the FIG. 8 a further embodiment of the invention is shown. The embodiment of FIG. 8 the letter g is readjusted.

FIG. 8 shows exemplary, not to scale true power-time curves of a first inverter 10g and a second inverter 12g another cooking appliance device.

An operation of the inverters 10g, 12g is at least substantially analogous to an operation of the previous embodiment. In this case, however, a control unit 14g is provided for simultaneously operating the inverters 10g, 12g in a time window 16g, in particular over a total time duration of the time window 16g.

In this case, 10g _trans1, the first inverter in a first time interval t _a and / or in a first transition time interval t and / or in a fourth transition time interval t _trans4 a higher output power P ₁ as the second inverter 12g. In a second transition time interval t _trans2 and / or in a fourth time interval t _d and / or in a third transition time interval t _trans3 , the second inverter 12g has a higher output power P ₂ than the first inverter 10g.

A control algorithm of a control unit may in particular be provided for carrying out all operating modes disclosed in the exemplary embodiments in at least one operating state and / or application state and / or at least two the operating modes and / or exactly one of the operating modes. In particular, it is conceivable that a control unit at the beginning of a time window selects one of the operating modes from a catalog of operating modes, in particular operating modes stored in a memory unit and / or only at the beginning of an operation and / or in the event of a detected change, for example a heating power and / or or a number of cookware sets a control algorithm. In particular, it is conceivable that a first time window corresponds to the first exemplary embodiment and / or another disclosed exemplary embodiment and / or a combination of the exemplary embodiments, while a second, in particular directly adjacent to the first time window, time window corresponds to an embodiment different from the first time window.

reference numeral

10

inverter

12

inverter

14

control unit

16

Time window

18

Cooking appliance

20

heating zones

22

operating unit

24

abscissa

26

axis of ordinates

28

Curve

30

Curve

32

Curve

t _a

time interval

t _b

time interval

t _c

time interval

t _d

time interval

t _e

time interval

t _f

time interval

t _trans1

Transition time interval

t _trans2

Transition time interval

t _trans3

Transition time interval

t _trans4

Transition time interval

T _G1

Limit time

T _G2

Limit time

T _G3

Limit time

P _T

Total output power

P ₁

output

P ₂

output

P _obj1

target power

P _obj2

target power

P _ave1

average output power

P _ave2

average output power

Claims (13)

1. Induction hob device having at least two inverters (10a-10g; 12a-12g), which are provided to operate at least one inductor in each case, and having a control unit (14a-14g) which is provided to jointly operate the at least two inverters (10a-10g; 12a-12g) in at least one time frame (16a-16g) of a continuous operation state and indeed simultaneously at least at times and/or consecutively and to divide the at least one time frame (16a-16g) into at least two time intervals (t _a, t_b ,t _c, t _d, t _e, t_f ), characterised in that the control unit (14a-14g) is provided to embody at least one of the at least two time intervals (t _a, t_b ,t _c, t _d, t _e,t _f) as a transition time interval (t _trans1, t _trans2, t _trans3) and to continuously change an overall output power (P_T ) of the at least two inverters (10a - 10g; 12a-12g) in the transition time interval (t _trans1, t _trans2, t _trans3).
2. Induction hob device according to claim 1, characterised in that the control unit (14a-14g) is provided to change the overall output power (P_T ) in the transition time interval (t _trans1, t _trans2, t _trans3) at least substantially linearly in terms of time.
3. Induction hob device according to claim 1 or 2, characterised in that the control unit (14a-14g) is provided to change at least one switching frequency and/or at least one pulse duty factor and/or at least one phase in the transition time interval (t _trans1, t _trans2, t _trans3).
4. Induction hob device according to one of the preceding claims, characterised in that the control unit (14c; 14d; 14g) is provided to operate the at least two inverters (10c, 12c; 10d, 12d; 10g, 12g) in the transition time interval (t _trans1, t _trans2, t _trans3) simultaneously.
5. Induction hob device according to one of the preceding claims, characterised in that the control unit (14c; 14d; 14g) is provided to change both an output power (P ₁) of a first and also an output power (P ₂) of a second of the at least two inverters (10c, 12c; 10d, 12d; 10g, 12g) simultaneously in the transition time interval (t _trans1, t _trans2, t _trans3).
6. Induction hob device according to one of claims 1 to 3, characterised in that the control unit (14a; 14b; 14e; 14f) is provided to operate precisely one of the at least two inverters (10a, 12a; 10b, 12b; 10e, 12e; 10f, 12f) in the transition time interval (t _{trans1 ,}t _{trans2 ,}t _trans3).
7. Induction hob device according to one of claims 1 to 5, characterised in that the control unit (14a-14g) is provided to change at least one output power (P ₁, P ₂) of the inverter (10a-10g; 12a-12g) with a highest output power in the transition time interval (t _trans1, t _trans2, t _trans3).
8. Induction hob device according to one of the preceding claims, characterised in that the at least one time frame (16a-16g) comprises at least one time interval (t_a,t_b,t _c, t _d, t _e, t_f ), in which the at least two inverters (10a-10g; 12a-12g) have a finite and at least substantially constant overall output power (P_T ) and which has at least one joint critical time instant (T _G1, T _G2, T _G3) with the transition time interval (t _trans1, t _trans2, t _trans3).
9. Induction hob device according to claim 8, characterised in that the overall output power (P_T ) at the at least one critical time instant (T _G1, T _G2, T _G3) is continuous.
10. Induction hob device according to one of the preceding claims, characterised in that the at least one time frame (16a-16g) comprises at least one further time interval (t _a, t_b ,t _c, t _d, t _e, t_f ), in which the at least two inverters (10a-10g; 12a-12g) have a finite overall output power (P_T ) and which has at least one further critical time instant (T _{G1 ,}T _G2, T _G3) with the transition time interval (t _trans1, t _trans2, t _trans3).
11. Induction hob device according to claim 10, characterised in that the overall output power (P_T ) at the at least one further critical time instant (T _G1, T _G2, T _G3) is continuous.
12. Induction hob (18a-18g) with at least one induction hob device according to one of the preceding claims.
13. Method for operating an induction hob device, in particular according to one of claims 1 to 11, having at least two inverters (10a-10g; 12a-12g), which are provided to operate at least one inductor in each case, wherein the at least two inverters (10a-10g; 12a-12g) are operated jointly in at least one time frame (16a-16g) of a continuous operation state and indeed simultaneously at least at times and/or consecutively and the at least one time frame (16a-16g) is divided into at least two time intervals (t _a, t_b ,t _c, t _d, t _e, t_f ), characterised in that at least one of the at least two time intervals (t _a, t_b ,t _c, t _d, t _e, t_f ) is embodied as a transition time interval (t _trans1, t _trans2, t _trans3) and an overall output power (P_T ) of the at least two inverters (10a-10g; 12a-12g) is changed continuously in the transition time interval (t _trans1, t _trans2, t _trans3).

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