EP2911472A2 - Cooking appliance, in particular cooking hob device, with a plurality of inverters - Google Patents

Abstract

The invention relates to a cooking device device, in particular a cooktop device, with a plurality of inverters (10), which are each provided to operate at least one inductor, and with a control unit (12), which is intended to at least a part of Inverter (10) in at least one operating state together and at least within a first time window (T _a , T _b ) to operate continuously.

In order to provide an optimized power supply, it is proposed that the control unit (12) be provided for subdividing the first time window (T _a , T _b ) into a first number (M) at time intervals (t _a , t _b , t _c ) which is at least one greater than a second number (N) of inverters (10) to be operated simultaneously.

Description

The invention relates to a cooking appliance apparatus according to the preamble of claim 1 and to a method for operating a cooking apparatus apparatus according to the preamble of claim 11.

Induction hobs are known from the prior art, which have two inverters and a control unit which is provided to operate the two inverters together periodically with a period duration and to operate continuously at least within the period. In order to avoid flicker and / or an intermodulation hum, which may occur in the simultaneous operation of two inverters, the control unit is intended to subdivide the period into two time intervals.

Furthermore, from the EP 1 951 003 A1 an induction hob is known, which has two inverters, which are operated together periodically with a period duration. In this case, a control unit may be provided to subdivide the period into three time intervals, wherein none of the inverters is operated in one of the three time intervals. This operating mode is used in particular for low output powers.

The object of the invention is in particular to provide a generic device with improved properties in terms of a power supply. The object is achieved by the features of claims 1 and 11, while advantageous embodiments and refinements of the invention can be taken from the dependent claims.

The invention is based on a cooking device device, in particular a cooktop device, with a plurality of inverters, in particular at least two, preferably at least four, and more preferably at least six inverters, which are each provided with at least one inductor operate, and with a control unit, which is intended to operate at least a portion of the inverter, at least in one operating state together and at least within a first time window continuously.

It is proposed that the control unit is intended to subdivide the first time window into a first number of time intervals, which is greater by at least one, preferably exactly one, than a second number of simultaneously operated inverters. By "a number of simultaneously operated inverters" should be understood at least two inverters. Thus, a number of time intervals corresponds to at least three time intervals. 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 inverters are intended to provide a high frequency heating current for the inductors. For this purpose, the inverters are operated in at least one operating state with a 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. Furthermore, a "time window" is to be understood as meaning, in particular, a time duration between 5 ms and 2.5 s, preferably between 8 ms and 2.3 s and particularly preferably between 9 ms and 2.1 s. In particular, a minimum time duration of the time window is predetermined by at least one flicker standard. Below this minimum period of time, the at least one flicker standard is violated. Furthermore, a maximum time duration of the time window is determined by a thermal inertia of the cooking utensil. The control unit is preferably provided to subdivide an operating time of the cooking appliance device into at least one, preferably at least two, advantageously a plurality of time windows, preferably with the same time duration, which follow one another directly in particular. Furthermore, "at least one part of the inverters" should be understood to mean at least two inverters. Under the phrase that the control unit is intended to at least part of the inverter at least Within a time window "continuous operation", it should be understood in particular that the at least two inverters have at least within the time window a finite output power, which is different in particular from zero. 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 inductor. Preferably, the output power corresponds at least substantially to a power consumption of the inverter. In this context, a "power consumption" of an inverter is to be understood as meaning, in particular, a power which, in particular, is provided by a power grid and is picked up by the inverter at least in an operating state. The fact that the output power "at least substantially" corresponds to the power consumption of the inverter should in this context be understood in particular to mean that the two power values deviate from one another by a maximum of 5%, preferably a maximum of 3% and particularly preferably a maximum of 1%. In this context, a "time interval" should be understood as meaning, in particular, a time duration between 0.1 ms and 1.5 s, preferably between 1 ms and 1 s and particularly preferably between 0.1 s and 0.5 s. In particular, in this case, the inverters are operated at least substantially over the time duration of one of the time intervals with a constant output power, which in particular has a relative fluctuation of at most 5%, preferably of at most 3% and particularly preferably of not more than 1%.

By means of an embodiment according to the invention, a generic device with improved properties with respect to a power supply can be provided. Furthermore, advantageously, a maximum output power can be increased and / or, in particular, an efficiency of the cooking appliance device can be increased. Furthermore, advantageously a reliability can be increased. Furthermore, the cooking appliance device can advantageously be adapted to different requirements. Furthermore, in particular a particularly uniform power output can be achieved and advantageously a selected desired power can be provided as accurately as possible.

Preferably, the control unit is provided to at least two of the operated inverters, preferably all powered inverters, in at least one of the time intervals, preferably in all time intervals, in particular in all time intervals of a time window, with at least one at least 15 kHz, preferably at least 16 kHz and particularly preferably at least 17 kHz discriminating frequency or the same frequency to operate. In this way, in particular a possible Intermodulationsbrummen can be reduced and / or avoided.

Furthermore, it is proposed that the control unit is provided to operate the inverter operated in the first time window such that for each of the operated inverters an output power averaged over the first time window corresponds at least substantially to a desired power assigned by the control unit. The expression "to be operated in this way" is to be understood in this context as meaning that the control unit is provided to select an operating parameter in such a way that an output power averaged over the first time window corresponds at least substantially to a desired power assigned by the control unit. An "operating parameter" is to be understood in particular as the time duration of the time intervals and / or the frequency and / or a duty cycle and / or the output power of the inverters. In particular, a ratio of a time period in which a periodic control signal of the inverter assumes a switch-on value within a period duration should be understood to mean the period duration of the control signal. Preferably, at a fixed switching frequency of one of the inverters by changing the duty cycle, the output power of the inverter can be changed. Furthermore, an "average output power" is to be understood as meaning, in particular, a time-averaged output power, which corresponds in particular to an arithmetic mean of the output powers of the individual time intervals of the time window, in particular of a single time window. In this context, the phrase that the average output power "at least substantially" corresponds to a desired power assigned 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 more preferably at most 1%. In this context, a "target power" is to be understood in particular as meaning a power which is to be effectively provided by at least one of the inverters. In particular, the desired power assigned by the control unit can correspond to a power selected by a user. As a result, several inverters can advantageously be operated together and, in particular, a possible intermodulation hum can be avoided.

Furthermore, it is proposed that the control unit is provided for subdividing the first time window into the first number of time intervals in such a way that successive, preferably all, time intervals within the first time window 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 at least two time intervals of a time window, which in particular immediately adjoin one another in terms of time. By the fact that two time intervals "immediately adjoin one another in time" should be understood in particular that the two time intervals, at least in terms of time, lie directly behind one another and, in particular, have at least one common time. As a result, it is possible in particular advantageously to achieve a desired power and, in particular, to achieve an advantageously uniform power output, as a result of which, in particular, flicker can be reduced.

If a total power consumption of the inverters, in particular in a time interval, at least substantially constant over at least two successive time intervals, preferably at least within the first time window, is at least substantially constant, advantageously a requested desired power can be provided and an efficiency of the cooking appliance device can be increased. Furthermore, a flicker can be at least largely avoided. Advantageously, a total power consumption of the inverters, at least in an operating state over all successive time intervals, preferably at least substantially within a time window, is at least substantially constant. In this context, a "total power consumption of the inverters" is to be understood as meaning, in particular, a sum of the power consumptions of all the operated inverters, in particular in a time interval. The term "at least essentially" constant is understood to mean in particular that a relative deviation of the total power consumption of the inverters in at least two successive time intervals is at most 2%, preferably at most 1.5% and more preferably at most 1%.

In an advantageous embodiment of the invention, it is proposed that a total power consumption of the inverters, in particular in a time interval, be at least substantially different at least in one operating state at least over two successive time intervals, preferably at least within the first time window. Advantageously, a total power consumption of the inverters is at least substantially different at least in one operating state over all time intervals, preferably at least within the first time window. The term "at least substantially" different is to be understood in particular that a relative deviation of the total power consumption of the inverter in at least two successive time intervals at least 2%, preferably at least 3% and more preferably at least 4% and especially at most 40%, preferably maximum 20% and more preferably at most 10%. In this way, in particular a maximum achievable power and / or maximum achievable target power can be increased.

Furthermore, it is proposed that an output power of at least one first inverter at least substantially increases in successive, in particular all, time intervals of the first time window and an output power of at least one second inverter at least substantially decreases in successive, in particular all, time intervals of the first time window. By an output power of an inverter "at least substantially increasing and / or decreasing" should be understood in this context that a relative deviation of the power consumption of an inverter in successive time intervals at least 2%, preferably at least 10%, preferably at least 20% and special preferably at least 40%. In this way, in particular a flicker can be reduced. Furthermore, an operational safety of the cooking appliance device can advantageously be increased, since in particular power fluctuations, in particular when switching between two intervals, can be minimized.

In a further embodiment of the invention it is proposed that the control unit is provided to at least a part of the inverters, at least in one operating state together and at least within a second time window, which is different in particular from the first time window, to operate continuously and the control unit is arranged to divide the second time window into a third number of time intervals, which is at least one, preferably exactly one, greater than a fourth number of simultaneously operated inverters , In particular, the second time window is arranged at least in time before and / or behind the first time window. Preferably, the second time window directly adjoins the first time window. In this case, the first time window and the second time window may differ in particular in at least one operating parameter. Furthermore, the third number of time intervals of the first number of time intervals and / or the fourth number of inverters to be operated can also be different from the second number of inverters to be operated. In this context, two time windows "adjoin one another directly" should be understood in particular as meaning that the two time windows, at least in terms of time, lie directly behind one another and, in particular, have at least one common time. In this way, in particular, an efficiency of the cooking device device can be increased. Furthermore, the cooking appliance device can advantageously be adapted to different operating conditions.

It is also proposed that the second time window immediately adjoin the first time window and both time windows have an equal number of time intervals with identical operating parameters, wherein the time intervals of the second time window are arranged in a reverse order compared to the time intervals of the first time window. In this context, a "reverse order" is to be understood in particular as meaning that the control unit is intended to arrange the time intervals of the first time window in the second time window such that the time intervals in the second time window are mirrored in comparison to an end point of the first time window Have sequence. In this context, an "end point of the first time window" should be understood as meaning, in particular, a point in time of the first time window, which in particular directly adjoins another time window, preferably the second time window. Alternatively, the time intervals of the second time window can also be arranged in any order. This can further reduce flicker and operational safety, especially when lifting a cooking utensils, further increased.

A method according to the invention is based on a method for operating a cooking device device, with a plurality of inverters which are each provided to operate at least one inductor and are operated continuously at least in one operating mode and at least within a first time window.

It is proposed that the first time window is subdivided into a first number of time intervals, which is at least one greater than a second number of simultaneously operated inverters.

Further advantages emerge from the following description of the drawing. In the drawing, an embodiment of the invention is 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 meaningful further combinations.

Fig. 1

ein Induktionskochfeld mit einer erfindungsgemäßen Gargerätevorrichtung mit zwei Wechselrichtern,

Fig. 2

schematische, nicht maßstabsgetreue Leistungs-Frequenz-Kurven für die zwei Wechselrichter,

Fig. 3

beispielhafte, nicht maßstabsgetreue Leistungs-Zeit-Kurven für die zwei Wechselrichter für ein erstes Zeitfenster,

Fig. 4

beispielhafte, nicht maßstabsgetreue Leistungs-Zeit-Kurven für die zwei Wechselrichter für das erste Zeitfenster und ein zweites Zeitfenster,

Fig. 5

beispielhafte, nicht maßstabsgetreue Frequenz-Zeit-Kurven für die zwei Wechselrichter und

Fig. 6

eine schematische Darstellung eines maximal erreichbaren Leistungsbereichs der erfindungsgemäßen Gargerätevorrichtung.

Show it:

Fig. 1

an induction hob with a cooking device device according to the invention with two inverters,

Fig. 2

schematic, not to scale power frequency curves for the two inverters,

Fig. 3

exemplary, not to scale power-time curves for the two inverters for a first time window,

Fig. 4

exemplary, not to scale power-time curves for the two inverters for the first time window and a second time window,

Fig. 5

exemplary, not to scale true frequency-time curves for the two inverters and

Fig. 6

a schematic representation of a maximum achievable power range of the cooking appliance device according to the invention.

FIG. 1 shows an exemplary cooking appliance designed as an induction hob with a cooking appliance device according to the invention in a schematic plan view. The cooking device has a hob plate with two heating zones 14. Furthermore, the cooking appliance device has an operating unit 16. The operating unit 16 serves for input and / or selection of a power level by a user. Furthermore For example, the cooking appliance device has two inverters 10 in the present case. The inverters 10 are arranged below the hob plate of the cooking appliance. In addition, the cooking appliance device has two inductors (not shown). The two inductors are arranged below the hob plate. Each inductor is assigned to one of the two heating zones 14. Furthermore, each inductor is assigned to one of the two inverters 10. Furthermore, the hob device has a control unit 12. The control unit 12 has at least one arithmetic unit and at least one memory unit. A control program is stored on the storage unit and can be retrieved during operation of the cooking appliance device. The control unit 12 is intended to operate the two inverters 10. Furthermore, the control unit 12 together with the inductors forms a detection unit for detecting a cooking utensil. For this purpose, the control unit 12 may use the inductors as inductive sensors for detecting the cooking utensils. Furthermore, each of the two inverters 10 is provided to supply one of the inductors with a high-frequency heating current, whereby in particular a cooking utensil placed on the hob plate can be inductively heated. However, a cooking device device according to the invention is not limited to two inverters and / or two inductors, but may have any number of inverters and / or inductors. In particular, a cooking appliance device according to the invention can also be provided for a matrix cooking field. Furthermore, a cooking device device may also have an additional switching unit, which is provided to interrupt a conduction path between inverters and inductors and / or to assign a plurality of inverters to an inductor.

In the present case, an operator can select a power level for each of the two heating zones 14 by means of the operating unit 16. Based on the selected value, the control unit 12 can set a target power P _obj1 , P _obj2 for the two inverters 10. In the present case, the power level selected by the operator directly corresponds to the target power P _obj1 , P _{obj2 of} the two inverters 10. If a cooking utensil are now to be heated, the control unit 12 and / or the detection unit first checks whether cooking utensils suitable for inductive heating are being used Heating zones 14 of the hob plate is placed. If this is the case, the control unit 12 and / or the detection unit determines in a next step in a known manner for different duty cycles a power-frequency curve of a given combination of inductor and cookware. In this case, the control unit 12 for a fixed duty cycle gradually changes a frequency of a control signal of the inverter 10, starting from a maximum frequency f _max to a respective minimum frequency f _min1 , f _min2 . By way of example, for the two inverters 10, the in FIG. 2 shown power frequency curves. In this case, the frequency of the inverters 10 is plotted on an abscissa axis 22 and the output power of the inverters 10 is plotted on an ordinate axis 24. In the present case, the first of the two inverters 10 has a maximum output power of 2300 W. The second inverter 10 has a maximum output power of 2350 W.

FIG. 3 shows exemplary, not true-to-scale power-time curves for the two inverters 10. In this case, on an abscissa axis 26 each have a time and on an ordinate axis 28 in each case the output power of the inverter 10 is plotted. In an operating state in which only one of the two inverters 10 is operated, the control unit 12 may be provided to continuously provide an output power. In an operating state in which the inverters 10 are simultaneously operated continuously with a frequency difference greater than or equal to 17 kHz, the control unit 12 is provided to operate the inverters 10 continuously. In an operating state in which the inverters 10 are to be operated simultaneously and can not be operated continuously, the control unit 12 is provided to operate the inverters 10 together and at least within a first time window T _a continuously and the first time window T _a in one Divide the number M of time intervals t _a , t _b , t _c , wherein a number N of inverters 10 are to be operated simultaneously. In this case, the control unit 12 is provided, depending on the target power P _obj1, P _obj2 the inverter 10 suitable frequencies f _1a , f _1b , f _1c , f _2a , f _2b , f _2c and / or time periods of the time intervals t _a , t _b to determine t _c . For this purpose, the control unit 12 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 _1a , P _1b , P _1c , P _2a , P _2b , P _{2c of} each inverter 10 (rows i) in the various time intervals t _a , t _b , t _c (columns j) , This results in a value P _ij for each element of the matrix A. A number of the rows corresponds to the number N of operated inverters 10. Further, a number of columns corresponds to the number M of time intervals t _a , t _b , t _c . In general, the matrix A thus corresponds to an N × M matrix. Furthermore, an M × 1 vector x is composed of a normalized time period r _{j of} the time intervals t _a , t _b , t _c , wherein a time duration of one of the time intervals t _a , t _b , t _{c is determined} in particular by a time duration of the time window T _a , T _{b is} normalized. Further, an N × 1 vector b is composed of the target power P _obj1 , P _{obj2 of} the inverters 10. In general, the matrix equation or the equation system can be solved if the number M is at least equal to the number N.

Furthermore, the time intervals t _a , t _b , t _c and / or the normalized durations r _{j have the} following relationship: $${\mathrm{.sigma..sub.r}}_{\mathrm{j}}={\mathrm{\Sigma t}}_{\mathrm{j}}/{\mathrm{T}}_{\mathrm{a}.\mathrm{b}}=\mathrm{1}$$

In this case, the control unit 12 is provided to divide the first time window T _a into a number M of time intervals, which is equal to a number N of simultaneously operated inverters, the matrix equation has no solution because there is an overdetermined system of equations (N> M).

For this reason, in this case, the control unit 12 is provided to keep a total power consumption P _Ta , P _Tb , P _{Tc of} the inverters 10 constant over successive time intervals t _a , t _b , t _c . In this case: $${\mathrm{\Sigma P}}_{\mathrm{ij}}={\mathrm{\Sigma P}}_{\mathrm{OBJ\; i}}\mathrm{for\; all\; j}$$

This also reduces a number of equations to be solved by one. Thus, a particular system of equations exists and the matrix equation can be solved (N = M). This corresponds to a state in which no flicker occurs.

The cooking device device according to the invention now proposes that the control unit 12 is provided to subdivide the first time window T _a into a first number M of time intervals t _a , t _b , t _c which is at least one greater than a second number N At the same time to be operated inverters 10. Thus, a certain equation system results even if only equation (2) is met. Thus, a total power consumption P _Ta , P _Tb , P _{Tc of} the inverter 10 at least in one Operating state at least over two successive time intervals t _a , t _b , t _{c be} different, which in particular a maximum output power of the cooking appliance device can be increased.

Furthermore, at least in one operating state, a total power consumption P _Ta , P _Tb , P _{Tc of} the inverters 10 can be constant at least over two successive time intervals t _a , t _b , t _c , whereby in particular equation (3) is fulfilled. In this case, an underdetermined equation system results in the solution of the matrix equation, which results in an infinite number of solutions for a division of the time intervals t _a , t _b , t _c . In this case, the control unit 12 is provided to select the time intervals t _a , t _b , t _c such that the most efficient operation of the cooking appliance device is made possible.

Such a control program and / or maximum and / or minimum time durations of the time intervals t _a , t _b , t _c and / or the time windows T _a , T _b are stored in the memory unit of the control unit 12c.

In the present case, two inverters 10 are to be operated simultaneously, so that the control unit 12 is intended to subdivide the first time window T _a into three time intervals t _a , t _b , t _c . The first time window T _a has a fixed time duration of 1 s. The three time intervals t _a , t _b , t _c have different durations in the present case. A first time interval t _a has a duration of 460 ms. A second time interval t _b has a duration of 490 ms. A third time interval t _c has a duration of 50 ms. Furthermore, the control unit 12 is provided to subdivide the first time window T _a into the three time intervals t _a , t _b , t _c such that successive time intervals t _a , t _b , t _c within the first time window T _a at least in one Distinguish operating parameters. In the present case, the three time intervals t _a , t _b , t _c differed in a time duration of the time intervals t _a , t _b , t _c , a frequency f _1a , f _1b , f _1c , f _2a , f _2b , f _2c of two inverters 10 and in an output power P _1a , P _1b , P _1c , P _2a , P _2b , P _{2c of} the two inverters 10th

The first inverter 10 has a constant output power P _1a and / or a constant frequency f _1a over a total duration of the first time interval t _a . Furthermore, the first inverter 10 has an output power P _1a over the entire duration of the first time interval t _a , which corresponds to the maximum output power of the first inverter 10. The first inverter 10 thus has in the present Case over the entire duration of the first time interval t _a an output power P _1a of 2300 W. Furthermore, the first inverter 10 has a frequency f _1a over the entire duration of the first time interval t _a , which corresponds to the minimum frequency f _{min1 of} the first inverter 10 (cf. FIG. 2 ). The first inverter 10 has a frequency f _1a of 41.7 kHz over the entire duration of the first time interval t _a . Furthermore, the first inverter 10 over an entire duration of the second time interval t _b a constant output power P _1b and / or a constant frequency f _1b. In this case, the first inverter 10 has a smaller output power P _1b in the second time interval t _b than in the first time interval t _a . In the present case, the first inverter 10 has an output power P _1b of 1630 W over the entire duration of the second time interval t _b . Furthermore, the first inverter 10 has a frequency f _1b of 46.3 kHz over the entire duration of the second time interval t _b .

In this case, the first inverter 10 has a greater frequency f _1b in the second time interval t _b than in the first time interval t _a . Furthermore, the first inverter 10 has a constant output power P _1c and / or a constant frequency f _1c over a total duration of the third time interval t _c . In this case, the first inverter 10 has a smaller output power P _1c in the third time interval t _c than in the second time interval t _b . In the present case, the first inverter 10 has an output power P _1c of 850 W over the entire duration of the third time interval t _c . The first inverter 10 has a larger frequency f _1c in the third time interval t _c than in the second time interval t _b . Furthermore, the first inverter 10 has a frequency f _1c of 58.8 kHz over the entire duration of the third time interval t _c .

Furthermore, the control unit 12 is provided to operate the first inverter 10 operated in the first time window T _{a in} such a way that for the first inverter 10 an output power P _ave1 averaged over the first time window T _a corresponds to the setpoint power P _obj1 assigned by the control unit 12 , In the present case, the desired power P _obj1 requested by the control unit 12 and / or an operator P _{obj1 is} 1900 W. The output power P _{ave1 of} the first inverter 10 averaged over the first time window T _a is also 1900 W.

The second inverter 10 has a constant output power P _2a and / or a constant frequency f _2a over the entire duration of the first time interval t _a . The second inverter 10 has in the present case over the entire duration of first time interval t _a an output power P _2a of 710 W. Furthermore, the second inverter 10 has a frequency f _2a of 58.7 kHz over the entire duration of the first time interval t _a . Further, the second inverter 10 over the entire duration of the second time interval t _b a constant output power P _2b and / or a constant frequency f _2b. In this case, the second inverter 10 has a larger output power P _2b in the second time interval t _b than in the first time interval t _a . In the present case, the second inverter 10 has an output power P _2b of 1600 W over the entire duration of the second time interval t _b . In the second time interval t _{b, the} second inverter 10 has a smaller frequency f _2b than in the first time interval t _a . Furthermore, the second inverter 10 has a frequency f _2b of 46.3 kHz over the entire duration of the second time interval t _b . Furthermore, the second inverter 10 has a constant output power P _2c and / or a constant frequency f _2c over the entire duration of the third time interval t _c . Furthermore, the second inverter 10 has an output power P _2c over the entire duration of the third time interval t _c , which corresponds to the maximum output power of the first inverter 10. In this case, the second inverter 10 has a larger output power P _2c in the third time interval t _c than in the second time interval t _b . The first inverter 10 thus has an output power P _2c of 2350 W in the present case over the entire duration of the third time interval t _c . Furthermore, the second inverter 10 has a frequency f _2c over the entire duration of the third time interval t _c , which corresponds to the minimum frequency f _{min2 of} the second inverter 10 (cf. FIG. 2 ). The second inverter 10 thus has a smaller frequency f _2c in the third time interval t _c than in the second time interval t _b . The second inverter 10 has a frequency f _2c of 41.8 kHz over the entire duration of the third time interval t _c .

In this case, the control unit 12 is provided for operating the second inverter 10 operated in the first time window T _{a in} such a way that for the second inverter 10 an output power P _{ave 2} averaged over the first time window T _a corresponds to the setpoint power P _{obj 2} assigned by the control unit 12 , In the present case, the requested by the control unit 12 and / or an operator target power P _obj2 1200 W. The averaged over the first time window T _a output power P _{ave2 of} the second inverter 10 is also 1200 W.

Furthermore, the control unit 12 is provided to the two inverters 10 in at least one of the time intervals t _a, t _b, t _c to operate with differing by at least 15 kHz frequency or the same frequency. In this case, the first inverter 10 has a higher output power P _1a and / or a smaller frequency f _1a than the second inverter 10 over the entire duration of the first time interval t _a . Over the entire duration of the second time interval t _b , the first inverter 10 has a higher output power P _1b than the second inverter 10. In this case, however, the first inverter 10 has the same frequency f _1b as the second inverter 10 over the entire duration of the second time interval t _b . Thus, the two inverters 10 are operated at the same frequency over the entire duration of the second time interval t _b . In addition, the first inverter 10 has a smaller output power P _1c and / or a higher frequency f _1c than the second inverter 10 over the entire duration of the third time interval t _c . Thus, the two inverters 10 are operated over the entire duration of the first time interval t _a and over the entire duration of the third time interval t _c with a frequency differing by 17 kHz. Further, the output power P _1a , P _1b , P _{1c of} the first inverter 10 increases in successive time intervals t _a , t _b , t _{c of} the first time window T _a and the output power P _2a , P _2b , P _{2c of} the second inverter 10 decreases in successive ones Time intervals t _a , t _b , t _{c of} the first time window T _a .

The total power consumption P _Ta , P _Tb , P _Tc in one of the time intervals t _a , t _b , t _c results in the present case by a summation of the output power P _1a , P _1b , P _{1c of} the first inverter 10 in one of the time intervals t _a , t _b , t _c and the output power P _2a , P _2b , P _{2c of} the second inverter 10 in the same time interval t _a , t _b , t _c . In the present case, the total power consumption P _Ta , P _Tb , P _{Tc of} the two inverters 10 is different, at least in one operating state, over at least two successive time intervals t _a , t _b , t _c , and differs in particular by at least 200 W, whereby in particular one maximum output power can be increased. Alternatively, however, a total power consumption of the inverters, at least in one operating state, may also be constant over at least two successive time intervals.

FIG. 4 shows exemplary power-time curves for the two inverters 10 for the first time window T _a and a second time window T _b during FIG. 5 exemplary Frequency-time curves for the two inverters 10 for the first time window T _a and the second time window T _b shows. In FIG. 4 is on an abscissa axis 30 a time and plotted on an ordinate axis 32, the output of the inverter 10. In FIG. 5 on an abscissa axis 34 a time and on an ordinate axis 36, the frequency of the inverter 10 is plotted. In the present case, the second time window T _b directly adjoins the first time window T _a . In this case, the control unit 12 is provided to operate the two inverters 10 at least in one operating state together and at least within the second time window T _b and subdivide the second time window T _b into a third number of time intervals t _a , t _b , t _c which is at least one greater than a fourth number of simultaneously operated inverters 10 within the time window T _b . In the present case, the second time window T _{b has} a fixed time duration, which is identical to the time duration of the first time window T _a . Thus, the second time window T _{b has} a fixed time duration of 1 s. Alternatively, in this case, however, a time duration of a second time window may also be different at a time duration of a first time window. Furthermore, it can also be provided to vary a plurality of time windows with a network frequency and / or a multiple of the network frequency, in particular a double network frequency.

Furthermore, the two inverters 10 are also operated simultaneously in the second time window T _b , so that the control unit 12 is provided for the second time window T _b in three time intervals t _a , t _b , t _c , which in particular at the three time intervals t _a , t _b , t _c , in which the first time window T _{a is} divided, are identical to divide. Thus, the two time windows T _a , T _{b have} an equal number of time intervals t _a , t _b , t _c with identical operating parameters, in particular frequencies and output powers, wherein the time intervals t _a , t _b , t _{c of} the second time window T _b however, are arranged in _a reverse order compared to the time intervals t _a , t _b , t _{c of} the first time window T _a . In this case, corresponds to an over the second time window T _b averaged output power P _ave3 of the first inverter 10 via the first time window T _a average output power P _ave1 of the first inverter 10. Further, on the second time window T _b averaged output power P _ave4 of the second inverter 10 corresponds to The output power P _{ave2 of} the second inverter 10 averaged over the first time window T _a thus corresponds to an output power P _{ave 3} , P _{ave 4 of} a target power P _obj1 , P _obj2 assigned by the control unit 12 for both inverters 10 averaged over the second time window T _b .

FIG. 6 schematically shows a maximum achievable power range of the two inverters 10. In this case, the output power of the first inverter 10 is plotted on an abscissa axis 38 and the output power of the second inverter 10 is plotted on an ordinate axis 40. The cooking appliance device according to the invention has a larger maximum power range than a maximum power range of a cooking appliance device from the prior art. The area 18 shows a power range which is unattainable by a cooking appliance device of the prior art, in particular because the cooking appliance device is operated in a state in which no flicker occurs. In this case, a maximum power range of about 94% of a total power range can be achieved. The area 20 shows a power range, which is unattainable by a cooking appliance device according to the invention. In the present case, the maximum power range is limited only by a maximum supply voltage and / or a maximum current and / or by a flicker limit value of a Flickernorm. Overall, in the present case, a maximum power range of about 98% of a total power range can thus be achieved. The maximum achievable power range thus increases in comparison to the maximum achievable power range of the prior art, since operation in a range between a state without flicker and the flicker limit value is possible.

reference numeral

10

inverter

12

control unit

14

heating zone

16

operating unit

18

power range

20

power range

22

abscissa

24

axis of ordinates

26

abscissa

28

axis of ordinates

30

abscissa

32

axis of ordinates

34

abscissa

36

axis of ordinates

38

abscissa

40

axis of ordinates

A

matrix

b

vector

f _max

High frequency

f _min1

minimum frequency

f _min2

minimum frequency

f _1a

frequency

f _1b

frequency

f _1c

frequency

f _2a

frequency

_2b

frequency

f _2c

frequency

N

M Number of time intervals Number of inverters

P _ave1

Average output power

P _ave2

Average output power

P _ave3

Average output power

P _ave4

Average output power

P _obj1

target power

P _obj2

target power

P _Ta

Total power consumption

P _Tb

Total power consumption

P _Tc

Total power consumption

P _1a

output

P _1b

output

P _1c

output

P _2a

output

P _2b

output

P _2c

output

P _ij

matrix value

r _j

Normalized duration

T _a

Time window

T _b

Time window

t _a

time interval

t _b

time interval

t _c

time interval

x

vector

Claims (11)

Cooking appliance device, in particular hob device, with a plurality of inverters (10) which are each provided to operate at least one inductor, and with a control unit (12) which is provided to at least a part of the inverters (10) in at least one Operating state together and at least within a first time window (T _a , T _b ) to operate continuously, characterized in that the control unit (12) is provided to the first time window (T _a , T _b ) in a first number (M) Divide time intervals (t _a , t _b , t _c ), which is at least one greater than a second number (N) of simultaneously operated inverters (10). Cooking apparatus according to claim 1, characterized in that the control unit (12) is provided to at least two of the operated inverters (10) in at least one of the time intervals (t _a , t _b , t _c ) with at least one differing by at least 15 kHz Frequency or the same frequency. Cooking device according to claim 1 or 2, characterized in that the control unit (12) is provided to operate in the first time window (T _a , T _b ) operated inverter (10) such that for each of the powered inverter (10) an output power (P _ave1 , P _ave2 ) averaged over the first time window (T _a , T _b ) _corresponds at least substantially to a desired power (P _obj1 , P _obj2 ) assigned by the control unit (12). Cooking appliance device according to one of the preceding claims, characterized in that the control unit (12) is provided in _{such a way} that the first time window (T _a , T _b ) in the first number (M) at time intervals (t _a , t _b , t _c ) subdivide that successive time intervals (t _a , t _b , t _c ) within the first time window (T _a , T _b ) differ in at least one operating parameter. Cooking appliance device according to one of the preceding claims, characterized in that a total power consumption (P _Ta , P _Tb , P _Tc ) of the inverter (10) at least in an operating state at least over two consecutive time intervals (t _a , t _b , t _c ) at least Is essentially constant. Cooking appliance device according to one of the preceding claims, characterized in that a total power consumption (P _Ta , P _Tb , P _Tc ) of the inverter (10) at least in an operating state at least two consecutive time intervals (t _a , t _b , t _c ) at least substantially is different. Cooking device according to one of the preceding claims, characterized in that an output power (P _1a , P _1b , P _1c ) of at least one first inverter (10) in successive time intervals (t _a , t _b , t _c ) of the first time window (T _a , T _b ) at least substantially increases and an output power (P _2a , P _2b , P _2c ) of at least one second inverter 10 at successive time intervals (t _a , t _b , t _c ) of the first time window (T _a , T _b ) at least substantially decreases , Cooking appliance device according to one of the preceding claims, characterized in that the control unit (12) is provided to at least a part of the inverter (10) at least in one operating state together and at least within a second time window (T _a , T _b ) to operate continuously and the control unit (12) is arranged to subdivide the second time window (T _a , T _b ) into a third number of time intervals (t _a , t _b , t _c ) which is at least one greater than a fourth number at a time Inverters to be operated (10). Cooking apparatus according to claim 8, characterized in that the second time window (T _a , T _b ) directly adjacent to the first time window (T _a , T _b ) and both time windows (T _a , T _b ) an equal number of time intervals (t _a , t _b , t _c ) having identical operating parameters, wherein the time intervals (t _a , t _b , t _c ) of the second time window (T _a , T _b ) in a compared to the time intervals (t _a , t _b , t _c ) of the first time window (T _a , T _b ) are arranged in reverse order. Cooking appliance, in particular induction hob, with a cooking appliance device according to one of the preceding claims. Method for operating a cooking device device, in particular according to one of claims 1 to 9, with a plurality of inverters (10), which are each provided to operate at least one inductor and at least a part of the inverters (10) at least in one operating mode together and at least within a first time window (T _a , T _b ) are continuously operated, characterized in that the first time window (T _a , T _b ) into a first number (M) at time intervals (t _a , t _b , t _c ) divided which is at least one greater than a second number (N) of inverters (10) to be operated simultaneously.

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