EP2432296A2 - Heating device - Google Patents

Abstract

The device has an allocation unit (14) allocating one of frequency units (10) to one of heating zones (12a, 12b) formed by heating units (11) based on a variable criterion e.g. heating time, temperature, cooking condition and power level, of the heating zones. The frequency units supply high frequency alternating current to the heating units. The allocation of the frequency units to the heating zones is defined by a switching position of a switching unit (26). A switching element (28) i.e. MOSFET, is attached to each heating unit for interrupting power supply of the individual heating units. An independent claim is also included for a method for operating a heating device.

Description

The invention relates to a heating device according to the preamble of claim 1.

Matrix hobs with a large number of inductors are known from the prior art, which are arranged in a matrix and can be flexibly combined into freely definable heating zones. Each inductor is uniquely associated with an inverter that generates a high frequency heating current to operate the inductor. A frequency of the heating current can be set by a control unit of the induction hob independently of the heating frequency of the other inductors.

The object of the invention is, in particular, to provide a generic heating device which combines low costs with a comfortable operability. The object is achieved by the features of claim 1, while advantageous embodiments and refinements of the invention can be taken from the dependent claims and an independent claim.

The invention is based on a heating device with frequency units, heating units and at least one allocation unit which is provided to allocate at least one frequency unit to at least one heating zone formed by at least one of the heating units.

It is proposed that the allocation unit is provided for allocating at least one frequency unit to at least two heating zones as a function of at least one variable criterion. By "provided" is to be understood here and below in particular specially designed and / or equipped and / or programmed. A "frequency unit" is to be understood in particular as a unit which generates an oscillating electrical signal of a specific heating frequency for a heating unit and which preferably comprises at least one inverter. A "heating unit" is to be understood in particular as meaning a unit which is intended to heat a cookware set up on a cooktop plate above the heating unit. Preferably, the heating unit comprises an inductor coil with high-frequency alternating current the heating frequency is fed from a frequency unit. A "heating zone" is to be understood as meaning at least one heating unit and preferably a combination of a plurality of heating units, which thereby form, in particular, a contiguous surface area of the hob plate which is provided for heating a cooking utensil parked on the surface area. Preferably, all of a heating zone associated heating units are powered by a single frequency unit with electrical energy. An "allocation unit" is to be understood in particular as an electronic unit which is preferably at least partially integrated in a control and / or regulating unit of a hob, in particular an induction hob. The allocation unit preferably comprises a computing unit and, in particular in addition to the computing unit, a memory unit with a mapping program stored therein. A "variable criterion" is to be understood in particular as meaning an assignment made by an operator and / or a criterion having a variable parameter, which may assume different characteristic values, in particular in different operating modes. The fact that a frequency unit is "assigned" to at least two heating zones means, in particular, that a live connection, in particular in the form of an electrical line, is provided between the frequency unit and the heating zones.

By means of such an embodiment, a larger number of heating zones can be operated with an advantageously low number of frequency units. As a result, costs can be saved, and yet a high ease of use can be achieved. Advantageously, each frequency unit is assigned exactly one heating zone as long as the number of heating zones is less than the number of available frequency units. However, if the number of heating zones is greater than the number of available frequency units, the allocation unit assigns at least one frequency unit to at least two heating zones, taking into account the variable criterion, so as to achieve advantageous operation of all existing heating zones. As a result, a high level of operating comfort can be achieved. Advantageously, the allocation unit allows at least two different operating modes for the creation of new heating zones, in particular one or more manual modes and / or one or more automated modes. A "manual mode" is to be understood here in particular as a mode in which an operator intervenes in the assignment by means of at least one manual input. An "automated mode" is to be understood in particular as a mode in which the allocation unit automatically makes an assignment by evaluating at least one criterion.

Advantageously, the heating zones are formed by a combination of a plurality of heating units arranged in a matrix. The heating units being arranged in a matrix should be understood to mean, in particular, that the heating units are arranged in a regular grid under the hob plate, and a region of the hob plate which can be heated by means of the heating units is preferably at least 60%, in particular at least 70%. advantageously comprises at least 80% and particularly advantageously at least 90% of a total area of the hob plate. In particular, the matrix comprises at least 10, in particular at least 20, advantageously at least 30 and particularly advantageously at least 40 heating units. In this way, a particularly flexible usable hob can be created.

It is also proposed that the variable criterion is an assignment by an operator. An "assignment by an operator" is understood in particular to mean that an operator decides which frequency unit is assigned to which heating zones. As a result, high transparency of operation can be achieved. Advantageously, the allocation unit is provided to issue an operating request, in particular acoustically and / or visually on an operating display, if in addition to already operated heating zones another heating zone is added and particularly advantageous if the number of heating zones is greater than the number by the further heating zone the frequency units. As a result, a particularly comfortable operation can be achieved. In particular, if the same dish is prepared in several cookware, the heating zones associated with the cookware can be assigned to a frequency unit.

In a preferred embodiment, it is proposed that the variable criterion is a power level selected by an operator of at least one heating zone. A "power level selected by an operator" is to be understood in particular as meaning a set power level for a heating zone and / or in particular a power level selected by an operator when setting up a cookware for the newly created heating zone. By such a configuration, a comfortable operation can be achieved. Preferably, the allocation unit in the formation of another Heating zone by setting up another cookware an audible and / or visual control prompt for entering a power level for the new heating zone. The allocation unit then decides preferably based on the selected power levels, in particular all heating zones, which frequency units are assigned to which heating zones, so that an actual heating power of each heating zone of the selected power level comes as close as possible. Advantageously, the allocation unit summarizes those heating zones whose selected power levels are identical. As a result, a particularly comfortable operation can be achieved. When allocating the frequency units to the heating zones, the allocation unit advantageously takes into account that a maximum power of a frequency unit is maintained. As a result, an unexpected loss of heating power can be avoided at least one heating zone.

In a further embodiment of the invention, it is proposed that the variable criterion is an elapsed heating time of at least one heating zone. A "heating time" is to be understood here in particular as a time span which has elapsed since an activation and preferably since a last setting of a power level not equal to zero of the heating zone. In this way, a particularly advantageous information content can be developed, which can be advantageously used when assigning at least one frequency unit to at least two heating zones. In particular, the allocation unit is intended to take into account the heating time of a heating zone in addition to the power level selected by an operator when assigning the frequency units to the heating zones. As a result, an intelligent control can be achieved, which reduces the heating power at those heating zones, where this has the least disturbing effect. This can further relieve an operator.

It is further proposed that the variable criterion is a temperature of at least one heating zone. A "temperature of a heating zone" is to be understood here in particular as meaning a temperature of a surface area of the cooking field plate assigned to the heating zone and / or of a cookware on the hob plate. Therefore, at least some and in particular all heating units of the hob advantageously have a temperature sensor. As a result, a frequency unit can be assigned to several heating zones with a similar surface temperature. Advantageously, the allocation unit is provided to the temperature of a heating zone in addition to the selected by an operator power level in the allocation of the frequency units to consider the heating zones. As a result, an intelligent control can be achieved, which reduces the heating power at those heating zones whose temperatures are above a specified temperature threshold. This can contribute to a relief of an operator and improve a cooking result advantageous.

In a further embodiment, it is proposed that the variable criterion is at least one state of the gas. In this context, a "cooking state" is to be understood as meaning, in particular, a drainage status of a cooking program and / or a state of a cooking item, in particular a phase transition and particularly advantageously a boiling of at least a portion of the item to be cooked. As a result, a cooking result can be advantageously improved. Preferably, the allocation unit is provided to take into account the state of cooking a food on a heating zone in addition to the selected by an operator power level in the allocation of the frequency units to the heating zones. As a result, an intelligent control can be achieved, which reduces the heating power at those heating zones, where this is possible by a state of cooking. As a result, ease of use can be increased particularly advantageous.

In an advantageous embodiment, it is proposed that the variable criterion is a difference and / or a time profile of at least one variable. A "size" here is to be understood in particular as meaning a physical parameter, in particular a power and / or an energy and / or a temperature and / or a time and / or a voltage and / or an electric current. As a result, an advantageous better cooking result can be achieved.

It is further proposed that the variable criterion is an overall performance of all heating zones selected by an operator. If the sum of the power levels of all heating zones selected by an operator exceeds the total power of all frequency units, this preferably takes the allocation unit into account. Preferably, the heating zones are prioritized according to various criteria which appear appropriate to a person skilled in the art, so that the heating zones of high priority are operated with the selected power stage, the heating power required for this being subtracted from the other heating zones of lower priority. By such a configuration, a temporary peak performance can be intercepted.

In an advantageous embodiment of the invention, it is proposed that the allocation unit is provided to perform a clocked operation of at least one of the heating zones. A "clocked operation" is to be understood as an operation of a heating unit in which the heating unit is switched off temporarily and in particular during integer half-waves of the frequency unit. As a result, any average heating power for a heating unit can be achieved. If in particular a frequency unit is assigned to at least two heating zones, at least one of the heating zones can be operated in a clocked manner. As a result, different average heating capacities for the heating units of the two heating zones can be achieved. If in particular all heating units have a switching element, in particular a semiconductor switch and preferably a MOSFET, for deactivating the heating unit, any number of heating zones with arbitrary power levels can be operated with a limited number of frequency units until a maximum power of each frequency unit is reached.

Furthermore, a hob, in particular an induction hob with a heating device according to the invention is proposed.

In addition, a method with a heating device with frequency units and heating units is proposed in which at least one frequency unit is assigned to at least one heating zone formed by at least one heating unit, wherein at least one frequency unit is assigned at least two heating zones depending on at least one variable criterion.

Further advantages can be found in the following drawing descriptions. In the drawings, an embodiment of the invention is shown. The drawings, the descriptions 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

eine schematische Darstellung eines Matrixinduktionskochfelds mit einer Zuordnungseinheit, Frequenzeinheiten und einer Schalteinheit in einer perspektivischen Ansicht,

Fig. 2a

das Matrixinduktionskochfeld mit vier Heizzonen in einer Draufsicht,

Fig. 2b

das Matrixinduktionskochfeld mit fünf Heizzonen in einer Draufsicht,

Fig. 3a

ein Ablaufdiagramm für eine Erstellung von Heizgruppen,

Fig. 3b

ein Ablaufdiagramm für eine Zuordnung von Heizzonen zu den Heizgruppen,

Fig. 3c

ein Ablaufdiagramm für eine Leistungspriorisierung.

Show it:

Fig. 1

1 is a schematic representation of a matrix induction cooking field with an allocation unit, frequency units and a switching unit in a perspective view,

Fig. 2a

the matrix induction hob with four heating zones in a plan view,

Fig. 2b

the matrix induction hob with five heating zones in a plan view,

Fig. 3a

a flow chart for creating heating groups,

Fig. 3b

a flow chart for an assignment of heating zones to the heating groups,

Fig. 3c

a flow chart for performance prioritization.

Fig. 1 shows in a schematic representation obliquely from above a heating device 18 of an induction cooktop, which has 64 heating units 11 in the form of inductor coils 20 which are arranged in a square 8x8 grid. Furthermore, the heating device 18 has four frequency units 10, each comprising an inverter 22 and which are provided to supply the heating units 11 in a known manner with high-frequency alternating current. Furthermore, the heating device 18 has an allocation unit 14 which is provided to form heating zones 12a, 12b from the heating units 11 which are at least partially covered by the cooking utensils 24a, 24b and to assign at least one frequency unit 10 to these heating zones 12a, 12b. To determine a set-up position of a cookware 24a, 24b, the heating device 18 has pot detection means (not shown). The assignment of the frequency units 10 to the heating zones 12a, 12b is defined by a switching position of a switching unit 26. In addition to the switching unit 26, which is provided for an assignment of the frequency units 10 to the heating units 11, each heating unit 11 is assigned its own switching element 28 in the form of a MOSFET, which is provided for interrupting the power supply of the individual heating units 11.

As long as according Fig. 2a only four cookware 24c-f are placed on a hob plate 30 of the induction cooktop, each of the four heating zones 12c-f corresponding to the cooking utensils 24c-f is assigned a frequency unit 10, respectively. When setting up a fifth cookware 24g, the number of heating zones 12c-f exceeds the number of frequency units 10. A heating zone 12g corresponding to the fifth cookware 24g is added to one of the already existing heating zones 12c-f, as shown in FIG Fig. 2b indicated by the different hatching. Here, the heating zones 12f and 12g are operated by a single common frequency unit 10. The allocation unit 14 is provided to allocate at least one frequency unit 10 depending on at least one variable criterion at least two heating zones 12f, 12g. In addition, the allocation unit 14 can also be provided to allocate at least two frequency units 10 depending on at least one variable criterion of a heating zone 12g. As a result, a heating power exceeding a maximum power of a single frequency unit 10 can be achieved for a heating zone 12g.

The induction hob has a choice of two operating modes for the assignment of frequency units 10 to heating zones 12f, 12g. This is a manual mode and an automated mode with little interaction with an operator. In alternative embodiments of the invention, the cooktop may also have only a manual mode or even an automated mode.

In manual mode, the variable criterion is an assignment by an operator. As in the Fig. 2a and 2b As shown, the induction hob in a side portion of the cooktop panel 30 has an operating device 32. The operating device 32 includes touch-sensitive buttons. Furthermore, the operating device 32 has a display unit 34. The display unit 34 is in the form of a touchscreen. When setting up the fifth cookware 24g and with a related creation of a new cooking zone 12g, the allocation unit 14 outputs a visual control request on the display unit 34 and additionally an audible signal to alert an operator to a necessary input. By means of the operating device 32, the operator can then select an already existing heating zone 12c-f. The newly created heating zone 12g and the selected heating zone 12f are then operated by the same frequency unit 10 and therefore also with the same heating power per heating unit 11. The operator thereby obtains the possibility of creating a performance-dependent cooking zone from a plurality of heating zones 12g, 12f.

Should the sum of the set power levels of the manually selected heating zones 12g, 12f exceed a maximum power of a frequency unit 10, then the operator is visually and acoustically notified of this and asked to select a different assignment. Alternatively or additionally, the heating power of the selected heating zones 12g, 12f can also be reduced, in particular if each assignment of heating zones 12g, 12f would exceed the maximum power of a frequency unit 10.

In the automated mode, the variable criteria are selected power levels, namely differences of two power levels, a selected total power, elapsed heating times and temperatures of the heating zones 12c-g, and a respective state of cooking of a food on the heating zones 12c-g. The allocation unit 14 is designed to carry out a method with a heating device with frequency units 10 and heating units 11, in which at least one frequency unit 10 is allocated to at least one heating zone 12a-g formed by at least one of the heating units 11, wherein at least one frequency unit 10 depends on at least a variable criterion at least two heating zones 12f, 12g is assigned. The assignment takes place according to the in the Fig. 3a . 3b and 3c shown flowcharts. Fig. 3a shows the flow diagram of a Heizgruppenerstellung to create new heating groups, wherein a heating group is defined by the fact that it comprises at least one heating zone 12c-g and the heating zones 12c-g of the heating group are operated by a single frequency unit 10. Fig. 3b shows the flowchart of a heating group assignment for the assignment of heating zones 12c-g to the previously created heating groups. 3 c shows the flowchart of a performance prioritization for prioritizing the heating zones 12c-g in the case of a choice of too high a total power of all heating zones 12c-g. Heating group creation is started whenever a parameter of the induction hob is changed. Additionally or alternatively, the Heizgruppenerstellung can be restarted at regular time intervals, in particular at intervals of 60 s. In this way it can be ensured that in each case an optimal allocation of heating zones 12c-g to heating groups is made.

In the following, the index "i" designates in each case a parameter of a heating zone H _i , eg a selected power stage P _i , a heating time t _i and a temperature T _i , and the index "k" respectively a parameter of a heating group G _k , eg a heating power P _k . The number of available frequency units 10 of the induction hob is denoted by "X".

When creating the heating groups G _k is as in Fig. 3a shown proceeded. In a first step 36 it is determined whether the sum of the selected power levels P _{i of} all heating zones H _i exceeds a maximum total power of all frequency units 10. If this is the case, then in step 37 with the performance prioritization according to Fig. 3c continued.

If the maximum total power of all frequency units 10 is sufficient, then a step 38 is continued. In step 38, for each heating zone H _i whose heating time t _{i is} less than a predetermined lower time limit t _1, a separate heating group G _{k is} created so that each of these heating groups G _k comprises exactly one heating zone H _i . This makes it possible to ensure that a heating zone H _i with a low heating time t _i and, in particular, those which have just been created are operated with the selected power stage P _i . A determination of the lower time limit t ₁ takes place in a current cooking program due to specifications of the cooking program or in a program-less cooking by a stored numerical value. In a further step 39, a check is made as to whether the number of heating groups G _k created in step 38 exceeds the number of frequency units 10. If this is the case, the automatic assignment is aborted in favor of a manual and it is issued in step 40, an operating request, which prompts an operator to manually assign the frequency units 10 to the heating zones H _i . In a further step 42 it is checked whether the number of heating groups G _{k is} exactly X. If this is the case, then in step 43 with the Heizgruppenzuordnung according to Fig. 3b continued. If the number of heating groups G _{k is} still smaller than X, then in a further step 44 for heating zones H _i whose heating time t _{i is} less than a defined lower time limit t ₂ and whose selected power level P _{i is} 100%, further heating groups G _{k are} formed until a maximum of X heating groups G _{k are} reached. Heating zones H _i with a small heating time t _i are considered here first. This makes it possible to ensure that a maximum power level P _i at a heating zone H _{i is maintained} at least during a predefined time. This can be advantageous in particular during a frying process. A determination of the lower time limit t ₂ takes place in a running cooking program due to specifications of the cooking program or in a program-less cooking process by a stored numerical value.

A renewed check of the number of previously formed heating groups G _k takes place in step 45. If exactly X heating groups G _{k were} reached in step 44, then the heating group assignment is performed in step 46 Fig. 3b continued. If less than X heating groups G _k created, the remaining heating groups G _{k are created} in a final step 47. In this step, a heating group G _{k is} formed in each case for heating zones H _i with the same power level P _i until a total of X heating groups G _k exist. It should be noted that a total power level of a heating group G _k remains below a maximum power of a single frequency unit 10. Exceeds the overall performance level for an assignment a heating group G _k, the maximum power of a single frequency unit 10, this assignment is discarded. If only heating zones H _i with different power level P _i exist or matching pairs exceed the maximum power of a single frequency unit 10 in their total power stage, individual heating zones H _{i are assigned to} a heating group G _k in the order of descending power levels P _i .

At the end of Heizgruppenerstellung exist a maximum of X heating groups G _k , each comprising one or more heating zones H _i . Each of these heater groups G _k is assigned to a frequency unit 10 of the respective heating group G _k feeds the heating zones H _i with a heating power P _k, where the heating power P _k of the power level of the heating group G _k corresponds to P _i of the first heating zone H _i. Furthermore, there are a lot of allocationless heating zones H _i .

If a maximum of X heating groups G _{k have been} created, then the allocation-less heating zones H _i according to the flowchart in FIG Fig. 3b assigned. Starting from the unadjusted heating zone H _i with the largest power level P _{i selected} , it is checked in step 50 whether the selected power level P _{i of} the heating zone H _{i is} greater than the heating power P _{k of} the heating group G _k . It is thus checked whether in an assignment of the heating zone H _i to the heating group G _k, the power level P _{i of} the heating zone H _{i is} increased or decreased. Both are acceptable only under certain conditions.

If an assignment would lead to an increase in the power level P _i , it is checked in step 52 whether the temperature T _{i of} the heating zone H _i has already exceeded an upper temperature limit T _o . A determination of the upper temperature limit T _o is carried out at a current cooking program due to specifications of the cooking program or a program-less cooking by a stored numerical value. If so, then a takeover of the heating zone H _{i is} rejected in the heating group G _k and step 50 is repeated with the allocation-less heating zone H _i with the next smaller power level P _i . If the temperature T _{i of} the heating zone H _i has not yet exceeded the upper temperature limit value T _o , then it is checked in step 54 whether the heating time t _i has exceeded an upper time limit t ₃ . In this way, it is ruled out that the power level P _i is suddenly increased when the heating zone H _i has been operated for some time. A determination of the upper time limit t ₃ takes place in a running cooking program due to specifications of the cooking program or in a program-less cooking by a stored numerical value. If the heating time t _i has already exceeded the upper time limit t ₃ , then a takeover of the heating zone H _i into the heating group G _{k is} discarded and step 50 is repeated with the allocationless heating zone H _i with the next lower power level P _i . If the heating time t _{i is} still equal to or less than the upper time limit t ₃ , it is finally checked in step 56 whether the relative difference (P _k -P _i ) / P _k between the heating power P _{k of} the heating group G _k and the selected Power level P _{i of} the heating zone H _{i is} less than 20%. Alternatively, it can also be checked at this point whether the difference between the heating power P _{k of} the heating group G _k and the selected power level P _{i of} the heating zone H _{i is} minimal in comparison to the differences between the heating power P _{k of} the heating group G _k and the others Power levels P _{i of} the allocationless heating zones H _i . If the relative difference is equal to or greater than 20% or a smaller difference exists, then a recording of the heating zone H _i in the heating group G _{k is} discarded and step 50 is repeated with the allocationless heating zone H _i with the next lower power level P _i .

If an assignment would lead to a reduction of the power level P _i , it is checked in step 58 whether the temperature T _{i of} the heating zone H _i has already fallen below a lower temperature limit T _U. As a result, further cooling of a heating zone H _i that is already too cold can be avoided. A determination of the lower temperature limit T _U is carried out at a running cooking program due to specifications of the cooking program or in a program-less cooking by a stored numerical value. If the temperature T _i has already fallen below the lower temperature limit T _U , then a recording of the heating zone H _i in the heating group G _{k is} discarded and step 50 is repeated with the allocation-less heating zone H _i with the next smaller power level P _i . If the temperature T _{i is} still at or above the lower temperature limit T _U , then it is finally also checked in step 56 whether the relative difference (P _k -P _i ) / P _k between the heating power P _{k of} the heating group G _k and the selected Power level P _{i of} the heating zone H _{i is} less than 20%. Alternatively, it can also be checked at this point whether the difference between the heating power P _{k of} the heating group G _k and the selected power level P _{i of} the heating zone H _{i is} minimal in comparison to the differences between the heating power P _{k of} the heating group G _k and the others Power levels P _{i of} the allocationless heating zones H _i . If the relative difference is equal to or greater than 20% or there is a smaller difference, then a recording of the heating zone H _i in the Heating group G _k discarded and step 50 is repeated with the allocation without heating zone H _i with the next smaller power level P _i .

Finally, if a potential heating zone H _{i is found} for assignment to the heating group G _k , it is checked in step 60 whether the maximum power of a frequency unit 10 is exceeded when adding the heating zone H _i to the heating group G _k . If so, a takeover of the heating zone H _{i is} rejected in the heating group G _k and step 50 is repeated with the allocation-less heating zone H _i with the next smaller power level P _i . By contrast, if the maximum power of a frequency unit 10 is large enough, then in step 64 the heating zone H _{i is} assigned to the heating group G _k . In a further step 66, a query is made as to whether all allocation-less heating zones H _{i have been} checked. If not, then the process continues with step 50 with the unadjusted heating zone H _i with the next lower power level P _i . Otherwise, a query is made in step 68 as to whether all X heating groups G _{k have been} processed. If so, then the Heizgruppenzuordnung ends with a step 70. If there are still unadjusted heating zones H _i , then follows an optical and acoustic control request to an operator to assign the relevant heating zones H _i manually a heating group G _k . In addition, the operator has the option here of manually changing the automatic assignment of heating zones H _i to heating groups G _k .

If the sum of selected power levels P _{i of} the heating zones H _i exceeds the maximum total power of all frequency units 10, then according to the flowchart in FIG Fig. 3c a performance prioritization made. The power prioritization assigns a priority number Prio _i to each heating zone H _i . Heating zones H _i with a high priority number Prio _i are preferred in allocating the remaining heating power to such heating zones H _i with a low priority number Prio _i .

In the performance prioritization according to the flowchart in FIG Fig. 3c Parameters of the heating zone H _{i are} queried in various steps which lead to an increase or decrease of a priority counter "Prio" which was initially set to zero in step 72. Thus, in step 73 it is queried whether the heating time t _{i of} the heating zone H _i lies below a time limit value t ₄ . If this is the case, Prio is increased by 2 in step 74. A determination of the time limit t ₄ takes place during a running cooking program on the basis of specifications of the cooking program or during a program-less cooking process by a stored numerical value. In a further step 75, it is queried whether the temperature T _{i of} the heating zone H _{i is} below the lower temperature limit T _U. A determination of the lower temperature limit T _U is carried out at a running cooking program due to specifications of the cooking program or in a program-less cooking by a stored numerical value. If the temperature T _{i of} the heating zone H _{i is} below the lower temperature limit T _U , the heating zone H _{i is} too cold and Prio is increased by 3 in step 76. In a further step 77 it is determined whether a state of cooking of a prepared on the heating zone H _i item to be cooked, the selected power level P _i required. On the one hand, the cooking state can be a status of a running cooking program or, on the other hand, if a program-less cooking process is carried out with the heating zone H _i , a boiling state of the cooking product which is due to a high power level P _{i and} at the same time a disappearing temperature T _i is marked. If the cooking state requires the set power level according to a cooking program, Prio is incremented by 4 in step 78. If a boiling state of the food is detected, Prio is decremented by 4 in step 79. In step 80 it is checked whether the heating time t _{i of} the heating zone H _{i is} above a time limit t ₅ , which is significantly greater than the time limit t ₄ . A determination of the time limit t ₅ takes place during a running cooking program on the basis of specifications of the cooking program or during a program-less cooking process by a stored numerical value. If the heating time t _{i of} the heating zone H _{i is} above a time limit value t ₅ , Prio is decremented by 2 in step 81. In a further step 82, it is finally queried whether the temperature T _{i of} the heating zone H _i lies above the upper temperature limit value T _o . A determination of the upper temperature limit T _o is carried out at a current cooking program due to specifications of the cooking program or a program-less cooking by a stored numerical value. If the temperature T _{i of} the heating zone H _{i is} above the upper temperature limit T _o , the heating zone H _i overheats and Prio is reduced by 3 in step 84. In step 86, Prio _i = Prio and then Prio = 0 are set first. In step 88 it is queried whether all heating zones H _{i have been} processed. If not all the heating zones H _{i have been} processed yet, the next unprocessed heating zone H _{i is continued} with step 72. If all heating zones H _{i have been} processed, the performance prioritization ends with step 90. In alternative embodiments, other numerical values that appear meaningful to a person skilled in the art for increasing or decreasing the counter Prio may also be used. In particular, the choice of numerical values may also depend on a particular hob. After completion of the performance prioritization, each heating zone H _{i is assigned} a priority number Prio _i . Only the X heating zones H _i with the highest priority numbers Prio _i are operated individually and with the selected power stage P _i at the X frequency units 10. An operator is made visually and acoustically aware of which heating zones H _{i have} been switched off due to a too high overall output. In an alternative embodiment, the selected power levels P _i in the ratio of the priority number Prio _{i are} all reduced, so that the maximum total power of all X frequency units 10 is sufficient again. This means that the power levels P _i of heating zones H _i with a lower priority number Prio _{i are} lowered more than the power levels P _i of heating zones H _i with a high priority number Prio _i . With the thus determined new power levels P _{i of} the heating zones H _i , the Heizgruppenerstellung according to the flowchart in Fig. 3a then started. Also in this case, the operator is visually and acoustically informed of the facts and the new power levels P _i are output via the display unit 34. In a further alternative embodiment, a performance prioritization can be completely dispensed with. In this case, the power level P _{i of} all heating zones H _i is reduced proportionally until the total power of all X frequency units 10 has fallen below. With the thus obtained new power levels Pi then the Heizgruppenerstellung according to the flowchart in Fig. 3a started.

In an advantageous further development of the invention, the allocation unit 14 is provided to perform a clocked operation of at least one of the heating zones 12a, 12b. For this purpose, according to Fig. 1 the heating units 11 associated with a heating zone 12a, 12b are separated from the frequency unit 10 by the switching elements 28 associated therewith during a certain number of half cycles of the high-frequency alternating current. To avoid a surge, the separation should occur at a zero crossing of the high frequency alternating current. As a result, given a sufficient maximum power of the frequency units 10, with a few frequency units 10 any number of heating zones 12a, 12b can be operated at any desired power levels. Advantageously, the allocation unit 14 is provided to assign a frequency unit 10 to those heating zones 12a, 12b, which allow a clocked operation with the shortest possible shutdown due to a selected power level. As a result, as uniform as possible heating of a cookware can be achieved.

10

Frequenzeinheit

11

Heizeinheit

12a

Heizzone

12b

Heizzone

12c

Heizzone

12d

Heizzone

12e

Heizzone

12f

Heizzone

12g

Heizzone

14

Zuordnungseinheit

18

Heizvorrichtung

20

Induktorspule

22

Wechselrichter

24a

Kochgeschirr

24b

Kochgeschirr

24c

Kochgeschirr

24d

Kochgeschirr

24e

Kochgeschirr

24f

Kochgeschirr

24g

Kochgeschirr

26

Schalteinheit

28

Schaltelement

30

Kochfeldplatte

32

Bedienvorrichtung

34

Anzeigeneinheit

36

Schritt

37

Schritt

38

Schritt

39

Schritt

40

Schritt

42

Schritt

43

Schritt

44

Schritt

45

Schritt

46

Schritt

47

Schritt

50

Schritt

52

Schritt

54

Schritt

56

Schritt

58

Schritt

60

Schritt

64

Schritt

66

Schritt

68

Schritt

70

Schritt

72

Schritt

73

Schritt

74

Schritt

75

Schritt

76

Schritt

77

Schritt

78

Schritt

79

Schritt

80

Schritt

81

Schritt

82

Schritt

84

Schritt

86

Schritt

88

Schritt

90

Schritt

reference numeral

10

frequency unit

11

heating unit

12a

heating zone

12b

heating zone

12c

heating zone

12d

heating zone

12e

heating zone

12f

heating zone

12g

heating zone

14

allocation unit

18

heater

20

inductor

22

inverter

24a

Cookware

24b

Cookware

24c

Cookware

24d

Cookware

24e

Cookware

24f

Cookware

24g

Cookware

26

switching unit

28

switching element

30

Hotplate

32

operating device

34

display unit

36

step

37

step

38

step

39

step

40

step

42

step

43

step

44

step

45

step

46

step

47

step

50

step

52

step

54

step

56

step

58

step

60

step

64

step

66

step

68

step

70

step

72

step

73

step

74

step

75

step

76

step

77

step

78

step

79

step

80

step

81

step

82

step

84

step

86

step

88

step

90

step

H_i

Heizzone

P_i

Leistungsstufe

T_i

Temperatur

t_i

Heizzeit

G_k

Heizgruppe

P_k

Heizleistung

T_U

Temperaturgrenzwert

T_o

Temperaturgrenzwert

t₁

Zeituntergrenze

t₂

Zeituntergrenze

t₃

Zeitobergrenze

t₄

Zeitgrenzwert

t₅

Zeitgrenzwert

Prio_i

Prioritätsnummer

Prio

Prioritätszähler

X

Anzahl Frequenzeinheiten

symbols

H _i

heating zone

P _i

power stage

T _i

temperature

t _i

heating

G _k

heating group

P _k

heating capacity

T _U

temperature limit

T _o

temperature limit

t ₁

Time limit

t ₂

Time limit

t ₃

Time limit

t ₄

time limit

t ₅

time limit

Prio _i

priority number

Prio

priority counter

X

Number of frequency units

Claims (12)

Heating device with frequency units (10), heating units (11) and at least one allocation unit (14), which is provided to assign at least one frequency unit (10) at least one of at least one of the heating units (11) formed heating zone (12a-g), characterized characterized in that the allocation unit (14) is provided to assign at least one frequency unit (10) depending on at least one variable criterion at least two heating zones (12f, 12g). Heating device according to claim 1, characterized in that the heating zones (12a-g) are formed by a combination of a plurality of heating units (11) arranged in a matrix. Heating device according to one of the preceding claims, characterized in that the variable criterion is an assignment by an operator. Heating device according to one of the preceding claims, characterized in that the variable criterion is a power level selected by an operator of at least one heating zone (12a-g). Heating device according to one of the preceding claims, characterized in that the variable criterion is an elapsed heating time of at least one heating zone (12a-g). Heating device according to one of the preceding claims, characterized in that the variable criterion is a temperature of at least one heating zone (12a-g). Heating device according to one of the preceding claims, characterized in that the variable criterion is at least one cooking state. Heating device according to one of the preceding claims, characterized in that the variable criterion is a difference and / or a time course of at least one size. Heating device according to one of the preceding claims, characterized in that the variable criterion is an overall performance of all the heating zones (12a-g) selected by an operator. Heating device according to one of the preceding claims, characterized in that the allocation unit (14) is provided to perform a clocked operation of at least one of the heating zones (12a-g). Hob, in particular induction hob, with a heating device according to one of the preceding claims. Method with a heating device, in particular according to one of the preceding claims, with frequency units (10) and heating units (11), in which at least one frequency unit (10) is assigned to at least one heating zone (12a-g) formed by at least one of the heating units (11) , characterized in that at least one frequency unit (10) is assigned at least two heating zones (12f, 12g) depending on at least one variable criterion.

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