Method for operating induction hob and induction hob

Abstract

The invention relates to a method for operating an induction hob (1). The induction hob (1) comprises at least two cooking zones (4, 6). The method comprises:-providing at least two different pre-programmed cooking schemes (B, G, F, S, W) for selection by a user for controlling a respective cooking zone (4, 6) according to a predefined heating process,-assigning a different priority value to each cooking scheme (B, G, F, S, W), and-assigning a different priority value to each cooking scheme (B, G, F, S, W) when a respective cooking scheme (B, G, F, S, W) is selected for at least two cooking zones (4, 6). The heating power (P) is transferred to the respective cooking zone (4, 6) as a function of the assigned respective priority value.

Description

[0001] The present invention relates to a method for operating an induction cooking hob. Further, the present invention relates to an induction cooking hob.

[0002] The induction cooking hob transfers induction energy to a cooking utensil (or tableware) through induction coils, thereby introducing eddy currents in the bottom wall of the cooking utensil, which in turn heats the cooking utensil. Usually, the user selects a power level for the cooking zone of the cooking hob (on which the cooking utensil has been placed). Therefore, the user must personally control the cooking process, for example, by reducing the applied power level to avoid burning the food.

[0003] Modern cooking hobs, as described in EP2741570B1, have the function of being able to automatically control the cooking process (such as boiling). This function is quite helpful to the user because the user can start the cooking process without having to pay as close attention to the food on the cooking hob as a "standard" cooking hob. Therefore, the user has greater flexibility and / or can focus more on other tasks, such as preparing other ingredients.

[0004] The object of the present invention is to improve the comfort of the user when using the cooking hob.

[0005] According to the present invention, this object is solved by a method for operating an induction cooking hob according to claim 1. Additionally, according to the present invention, this object is solved by an induction cooking hob according to claim 9. Other advantageous and partially inventive embodiments and developments are given in the dependent claims and the following description.

[0006] According to the present invention, the method is for operating an induction cooking hob including at least two cooking zones. According to the method, at least two different pre-programmed cooking programs are provided for the user to select for controlling the corresponding cooking zones according to a predefined heating process. Further, different priority values are assigned to each cooking program. When the corresponding cooking programs are selected for at least two of the cooking zones (by the user), the heating power is transferred to the corresponding cooking zones according to the assigned corresponding priority values.

[0007] The induction cooking hob according to the present invention is preferably configured for household use. The induction cooking hob includes at least two cooking zones and a controller for controlling the corresponding induction heating elements of the cooking zones. The controller is configured to provide at least two different pre-programmed cooking programs (for the user to select) for controlling the corresponding cooking zones according to a predefined heating process. Further, the controller is configured to assign different priority values to each cooking program, and when selecting one (preferably a corresponding) cooking program for at least two of the cooking zones, the heating power is transferred to the corresponding cooking zones according to the assigned corresponding priority values. Therefore, preferably, the controller is configured to operate the induction cooking hob according to the method described herein and hereinafter.

[0008] The inventive concept of the method and the cooking hob enables the heating power available at the cooking hob to be advantageously distributed even in the case of limited power being available, for example, only via the mains power grid. Thus, the method according to the invention is most preferably used for induction cooking hobs with limited input power. Further, due to the advantageous distribution of the heating power, a faster and / or easier (and thus more comfortable) cooking process can be achieved.

[0009] In particular, the method and the cooking hob share corresponding features, both physically and in the form of method steps (which are preferably to be executed by a controller). Thus, the method and the cooking hob also share the same advantages.

[0010] According to a preferred embodiment, the cooking hob comprises a user interface operatively connected to the controller for communication of the user with the controller.

[0011] In a preferred embodiment, the controller is formed, at least in its core part, by a microcontroller having a processor and a data memory, wherein the functions for performing the method according to the invention are implemented in the form of operating software (firmware) by programming, such that when the operating software is executed in the microcontroller, the method is automatically executed, interacting with the user if necessary. However, within the scope of the invention, the controller may alternatively be formed by non-programmable electronic components (such as an ASIC), wherein the functions for performing the method according to the invention are implemented by circuitry.

[0012] Preferably, the cooking hob is configured to have a limited input power of less than 6 kW, in particular a limited input power of at most 4 kW or less than 4 kW (for example 3.6 kW). This is advantageous for countries where the mains power grid only provides such low power output.

[0013] According to an advantageous variant of the method, a power limit which restricts the heating power of the respective cooking zone to which a cooking program with a higher priority value has been assigned is set to a predefined power upper limit value. This power upper limit value is higher than the power limit value assigned to the cooking zone to which a cooking program with a lower priority value has been selected. Thus, the cooking zone to which a cooking program with a higher priority has been assigned receives (or is at least allowed to receive) more heating power than at least one of the cooking zones to which a cooking program with a lower priority has been assigned. Thereby, the cooking hob can transfer more heating power to the currently higher-priority cooking zone, such that the corresponding cooking program can be executed more easily or faster than the other.

[0014] According to another advantageous variant of the method, when the power demand of the heating process of the assigned cooking program drops to a predefined switching value, the power limit that restricts the heating power of the cooking zone that has been assigned a cooking program with a higher priority value is reduced from the power upper limit value to a predefined power lower limit value. In other words, when the heating process of the higher-priority cooking program no longer requires high heating power, the power limit of the corresponding cooking zone is reduced to the power lower limit value. Thereby, the heating power, in particular the grid power available at the cooking hob, becomes available for other cooking programs and / or other cooking zones.

[0015] According to an alternative variant of the above advantageous variant, the demand for heating power during the corresponding heating process can be related to a predefined time (duration) of a specific phase of the heating process (such as warming up). Advantageously, the demand for heating power is monitored by a sensor (optionally, in addition to the above time control). For example (for a boiling cooking program), the boiling of the corresponding food (such as water, sauce, etc.) is detected by an optical sensor or a motion sensor that detects the vibrations caused by the boiling food. Generally, when the food is boiling, the heating power can be reduced by a certain amount without the food cooling below its boiling temperature. In this case, if boiling is assigned a priority of 1, the food can be boiled as quickly as possible.

[0016] According to yet another advantageous variant of the method, when the power limit of another cooking zone (which is assigned a higher-priority cooking program) has been reduced from the power upper limit value to the power lower limit value (due to its decreasing demand for heating power), the power limit of the cooking zone that has been assigned a cooking program with a lower priority value is increased to a predefined power upper limit value.

[0017] Therefore, according to the concept of the present invention, a certain alternation can be made between different cooking zones and the corresponding cooking programs, so that an automatic and as fast as possible heating process for the entire cooking process can be achieved, even for a cooking hob with limited input power from the grid side.

[0018] According to a preferred variant of the method, a fallback priority value is assigned to the respective cooking zone. In the case where the user has selected cooking programs with equal priority values, this fallback priority value is used (i.e., taken into account). Generally, this fallback priority value can be assigned according to the first-come, first-served scheme (also known as first-in, first-out or "fifo"). In other words, a higher-priority fallback value is assigned to the cooking program of the respective cooking zone that the user selects first. Alternatively, the fallback priority value is selected (assigned) according to the geometric position of the cooking programs on the cooking hob. In other words, the fallback priority depends on the cooking zone to which the cooking program has been assigned. For example, a higher fallback priority value is always assigned to the left cooking zone (from the user's perspective), the cooking zone with a larger cooking area, the cooking zone with a larger cooking utensil placed on it, etc.

[0019] According to an advantageous variant of the method, an upper power limit value and a lower power limit value are selected such that they together reach the maximum operating power value (or: input power value) available for the induction hob. Thereby, an excessive power output does not occur in the power grid.

[0020] Advantageously, the upper power limit value and the lower power limit value are restricted to only include one upper power limit value and one or more lower power limit values. For example, if there are more than two cooking zones and if these cooking zones operate in parallel using the respective cooking programs, then only one cooking program or cooking zone is assigned the upper power limit value, while the other cooking programs or cooking zones are assigned the lower power limit values. In this case, all power limit values together reach the maximum operating power value.

[0021] According to another advantageous variant of the method, the upper power limit value is selected to be in the range of approximately 0.55% to 0.66% of the maximum available operating power value, and / or wherein the lower power limit value is selected to be in the range of approximately 0.45% to 0.35% of the maximum available operating power value. For example, if the maximum available operating power value is 3.6 kW, then the upper power limit value is 2 kW and the lower power limit value is 1.6 kW. In the case of three power limit values, the power distribution can also be 50% upper power limit value and 25% each of the lower power limit values.

[0022] According to a preferred variant of the method, the priority value assigned to the boiling cooking program is 1, the priority value assigned to the grilling cooking program is 2, the priority value assigned to the frying cooking program is 3, the priority value assigned to the slow cooking program is 4, and the priority value assigned to the keeping warm cooking program is 5. Advantageously, as a further limitation, the slow cooking and keeping warm cooking programs can only be assigned the lower power limit value. The latter is beneficial because these cooking programs generally do not require a heating power higher than the usual lower power limit value.

[0023] The conjunction "and / or" shall be understood here and hereinafter as meaning in particular that the features connected by this conjunction can both be formed together and alternatively to one another.

[0024] In the following, embodiments of the invention will be explained in more detail with reference to the accompanying drawings. Shown therein are:

[0025] Figure 1 a top view schematic diagram of an induction cooktop,

[0026] Figure 2 a schematic flow chart of a method executed by the controller of the cooktop, and

[0027] Figure 3 a schematic diagram of the variation of power over time for three different heating processes of an automatic cooking program during corresponding operations of the controller.

[0028] In all the figures, the parts and measures corresponding to one another always carry the same reference numerals.

[0029] Figure 1 Shown is an induction cooktop 1. The induction cooktop 1 is intended for household use. The induction cooktop 1 includes a cooktop cover 2 made of glass ceramic. Further, the induction cooktop 1 includes two cooking zones 4 and 6 which, according to the illustrated embodiment, in turn include corresponding induction coils (not shown) similar to heating elements. Additionally, the induction cooktop 1 includes a controller 8 which is configured to control the heating power supplied to the corresponding induction coils. The controller 8 is connected to a user interface 10 which, in the present embodiment, is similar to a touch-sensitive area of the cooktop cover 2. Additionally, the controller 8 is connected to a mains connection (not shown) to receive input power and supply it as heating power P to the corresponding induction coils.

[0030] However, the induction cooktop 1 is configured to operate at a limited mains input power of 3.6 kW (i.e., the power grid cannot output a higher power value). Further, the induction cooktop 1 is configured to provide, in particular via corresponding programming of the controller 8, an automatic cooking program for selection by the user via the user interface 10. The cooking program includes corresponding predefined heating processes which are intended to achieve a desired cooking result for the corresponding foodstuffs.

[0031] Two cooking programs used hereinafter to describe the inventive concept are boiling B and grilling G. Figure 3 The corresponding heating processes of boiling B and grilling G (specifically, the variation of heating power P over time t) are schematically shown in the upper and middle figures, and the corresponding heating processes are controlled by the controller 8 by supplying the corresponding heating power P to the cooking zone 4 or 6 (whichever is used for the corresponding cooking program).

[0032] As long as only one of the two cooking zones 4 or 6 uses only one cooking program (and the corresponding other cooking zone 6 or 4 is not in use), the controller 8 sets the power limit Pl of the corresponding cooking zone 4 or 6 to the power upper limit value Plh. For clarity, hereinafter, the cooking zone 4 is referred to as the cooking zone for the selected cooking program. Since only the cooking zone 4 is operating and the other cooking zone 6 is not in use, the power upper limit value Plh is set to the maximum available heating power Pmax (which will generally correspond to the available mains power), which is 3.6 kW in the course of the current embodiment.

[0033] Accordingly, in the case of boiling B, the controller 8 supplies the heating power P to the cooking zone 4 at the power upper limit value Plh. Additionally, the controller 8 monitors the temperature rise of the ingredients of the cookware placed on the cooking zone 4. According to one embodiment, the controller 8 is connected to a vibration sensor (not shown) in contact with the cover plate 2. If there is vibration of the cover plate 2 that is considered characteristic of boiling food (e.g., obtained by signal comparison), the controller 8 reduces the power limit Pl to the power lower limit value Pll, which is high enough to maintain the temperature of the ingredients within the cookware. Alternatively, the controller 8 can be connected to an optical (e.g., infrared) temperature sensor, which can be located above the head of the cooking hob 1, e.g., at the extractor hood above the head, and is configured to monitor the cover plate 2 and the cookware placed on the cover plate 2.

[0034] As shown in the Figure 3 middle figure, the cooking program grill G is also assigned only to the cooking zone 4. Accordingly, the controller 8 delivers the heating power P according to the above-described embodiment. However, the current value of the heating power P transmitted by the controller 8 will be lower than the higher power limit Plh, since this is still sufficient for grilling G. Having reached, for example, a predefined duration at the provided higher power level, or alternatively having reached the desired temperature, the heating power P is reduced again in order to maintain the temperature, e.g., to allow the grilled food to rest.

[0035] In the case where both cooking zones 4 and 6 are to be used, with boiling B in cooking zone 4 and grilling G in cooking zone 6, the controller 8 performs the method described in more detail by Figure 2 and Figure 3 (bottom figure).

[0036] According to the first method step S1, the controller 8 provides several cooking programs with predefined heating processes. In addition to the already named boiling B and grilling G cooking programs, the controller 8 also provides frying F, slow cooking S, and warming W. For each cooking program, the controller 8 also provides a priority value. For boiling B, grilling G, frying F, slow cooking S, and warming W, the priority values are 1 to 5 in the corresponding order of introduction. The user can select a cooking program for each of the two cooking zones 4 and 6 via the user interface 10. In this case, the user selects grilling G for the two cooking zones 4 and 6 and thus selects the same priority value. The controller 8 provides and activates a fallback priority value, which gives the cooking program assigned to cooking zone 4 a higher priority.

[0037] Within the second method step S2, the user has selected two cooking programs, where cooking zone 4 is boiling B and cooking zone 6 is grilling G. The controller 8 records this selection via the user interface 10.

[0038] In the third method step S3, the controller 8 sets the power limit Pl of cooking zone 4 to the power upper limit value Plh because cooking zone 4 has been selected for boiling B with the highest priority value. However, since two cooking programs are to be executed in parallel, the power upper limit value Plh is set to 2 kW (about 55% of the maximum available power of 3.6 kW). The power limit Pl of cooking zone 6 (selected for grilling G with a lower priority value) is set to the power lower limit value Pll, specifically 1.6 kW. Thus, cooking zone 4 can be powered on and heated up as much and as quickly as possible, where cooking zone 6 is only allowed to heat up to a limited amount.

[0039] The controller 8 monitors whether the ingredients of the cooking utensil placed on cooking zone 4 start to boil. If boiling is detected (compare the above description), then within the fourth method step S4, the controller 8 regards this as the power demand for boiling B dropping below the corresponding switching value and thus reduces the power limit Pl of cooking zone 4 to the power lower limit value Pll. At the same step, the controller 8 sets the power limit Pl of cooking zone 6 to the power upper limit value Plh. Thus, cooking zone 4 still receives the heating power P so that the ingredients can remain boiling. Cooking zone 6 is allowed to heat up and start the normal heating process of grilling G, just with an automatic time delay.

[0040] As described above, the controller 8 also monitors the state of the ingredients of the cooking utensil placed on cooking zone 6, for example by monitoring the grilling duration and / or the temperature of the ingredients. After the corresponding criteria are met (such as duration and / or temperature), the controller 8 reduces the power limit Pl of cooking zone 6 (again) to the power lower limit value Pll. After a predetermined duration at the power lower limit value Pll, the cooking programs of both cooking zones 4 and 6 end, and preferably an indication is given to the user.

[0041] The subject matter of the present invention is not limited to the above embodiments. On the contrary, those skilled in the art can obtain other embodiments of the present invention from the above description.

[0042] List of reference numerals

[0043] 1 Cooktop

[0044] 2 Cover plate

[0045] 4 Cooking area

[0046] 6 Cooking area

[0047] 8 Controller

[0048] 10 User interface

[0049] B Boiling

[0050] G Grilling

[0051] F Frying

[0052] S Slow cooking

[0053] W Keeping warm

[0054] P Heating power

[0055] Pl Power limit

[0056] Plh Upper power limit value

[0057] Pll Lower power limit value

[0058] Pmax Maximum available heating power

Claims

1. A method for operating an induction cooktop (1) comprising at least two cooking zones (4, 6), the method comprising - providing at least two different pre-programmed cooking recipes (B, G, F, S, W) for user selection to control the corresponding cooking zones (4, 6) according to a predefined heating process, - assigning different priority values to each cooking recipe (B, G, F, S, W), and - when selecting the corresponding cooking recipes (B, G, F, S, W) for at least two cooking zones (4, 6), transferring the heating power (P) to the corresponding cooking zones (4, 6) according to the assigned corresponding priority values.

2. The method according to claim 1, Among them, a power limit (Pl) that limits the heating power (P) transferred to the cooking zone (4, 6) that has been assigned the cooking recipe (B, G, F, S, W) with the higher priority value is set to a predefined power upper limit value (Plh), which is higher compared to the cooking zone () that has selected the cooking recipe (B, G, F, S, W) with the lower priority value.

3. The method according to claim 2, Among them, when the power demand of the heating process of the assigned cooking recipe (B, G, F, S, W) drops below a predefined switching value, the power limit (Pl) that limits the heating power (P) transferred to the cooking zone (4, 6) that has been assigned the cooking recipe (B, G, F, S, W) with the higher priority value is reduced from the power upper limit value (Plh) to a predefined power lower limit value (Pll).

4. The method according to claim 3, Among them, the power limit (Pl) assigned to the cooking zone (4, 6) that has been assigned the cooking recipe (B, G, F, S, W) with the lower priority value is increased to the predefined power upper limit value (Plh).

5. The method according to any one of claims 1 to 4, Among them, assigning fallback priority values to the corresponding cooking zones (4, 6), in particular according to the geometric position of the cooking zone on the cooktop (1), and when the priority values of the at least two cooking zones (4, 6) are equal, considering the fallback priority values.

6. The method according to any one of claims 2 to 5, Among them, selecting the power upper limit value (Plh) and the power lower limit value (Pll) such that they together amount to the maximum operating power value (Pmax) available for the induction cooktop (1).

7. The method according to claim 6, Among them, the power upper limit value and the power lower limit value (Plh, Pll) are restricted to only include the power upper limit value (Plh) once and one or more power lower limit values (Pll).

8. The method according to claim 6, Among them, the power upper limit value (Plh) is selected to be in the range of approximately 0.55% to 0.66% of the maximum available operating power value (Pmax), and / or wherein, The lower power limit value (Pll) is selected to be in the range of approximately 0.45% to 0.35% of the maximum available operating power value (Pmax). For example, if the maximum available operating power value (Pmax) is 3.6 kW, then the upper power limit value (Plh) is 2 kW and the lower power limit value (Pll) is 1.6 kW.

9. An induction cooktop (1) especially for domestic use, the induction cooktop (1) comprising - at least two cooking zones (4, 6), and - a controller (8) for controlling the respective induction heating elements of these cooking zones (4, 6), the controller (8) being configured to + provide at least two different pre-programmed cooking programs (B, G, F, S, W) for the user to select for controlling the respective cooking zones (4, 6) according to a predefined heating process, + assign different priority values to each cooking program (B, G, F, S, W), and + when selecting the respective cooking programs (B, G, F, S, W) for at least two cooking zones (4, 6), transfer the heating power (P) to the respective cooking zones (4, 6) according to the assigned respective priority values, + in particular, operate the induction cooktop (1) according to the method according to claims 1 to 8.

10. The induction cooktop (1) according to claim 9, comprising a user interface (10) operatively connected to the controller (8) for the user to communicate with the controller (8).

11. The induction cooktop (1) according to claim 9 or 10, wherein, The controller (8) is configured to assign the priority value 1 to the boiling cooking program (B), the priority value 2 to the grilling cooking program (G), the priority value 3 to the frying cooking program (F), the priority value 4 to the slow cooking program (S), and the priority value 5 to the warming cooking program (W).

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