KR20240030925A - Induction heating device and control method of induction heating device - Google Patents

Abstract

The present invention is a method for controlling an induction heating device, comprising: (a) applying heat to a cooking vessel containing the food through a first output from a working coil built in a heating area of the induction heating device; (b) In the process of heating the cooking vessel by operating the working coil, the temperature of the working coil is sensed from a coil temperature sensor provided on the side of the working coil, and when the sensed temperature rises by the preset reference temperature A step of repeatedly collecting time information; (c) when the nth time information is greater than or equal to a preset first reference time, comparing it with the n-1th time information to determine whether the nth time information is less than the n-1th time information; and (d) when the nth time information decreases compared to the n-1th time information, reducing the output of the working coil to a second output; Provides a method including.

Description

Induction heating device and control method of induction heating device {INDUCTION HEATING DEVICE AND CONTROL METHOD OF INDUCTION HEATING DEVICE}

The present invention relates to an induction heating device and a control method of the induction heating device.

Electric ranges, which are currently widely used, are home appliances that use electric energy to heat an electric heater or a separate burner. Compared to gas ranges, there is no risk of gas leakage or explosion, it is easy to clean, and it has the advantage of low energy consumption due to its high thermal conductivity, so it is widely used as a substitute for gas ranges.

These electric ranges have an induction heater that uses an induction heating method. In this type of induction heater, when power is applied, a high frequency voltage of a certain magnitude is applied to the working coil to generate a magnetic field around the working coil, and the magnetic field lines of the induced magnetic field generated at this time create an eddy current inside the fire bowl. This generates eddy currents, and the crater is heated by this eddy current.

These electric ranges are so-called cooktops and are excellent in terms of safety because they allow cooking without an actual flame. Additionally, it has the advantage of achieving a simple and beautiful appearance.

Working coils of recently developed electric ranges use a temperature sensor or bimetal to reduce output or stop heating when overheating exceeds a certain temperature to prevent component damage and fire when overheating. In particular, in control using a coil temperature sensor, a method is used to limit the output to no more than n stages when the measured temperature exceeds a certain temperature.

The coil temperature sensor is usually located at the center of the working coil and is structured to be in close contact with the bottom of the top plate. When trying to measure the temperature of food using the coil temperature sensor of the working coil, there is a problem that the temperature measurement value varies not only due to the temperature of the food and the container, but also due to the influence of heat generation and residual heat of the working coil.

In addition, because it takes time for the heat generated at the bottom of the cooking vessel to be transmitted through the top plate, even if a rapid change in temperature of the food occurs, the measured temperature value detects the temperature change after a few seconds.

Therefore, when a coil temperature sensor is used to control the temperature of food, a problem occurs in which accurate control is not achieved due to variables such as the number of output stages, the material of the container, and the temperature of the coil before starting cooking.

The existing method to solve this problem is to use a separate sensor to more precisely measure the temperature of the bottom of the container or the food. For example, there is a method of measuring the temperature of the bottom of the container using an infrared temperature sensor or directly measuring the temperature of the food by connecting a probe-type thermometer to an induction cooker through wired or wireless communication. However, when applying such a separate additional configuration, a problem arises in which the number of parts, man-hours, and material costs increase.

As a prior art, Korean Patent Publication No. 10-2021-0099821 (induction heating device) is disclosed. The prior art is a configuration that prevents overheating of the container through a temperature sensor that senses the temperature of the container and outputs a sensing voltage corresponding to the temperature of the container, and a controller that supplies a driving signal to the driving circuit based on the size of the sensing voltage. commences.

However, the open technology only discloses a simple configuration to prevent overheating based on the temperature of the container, and does not disclose specific details on controlling output by processing temperature information. In particular, there is no awareness of water evaporation or water replenishment in the container.

Korean Patent Publication No. 10-2021-0099821 (induction heating device)

The induction heating device and the induction heating control method according to an embodiment of the present disclosure adjust the output by detecting moisture evaporation that can burn the food using only a coil temperature sensor that is widely used without a separate sensor or additional configuration. I would like to propose a method and structure.

In addition, even if the resolution of the coil temperature sensor is not precise, we would like to propose a method and structure that can determine moisture evaporation or overheating through processing and calculation of temperature information.

A method of preventing overheating of food using a coil temperature sensor of an induction heating device according to an embodiment of the present disclosure, comprising: (a) a first output from a working coil built into the heating area of the induction heating device; Applying heat to the accommodated cooking vessel; (b) In the process of heating the cooking vessel by operating the working coil, the temperature of the working coil is sensed from a coil temperature sensor provided on the side of the working coil, and when the sensed temperature rises by the preset reference temperature A step of repeatedly collecting time information; (c) when the nth time information is greater than or equal to a preset first reference time, comparing it with the n-1th time information to determine whether the nth time information is less than the n-1th time information; and (d) when the nth time information decreases compared to the n-1th time information, reducing the output of the working coil to a second output; Provides a method including.

Alternatively, in step (c), (c1) the nth time information is compared with a preset second reference time, wherein the second reference time is a time set larger than the first reference time, and the second reference time is set to be larger than the first reference time. n determining whether time information is less than or equal to the second reference time; Further comprising, step (d) provides a method of reducing the working coil to the second output when, in step (c1), the nth time information is less than or equal to the second reference time.

Alternatively, in step (c), if it is determined in step (c2) that the n-th time information exceeds the second reference time, the n-th time information and the second reference time are calculating the difference; Provides a method further including.

Alternatively, in step (c2), if at least two of the nth time information to n+kth time information exceed the second reference time, each of the time information exceeding the second reference time For example, the difference with the second reference time is accumulated, and in step (d), in step (c2), if the accumulated value of the difference is greater than or equal to a preset third reference time, the working coil is connected to the second reference time. Provides a method to reduce output.

Alternatively, after step (d), (e) in the process of applying the second output, the temperature of the working coil is sensed from the coil temperature sensor, and information on the time required to rise by the preset reference temperature is provided. repeatedly collecting; and (f) comparing the mth time information collected in step (e) with the fourth time information set in advance, and if the mth time information is greater than or equal to the fourth time information, the output of the working coil is returned to the fourth time information. Rising and returning to output 1; Provides a method further including.

Alternatively, in step (f), (f1) when the mth time information is less than the fourth time information, current temperature information is provided from the coil temperature sensor, and based on the current temperature information, the first Performing control with through to nth intermediate outputs, wherein the intermediate output is controlled so that the larger the current temperature information is, the lower the intermediate output is; It further includes, and step (f1) provides a method of controlling the intermediate outputs to sequentially change based on the current temperature information when performing control with the first to nth intermediate outputs.

In addition, as an induction heating device for heating a cooking container according to an embodiment of the present disclosure, a first output is input to a working coil built into the heating area of the induction heating device so that heat is applied to the cooking container containing food. user operation panel; A coil temperature sensor provided on the working coil side to sense temperature information of the working coil; A time information collection unit that receives temperature information of the working coil from the coil temperature sensor and repeatedly collects time information required when the sensed temperature information rises by a preset reference temperature; If the n-th time information transmitted from the time information collection unit is greater than or equal to the preset first reference time, an operation unit that compares the n-th time information with the n-1th time information and determines whether the n-th time information has decreased compared to the n-1th time information. ; A control unit that controls the output of the working coil based on the output control command of the working coil transmitted from the calculation unit; It includes an induction heating device, wherein the calculation unit transmits an output control command to the control unit to reduce the output of the working coil to the second output when the nth time information decreases compared to the n-1th time information. to provide.

The induction heating device and the induction heating control method according to an embodiment of the present disclosure can adjust the output by detecting a moisture evaporation situation that can burn the food using only a coil temperature sensor that is widely used without a separate sensor or additional configuration. there is.

In addition, even if the resolution of the coil temperature sensor is not precise, it is possible to determine moisture evaporation or overheating through processing and calculation of temperature information.

1 is a conceptual diagram schematically showing a control method according to an embodiment of the present disclosure.
Figure 2 is a flowchart of a control method according to an embodiment of the present disclosure.
Figure 3 is a schematic diagram schematically showing a process of determining and controlling overheating of a cooking vessel using a control method according to an embodiment of the present disclosure.
FIG. 4 is a flowchart showing the process of controlling the output of the working coil using the second reference time after the flowchart of FIG. 2.
Figure 5 is a schematic diagram showing that in the control method according to an embodiment of the present disclosure, sections are divided using first and second reference times, and the flow varies depending on which section the nth time information belongs to.
Figure 6 is a flowchart showing the process of determining that food has been replenished and controlling the output after overheating is determined and the output of the working coil is changed in the control method according to an embodiment of the present disclosure.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to be “connected” to another part, this is not only the case when it is “directly connected”, but also when there is another component in between, and when there is another component in between. This also includes cases where they are “electrically connected.” Additionally, when a part "includes" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

The 'induction heating device' used herein includes the currently widely used electric range, induction, etc., and it is stated in advance that the present disclosure can be applied to all known means of applying heat to a cooking object using the induction heating method. do.

In addition, the induction heating device and the induction heating control method according to the present disclosure are explained by taking the moisture evaporation state (meaning complete moisture evaporation) of a cooking vessel, which is a representative case of overheating, as an example. However, in addition to moisture evaporation, the present invention It is specified in advance that the principle can be applied to all overheating situations where it can be applied.

Hereinafter, the induction heating device and the induction heating control method according to the present disclosure will be described with reference to the drawings.

1 is a conceptual diagram schematically showing a control method according to an embodiment of the present disclosure.

As shown in Figure 1, the induction heating device may have a plurality of heating zones. The heating area refers to the location where the cooking vessel is placed and is located on the glass ceramic top. Working coils (100A, 100B, 100C) are built into the position corresponding to the heating area under the glass ceramic top plate. Figure 1 illustrates an example of an induction heating device equipped with three heating zones.

Each of the three heating zones can have different outputs of the working coils (100A, 100B, 100C), so the user can use the most appropriate heating zone depending on the size of the cooking object or cooking vessel. A user operation panel 140 is provided on the front side of the glass ceramic top plate, and the output and time of each working coil (100A, 100B, 100C) can be adjusted by the user.

Coil temperature sensors (S1, S2, and S3) may be provided at the center of the working coils (100A, 100B, and 100C), respectively. The coil temperature sensors (S1, S2, and S3) are configured to sense the temperature information of the working coils (100A, 100B, and 100C) and transmit it to the time information collection unit 110.

The time information collection unit 110 is configured to repeatedly collect time information required when the working coils (100A, 100B, 100C) change by a preset reference temperature. For this purpose, a timer is built in. The time information collection unit 110 is configured to repeatedly collect time information starting when the temperature information of the working coils (100A, 100B, 100C) is below a predetermined set temperature. If the temperature information of the working coils (100A, 100B, 100C) exceeds the predetermined set temperature, this is already considered an overheating state, and control to immediately reduce the output of the working coils (100A, 100B, 100C) is required. Because it does.

Accordingly, in this application, the flow is explained on the assumption that the temperature information of the working coils (100A, 100B, 100C) is below the predetermined set temperature.

Based on the temperature information transmitted through the coil temperature sensors (S1, S2, S3), it is configured to continuously collect time information whenever the reference temperature changes. Since the time information collection unit 110 and the calculation processing unit 120 receive information continuously, it is specified in advance that the control method of the present application can be identically repeated during the operation of the induction heating device.

The calculation processing unit 120 is configured to receive time information from the time information collection unit 110 and determine the moisture evaporation state of the cooking vessel in a preset manner. If it is determined that the cooking vessel is in a moisture evaporation state, an output control command is transmitted to the control unit 130 to control the output of the working coils 100A, 100B, and 100C.

Figure 2 is a flowchart of a control method according to an embodiment of the present disclosure.

The control method according to an embodiment of the present disclosure includes steps S110 to S140. Hereinafter, the description will be based on the first working coil (100A) and the coil temperature sensor (S1) connected to the first working coil (100A).

Step S110 is a step in which heat is applied to the cooking vessel containing the food through the first output from the working coil 100A built in the heating area of the induction heating device. After placing the cooking vessel on the heating area of the induction heating device, a control signal is input through the user operation panel 140 and operated.

In step S120, while the working coil 100A operates and the cooking vessel is heated, the temperature of the working coil 100A is sensed from the coil temperature sensor S1 provided on the working coil 100A side, and the sensing This is a step to repeatedly collect information on the time it takes for the temperature to rise to the preset standard temperature.

Step S120 further includes a process of determining whether the temperature information of the working coil 100A from the coil temperature sensor S1 is below a predetermined set temperature. As described above, when the temperature information of the working coil (100A) exceeds the set temperature, output control is immediately performed. If the temperature information of the working coil (100A) is below the set temperature, the flow described later goes through. As an example, the set temperature can be set in advance by distinguishing between moisture-containing cooking such as boiling and stewing and high-temperature cooking such as grilling. It is desirable to set the coil sensor temperature (S1) to a temperature that will not be reached in general boiling cooking, approximately 130°C.

In step S120, information on the time required to rise to the above-mentioned reference temperature may be collected and stored, and then the timer built into the time information collection unit 110 may be reset. This process is performed repeatedly, and can be divided into first to nth time information based on the number of time information collections. Hereinafter, the description will be based on the nth time information.

At this time, the reference temperature is determined according to the resolution of the coil temperature sensor (S1). As an example, in the case of a coil temperature sensor (S1) that measures in units of 0.1℃, when the temperature measurement value changes from 99 degrees to 99.1 degrees, 99℃ and 99.1℃ may be repeated and the measured value may be maintained at 99.1℃. there is.

In this case, the standard temperature is set at 0.2 to 0.3°C. By appropriately setting the reference temperature, the moisture evaporation state can be determined even when using a coil temperature sensor (S1) with a relatively poor resolution that measures in units of 1°C.

Figure 3 is a schematic diagram schematically showing a process of determining and controlling overheating of a cooking vessel using a control method according to an embodiment of the present disclosure. The following step (S130) will be described with reference to FIG. 3.

In step S130, when the n-th time information is greater than or equal to the preset first reference time, it is compared with the n-1th time information to determine whether the n-th time information has decreased compared to the n-1th time information. That is, ① determine whether the nth time information is greater than or equal to the first reference time, and ② compare the nth time information and the n-1th time information to determine whether the nth time information has decreased from the immediately preceding n-1 time information. do. The fact that the n-th time information decreases from the previous n-1 time information means that the time required for the same temperature rise is shorter, which means that it is close to the moisture evaporation state.

As an example, the first reference time and the second reference time are values determined depending on the cooking vessel and cooking situation. By comparing the case of heating oil and the case of heating water, the time required for the temperature to rise to the standard temperature can be checked and set in advance.

As an example, the first reference time can be set as the time required for the temperature of the coil temperature sensor S1 to rise by the reference temperature when water begins to boil (this time is taken as the reference point). The second standard time can be set as the time it takes for the temperature to rise by the standard temperature from when the coil temperature sensor (S1) reaches the set temperature when boiling oil. That is, the first reference time may be set based on 'water', and the second reference time may be set based on 'oil'.

In general, when oil and water are heated at the same volume, the specific heat of water and latent heat of vaporization are greater than the specific heat of oil below the above set temperature. Accordingly, the time required to raise the temperature by the standard temperature when heating water appears to be longer than when heating oil. However, since cooking vessels are made of various materials such as enamel, cast iron, and aluminum and have various thicknesses and sizes, it is desirable to set the first and second reference times through experiments under various conditions.

In addition, the control method according to the present disclosure is an algorithm that compensates for the situation where it takes a long time for the temperature to rise rapidly even when moisture evaporation is completed and the empty container is heated in the case of a thick cooking container such as cast iron.

Because these cooking vessels have high specific heat, it takes a relatively long time to raise the temperature, and even when output is stopped, the temperature of the coil temperature sensor (S1) continues to rise due to the latent heat of the cooking vessel. The time it takes for an empty container to heat up may be prolonged, causing the food or the working coil (100A) to overheat. The present invention is a method that can reduce output by early determining that the container is empty even if the time required to increase the temperature does not decrease below the second reference time.

Step S130 further includes the process of comparing the ③nth time information and the preset second reference time again. At this time, the second reference time is a time set larger than the first reference time, and is configured to determine whether the nth time information is less than or equal to the second reference time. The lower limit in case of exceeding the first reference time is not specified, and this is to limit the range of nth time information that can be considered as a moisture evaporation state.

In step S140, if it is determined in step S130 that the n-th time information has decreased compared to the n-1 time information, the output of the working coil 100A is reduced to the second output through the control unit 140. It's a step. In other words, step S140 can be understood as a step of controlling the output of the working coil (100A).

In the above step (S130), if the n-th time information is less than or equal to the second reference time, the output of the working coil (100A) is reduced to the second output.

In other words, when controlling the output of the working coil (100A) from the first output (meaning initial output) to the second output (meaning reduced output), it is necessary to satisfy all of the above conditions ①, ② and ③. .

FIG. 4 is a flowchart showing the process of controlling the output of the working coil using the second reference time after the flowchart of FIG. 2, and FIG. 5 shows the first and second control methods in the control method according to an embodiment of the present disclosure. This is a schematic diagram showing that sections are divided using a reference time, and the flow varies depending on which section the nth time information belongs to. This will be explained with reference to FIGS. 4 and 5.

Step S130 further includes step S132. Step S132 is a step of calculating the difference between the nth time information and the second reference time when it is determined in step S131 that the nth time information exceeds the second reference time.

At this time, in step S132, when at least two of the nth time information to the n+kth time information exceed the second reference time, for each time information exceeding the second reference time, the second reference time It is configured to accumulate the difference between and . Referring to Figure 5, 'nth time information ③' corresponds to this case. In most cases, all of the nth time information to the n+kth time information will continuously exceed the second standard time, but if only some of them exceed the second standard time, the difference is configured to accumulate for only part of the time information. It can be.

In step S140, if the accumulated value of the difference in step S132 is greater than or equal to a preset third reference time, the working coil 100A is controlled to decrease to the second output. If the cumulative value of the car is more than the third standard time, it is considered to be in a moisture evaporation state. Accordingly, the output can be lowered to prevent the cooking vessel from overheating.

If the accumulated value of the difference is less than the third reference time, the temperature information of the working coil (100A) is sensed again through the coil temperature sensor (S1), and the process is repeated from the above-described step (S120).

An example is an induction heating device set to medium output at 160℃, minimum output at 180℃, and OFF at 200℃ based on temperature information detected by the coil temperature sensor (S1) in a typical cooking situation. You can. In this case, if the temperature information of the coil temperature sensor (S1) is 110°C, the moisture evaporation state can be set.

On the other hand, if the power is immediately changed to the lowest power when determining the moisture evaporation state, a situation may occur where the power is suddenly lowered during cooking at high power, making it impossible to cook the food. Therefore, when the moisture evaporation state is detected, the temperature set value of the coil temperature sensor (S1), whose output is changed and changed step by step to the intermediate output, is adjusted. As an example, when moisture evaporation is detected, the output may be set to the lowest at 130°C and the output may be set to OFF at 150°C.

The control method according to the present disclosure further includes steps S151 and S152.

In step S151, in the process of applying the second output, the temperature of the working coil (100A) is sensed from the coil temperature sensor (S1), and information on the time required to rise to a preset reference temperature is repeatedly collected. am.

Step S152 compares the m-th time information collected in step S151 with the fourth time information set in advance, and if the m-th time information is greater than or equal to the fourth time information, the output of the working coil is returned to the first time information. This is the stage where the output rises and returns. This applies to cases where the algorithm malfunctions even though there is moisture, or when water is replenished from an empty container.

At this time, if the mth time information is less than the fourth time information, current temperature information is provided from the coil temperature sensor (S1), and control is performed with the first to nth intermediate outputs based on the current temperature information. , the intermediate output is controlled to be lower as the current temperature information increases. Here, when performing control with the first to nth intermediate outputs, it is desirable to control the intermediate outputs to change sequentially based on current temperature information.

In the present disclosure, the above-mentioned embodiment is an example, and the present disclosure is not limited thereto. Anything that has substantially the same structure as the technical idea described in the claims of the present disclosure and achieves the same effect is included in the technical scope of the present disclosure.

100A, 100B, 100C: Working coil
110: Time information collection department
120: Operation processing unit
130: control unit
140: User operation panel

Claims (7)

As an induction heating device control method,
(a) applying heat to the cooking vessel containing the food through a first output from a working coil built into the heating area of the induction heating device;
(b) In the process of heating the cooking vessel by operating the working coil, the temperature of the working coil is sensed from a coil temperature sensor provided on the side of the working coil, and when the sensed temperature rises by the preset reference temperature A step of repeatedly collecting time information;
(c) when the nth time information is greater than or equal to a preset first reference time, comparing it with the n-1th time information to determine whether the nth time information is less than the n-1th time information; and
(d) when the nth time information decreases compared to the n-1th time information, reducing the output of the working coil to a second output; Including,
method. According to paragraph 1,
In step (c),
(c1) Compare the nth time information with a preset second reference time, wherein the second reference time is a time set larger than the first reference time, and whether the nth time information is less than or equal to the second reference time. judging step; It further includes,
In step (d),
In step (c1), when the n-th time information is less than or equal to the second reference time, reducing the working coil to the second output,
method. According to paragraph 2,
In step (c),
(c2) in step (c1), if it is determined that the n-th time information exceeds the second reference time, calculating the difference between the n-th time information and the second reference time; Containing more,
method. According to paragraph 3,
In step (c2),
When at least two of the nth time information to the n+kth time information exceed the second reference time, for each time information exceeding the second reference time, the difference with the second reference time is calculated. Accumulating,
In step (d),
In step (c2), if the cumulative value of the difference is greater than or equal to a preset third reference time, reducing the working coil to the second output,
method. According to any one of claims 1 to 4,
After step (d) above,
(e) in the process of applying the second output, the temperature of the working coil is sensed from the coil temperature sensor, and information on the time required to rise to a preset reference temperature is repeatedly collected; and
(f) Compare the mth time information collected in step (e) with the fourth time information set in advance, and if the mth time information is greater than or equal to the fourth time information, the output of the working coil is redirected to the first time information. Step of rising and returning to output; Containing more,
method. According to clause 5,
In step (f) above,
(f1) When the mth time information is less than the fourth time information, current temperature information is provided from the coil temperature sensor, and control is performed with the first to nth intermediate outputs based on the current temperature information, controlling the intermediate output to be lower as the current temperature information increases; It further includes,
In step (f1),
When performing control with the first to nth intermediate outputs, controlling the intermediate outputs to change sequentially based on the current temperature information,
method. An induction heating device that heats a cooking vessel,
a user operation panel for inputting a first output to a working coil built in a heating area of the induction heating device so that heat is applied to the cooking vessel containing food;
A coil temperature sensor provided on the working coil side to sense temperature information of the working coil;
A time information collection unit that receives temperature information of the working coil from the coil temperature sensor and repeatedly collects time information required when the sensed temperature information rises by a preset reference temperature;
If the n-th time information transmitted from the time information collection unit is greater than or equal to the preset first reference time, an operation unit that compares the n-th time information with the n-1th time information and determines whether the n-th time information has decreased compared to the n-1th time information. ;
A control unit that controls the output of the working coil based on the output control command of the working coil transmitted from the calculation unit; Includes,
The calculation unit is,
When the nth time information decreases compared to the n-1th time information, transmitting an output control command to the control unit to reduce the output of the working coil to the second output,
Induction heating device.