Induction heating device for controlling power distribution, and control method therefor

Abstract

The present disclosure relates to an induction heating device for controlling power distribution, and a control method therefor, and provides a configuration in which power that is output from a plurality of inverters included in the induction heating device is detected and, if the ratio between the detected powers exceeds or is less than a set ratio, the duty of a switching element included in at least one from among the plurality of inverters is adjusted to uniformly distribute power that is output from the plurality of inverters.

Description

Induction heating device for controlling power distribution and its control method

[0001] One embodiment of the present disclosure relates to an induction heating device for controlling power distribution and a control method thereof.

[0002] Induction heating devices are devices that utilize the phenomenon of magnetic induction to cook food. Induction heating devices can use an inverter to supply harmonic AC power to a working coil. When this harmonic AC power is supplied, a magnetic field is formed around the working coil. This magnetic field, formed around the working coil, induces eddy currents as it passes through the bottom (or bottom surface) of a conductive cooking vessel. This heats the conductive cooking vessel and its contents.

[0003] The inverter built into the induction heating device can output power (high-frequency AC power) based on the resonant frequency of the working coil. The resonant frequency of the working coil may vary depending on the size and shape of the coil. Accordingly, when a cooking vessel is placed on multiple working coils, the power output from the inverter corresponding to each working coil may differ due to differences in the resonant characteristics between the working coils. If there is a difference in the power output from the inverter corresponding to each working coil, the heat distribution between the multiple working coils may become uneven, which may reduce the thermal efficiency of the cooking vessel. For example, some parts of the cooking vessel may heat faster than others, causing some of the contents in the cooking vessel to burn or overheat.

[0004] An induction heating device including a plurality of working coils according to one embodiment of the present disclosure includes a first inverter for supplying current to a first working coil among the plurality of working coils. The induction heating device includes a second inverter for supplying current to a second working coil among the plurality of working coils. The induction heating device includes a memory for storing at least one instruction and at least one processor for controlling operations of the first inverter and the second inverter by executing at least one instruction. At least one processor according to one embodiment of the present disclosure can obtain a first power output from the first inverter. After identifying a state in which a cooking vessel is placed on the first working coil and the second working coil, the at least one processor can obtain a second power output from the second inverter. The at least one processor can obtain a ratio value between the first power and the second power. When the obtained ratio value exceeds or is less than a set ratio value, the at least one processor can perform an operation of adjusting a duty of a switching element included in at least one of the first inverter and the second inverter to include the ratio value within the set ratio value.

[0005] A method for controlling an induction heating device including a plurality of working coils according to one embodiment of the present disclosure may include a step of obtaining a first power output from a first inverter supplying current to a first working coil among the plurality of working coils. A method according to one embodiment of the present disclosure may include a step of obtaining a second power output from a second inverter supplying current to a second working coil among the plurality of working coils. A method according to one embodiment of the present disclosure may include a step of obtaining a ratio value between the first power and the second power. A method according to one embodiment of the present disclosure may include a step of adjusting a duty of a switching element included in at least one of the first inverter and the second inverter so that the ratio value falls within the set ratio value when the ratio value (R1) exceeds or is less than a set ratio value (α).

[0006] FIG. 1 is a drawing for explaining an induction heating device according to one embodiment of the present disclosure.

[0007] FIG. 2 is a cross-sectional view of a cooking vessel placed on a working coil included in an induction heating device according to one embodiment of the present disclosure.

[0008] FIG. 3a is a drawing for explaining the configuration of a working coil and an inverter included in an induction heating device according to one embodiment of the present disclosure.

[0009] FIG. 3b is a drawing for explaining the configuration of a working coil and an inverter included in an induction heating device according to one embodiment of the present disclosure.

[0010] FIG. 3c is an example of a plurality of temperature values ​​of a cooking vessel and a difference value between the plurality of temperature values ​​obtained by a processor of an induction heating device according to one embodiment of the present disclosure.

[0011] FIG. 3D is an example diagram of power waveforms of a first inverter and a second inverter in an induction heating device according to one embodiment of the present disclosure.

[0012] FIG. 4 is a detailed circuit diagram of an inverter and a working coil included in an induction heating device according to one embodiment of the present disclosure.

[0013] FIG. 5 is a functional block diagram of an induction heating device according to one embodiment of the present disclosure.

[0014] FIG. 6 is a flowchart of a control method of an induction heating device according to one embodiment of the present disclosure.

[0015] FIG. 7 is a waveform diagram for explaining frequency control and duty control of an inverter performed in an induction heating device according to one embodiment of the present disclosure.

[0016] FIG. 8 is a flowchart of a control method of an induction heating device according to one embodiment of the present disclosure.

[0017] FIG. 9 is a diagram showing the relationship between power and frequency output from two inverters in an induction heating device according to one embodiment of the present disclosure.

[0018] FIG. 10 is a flowchart of a control method of an induction heating device according to one embodiment of the present disclosure.

[0019] FIG. 11 is a flowchart of a control method of an induction heating device according to one embodiment of the present disclosure.

[0020] FIG. 12 is a diagram for explaining an example of increasing the duty based on the phase angle detected from multiple inverters described in FIG. 11.

[0021] Fig. 13 is a flowchart of a control method of an induction heating device according to one embodiment of the present disclosure.

[0022] FIG. 14 is a drawing for explaining the point in time at which an induction heating device according to one embodiment of the present disclosure begins performing an operation to reduce the duty of an inverter.

[0023] FIG. 15 is a flowchart of a control method of an induction heating device according to one embodiment of the present disclosure.

[0024] Fig. 16 is a flowchart of a control method of an induction heating device according to one embodiment of the present disclosure.

[0025] The terms used in this disclosure will be briefly explained, and one embodiment of the present disclosure will be specifically described.

[0026] The terms used in this disclosure are selected from widely used, current terms, taking into account the functions of one embodiment of the disclosure. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, and in such cases, their meanings will be described in detail in the description of the relevant embodiments of the disclosure. Therefore, the terms used in this disclosure should not be defined simply as names of terms, but rather based on the meanings of the terms and the overall content of the disclosure.

[0027] In this disclosure, the expression “at least one of a, b or c” may refer to “a”, “b”, “c”, “a and b”, “a and c”, “b and c”, “all of a, b and c”, or variations thereof.

[0028] In this disclosure, the term "and / or" includes a combination of a plurality of described elements or any element among a plurality of described elements. In this disclosure, terms such as "first," "second," or "first" or "second" may be used simply to distinguish the corresponding element from other corresponding elements and do not limit the corresponding elements in any other respect (e.g., importance or order).

[0029] Throughout this disclosure, whenever a part is said to "include" a certain component, this does not mean that it excludes other components, but rather that it may include other components, unless specifically stated otherwise.

[0030] In addition, terms such as "... unit", "module", etc. described in the present disclosure mean a unit that processes at least one function or operation. The "... unit", "module" described in the present disclosure may be implemented by hardware such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), software, or a combination of hardware and software. The term "~ unit" used in one embodiment of the present disclosure is not limited to software or hardware. The "~ unit" described in the present disclosure may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. In one embodiment of the present disclosure, the "~ unit" may include components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided by a particular component or a particular "part" may be combined or separated into additional components to reduce the number of components. Furthermore, in one embodiment, a "part" may include one or more processors.

[0031] In one embodiment of the present disclosure, each block of the flowchart diagrams and combinations of the flowchart diagrams can be performed by computer program instructions. The computer program instructions can be installed on a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment. Instructions executed by the processor of the computer or other programmable data processing equipment can generate means for performing the functions described in the flowchart block(s). The computer program instructions can also be stored in a computer-accessible or computer-readable memory that can direct the computer or other programmable data processing equipment to implement the functions in a particular manner. The instructions stored in the computer-accessible or computer-readable memory can also produce an article of manufacture that includes instruction means for performing the functions described in the flowchart block(s). The computer program instructions can also be installed on a computer or other programmable data processing equipment.

[0032] Additionally, each block in the flowchart diagram may represent a module, segment, or portion of code that includes one or more executable instructions for performing a specified logical function(s). In one embodiment of the present disclosure, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may be executed substantially simultaneously or, depending on the function, may be executed in reverse order.

[0033] Below, with reference to the attached drawings, embodiments of the present disclosure are described in detail so that those skilled in the art can easily implement the present disclosure. However, one embodiment of the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description are omitted to clearly describe one embodiment of the present disclosure, and similar parts are designated with similar drawing reference numerals throughout the present disclosure.

[0034] When a cooking vessel is placed on a plurality of working coils included in an induction heating device, the frequency of an inverter corresponding to each working coil may be reduced in order to increase the power applied to the plurality of working coils. When the frequency of the inverter is reduced, the difference between the power output from the inverters corresponding to each of the plurality of working coils may gradually increase due to the difference between the resonance coefficients (Quality factors, Q-factors) of the plurality of working coils. When the difference between the power output from the inverters gradually increases, the distribution of the power output from the inverter may become uneven.

[0035] If the distribution of power output from the inverters corresponding to multiple working coils becomes uneven, the efficiency of the inverter may decrease or the heat distribution of the working coils may become uneven. This may result in a decrease in the thermal efficiency of the cooking vessel, which may result in longer cooking times and uneven cooking results. For example, some of the contents of the cooking vessel may burn or overheat. The decrease in the thermal efficiency of the cooking vessel due to the uneven heat distribution of the working coils may lead to a decrease in the thermal efficiency of the induction heating device. Furthermore, if the distribution of power output from the inverters corresponding to multiple working coils becomes uneven, a large current may flow in the resonant network of some working coils (e.g., the inner working coil). If a large current flows in the resonant network, the working coils may be damaged or the switching elements built into the inverters corresponding to the working coils may burn out. A resonant network refers to a resonant circuit configured based on a working coil. The resonant network may include, but is not limited to, a working coil and a capacitor.

[0036] When a cooking vessel is placed on a plurality of working coils, it may indicate that the cooking vessel is electrically connected to the plurality of working coils. This is because the magnetic field of the working coils passes through the cooking vessel and generates eddy currents. When a cooking vessel is placed on a plurality of working coils, it may indicate that the cooking vessel uses a plurality of working coils. The plurality of working coils may have an inner and an outer structure. The inner and outer structures may be structures that divide the plurality of working coils into an inner and an outer part. The plurality of working coils may have a separate structure. The separate structure may be a structure in which the plurality of working coils are placed adjacent to each other at different locations. The plurality of working coils may have a structure that combines the inner and outer structures with the separate structure. The shape of the working coils may be a circular working coil, an oval working coil, or a square working coil. The structure of the plurality of working coils according to an embodiment of the present disclosure is not limited to the above-described structure.

[0037] According to one embodiment of the present disclosure, an induction heating device and a control method thereof can be provided that control power distribution so that power output from an inverter corresponding to each of a plurality of working coils is evenly distributed when a cooking vessel is placed on a plurality of working coils.

[0038] According to one embodiment of the present disclosure, an induction heating device and a control method thereof can be provided that control power distribution so that power output from an inverter corresponding to each of a plurality of working coils is uniformly distributed over a wide power range when a cooking vessel is placed on a plurality of working coils.

[0039] According to one embodiment of the present disclosure, an induction heating device and a control method thereof can be provided that control power distribution so that power applied to a plurality of working coils is uniformly distributed over a wide power range when a cooking vessel is placed on a plurality of working coils.

[0040] FIG. 1 is a drawing for explaining an induction heating device (100) according to one embodiment of the present disclosure.

[0041] Referring to FIG. 1, an induction heating device (100) according to one embodiment of the present disclosure may be referred to as an induction cooking apparatus, an induction range, an induction cooktop, or a heating device, but is not limited thereto.

[0042] An induction heating device (100) according to one embodiment of the present disclosure may include, but is not limited to, a plurality of burners (101, 102, 103) as illustrated in FIG. 1. For example, although the plurality of burners (101, 102, 103) illustrated in FIG. 1 are configured in a circular shape, at least some of the burners may be configured in a square shape. For example, all of the plurality of burners (101, 102, 103) may be configured in a square shape. For example, the induction heating device (100) may include a smaller number of burners than the plurality of burners (101, 102, 103) illustrated in FIG. 1. For example, the induction heating device (100) may include a larger number of burners than the plurality of burners (101, 102, 103) illustrated in FIG. 1. For example, the first crater (101) may correspond to a plurality of working coils (210_1, 210_2) having a structure in which two working coils are arranged as an inner working coil (210_1) and an outer working coil (210_2), as illustrated in FIG. 3a, which will be described later. For example, the plurality of craters (102, 103) may correspond to a plurality of working coils (210_3, 210_4) having an independent structure, as illustrated in FIG. 3b, which will be described later. For example, the plurality of craters (101, 102, 103) may each correspond to a plurality of working coils (210_1, 210_2) arranged as an inner and outer structure, as illustrated in FIG. 3a, which will be described later. For example, the plurality of craters (101, 102, 103) may each correspond to a plurality of working coils (210_3, 210_4) having an independent structure, as illustrated in FIG. 3b, which will be described later. When the plurality of craters (101, 102, 103) are configured in a square shape, the working coils corresponding to the plurality of craters (101, 102, 103) may also be configured to conform to the square structure.

[0043] The cooking vessel (104) illustrated in FIG. 1 may include a conductive cooking vessel. The cooking vessel (104) illustrated in FIG. 1 may be a device for cooking (or heating) the contents within the cooking vessel (104). For example, the contents within the cooking vessel (104) may be liquids such as water, tea, coffee, soup, juice, oil, etc. For example, the contents within the cooking vessel (104) may be solids such as butter, meat, vegetables, bread, rice, etc. The contents within the cooking vessel (104) are not limited to those described above.

[0044] According to one embodiment of the present disclosure, the cooking vessel (104) may be powered wirelessly from the induction heating device (100) using electromagnetic induction. Accordingly, the cooking vessel (104) may not include a power cord connected to a power outlet.

[0045] According to one embodiment of the present disclosure, the type of cooking vessel (104) may vary. The type of cooking vessel (104) may be classified according to size and magnetic material (e.g., iron, stainless steel, aluminum-coated iron, etc.). The cooking vessel (104) may include an induction heating (IH) vessel or a magnetic vessel. For example, the cooking vessel (104) may be an IH vessel such as a pot, a frying pan, or a steamer. The cooking vessel (104) may also include a cooker device. The cooker device may be a device into which an IH vessel can be inserted or removed. The cooker device may be a device capable of automatically cooking contents according to a recipe.

[0046] According to one embodiment of the present disclosure, when the cooking vessel (104) includes a communication interface, the cooking vessel (104) can communicate with the induction heating device (100). The cooking vessel (104) may also communicate with an external device (e.g., a mobile device) other than the induction heating device (100). The communication interface may include a short-range communication unit, a long-range communication unit, etc. The short-range wireless communication interface may include, but is not limited to, a Bluetooth communication unit, a BLE (Bluetooth Low Energy) communication unit, a NFC (Near Field Communication interface), a WLAN (Wi-Fi) communication unit, a Zigbee communication unit, an IrDA (Infrared Data Association) communication unit, a WFD (Wi-Fi Direct) communication unit, an UWB (Ultra WideBand) communication unit, or / and an Ant+ communication unit.

[0047] When the cooking vessel (104) is remotely controlled by a server device (not shown) in an IoT (Internet of Things) environment, the remote communication unit may be used to communicate with the server device (not shown). In this case, the cooking vessel (104) may be an IoT device. The remote communication unit may include at least one of the Internet, a computer network (e.g., a LAN or WAN), and / or a mobile communication unit. The mobile communication unit may include at least one of a 3G (Generation) module, a 4G (Generation) module, a 5G (Generation) module, an LTE (Long Term Evolution) module, an NB-IoT (NarrowBand Internet of Things) module, and / or an LTE-M (LTE-Machine Type Communication) module, but is not limited thereto.

[0048] According to one embodiment of the present disclosure, the cooking vessel (104) may transmit information to the server device via the induction heating device (100). For example, the cooking vessel (104) may transmit information obtained from the cooking vessel (104) (e.g., temperature information of the contents, etc.) to the induction heating device (100) via short-range wireless communication (e.g., Bluetooth, BLE, etc.). At this time, the induction heating device (100) may transmit the information obtained from the cooking vessel (104) to the server device by connecting to the server device using a WLAN (Wi-Fi) communication unit or a long-distance communication unit (e.g., the Internet).

[0049] Meanwhile, the server device may provide the user with information obtained from the cooking vessel (104) received from the induction heating device (100) through a mobile device (not shown) connected to the server device. According to another embodiment of the present disclosure, the induction heating device (100) may directly transmit the information obtained from the cooking vessel (104) to the user's mobile device through D2D (device to device) communication (e.g., WFD (Wi-Fi Direct) communication or BLE communication). The mobile device may be a smart phone, a smart watch, smart glasses, a smart accessory, a wearable device (e.g., a smart band, a smart helmet), a self-driving car, a laptop computer, a tablet PC, a digital camera, an e-book terminal, a digital broadcasting terminal, a PDA (Personal Digital Assistants), a PMP (Portable Multimedia Player), a navigation device, an MP3 player, or a movable home appliance (e.g., a robot vacuum cleaner), but the mobile device is not limited thereto. The mobile device may also be referred to as a user terminal.

[0050] According to one embodiment of the present disclosure, the cooking vessel (104) may transmit information of the cooking vessel (104) (e.g., temperature information of the contents, temperature information of the bottom surface of the cooking vessel (104), etc.) to a server device via a communication interface (e.g., WLAN (Wi-Fi) communication unit). In addition, the cooking vessel (104) may transmit information obtained from the cooking vessel (104) (e.g., temperature information of the contents, etc.) to a user's mobile device via short-range wireless communication (e.g., Bluetooth, BLE, etc.) or device to device (D2D) communication (e.g., Wi-Fi Direct (WFD) communication).

[0051] An induction heating device (100) according to one embodiment of the present disclosure may be a device that wirelessly transmits power to a cooking vessel (104) positioned on a top plate (or on a plurality of working coils) using electromagnetic induction. The induction heating device (100) may include a plurality of working coils that generate a magnetic field for inductively heating the cooking vessel (104).

[0052] Generating a magnetic field by a working coil may involve transmitting power by utilizing a magnetic field induced in an IH metal (e.g., iron) through self-induction. For example, an induction heating device (100) may generate eddy currents in a cooking vessel (104) by flowing a current through the working coil to form a magnetic field.

[0053] According to one embodiment of the present disclosure, the induction heating device (100) may include a plurality of working coils. For example, the induction heating device (100) may include a plurality of working coils corresponding to each of the plurality of burners (101, 102, 103). In addition, the induction heating device (100) may include a high-power burner in which a first working coil (210_1) is provided on the inner side and a second working coil (210_2) is provided on the outer side, as illustrated in FIG. 3A, which will be described later. The high-power burner may include three or more working coils. In one embodiment of the present disclosure, the burner may also be referred to as a cooking zone.

[0054] The top plate of the induction heating device (100) according to one embodiment of the present disclosure may be made of reinforced glass, such as ceramic glass, so as not to be easily damaged. In addition, a guide mark may be provided on the top plate of the induction heating device (100) to guide the burner where the cooking vessel (104) should be positioned.

[0055] An induction heating device (100) according to one embodiment of the present disclosure can identify (or detect) a state in which a cooking vessel (104) is placed on a plurality of working coils. For example, the induction heating device (100) can identify that the cooking vessel (104) is placed on the corresponding plurality of working coils when the current values ​​of the plurality of working coils (inductance) are equal to or greater than a set current value. For example, the induction heating device (100) can identify that the cooking vessel (104) is placed on the corresponding plurality of working coils when the output values ​​of the plurality of working coils are equal to or greater than a set output value. For example, the set current value may be a current value corresponding to about 10 to 20% of the capacity of the working coils. For example, the set output value may be an output value corresponding to about 10 to 20% of the capacity of the working coils. The set current value or the set output value is not limited to what has been described above. The current value of the working coil or the output values ​​of multiple working coils may be acquired (or detected) using a magnetic field detection sensor. The magnetic field detection sensor may be provided on a part of the upper plate of the induction heating device (100).

[0056] For example, the magnetic field detection sensor may connect an input terminal of the magnetic field detection sensor to an output terminal of each working coil corresponding to a plurality of burners (101, 102, 103) included in the induction heating device (100), and may connect the output terminal of the magnetic field detection sensor to a processor (310) of the induction heating device (100). For example, the magnetic field detection sensor may receive a magnetic field of each working coil corresponding to a plurality of burners (101, 102, 103) via radio waves, and transmit the measured magnetic field to the processor (310). The number of magnetic field detection sensors may be the same as the number of working coils. The magnetic field detection sensor may be configured as a single magnetic field detection sensor capable of detecting a current value, an output value, or a magnetic field of a plurality of working coils.

[0057] An operation of identifying (or detecting) a state in which a cooking vessel (104) according to one embodiment of the present disclosure is placed on a plurality of working coils may include an operation of identifying a state in which the cooking vessel (104) is placed on a plurality of working coils (201_1, 201_2) having a structure as illustrated in FIG. 3A. An operation of identifying a state in which the cooking vessel (104) according to one embodiment of the present disclosure is placed on a plurality of working coils may include an operation of identifying a state in which the cooking vessel (104) is placed on a plurality of working coils (201_3, 202_4) having a structure as illustrated in FIG. 3B. An operation of identifying a state in which the cooking vessel (104) according to one embodiment of the present disclosure is placed on a plurality of working coils may include an operation of identifying a state in which the cooking vessel (104) is placed on a plurality of working coils corresponding to a plurality of burners (101, 102, 103) as illustrated in FIG. 1. An operation of identifying a state in which a cooking vessel (104) according to one embodiment of the present disclosure is placed on a plurality of working coils may include an operation of identifying a state in which a cooking vessel (104) is placed on a plurality of working coils (201_1, 201_2) having a structure as illustrated in FIG. 3a and a plurality of working coils (201_3, 201-4) having a structure as illustrated in FIG. 3b.

[0058] In addition, the induction heating device (100) can identify that the cooking vessel (104) is placed on the plurality of working coils when the input power supplied to the plurality of working coils is equal to or greater than the set power. The input power supplied to the plurality of working coils can be calculated using the current values ​​measured using the current sensors (410_1, 410_2) illustrated in FIG. 4, which will be described later. The induction heating device (100) can also identify that the cooking vessel (104) is placed on the plurality of working coils when a phase difference occurs between the voltage supplied to the plurality of working coils and the current induced therein. The voltage supplied to the plurality of working coils and the current induced therein can be detected using the current values ​​measured by the current sensors (410_1, 410_2) and the output values ​​of the plurality of working coils, respectively.

[0059] In addition, the induction heating device (100) may identify (or detect) a state in which the cooking vessel (104) is placed on the working coil by using a camera sensor. The camera sensor may be provided on a part of the top plate of the induction heating device (100). The camera sensor may also be provided on a part of the side of the induction heating device (100). For example, the induction heating device (100) may identify (or detect) a state in which the cooking vessel (104) is placed on the working coil by using a weight detection sensor. For example, the weight detection sensor may be provided on a part of the top plate of the induction heating device (100). The weight detection sensor may be provided on a part of the top plate adjacent to the working coil corresponding to a plurality of burners (101, 102, 103) included in the induction heating device (100).

[0060] The induction heating device (100) may also identify a state in which a cooking vessel (104) is placed on at least one working coil by using at least two of the magnetic field detection sensor, camera sensor, and weight detection sensor described above.

[0061] An induction heating device (100) according to one embodiment of the present disclosure can control the duty of a switching element included in an inverter so that the power distribution output from an inverter corresponding to each of the plurality of working coils is uniform after identifying a state in which a cooking vessel (104) is placed on a plurality of working coils. An induction heating device (100) according to one embodiment of the present disclosure can also control the duty of a switching element included in an inverter so that the power distribution output from an inverter corresponding to each of the plurality of working coils is uniform, without identifying a state in which a cooking vessel (104) is placed on a plurality of working coils. An induction heating device (100) according to one embodiment of the present disclosure can also control the duty of a switching element included in an inverter so that the power distribution output from an inverter corresponding to each of the plurality of working coils is uniform, regardless of whether or not the cooking vessel (104) is placed on a plurality of working coils (or regardless of an operation of identifying a state in which the cooking vessel (104) is placed on a plurality of working coils).

[0062] According to one embodiment of the present disclosure, the induction heating device (100) may include a communication interface (530) illustrated in FIG. 5, which will be described later, to communicate with an external device (e.g., a mobile device, a server device). For example, the induction heating device (100) may communicate with a cooking vessel (104) or a server device through the communication interface (530). The communication interface (530) may include at least one of a short-range communication unit (531) (e.g., an NFC communication unit, a Bluetooth communication unit, a BLE communication unit, etc.) or a mobile communication unit.

[0063] According to one embodiment of the present disclosure, the induction heating device (100) can identify a cooking vessel (104) placed on a plurality of working coils through the communication interface (530). For example, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils by receiving a packet transmitted from the cooking vessel (104) placed on a plurality of working coils using short-range wireless communication (e.g., a Bluetooth Low Energy Mesh (BLE) network, Bluetooth). The induction heating device (100) can also identify a state in which the cooking vessel (104) is placed on at least one working coil by receiving a packet transmitted from the cooking vessel (104) placed on at least one working coil using short-range wireless communication.

[0064] According to one embodiment of the present disclosure, the induction heating device (100) may transmit information about power output from a plurality of inverters to a server device (or an external device (e.g., a mobile device)) through a communication interface (530). The server device (or the external device) may transmit a signal for uniformly controlling power distribution from the plurality of inverters to the induction heating device (100) through the communication interface (530) included in the induction heating device (100) based on the received information about power output from the plurality of inverters. The server device (or the external device) may also generate a signal for uniformly controlling power distribution from the plurality of inverters by performing a method similar to the control method of the induction heating device (100) described in FIGS. 6 to 16 to be described later.

[0065] According to one embodiment of the present disclosure, the induction heating device (100) may display information related to the cooking vessel (104) through the user interface (540) illustrated in FIG. 5, which will be described later. For example, when the cooking vessel (104) is placed on a plurality of working coils, the induction heating device (100) may display identification information of the cooking vessel (104), position information of the cooking vessel (104) (e.g., (x, y) coordinate information of the top plate of the induction heating device (100) or information about the working coil on which the cooking vessel (104) is placed (e.g., position information of the working coil)) on the output interface (e.g., display) (541) included in the user interface (540) illustrated in FIG. 5, which will be described later. Even when the cooking vessel (104) is placed on at least one working coil, the induction heating device (100) may display identification information of the cooking vessel (104) and position information of the cooking vessel (104) on an output interface (541) included in the user interface (540).

[0066] Referring to FIG. 1, when a cooking vessel (104) (e.g., a pot) is placed on a plurality of working coils included in an induction heating device (100), the induction heating device (100) may provide identification information of the cooking vessel (104) (e.g., a pot) and position information of the cooking vessel (104) (e.g., position information of the right burner (101)) to the user through an output interface (e.g., a display) (541). Even when a cooking vessel (104) (e.g., a pot) is placed on at least one working coil included in the induction heating device (100), the induction heating device (100) may provide identification information of the cooking vessel (104) (e.g., a pot) and position information of the cooking vessel (104) (e.g., position information of the right burner (101)) to the user through an output interface (e.g., a display) (541).

[0067] FIG. 2 is a cross-sectional view of a cooking vessel (104) placed on a working coil included in an induction heating device (100) according to one embodiment of the present disclosure.

[0068] Referring to FIG. 2, the cooking vessel (104) may include a magnetic material (e.g., an IH metal) in which a magnetic field can be induced. The cooking vessel (104) may be a container of various shapes including a magnetic material and may be inductively heated by an induction heating device (100). Induction heating (IH) is a method of heating an IH metal using an electromagnetic induction phenomenon. For example, when a high-frequency current is supplied to a working coil (210) included in an induction heating device (100), a magnetic field that varies over time is induced inside the working coil (210). For example, the high-frequency current is a current having a frequency of 20 kHz to 1 MHz.

[0069] A working coil (210) according to an embodiment of the present disclosure may include first and second working coils (210_1, 210_2) having the structure illustrated in FIG. 3A. The working coil (210) may also include third and fourth working coils (210_3, 210_4) having the structure illustrated in FIG. 3B. The structure of the working coil (210) may also have a structure that combines the first and second working coils (210_1, 210_2) having the structure illustrated in FIG. 3A and the third and fourth working coils (210_3, 210_4) having the structure illustrated in FIG. 3B. The working coil (210) according to an embodiment of the present disclosure is not limited to those illustrated in FIGS. 3A and 3B. The first and second working coils (210_1, 210_2) illustrated in FIG. 3a and the third and fourth working coils (210_3, 210_4) illustrated in FIG. 3b may have the same capacity, but may also have different capacities. For example, the configurations of the first and second working coils (210_1, 210_2) illustrated in FIG. 3a and the third and fourth working coils (210_3, 210_4) illustrated in FIG. 3b may be determined according to the size (or diameter) of the bottom surface of the cooking vessel (104) to be covered, the material of the cooking vessel (104) (e.g., magnetic or non-magnetic), and the maximum output power.

[0070] The magnetic field generated by the working coil (210) can pass through the bottom surface (or bottom surface) of the cooking vessel (104). When the magnetic field that varies over time passes through the IH metal (e.g., iron, steel, nickel, or various types of alloys) included in the bottom surface of the cooking vessel (104), a current that rotates around the magnetic field can be generated in the IH metal. The rotating current is called an eddy current, and the phenomenon in which a current is induced by a magnetic field that varies over time is called an electromagnetic induction phenomenon. In the case of the cooking vessel (104), heat is generated at the bottom surface of the cooking vessel (104) by the eddy current and the resistance of the IH metal (e.g., iron). The contents of the cooking vessel (104) can be heated by the heat generated at this time. As illustrated in FIG. 2, the diameter of the bottom surface of the cooking vessel (104) and the diameter of the working coil (210) may be the same or similar.

[0071] FIG. 3A is a drawing for explaining the configuration of a working coil and an inverter included in an induction heating device (100) according to one embodiment of the present disclosure. FIG. 3A illustrates a case where multiple concentric circular working coils are arranged in one furnace. For example, the multiple concentric circular structure illustrated in FIG. 3A includes a first working coil (1) having a small size at the center of the circular coil. st coil)(210_1) is placed, and a second working coil (2) having a size larger than the size of the first working coil (210_1) is placed around the first working coil (210_1). nd This is the case where coil)(210_2) is arranged. The multi-concentric circular structure can also be composed of a triple circular structure, a multi-circular structure, etc. The triple circular structure is the case where three working coils are arranged in order of size. The multi-concentric circular structure is the case where N working coils are arranged in order of size.

[0072] The first and second working coils (210_1, 210_2) included in the induction heating device (100) may be referred to as burners. Accordingly, the first working coil (210_1) may be referred to as an inner burner, and the second working coil (210_2) may be referred to as an outer burner. When there are N working coils configured as a multi-concentric circular structure, the working coils configured as a multi-concentric circular structure may be referred to as a first burner, a second burner, ..., and an Nth burner.

[0073] When the working coil (210) included in the induction heating device (100) according to one embodiment of the present disclosure is composed of first and second working coils (210_1, 210_2) of a multi-concentric circular structure as illustrated in FIG. 3A, the induction heating device (100) according to one embodiment of the present disclosure may include first and second inverters (301_1, 301_2). The first and second inverters (301_1, 301_2) may be connected 1:1 with the first and second working coils (210_1, 210_2). For example, the first inverter (301_1) may be connected with the first working coil (210_1). The second inverter (301_2) may be connected with the second working coil (210_2). The first inverter (301_1) can supply current (high frequency current) to the first working coil (210_1). The second inverter (301_2) can supply current (high frequency current) to the second working coil (210_2). The power output from the first and second inverters (301_1, 301_2), respectively, can be the power supplied to the first and second working coils (210_1, 210_2).

[0074] When the cooking vessel (104) is placed on the first and second working coils (210_1, 210_2), the processor (310) according to one embodiment of the present disclosure can detect the power output from the first and second inverters (301_1, 301_2), respectively. The operation of detecting the power output from the first and second inverters (301_1, 301_2), respectively, by the processor (310) may also be referred to as an operation of obtaining the power output from the first and second inverters (301_1, 301_N), respectively, by the processor (310). In order to detect the power output from the first and second inverters (301_1, 301_2), respectively, the processor (310) can detect the voltage (voltage value) and current (current value) output from the first and second inverters (301_1, 301_2), respectively, and detect (or obtain) the power (power value) by multiplying the detected voltage (voltage value) and current (current value).

[0075] When the cooking vessel (104) is placed on the first and second working coils (210_1, 210_2), the processor (310) can evenly control the distribution of power based on the ratio value between the power output from the first and second inverters (301_1, 301_2) and the set ratio value (α). The set ratio value (α) may be a value set in advance. The processor (310) can detect (or obtain) the ratio value between the power output from the first and second inverters (301_1, 301_2). For example, the processor (310) can obtain the ratio value (R1) between the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2). In one embodiment of the present disclosure, the detected ratio value (R1) can be obtained based on the first power (P1). In this case, the ratio value (R1) can be obtained by dividing the second power (P2) by the first power (P1) (R1=P2 / P1). This may indicate that the ratio value (R1) is obtained based on the first power (P1) of the inner working coil (210_1). The ratio value (R1) may also be detected based on the second power (P2). In this case, the ratio value (R1) can be obtained by dividing the first power (P1) by the second power (P2) (R1=P1 / P2). This may indicate that the ratio value (R1) is obtained based on the second power (P2) of the outer working coil (210_2).

[0076] The processor (310) can compare the ratio value (R1) between the acquired first power (P1) and the second power (P2) with the set ratio value (α). As a result of the comparison, the processor (310) can determine whether the ratio value (R1) between the first power (P1) and the second power (P2) is included in the set ratio value (α). If the ratio value (R1) is included in the set ratio value (α), the processor (310) can determine that the distribution of the power output from the first and second inverters (301_1, 301_2) is uniform.

[0077] If the ratio value (R1) exceeds or is less than the set ratio value (α), the processor (310) may determine that the distribution of the power output from the first and second inverters (301_1, 301_2) is not uniform. If the distribution of the power output from the first and second inverters (301_1, 301_2) is not uniform, the processor (310) may control the operation of at least one of the first and second inverters (301_1, 301_2) to uniformly control the distribution of the power output from the first and second inverters (301_1, 301_2) according to an embodiment of the present disclosure. For example, the operation of at least one of the first and second inverters (301_1, 301_2) may include the operation of a switching element included in at least one of the first and second inverters (301_1, 301_2). For example, the operation of the switching element may include an operation of adjusting the duty of the switching element. For example, the operation of adjusting the duty of the switching element may include an operation of reducing the duty of the switching element from 50% to 40%. For example, the operation of adjusting the duty of the switching element may include an operation of increasing the duty of the switching element from 20% to 30%. The operation of adjusting the duty of the switching element according to an embodiment of the present disclosure is not limited to the above-described operation.

[0078] The set ratio value (α) according to one embodiment of the present disclosure is a reference value for determining whether the distribution of multiple powers (e.g., the first power (P1) and the second power (P2)) is in a uniform state (or situation). Therefore, the set ratio value (α) may be determined based on the state in which the distribution of multiple powers is uniform. For example, the set ratio value (α) may be determined based on the result value of measuring the temperature of the bottom surface of the cooking vessel (104) while the cooking vessel (104) is placed on a plurality of working coils. The temperature measurement of the bottom surface of the cooking vessel (104) may be performed when the induction heating device (100) outputs the maximum output (e.g., 3700 W) that it can output for a predetermined period of time (e.g., 10 minutes), but is not limited thereto.

[0079] The temperature measurement of the bottom surface of the cooking vessel (104) according to one embodiment of the present disclosure may be performed at multiple locations. For example, although the temperature of the bottom surface of the cooking vessel (104) may be measured at locations L1 and L2 as shown in FIG. 2, the temperature measurement of the bottom surface of the cooking vessel (104) may be measured at more locations than the locations shown in FIG. 2. To measure the temperature of the bottom surface of the cooking vessel (104), temperature sensors may be mounted at locations L1 and L2 of the cooking vessel (104). The temperature sensor mounted on the cooking vessel (104) may transmit the measured temperature value to the induction heating device (100) or an external device (e.g., a server device, a mobile device) not shown. The temperature sensor mounted on the cooking vessel (104) may be detachable. When the temperature sensor mounted on the cooking vessel (104) is detachable, the temperature sensor may be attached to the cooking vessel (104) only when measuring the temperature of the bottom surface of the cooking vessel (104).

[0080] The temperature measurement of the bottom surface of the cooking vessel (104) according to one embodiment of the present disclosure may be performed using a thermal imaging camera. When using a thermal imaging camera, the processor (310) of the induction heating device (100) may receive a thermal image acquired from the thermal imaging camera and analyze the received thermal image to acquire temperature values ​​at positions L1 and L2 as illustrated in FIG. 2. For example, the thermal imaging camera may be installed at least on the top, side, or inside of the cooking vessel (104), but the installation location is not limited thereto.

[0081] In the case where the working coil (210) illustrated in FIG. 2 has a structure as illustrated in FIG. 3a, the L1 position may be the bottom surface of the cooking vessel (104) affected by the output of the outer working coil (210_2), and the L2 position may be the bottom surface of the cooking vessel (104) affected by the output of the inner working coil (210_1). At this time, the diameter of the bottom surface of the cooking vessel (104) (e.g., 280 mm) and the diameter of the working coil (210) may be the same as or similar to each other.

[0082] The processor (310) of the induction heating device (100) according to one embodiment of the present disclosure can obtain a temperature value t1 at a position L1 through a temperature sensor mounted at a position L1 of the cooking vessel (104). The processor (310) can obtain a temperature value t2 at a position L2 through a temperature sensor mounted at a position L2 of the cooking vessel (104). The processor (310) can obtain a difference value (△t=t1-t2) between the temperature value t1 at a position L1 and the temperature value t2 at a position L2. The processor (310) can also obtain the temperature values ​​t1, t2, and the difference value (△t) periodically (e.g., every minute). When the temperature values ​​t1, t2, and the difference value (△t) are obtained periodically, the processor (310) can also obtain an average value of the difference values ​​(△t) that are periodically obtained for a predetermined period of time (e.g., 10 minutes). When the temperature values ​​t1, t2, and the difference value (△t) are acquired periodically, the processor (310) may acquire the average value of the temperature values ​​t1 and the average value of t2 acquired periodically for a predetermined period of time (e.g., 10 minutes), and may acquire the difference value (△t) using the average value of t1 and the average value of t2. The processor (310) may also acquire the temperature values ​​t1, t2, and the difference value (△t) non-periodically.

[0083] After obtaining the difference value (△t) between the temperatures, the induction heating device (100) according to one embodiment of the present disclosure can determine whether the temperature of the bottom surface of the cooking vessel (104) is uniform. To this end, the processor (310) of the induction heating device (100) can compare the obtained difference value (△t) with a set temperature value. The set temperature value may be determined based on, but is not limited to, the material of the cooking vessel (104), the condition of the bottom surface of the cooking vessel (104) (e.g., whether the bottom surface is flat or whether the bottom surface has scratches), and / or whether the diameter of the bottom surface of the cooking vessel (104) and the diameter of the working coil on which the cooking vessel (104) is placed are the same. For example, the set temperature value may be 5°C, but the reference temperature value may be 15°C depending on the material of the cooking vessel (104), the condition of the bottom surface of the cooking vessel (104), and / or whether the diameter of the bottom surface of the cooking vessel (104) and the diameter of the working coil on which the cooking vessel (104) is placed are the same. The set temperature value is not limited to the above-described example and may be set in advance.

[0084] FIG. 3c is an example of a difference value between a plurality of temperature values ​​of a cooking vessel (104) obtained by a processor (310) of an induction heating device (100) according to one embodiment of the present disclosure and the obtained plurality of temperature values.

[0085] As illustrated in FIG. 3c, when the temperature value t1 at the L1 position of the cooking vessel (104) is acquired as 246.0°C by the processor (310), and the temperature value t2 at the L2 position of the cooking vessel (104) is acquired as 250.7°C, the difference value (△t) between t1 and t2 is acquired as 4.7°C. At this time, if the set temperature value is 5°C, since the difference value (△t) between t1 and t2 of 4.7°C is smaller than the set temperature value of 5°C, the processor (310) can determine that the temperature of the bottom surface of the cooking vessel (104) is uniform. The state in which the temperature of the bottom surface of the cooking vessel (104) is uniform can indicate a state in which the distribution of the outputs of the plurality of working coils (210_1, 210_2) on which the cooking vessel (104) is placed is uniform. A state in which the distribution of the output of the plurality of working coils (210_1, 210_2) is uniform can indicate a state in which the distribution of the power output from the first and second inverters (301_1, 301_2) corresponding to the plurality of working coils (210_1, 210_2) is uniform.

[0086] When the temperature of the bottom surface of the cooking vessel (104) is determined to be uniform, the processor (310) according to one embodiment of the present disclosure can obtain the output power P1 of the first inverter (301_1) (or the output power of the first working coil (210_1)) and the output power P2 of the second inverter (301_2) (or the output power of the second working coil (210_2)). The processor (310) can obtain a ratio value between the obtained output power P1 of the first inverter (301_1) and the output power P2 of the second inverter (301_2).

[0087] For example, if the output power P1 of the acquired first inverter (301_1) is 2017 W and the output power P2 of the acquired second inverter (301_2) is 1670 W, the processor (310) may obtain a ratio value between the output power P1 (2017 W) of the first inverter (301_1) and the output power P2 (1670 W) of the second inverter (301_2) as P1:P2=1:0.83 based on the output power P1 (2017 W) of the first inverter (301_1). In this case, the set ratio value (α) may be 0.83.

[0088] For example, the processor (310) may obtain a ratio value between the output power P1 (2017 W) of the first inverter (301_1) and the output power P2 (1670 W) of the second inverter (301_2) as P1:P2=1.2:1 based on the output power P2 (1670 W) of the second inverter (301_2). In this case, the set ratio value (α) may be 1.2.

[0089] In addition, when the ratio value between the output power P1 of the first inverter (301_1) and the output power P2 of the second inverter (301_2) is 1:1 regardless of the temperature measurement operation on the bottom surface of the cooking vessel (104), the distribution of the output power P1 of the first inverter (301_1) and the output power P2 of the second inverter (301_2) may be uniform. In this case, the set ratio value (α) may be 1.

[0090] Accordingly, the induction heating device (100) does not limit the state in which the distribution of the power P1 and P2 output from the plurality of inverters (301_1, 301_2) corresponding to the plurality of working coils (210_1, 210_2) on which the cooking vessel (104) is placed to a state in which P1:P2=1:1, but can also expand the state to a state in which P1:P2=1:0.83, P1:P2=1:1, or P1:P2=1:1.2, depending on the conditions between the induction heating device (100) and the cooking vessel (104). Accordingly, the induction heating device (100) can expand the range in which the distribution of the power P1 and the power P2 output from the plurality of inverters (301_1, 301_2) is uniform.

[0091] According to one embodiment of the present disclosure, the processor (310) may store a set ratio value (α) in the memory (320) and use it to uniformly control the distribution of power output from the first inverter (301_1) and the second inverter (301_2). For example, if the set ratio value (α) stored in the memory (320) is 1, the processor (310) may use the set ratio value (α) of 1 to determine whether the distribution of power output from the first inverter (301_1) and the second inverter (301_2) is uniform. For example, if the set ratio value (α) stored in the memory (320) is 0.83, the processor (310) may use the set ratio value (α) of 0.83 to determine whether the distribution of power output from the first inverter (301_1) and the second inverter (301_2) is uniform. For example, if the set ratio value (α) stored in the memory (320) is 1.2, the processor (310) can use the set ratio value (α) of 1.2 to determine whether the distribution of the power output from the first inverter (301_1) and the second inverter (301_2) is uniform. For example, if the set ratio values ​​(α) stored in the memory (320) are 0.83, 1, and 1.2, the processor (310) can select one of the stored set ratio values ​​(α) of 0.83, 1, and 1.2 according to the conditions of the cooking vessel (104) (e.g., material, size of the bottom surface, etc.) to determine whether the distribution of the power output from the first inverter (301_1) and the second inverter (301_2) is uniform. To this end, information mapping between condition information of the cooking vessel (104) and a plurality of set ratio values ​​(α) is stored in the memory (320) and may be used by the processor (310) to select the set ratio value (α).

[0092] The set ratio value (α) is not determined by the processor (310), but may be determined by an experiment when manufacturing the induction heating device (100). The set ratio value (α) determined by the experiment may be stored in the memory (320) and then read and used by the processor (310). The set ratio value (α) according to one embodiment of the present disclosure may be defined as ± an error value. In this case, the set ratio value (α) is the set minimum ratio value (α). min )≤α≤Set maximum ratio value(α max ) can also be expressed as

[0093] According to one embodiment of the present disclosure, the duty of a switching element can be expressed as a percentage of the ratio of the on-state period (time that the switching element is turned on). The duty is to control the operation of the switching element. The processor (310) can obtain the duty of the switching element as (on-state period of the switching element) / (cycle of the switching element). When the duty of the switching element is reduced (lowered) by the processor (310), the power output from the corresponding inverter can be reduced. When the duty of the switching element is increased (increased) by the processor (310), the power output from the corresponding inverter can be increased.

[0094] For example, if the ratio value (R1) between the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2) exceeds or is less than the set ratio value (α), and the first power (P1) is higher (or has a high output) among the first power (P1) and the second power (P2), the processor (310) can control the first inverter (301_1) so that the duty of the switching element included in the first inverter (301_1) is reduced. Accordingly, the distribution of the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2) can become uniform. The uniform distribution of the first power (P1) and the second power (P2) may indicate a state in which the ratio value (R1) between the first power (P1) and the second power (P2) is included in the set ratio value (α). In this way, when the distribution of the first power (P1) and the second power (P2) becomes uniform, the heat distribution between the first working coil (210_1) and the second working coil (210_2) may become uniform. Accordingly, the thermal efficiency of the induction heating device (100) may be improved.

[0095] In addition, when the ratio value (R1) between the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2) exceeds or is less than the set ratio value (α), and the second power (P2) among the first power (P1) and the second power (P2) is low (or has a low output), the processor (310) can control the operation of the second inverter (301_2) so that the duty of the switching element included in the second inverter (301_2) increases. For example, if the first power (P1) is high (high output) among the first power (P1) and the second power (P2), but the duty of the switching elements included in the first inverter (301_1) and the second inverter (301_2) is low (e.g., duty = 0.2), the processor (310) may control the operation of the second inverter (301_2) so that the duty of the switching element included in the second inverter (301_2) that outputs low power increases (e.g., duty = 0.4). Accordingly, the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2) can be distributed evenly.

[0096] FIG. 3D is an exemplary diagram of power waveforms of a first inverter (301_1) and a second inverter (301_2) in an induction heating device (100) according to one embodiment of the present disclosure. FIG. 3D is an exemplary diagram of a power waveform in which the duty of the switching element of the second inverter (301_2), which outputs low power, is increased to 0.4 to evenly distribute power when the duty of the switching element included in the first inverter (301_1) and the second inverter (301_2) is 0.2.

[0097] In addition, when the ratio value (R1) between the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2) exceeds or is less than the set ratio value (α), the processor (310) may control the operation of the second inverter (301_2) so that the duty of the switching element included in the second inverter (301_2) outputting low power (or low output) increases, while controlling the operation of the first inverter (301_1) so that the duty of the switching element included in the first inverter (301_1) outputting high power (or high output) decreases. Accordingly, the distribution of the first power (P1) and the second power (P2) may be made even. The operation of increasing the duty of the switching element included in the second inverter (301_2) while decreasing the duty of the switching element included in the first inverter (301_1) can be performed when the duties of the switching elements included in the first inverter (301_1) and the second inverter (301_2) are both 0.5 or less, but is not limited thereto.

[0098] The memory (320) may store at least one instruction or at least one program that can be executed by the processor (310). The at least one instruction or at least one program may include at least one instruction related to an operation of uniformly controlling power distribution that can be performed in an induction heating device (100) according to an embodiment of the present disclosure. Data or information necessary for performing an operation of uniformly controlling power distribution according to an embodiment of the present disclosure (e.g., a set ratio value (α), connection information between an inverter and a working coil (e.g., information on the connection of the first inverter (301_1) to the first working coil (210_1)), a set temperature value, and a set phase value (θ)) may be stored in the memory (320). limit )) can be stored. The processor (310) and the memory (320) will be described in more detail in FIG. 5, which will be described later.

[0099] FIG. 3b is a drawing for explaining the configuration of a working coil and an inverter included in an induction heating device (100) according to one embodiment of the present disclosure. FIG. 3b illustrates a case where a working coil having a circular structure is arranged one per burner. For example, the third working coil (3) of FIG. 3b rd coil)(210_3) corresponds to the second crater (102), and the fourth working coil (4 th The third working coil (210_4) may correspond to the third crater (103). The size of the third working coil (210_3) illustrated in FIG. 3b may be the same as the size of the fourth working coil (210_4) illustrated in FIG. 3b, but may also be different.

[0100] The third inverter (301_3) illustrated in FIG. 3b may be connected to the third working coil (210_3), and the fourth inverter (301_4) may be connected to the fourth working coil (210_4). Accordingly, the third inverter (301_3) may supply current (high frequency current) to the third working coil (210_3). The fourth inverter (301_4) may supply current (high frequency current) to the fourth working coil (210_4). The power output from the third and fourth inverters (301_3, 301_4), respectively, may be the power applied to the third and fourth working coils (210_3, 210_4).

[0101] For convenience of explanation, the third working coil (210_3), the fourth working coil (201_4), the third inverter (301_3), and the fourth inverter (301_4) illustrated in FIG. 3b are given different drawing reference numerals from the first working coil (201_1), the second working coil (201_2), the first inverter (301_1), and the second inverter (301_2) illustrated in FIG. 3a, but they may have the same specifications (e.g., the size of the working coil) or different specifications.

[0102] The processor (310) illustrated in FIG. 3b can obtain (or detect) the third and fourth powers (P3, P4) output from the third and fourth inverters (301_3, 301_4), respectively, as described in FIG. 3a, when the cooking vessel (104) is placed on the third and fourth working coils (210_3, 210_4). When the processor (310) obtains the third and fourth powers (P3, P4) output from the third and fourth inverters (301_3, 301_4), respectively, the processor (310) can obtain a ratio value (R1) between the obtained third and fourth powers (P3, P4). For example, the processor (310) can obtain a ratio value (R1) between the third power (P3) output from the third inverter (301_3) and the fourth power (P4) output from the fourth inverter (301_4) based on the third power (P3) (R1=P4 / P3).

[0103] The processor (310) can compare the detected ratio value (R1) with the set ratio value (α). The set ratio value (α) is a value determined based on a state in which the distribution of the third power (P3) and the fourth power (P4) is uniform, and can be determined as described in FIG. 3A.

[0104] The processor (310) may perform an operation of uniformly controlling the distribution of the third power (P3) and the fourth power (P4) by adjusting the duty of the switching element included in at least one of the third inverter (301_3) and the fourth inverter (301_4) so ​​that the ratio value (R1) is included in the set ratio value (α) when the acquired ratio value (R1) exceeds or is less than the set ratio value (α). The operation of uniformly controlling the distribution of the switching element included in at least one of the third inverter (301_3) and the fourth inverter (301_4) may be performed in the same manner as or similar to the operation of uniformly controlling the distribution of the power output from the third inverter (301_3) and the fourth inverter (301_4). When the distribution of the third power (P3) output from the third inverter (301_3) and the fourth power (P4) output from the fourth inverter (301_4) becomes uniform, the heat distribution between the third working coil (210_3) and the fourth working coil (210_4) can become uniform. Accordingly, the thermal efficiency of the induction heating device (100) can be improved.

[0105] At least one instruction or at least one program that can be executed by the processor (310) may be stored in the memory (320) illustrated in FIG. 3B. Data or information necessary for performing an operation of controlling power distribution according to an embodiment of the present disclosure (e.g., a set ratio value (α), connection information between an inverter and a working coil (e.g., information that the first inverter (301_1) is connected to the first working coil (210_1)), a set temperature value, a set phase value (θ)) may be stored in the memory (320). limit )) can be stored. The processor (310) and the memory (320) will be described in more detail in FIG. 5, which will be described later.

[0106] FIG. 4 is a detailed circuit diagram of an inverter and a working coil included in an induction heating device (100) according to one embodiment of the present disclosure.

[0107] Referring to Fig. 4, the input power (401) is AC power. The EMI (Electro Magnetic Interference) filter (402) can output AC power (AC power composed of AC voltage and AC current) that blocks (absorbs or reflects) high-frequency noise (or electromagnetic interference (EMI)) generated from the AC power supplied from the input power (401). Accordingly, the induction heating device (100) can be protected from electromagnetic interference.

[0108] The AC power output from the EMI filter (402) is converted into DC power by the rectifier circuit (403). The rectifier circuit (403) may be configured with a bridge diode as illustrated in FIG. 4, but a thyristor or other type of switching element may also be used. The DC power output from the rectifier circuit (403) may be smoothed by the first and second DC link capacitors (404_1, 404_2).

[0109] The smoothed DC power from the first DC link capacitor (404_1) can be transmitted to the first inverter (301_1), and the smoothed DC power from the second DC link capacitor (404_2) can be transmitted to the second inverter (301_2). The first inverter (301_1) and the second inverter (301_1) can each convert the applied DC power into high-frequency power and supply it to the first working coil (210_1) and the second working coil (210_2). Although FIG. 4 depicts the first and second DC link capacitors (404_1, 404_2) as independent components from the first inverter (301_1) and the second inverter (301_2), the first inverter (301_1) may include the first DC link capacitor (404_1), and the second inverter (301_2) may include the second DC link capacitor (404_2).

[0110] The first inverter (301_1) can supply high-frequency power to the first working coil (210_1) by switching operations of SW1 (405_1) and SW2 (405_2) using the direct current power smoothed by the first DC link capacitor (404_1). The switching operations of SW1 (405_1) and SW2 (405_2) are controlled by a pulse width modulation (PWM) signal provided from the processor (310), thereby controlling the magnitude of the power output from the first inverter (301_1). According to one embodiment of the present disclosure, the magnitude of the voltage and the magnitude of the current of the signal output from SW1 (405_1) and SW2 (405_2) can be controlled by controlling the duty of the PWM signal. Controlling the magnitude of the voltage and the magnitude of the current of the signal output from SW1 (405_1) and SW2 (405_2) may indicate controlling the magnitude of the power output from the first inverter (301_1). For example, if the duty of the PWM signal is reduced, the first power (P1) output from the first inverter (301_1) may be reduced. For example, if the duty of the PWM signal is increased, the first power (P1) output from the first inverter (301_1) may be increased.

[0111] The first working coil (210_1) can generate a magnetic field by resonance between the resonance capacitor 1 (411_1) and the resonance capacitor 2 (411_2). The magnetic field generated in the first working coil (210_1) can generate an eddy current in the IH cooking vessel (104) placed on the top of the first working coil (210_1). Accordingly, the contents of the cooking vessel (104) are heated. The CT1 (410_1) is a first current detection unit (or current detection sensor) for detecting the current flowing in the first working coil (210_1). The processor (310) can detect the current flowing in the CT1 (410_1) to identify (or determine) whether the cooking vessel (104) is placed on the burner corresponding to the first working coil (210_1).

[0112] The second inverter (301_1) can supply high-frequency power to the second working coil (210_2) by the switching operation of SW3 (405_3) and SW4 (405_4) using the smoothed DC power by the second DC link capacitor (404_2). The processor (310) can control the switching operation of SW3 (405_3) and SW4 (405_4) with a pulse width modulation (PWM) signal to control the amount of power output from the second inverter (301_2). Controlling the switching operation of SW3 (405_3) and SW4 (405_4) by the PWM signal may mean an operation of controlling the voltage and current of signals output from SW3 (405_3) and SW4 (405_4).

[0113] The processor (310) can control the frequency of the first inverter (301_1) and the second inverter (301_2) by controlling the cycle of the PWM. For example, the processor (310) can increase the power output from the first inverter (301_1) and the second inverter (301_2) by reducing the frequency and increasing the PWM cycle. For example, the processor (310) can decrease the power output from the first inverter (301_1) and the second inverter (301_2) by reducing the frequency and increasing the PWM cycle.

[0114] The second working coil (210-2) can generate a magnetic field in the second working coil (210_2) due to resonance between the resonance capacitor 3 (411_3) and the resonance capacitor 4 (411_4). The magnetic field generated in the second working coil (210_2) generates an eddy current in the IH cooking vessel (104) placed on the top of the second working coil (210_2). Accordingly, the contents of the cooking vessel (104) are heated. The CT2 (410_2) is a second current detection unit (or current detection sensor) for detecting the current flowing in the second working coil (210_2). The processor (310) can also detect the current flowing in the CT2 (410_2) to identify (or determine) whether the cooking vessel (104) is placed on the burner corresponding to the second working coil (210_1).

[0115] The voltage at both ends (406, 407) of SW2 (405_2) illustrated in FIG. 4 corresponds to the first power (P1) output from the first inverter (301_1), and may be referred to as the pole voltage of the first inverter (301_1). The pole voltage refers to the voltage difference between the positive and negative poles. The voltage at both ends (408, 409) of SW4 (405_4) illustrated in FIG. 4 corresponds to the second power (P2) output from the second inverter (301_2), and may be referred to as the pole voltage of the second inverter (301_2).

[0116] The components illustrated in Fig. 4 are examples based on a first inverter (301_1) and a second inverter (301_2), but the components illustrated in Fig. 4 may also be illustrated based on N inverters. In this case, the first working coil (210_1) and the second working coil (210_2) illustrated in Fig. 4 may also be provided in N numbers, and the first current detection unit (CT1, 410_1) and the second current detection unit (CT2, 410_2) may also be provided in N numbers.

[0117] Additionally, the third inverter (301_3) and the fourth inverter (301_4) illustrated in FIG. 3b may be configured like the first inverter (301_1) and the second inverter (301_2) illustrated in FIG. 4.

[0118] According to one embodiment of the present disclosure, after adjusting the duty of the switching elements (SW1, SW2, SW3, SW4) included in at least one of the first inverter (301_1) and the second inverter (301_2), if the ratio value (R1) is included in the set ratio value (α), the processor (310) may stop the operation of adjusting the duty of the switching elements (SW1, SW2, SW3, SW4). For example, when adjusting the duty of the switching elements (SW1, SW2), if the ratio value (R1) is included in the set ratio value (α), the processor (310) may stop the operation of adjusting the duty of the switching elements (SW1, SW2). For example, when adjusting the duty of the switching elements (SW3, SW4), if the ratio value (R1) is included in the set ratio value (α), the processor (310) may stop the operation of adjusting the duty of the switching elements (SW3, SW4). For example, when the duty of the switching elements (SW1, SW2, SW3, SW4) is adjusted, if the ratio value (R1) is included in the set ratio value (α), the processor (310) can stop the operation of adjusting the duty of the switching elements (SW1, SW2, SW3, SW4).

[0119] A processor (310) according to one embodiment of the present disclosure may obtain a first phase angle (θ1) by using a waveform of a current supplied from a first inverter (301_1) to a first working coil (210_1) and a waveform of a voltage supplied from the first inverter (301_1) to the first working coil (210_1). The processor (310) may obtain a second phase angle (θ2) by using a waveform of a current supplied from a second inverter (301_2) to a second working coil (210_2) and a waveform of a voltage supplied from the second inverter (301_2) to the second working coil (210_2). When at least one of the first phase angle (θ1) and the second phase angle (θ2) is less than or equal to a set phase value (θlimit), the processor (310) may increase the duty of a switching element included in an inverter for which a phase angle less than or equal to the set phase value (θlimit) is obtained. For example, when the first phase angle (θ1) is less than or equal to the set phase value (θlimit), the processor (310) can increase the duty of the switching element included in the first inverter (301_1). For example, when the second phase angle (θ2) is less than or equal to the set phase value (θlimit), the processor (310) can increase the duty of the switching element included in the second inverter (301_2). Accordingly, since a phase margin between the current waveform and the voltage waveform supplied to the working coil can be secured, the switching element included in the inverter can be prevented from being damaged due to the ZCS (Zero Current Switching) operation. The ZCS operation can refer to an operation in which the current becomes 0 when the switching element included in the inverter is switched. If the current of the switching element does not become 0 when the ZCS operation is performed, the switching element may be damaged.

[0120] A processor (310) according to one embodiment of the present disclosure can obtain a phase angle (θ) using a waveform of an output voltage and a waveform of an output current of an inverter that outputs high power. The processor (310) can obtain the obtained phase angle (θ) by using a set phase value (θlimit ) or less, the duty of the switching element included in the inverter that outputs high power can be increased. For example, when the first inverter (301_1) outputs high power, the processor (310) can obtain the phase angle (θ) using the waveform of the output voltage and the waveform of the output current of the first inverter (301_1). The processor (310) can obtain the phase angle (θ) by using the waveform of the output voltage and the waveform of the output current of the first inverter (301_1). The processor (310) can determine whether the obtained phase angle (θ) is equal to the set phase value (θ limit ) or less, the duty of the switching element included in the first inverter (301_1) can be increased. For example, when the second inverter (301_2) outputs high power, the processor (310) can obtain the phase angle (θ) using the waveform of the output voltage and the waveform of the output current of the second inverter (301_2). The processor (310) can obtain the phase angle (θ) by using the obtained phase angle (θ) as the set phase value (θ limit ) below, the duty of the switching element included in the second inverter (301_2) can be increased. Accordingly, a phase margin between the current waveform and the voltage waveform supplied to the working coil corresponding to the inverter outputting high power can be secured, thereby preventing the switching element included in the inverter outputting high power from being damaged according to the ZCS operation.

[0121] A processor (310) according to one embodiment of the present disclosure calculates a sum (P) between a first power (P1) and a second power (P2). total ) is set to power (P x ) or more, an operation of adjusting the duty of the switching element can be performed using the ratio value (R1) and the set ratio value (α). The set power (P x ) is a power (e.g., 1 kW) that is a low power, which is the sum of the first power (P1) and the second power (P2), and the power distribution output from multiple inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) is uniform, but the command power (P ref) represents the power that has not yet reached the command power (P ref ) is the power set according to user input. For example, if the power that can be set according to user input is 1 to 15 stages, 15 command powers corresponding to each of stages 1 to 15 can be set.

[0122] FIG. 5 is a block diagram of an induction heating device (100) according to one embodiment of the present disclosure.

[0123] As illustrated in FIG. 5, an induction heating device (100) according to one embodiment of the present disclosure may include an induction heating unit (510), a processor (310), a communication interface (530), a user interface (540), and a memory (320).

[0124] The induction heating unit (510) may include, but is not limited to, a driving unit (520) and a working coil (210). The driving unit (520) may receive power from an input power source (401) and supply current to the working coil (210) according to a control signal of a processor (310). The driving unit (520) may include, but is not limited to, an EMI (Electro Magnetic Interference) filter (402), a rectifier circuit (403), a first inverter (301_1), a second inverter (301_2), and a current detection unit (410). For example, the current detection unit (410) included in the driving unit (520) may be expressed as a first current detection unit (410_1, CT1) and a second current detection unit (410_2, CT2).

[0125] According to one embodiment of the present disclosure, the driving unit (520) may be broadly referred to as an inverter. When the driving unit (520) is referred to as an inverter, the first inverter (301_1) and the second inverter (301_2) illustrated in FIG. 5 may also represent a configuration that includes only switching elements (SW1 to SW4) that perform a switching operation to supply current to the first working coil (210_1) and the second working coil (210_2) included in the working coil (210), as illustrated in FIG. 4. The power output from the first inverter (301_1) and the second inverter (301_2) mentioned in one embodiment of the present disclosure may refer to the power applied to the first working coil (210_1) and the second working coil (210_2) included in the working coil (210).

[0126] The EMI filter (402) blocks high-frequency noise (or electromagnetic interference) contained in the AC power supplied from the input power source (401) and allows AC voltage and AC current of a predetermined frequency (e.g., 50 Hz or 60 Hz) to pass. A fuse and a relay for blocking overcurrent may be provided between the EMI filter (402) and the input power source (401). The AC power from which high-frequency noise has been blocked by the EMI filter (402) is supplied to the rectifier circuit (403).

[0127] The rectifier circuit (403) can convert AC power into DC power. For example, the rectifier circuit (403) can convert AC voltage, whose magnitude and polarity (positive voltage or negative voltage) change over time, into DC voltage, whose magnitude and polarity are constant, and can convert AC current, whose magnitude and direction (positive current or negative current) change over time, into DC current, whose polarity does not change over time. The rectifier circuit (403) can include a bridge diode as a rectification element. For example, the rectifier circuit (403) can include four diodes. The bridge diode can convert AC voltage, whose polarity changes over time, into a positive voltage, whose polarity is constant, and can convert AC current, whose direction changes over time, into a positive current, whose direction is constant. The rectifier circuit (403) can be connected to first and second DC link capacitors (404_1, 404-2) that smooth the rectified DC voltage.

[0128] The first inverter (301_1) may include a switching circuit that supplies or blocks current (high frequency current) to the first working coil (210_1). The first inverter (301_1) may also include a resonant capacitor (411_1, 411-2) that resonates with the switching element and the first working coil (210_1). The switching circuit may include two switches per burner. For example, the first inverter (301_1) may include a first switch (SW1, 405_1) and a second switch (SW2, 405_2) for the first burner (101). The first switch (SW1, 405_1) and the second switch (SW2, 405_2) may be connected in series between the plus line and the minus line output from the rectifier circuit (403). The first switch (SW1, 405_1) and the second switch (SW2, 405_2) can be turned on or off according to a control signal (PWM signal) of the processor (310). In one embodiment, the induction heating device (100) may include a separate driving processor in addition to the processor (310) to generate the control signal.

[0129] The second inverter (301_2) may include a switching circuit that supplies or blocks current (high frequency current) to the second working coil (210_2). The second inverter (301_2) may also include a resonant capacitor (411_3, 411_4) that resonates with the switching element and the second working coil (210_2). The switching circuit may include two switches per burner. For example, the second inverter (301_2) may include a third switch (SW3, 405_3) and a fourth switch (SW4, 405_4) for the second burner (102). The third switch (SW3, 405_3) and the fourth switch (SW4, 405_4) may be connected in series between the plus line and the minus line output from the rectifier circuit (403). The third switch (SW3, 405_3) and the fourth switch (SW4, 405_4) can be turned on or off according to a control signal (PWM signal) of the processor (310). In one embodiment, the induction heating device (100) may include a separate driving processor in addition to the processor (310) to generate the control signal.

[0130] The first inverter (301_1) can control the current supplied to the first working coil (210_1). For example, the magnitude and direction of the current flowing in the first working coil (210_1) can change depending on whether the first switch (SW1, 405_1) and the second switch (SW2, 405_2) included in the first inverter (301_1) are turned on or off. In addition, the magnitude and direction of the current flowing in the second working coil (210_2) can change depending on whether the third switch (SW3, 405_3) and the fourth switch (SW4, 405_4) included in the second inverter (301_2) are turned on or off. In this case, a high-frequency current (high-frequency AC current) can be supplied to the first working coil (210_1) and the second working coil (210_2).

[0131] A high-frequency current can be supplied to the first working coil (210_1) according to the switching operation of the first switch (SW1, 405_1) and the second switch (SW2, 405_2). The turn-on or turn-off of the first switch (SW1, 405_1) and the second switch (SW2, 405_2) can be controlled by a PWM (Pulse Width Modulation) method. According to one embodiment of the present disclosure, the processor (310) can control the magnitude of the high-frequency current applied to the first working coil (210_1) by adjusting the duty of the PWM signal for controlling the turn-on or turn-off state of the first switch (SW1, 405_1) and the second switch (SW2, 405_2). For example, when the duty of the PWM signal applied to the first switch (SW1, 405_1) and the second switch (SW2, 405_2) is increased, the magnitude of the high-frequency current applied to the first working coil (210_1) may increase. An increase in the magnitude of the high-frequency current applied to the first working coil (210_1) means that the high-frequency power applied to the first working coil (210_1) increases. For example, when the duty of the PWM signal applied to the first switch (SW1, 405_1) and the second switch (SW2, 405_2) is decreased, the magnitude of the high-frequency current applied to the first working coil (210_1) may decrease. Duty control of the PWM signal may include adjusting the ratio of the time for which the switching element is maintained in an on state. Duty adjustment of the PWM signal may include adjusting the magnitude of power output from the first inverter (301_1).

[0132] In addition, the processor (310) may control the frequency of the first inverter (301_1) to control the amount of power output from the first inverter (301_1). For example, the processor (310) may control the period of a PWM signal for turning on or off the first switch (SW1, 405_1) and the second switch (SW2, 405_2) of the first inverter (301_1) to control the amount of power output from the first inverter (301_1). Controlling the period of the PWM signal may indicate controlling the frequency of the first inverter (301_1). When the period of the PWM signal is increased, the frequency of the first inverter (301_1) may decrease, and the power output from the first inverter (301_1) may increase. When the processor (310) reduces the period of the PWM signal, the frequency of the first inverter (301_1) may increase and the power output from the first inverter (301_1) may decrease.

[0133] As the switching frequency decreases (e.g., as the switching frequencies of the first switch (SW1, 405_1) and the second switch (SW2, 405_2) decrease), the current supplied to the first working coil (210_1) may increase, and the strength of the magnetic field output by the first working coil (210_1) (output of the induction heating device (100)) may increase. A small switching frequency may indicate a long switching cycle. In the above description, the first switch (SW1, 405_1) and the second switch (SW2, 405_2) and the first working coil (210_1) were mainly described, but the operations of the second working coil (210_2), the third switch (SW3, 405_3), and the fourth switch (SW4, 405_4) may also be performed in the same manner.

[0134] The current detection unit (410) may include a first current detection unit (CT1 (410_1)) that measures the current flowing in the first working coil (210_1) output from the first inverter (301_1) and a second current detection unit (CT2 (410_2)) that measures the current flowing in the second working coil (210_2) output from the second inverter (301_2). The first current detection unit (CT1 (410_1)) and the second current detection unit (CT2 (410_2)) may transmit an electrical signal corresponding to the measured current value to the processor (310). Although not shown, the induction heating device (100) may also include a voltage detection unit (not shown) that senses the voltage of the working coil (210) in addition to the current detection unit (410).

[0135] The processor (310) may determine the switching frequency (turn-on / turn-off frequency) of the switching elements included in the first inverter (301_1) and the switching elements included in the second inverter (301_2) based on the output strength (power level or command power) of the induction heating device (100). The processor (310) may generate a control signal (PWM signal) for turning the switching elements on / off according to the determined switching frequency. The induction heating device (100) may also include a separate driving processor from the processor (310) to control the operation of the induction heating unit (510) during the operation of the processor (310).

[0136] The processor (310) controls the overall operation of the induction heating device (100). The processor (310) can control the induction heating unit (510), the communication interface (530), the user interface (540), and the memory (320) by executing programs stored in the memory (320) or at least one instruction. The induction heating device (100) can include at least one processor. For example, the processor (310) can be one or multiple. The induction heating device (100) can include only a main processor, or a main processor and at least one sub-processor.

[0137] According to one embodiment of the present disclosure, the induction heating device (100) may be equipped with an artificial intelligence (AI) processor. The AI ​​processor may be manufactured in the form of a dedicated hardware chip for artificial intelligence (AI), or may be manufactured as part of an existing general-purpose processor (e.g., CPU or application processor) or a graphics-only processor (e.g., GPU) and equipped in the induction heating device (100).

[0138] The processor (310) may establish a short-range wireless communication channel (e.g., a BLE communication channel) with the cooking vessel (104) through the communication interface (530) if the unique identification information of the cooking vessel (104) is stored in the memory (320).

[0139] The processor (310) can control the distribution of power (high frequency power) output from the first and second inverters (301_1, 301_2) evenly. In one embodiment, when the ratio value (R1) between the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2) exceeds or is less than the set ratio value (α), an operation of controlling the distribution of the first power (P1) and the second power (P2) evenly by adjusting the duty of the switching element included in at least one of the first inverter (301_1) and the second inverter (301_2) can be performed.

[0140] For example, the processor (310) may perform an operation to reduce the duty of a switching element included in an inverter that outputs high power among the first inverter (301_1) and the second inverter (302_2) so as to include the ratio value (R1) in the set ratio value (α). When reducing the duty of a switching element included in an inverter that outputs high power, the processor (310) may synchronize the frequency of the inverter that outputs high power with the frequency of the inverter that outputs low power. For example, the processor (310) may increase the duty of a switching element included in an inverter that outputs low power among the first inverter (301_1) and the second inverter (302_2) so as to include the ratio value (R1) in the set phase value (α). For example, the processor (310) may reduce the duty of a switching element included in an inverter that outputs high power among the first inverter (301_1) and the second inverter (302_2), and increase the duty of a switching element included in an inverter that outputs low power among the first inverter (301_1) and the second inverter (302_2), thereby including the ratio value (R1) in the set phase value (α).

[0141] According to one embodiment of the present disclosure, the processor (310) may stop the operation of adjusting the duty of the switching element if, after adjusting the duty of the switching element, the ratio value (R1) is included in the set ratio value (α). At this time, if the sum of the first power (P1) and the second power (P2) output from the first inverter (301_1) and the second inverter (302_2) does not reach the command power (Pref), the processor (310) may control the frequency of the first inverter (301_1) and the second inverter (302_2) so that the sum of the first power (P1) and the second power (P2) reaches the command power (Pref). When the total of the first power (P1) and the second power (P2) output from the first inverter (301_1) and the second inverter (302_2) reaches the command power (Pref), the processor (310) can maintain the control state for the first inverter (301_1) and the second inverter (302_2).

[0142] The processor (310) may execute at least one program stored in the memory (320). The processor (310) may execute at least one instruction stored in the memory (320) to perform a control method of an induction heating device (100) according to an embodiment of the present disclosure. The processor (310) may be electrically connected to components included in the induction heating device (100). The processor (310) may be electrically connected to the components via a bus (not shown) included in the induction heating device (100). The processor (310) may control the components included in the induction heating device (100). For example, the processor (310) may control the induction heating unit (510), the communication interface (530), the user interface (540), and the memory (320). For example, the processor (310) may perform operations or variations of operations described in FIGS. 6 to 16, which will be described later.

[0143] The processor (310) may include at least one of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an APU (Accelerated Processing Unit), an MIC (Many Integrated Core), a DSP (Digital Signal Processor), or an NPU (Neural Processing Unit). The processor (310) may be implemented in the form of an integrated system on a chip (SoC) including one or more electronic components. Each processor (310) may be implemented as a separate hardware (H / W). The processor (310) may be expressed as a MICOM (Microprocessor controller), an MPU (Micro Processor unit), or an MCU (Micro Controller Unit). The processor (310) may be implemented as a single core processor. The processor (310) may be implemented as a multicore processor. The processor (310) may process data and perform operations through a circuitry. The processor (310) may process data through a circuit network by executing at least one instruction stored in the memory (320).

[0144] The processor (310) may detect the power output from the first inverter (301_1) and the second inverter (301_2) based on an AI (Artificial Intelligence) model and control the power output from the first inverter (301_1) and the second inverter (301_2) to be evenly distributed. The processor (310) may control the duty of the switching elements included in the first inverter (301_1) and the second inverter (301_2) using the power output from the first inverter (301_1) and the second inverter (301_2) detected based on the AI ​​model to evenly distribute the power output from the first inverter (301_1) and the second inverter (301_2).

[0145] The AI ​​model may be referred to as a pre-trained AI model (e.g., a Support Vector Machine (SVM) algorithm). The pre-trained AI model may include, but is not limited to, at least one of a Support Vector Machine (SVM) model, a Neural Networks model, a Random Forest model, or a Graphical Model. Since the SVM model has relatively high accuracy and a fast response speed, the operation of the induction heating device (100) can be quickly converted to optimal specifications, and therefore, the AI ​​model mentioned in one embodiment of the present disclosure may be an SVM model. The SVM model may be created through supervised learning. The SVM model is a model that learns with labeled learning data and then finds out which group among the learned groups newly input data belongs to. According to one embodiment of the present disclosure, the SVM model may be used to determine the material and type of the cooking vessel (104) by using the current value measured by the current detection unit (410) included in the induction heating device (100) as learning data. According to one embodiment of the present disclosure, the SVM model may learn a situation for uniformly controlling the distribution of the first power (P1) and the second power (P2) by using the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2) included in the induction heating device (100) as learning data.

[0146] Various information required for the operation of the induction heating device (100) is stored in the memory (320) (e.g., set ratio value (α), set phase value (θ) limit)) may be stored. At least one of instructions, applications (e.g., induction heating device (100) management application, smart things), data and / or programs required for the operation of the induction heating device (100) may be stored in the memory (320). The instructions, applications, data and / or programs stored in the memory (320) may be executed by the processor (310). The processor (310) may execute the instructions, applications, data and / or programs stored in the memory (320) to generate a control signal for controlling the operation of the induction heating device (100).

[0147] An AI model may be stored in the memory (320). An AI model that uses user input received through the user interface (540) in the memory (320) as learning data, an AI model for evenly distributing power output from the first inverter (301_1) and the second inverter (301_2) based on the power output from the first inverter (301_1) and the second inverter (301_2), an AI model for securing a phase margin between the voltage waveform and the current waveform by using the phase angle (θ) detected using the voltage waveform and the current waveform output from the first inverter (301_1) as learning data, etc. may be stored.

[0148] The memory (320) may include at least one type of storage medium among a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., SD or XD memory, etc.), a RAM (Random Access Memory), a SRAM (Static Random Access Memory), a ROM (Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), a PROM (Programmable Read-Only Memory), a magnetic memory, a magnetic disk, or an optical disk. The programs stored in the memory (320) may be classified into a plurality of modules according to their functions. The information stored in the memory (320) may be read and used by the processor (310).

[0149] The communication interface (530) may include one or more components that enable communication between the induction heating device (100) and the cooking vessel (104), the induction heating device (100) and a server device (not shown), or the induction heating device (100) and a user terminal (not shown). For example, the communication interface (530) may include a short-range wireless communication interface (531) and a long-range wireless communication interface (532). The short-range wireless communication interface (531) may include, but is not limited to, a Bluetooth communication interface, a BLE (Bluetooth Low Energy) communication interface, a near field communication interface, a WLAN (Wi-Fi) communication interface, a Zigbee communication interface, an IrDA (infrared Data Association) communication interface, a WFD (Wi-Fi Direct) communication interface, an UWB (Ultra Wideband) communication interface, an Ant+ communication interface, etc. The remote communication unit (532) can be used to communicate with a server device (not shown) when the cooking vessel (104) is remotely controlled by a server device in an IoT (Internet of Things) environment. The remote communication unit (532) can include the Internet, a computer network (e.g., a LAN or WAN), and a mobile communication unit. The mobile communication unit transmits and receives a wireless signal with at least one of a base station, an external terminal, and / or a server on a mobile communication network. Here, the wireless signal can include various types of data according to a voice call signal, a video call call signal, or a text / multimedia message transmission and reception. The mobile communication unit can include, but is not limited to, a 3G module, a 4G module, an LTE module, a 5G module, a 6G module, an NB-IoT module, and / or an LTE-M module.

[0150] The user interface (540) may include an output interface (541) and an input interface (542). The output interface (541) is for outputting an audio signal or a video signal and may include a display and an audio output unit, etc. When the display and the touchpad are configured as a touch screen in a layered structure, the display may be used as an input interface (542) in addition to the output interface (541). The display may include at least one of a liquid crystal display, a thin film transistor-liquid crystal display, a light-emitting diode (LED), an organic light-emitting diode (OLED), a flexible display, a 3D display, and an electrophoretic display. In addition, depending on the implementation form of the induction heating device (100), the induction heating device (100) may include two or more displays.

[0151] The audio output unit can output audio data received from the communication interface (530) or stored in the memory (320). In addition, the audio output unit can output audio signals related to functions performed in the induction heating device (100). The audio output unit can include a speaker, a buzzer, etc.

[0152] According to one embodiment of the present disclosure, the output interface (541) can display information about the cooking vessel (104). For example, the output interface (541) can output a GUI (Graphical User Interface) corresponding to identification information or product type information of the cooking vessel (104). The output interface (541) can output information about the current position of the cooking vessel (104). The output interface (541) can also output information about whether the power distribution output through the first working coil (210_1) and the second working coil (210_2) is uniform (e.g., information indicating a state in which the power distribution is uniform, information indicating a state in which the power distribution is not uniform). The output interface (541) can also output guidance information indicating that the induction heating device (100) is performing an operation of uniformly controlling the power distribution output from a plurality of inverters (the first inverter (301_1) and the second inverter (301_2)). The output interface (541) may output guidance information that allows a user to determine whether to perform an operation for controlling power distribution evenly. If guidance information that allows a user to determine whether to perform an operation for controlling power distribution evenly is output through the output interface (541) and a user input requesting the performance of an operation for controlling power distribution evenly is received through the input interface (542), the processor (310) may perform an operation for controlling power distribution evenly according to an embodiment of the present disclosure.

[0153] The input interface (542) is for receiving input from a user. The input interface (542) may be at least one of a key pad, a dome switch, a touch pad (contact electrostatic capacitance type, pressure resistive film type, infrared detection type, surface ultrasonic conduction type, integral tension measurement type, piezo effect type, etc.), a jog wheel, and a jog switch, but is not limited thereto.

[0154] The input interface (542) may include a voice recognition module. For example, the induction heating device (100) may receive a voice signal, which is an analog signal, through a microphone, and convert the voice portion into computer-readable text using an Automatic Speech Recognition (ASR) model. The induction heating device (100) may also interpret the converted text using a Natural Language Understanding (NLU) model to obtain the user's speech intent. Here, the ASR model or the NLU model may be an artificial intelligence model. The artificial intelligence model may be processed by an artificial intelligence-dedicated processor designed with a hardware structure specialized for processing artificial intelligence models. The artificial intelligence model may be created through learning. Here, being created through learning may mean that a basic artificial intelligence model is learned using a plurality of learning data by a learning algorithm, thereby creating a predefined operation rule or artificial intelligence model set to perform a desired characteristic (or purpose). The artificial intelligence model may be composed of a plurality of neural network layers. Each of the multiple neural network layers has multiple weight values, and neural network operations can be performed through operations between the operation results of the previous layer and the multiple weight values.

[0155] Linguistic understanding is the technology of recognizing, applying, and processing human language / characters, including natural language processing, machine translation, dialog systems, question answering, and speech recognition / synthesis.

[0156] The memory (320) may store a program for processing and controlling the processor (310), and may store input / output data (e.g., unique identification information of the cooking vessel (104), variable identification information of the cooking vessel (104), multiple power transmission patterns, cooking progress information of the cooking vessel (104), etc.). The induction heating device (100) may also operate a web storage or cloud server that performs a storage function on the Internet.

[0157] In the case of FIG. 5, the induction heating device (100) is shown as an example including a first working coil (210_1), a second working coil (210_2), a first inverter (301_1), and a second inverter (301_2), but may be modified to further include a third working coil (210_3), a fourth working coil (210_4), a third inverter (301_3), and a fourth inverter (301_4) as shown in FIG. 3b. The induction heating device (100) may be modified so as not to include a first working coil (210_1), a second working coil (210_2), a first inverter (301_1), and a second inverter (301_2). The induction heating device (100) may be modified to include a third working coil (210_3), a fourth working coil (210_4), a third inverter (301_3), and a fourth inverter (301_4).

[0158] Fig. 6 is a flowchart of a control method of an induction heating device (100) according to one embodiment of the present disclosure. Fig. 6 is a control method of an induction heating device (100) for uniformly distributing power output from multiple inverters.

[0159] In step S610, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2). For example, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2) using the first current detection unit (410_1) and the second current detection unit (410_2). For this purpose, the induction heating device (100) can read a predetermined value stored in the memory (320). The predetermined value may be a current value corresponding to about 10 to 20% of the capacity of the working coil, but the predetermined value is not limited thereto. For example, the predetermined value may be determined based on the output value of the working coil. The induction heating device (100) compares the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) with a predetermined value, and if the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) are equal to or greater than the predetermined value, it can identify that the cooking vessel (104) is in a state (or situation) placed on a plurality of working coils (210_1, 210_2). In step S610, the induction heating device (100) can also identify whether the cooking vessel (104) is placed on a plurality of working coils by using methods as described in the above-described FIG. 1.

[0160] After the cooking vessel (104) is identified as being placed on a plurality of working coils, in step S620, the induction heating device (100) can obtain (or detect) power output from each of the plurality of inverters. For example, the plurality of inverters may be a first inverter (301_1) and a second inverter (301_2), but are not limited thereto. The induction heating device (100) can detect the current and voltage output from the first inverter (301_1), and obtain the first power (P1) by multiplying the detected current and voltage. The induction heating device (100) can detect the current and voltage output from the second inverter (301_2), and obtain the second power (P2) by multiplying the detected current and voltage.

[0161] In step S630, the induction heating device (100) can obtain a ratio value (R1) between the obtained powers. For example, the induction heating device (100) can obtain a ratio value (R1) between the first power (P1) and the second power (P2). For example, when the first power (P1) is 2400 W and the second power (P2) is 1600 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 0.67, and the ratio of P1 and P2 can be expressed as P1:P2=2400:1600=1:0.67. In this case, the second power (P2) corresponds to approximately 67% of the first power (P1). For example, if the first power (P1) is 1200 W and the second power (P2) is 1800 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 1.5, and the ratio of P1 and P2 can be expressed as P1:P2=1200:1800=1:1.5. In this case, the second power (P2) corresponds to approximately 125% of the first power (P1).

[0162] In step S640, the induction heating device (100) compares the obtained ratio value (R1) with the set ratio value (α). The set ratio value (α) is a value determined based on a state in which the power distribution output from the plurality of inverters is uniform. As described in FIGS. 1 and 2, the set ratio value (α) may be determined based on a ratio value between the power output from the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)) in a situation in which the temperature of the bottom surface of the cooking vessel (104) is uniform. For example, the set ratio value (α) may be at least one of 1, 0.83, and 1.2, but is not limited thereto. When the set ratio value (α) is 1, P1:P2=1:1 based on P1. When the set ratio value (α) is 0.83, P1:P2=1:0.83 based on P1. In this case, P2 corresponds to 83% of P1 based on P1. If the set ratio value (α) is 1.2, P1:P2=1:1.2 based on P1. In this case, P2 corresponds to 120% of P1 based on P1. The set ratio value (α) is a ratio value between powers at which the distribution of power output from multiple inverters can be determined to be uniform, and may represent a value representing P2 based on P1. The set ratio value (α) may be determined in various ways depending on the conditions of the cooking vessel (104) and the multiple working coils (201_1, 201_2), and is therefore not limited to the above-described values.

[0163] In step S640, if the obtained ratio value (R1) is included in the set ratio value (α) as a result of comparing the obtained ratio value (R1) with the set ratio value (α) (if the obtained ratio value (R1) does not deviate from the set ratio value (α)), in step S650, the induction heating device (100) operates to maintain the current state because the distribution of the first power (P1) and the second power (P2) is uniform.

[0164] In step S640, if the obtained ratio value (R1) is compared with the set ratio value (α), and the obtained ratio value (R1) exceeds or is less than the set ratio value (α) (if the obtained ratio value (R1) deviates from the set ratio value (α)), in step S660, the induction heating device (100) can adjust the duty of the switching element included in at least one inverter among the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)).

[0165] In step S660, for example, the induction heating device (100) may reduce the duty of an inverter that outputs high power. Accordingly, the power output from the inverter that outputs high power may be reduced. The duty of the inverter may be used to adjust the magnitude of the voltage output by the inverter. The higher the duty of the inverter, the higher the voltage output by the inverter, and the lower the duty of the inverter, the lower the voltage output by the inverter. Therefore, when the duty of the inverter is reduced, the voltage output by the inverter decreases, and accordingly, the power output from the inverter also decreases. For example, when the input voltage applied to the inverter is 12 V and the duty is 50%, the power output by the inverter (P = V (12 V) * D (50%)) is 6 W. At this time, when the duty is reduced to 40%, the power output by the inverter (P = V (12 V) * D (40%)) is reduced to 4.8 W. A decrease in the power output (P) from the inverter may indicate a decrease in the output voltage of the inverter.

[0166] In step S660, for example, the induction heating device (100) may increase the duty of an inverter that outputs low power. Accordingly, the power output from the inverter that outputs low power may increase. When the duty of the inverter is increased, the voltage output from the inverter increases, and accordingly, the power output from the inverter also increases. For example, when the input voltage applied to the inverter is 12 V and the duty is 20%, the power output from the inverter (P = V (12 V) * D (20%)) is 2.4 W. At this time, when the duty is increased to 40%, the power output from the inverter (P = V (12 V) * D (40%)) increases to 4.8 W. An increase in the power (P) output from the inverter may indicate that the output voltage of the inverter increases. In the case of increasing the duty of an inverter outputting low power in step S660, it can be performed when the duties of all of the plurality of inverters are low, but is not limited thereto.

[0167] In step S660, for example, the induction heating device (100) may increase the duty of an inverter outputting low power while decreasing the duty of an inverter outputting high power. Accordingly, the power output from an inverter outputting low power increases while the power output from an inverter outputting high power decreases, so that the distribution of power output from multiple inverters can be controlled evenly.

[0168] The duty reduction amount or duty increase amount according to one embodiment of the present disclosure may be determined based on a ratio value (R1). For example, if the ratio value (R1) between the first power (P1) and the second power (P2) output from the first inverter (301_1) and the second inverter (301_2) respectively exceeds a set ratio value (α), the duty reduction amount of the switching element may be large. For example, if the ratio value (R1) between the first power (P1) and the second power (P2) output from the first inverter (301_1) and the second inverter (301_2) respectively indicates that the first power (P1) is more than twice the second power (P2), the induction heating device (100) may be set to reduce the duty reduction amount of the switching element by 10%. For example, if the ratio value (R1) between the first power (P1) and the second power (P2) output from the first inverter (301_1) and the second inverter (301_2) respectively indicates that the first power (P1) is less than twice the second power (P2), the induction heating device (100) may be set to reduce the duty reduction amount of the switching element by 5%, but the duty reduction amount of the switching element is not limited thereto.

[0169] After performing step S660, the induction heating device (100) may proceed to step S620 and repeat the above-described process until the ratio value (R1) is included in the set ratio value (α).

[0170] Each step of the flowchart illustrated in FIG. 6 may be performed by the processor (310) of the induction heating device (100). In addition, although not described in the flowchart of FIG. 6, the flowchart of FIG. 6 may include an operation of controlling the frequency of the first inverter (301_1) and the second inverter (301_2) to satisfy the output (Power) between each operation. Therefore, the flowchart of the control method of the induction heating device (100) according to one embodiment of the present disclosure is not limited to that illustrated in FIG. 6. The flowchart of FIG. 6 identifies a state in which the cooking vessel (104) is placed on a plurality of working coils in step S610, and then controls the command power (P ref ) may include an operation of controlling the frequency and duty of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) to achieve an output (Power) that satisfies the condition.

[0171] FIG. 7 is a waveform diagram for explaining frequency control and duty control of an inverter performed in an induction heating device (100) according to one embodiment of the present disclosure.

[0172] When the voltage (pole voltage) waveform and the current (high frequency current) waveform output from the first inverter (301_1) included in the induction heating device (100) are as shown in (710), when the frequency of the first inverter (301_1) is reduced, the number of voltage waveforms and the number of current waveforms output from the first inverter (301_1) are reduced as shown in (720). Accordingly, the power output from the first inverter (301_1) increases. After reducing the frequency of the first inverter (301_1), when the duty is reduced, the duty of the voltage waveform and the current waveform output from the first inverter (301_1) shown in (720) are reduced as shown in (730). Accordingly, the power output from the first inverter (301_1) is reduced. For convenience of explanation, FIG. 7 is described based on the first inverter (301_1), but FIG. 7 can be applied to all inverters included in the induction heating device (100).

[0173] Fig. 8 is a flowchart of a control method of an induction heating device (100) according to one embodiment of the present disclosure. Fig. 8 is an example in which a frequency synchronization operation is added to the flowchart of Fig. 6.

[0174] In step S810, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2). For example, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2) using the first current detection unit (410_1) and the second current detection unit (410_2). For this purpose, the induction heating device (100) can read a predetermined value stored in the memory (320). The predetermined value may be a current value corresponding to about 10 to 20% of the capacity of the working coil, but the predetermined value is not limited thereto. For example, the predetermined value may be determined based on the output value of the working coil. The induction heating device (100) compares the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) with a predetermined value, and if the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) are equal to or greater than the predetermined value, it can identify that the cooking vessel (104) is in a state (or situation) placed on a plurality of working coils (210_1, 210_2). In step S810, the induction heating device (100) can also identify whether the cooking vessel (104) is placed on a plurality of working coils by using methods as described in the above-described FIG. 1.

[0175] After the cooking vessel (104) is identified as being placed on a plurality of working coils, in step S820, the induction heating device (100) can obtain (or detect) power output from each of the plurality of inverters. For example, the plurality of inverters may be a first inverter (301_1) and a second inverter (301_2), but are not limited thereto. The induction heating device (100) can detect the current and voltage output from the first inverter (301_1), and obtain the first power (P1) by multiplying the detected current and voltage. The induction heating device (100) can detect the current and voltage output from the second inverter (301_2), and obtain the second power (P2) by multiplying the detected current and voltage.

[0176] In step S830, the induction heating device (100) can obtain a ratio value (R1) between the obtained powers. For example, the induction heating device (100) can obtain a ratio value (R1) between the first power (P1) and the second power (P2). For example, when the first power (P1) is 2400 W and the second power (P2) is 1600 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 0.67, and the ratio of P1 and P2 can be expressed as P1:P2=2400:1600=1:0.67. In this case, the second power (P2) corresponds to approximately 67% of the first power (P1). For example, if the first power (P1) is 1200 W and the second power (P2) is 1800 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 1.5, and the ratio of P1 and P2 can be expressed as P1:P2=1200:1800=1:1.5. In this case, the second power (P2) corresponds to approximately 125% of the first power (P1).

[0177] In step S840, the induction heating device (100) compares the obtained ratio value (R1) with the set ratio value (α). The set ratio value (α) is a value determined based on a state in which the power distribution output from the plurality of inverters is uniform. As described in FIGS. 1 and 2, the set ratio value (α) may be determined based on a ratio value between the power output from the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)) in a situation in which the temperature of the bottom surface of the cooking vessel (104) is uniform. For example, the set ratio value (α) may be at least one of 1, 0.83, and 1.2, but is not limited thereto. When the set ratio value (α) is 1, P1:P2=1:1 based on P1. When the set ratio value (α) is 0.83, P1:P2=1:0.83 based on P1. In this case, P2 corresponds to 83% of P1 based on P1. If the set ratio value (α) is 1.2, P1:P2=1:1.2 based on P1. In this case, P2 corresponds to 120% of P1 based on P1. The set ratio value (α) is a ratio value between powers at which the distribution of power output from multiple inverters can be determined to be uniform, and may represent a value representing P2 based on P1. The set ratio value (α) may be determined in various ways depending on the conditions of the cooking vessel (104) and the multiple working coils (201_1, 201_2), and is therefore not limited to the above-described values.

[0178] In step S840, if the obtained ratio value (R1) is included in the set ratio value (α) as a result of comparing the obtained ratio value (R1) with the set ratio value (α) (if the obtained ratio value (R1) does not deviate from the set ratio value (α)), in step S850, the induction heating device (100) can operate to maintain the current state because the distribution of the first power (P1) and the second power (P2) is uniform.

[0179] In step S840, if the obtained ratio value (R1) is compared with the set ratio value (α), and the obtained ratio value (R1) exceeds or is less than the set ratio value (α) (if the obtained ratio value (R1) deviates from the set ratio value (α)), in step S860, the induction heating device (100) can adjust the duty of the switching element included in at least one inverter among the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)).

[0180] In step S860, for example, the induction heating device (100) may reduce the duty of an inverter that outputs high power. Accordingly, the power output from the inverter that outputs high power may be reduced. The duty of the inverter may be used to adjust the magnitude of the voltage output by the inverter. The higher the duty of the inverter, the higher the voltage output by the inverter, and the lower the duty of the inverter, the lower the voltage output by the inverter. Therefore, when the duty of the inverter is reduced, the voltage output by the inverter decreases, and accordingly, the power output from the inverter also decreases. For example, when the input voltage applied to the inverter is 12 V and the duty is 50%, the power output from the inverter (P = V (12 V) * D (50%)) is 6 W. At this time, when the duty is reduced to 40%, the power output from the inverter (P = V (12 V) * D (40%)) is reduced to 4.8 W. A decrease in the power output (P) from the inverter may indicate a decrease in the output voltage of the inverter.

[0181] In step S860, for example, the induction heating device (100) may increase the duty of an inverter that outputs low power. Accordingly, the power output from the inverter that outputs low power may increase. When the duty of the inverter is increased, the voltage output from the inverter increases, and accordingly, the power output from the inverter also increases. For example, when the input voltage applied to the inverter is 12 V and the duty is 20%, the power output from the inverter (P = V (12 V) * D (20%)) is 2.4 W. At this time, when the duty is increased to 40%, the power output from the inverter (P = V (12 V) * D (40%)) increases to 4.8 W. An increase in the power (P) output from the inverter may indicate that the output voltage of the inverter increases. In the case of increasing the duty of an inverter outputting low power in step S660, it can be performed when the duties of all of the plurality of inverters are low, but is not limited thereto.

[0182] In step S860, for example, the induction heating device (100) may increase the duty of an inverter outputting low power while decreasing the duty of an inverter outputting high power. Accordingly, the power output from an inverter outputting low power increases while the power output from an inverter outputting high power decreases, so that the distribution of power output from multiple inverters can be controlled evenly.

[0183] After performing step S860, the induction heating device (100) can control the frequency of the inverter outputting low power to be synchronized with the frequency of the inverter outputting high power in step S870. For example, a frequency synchronization operation can be performed to match the frequencies of the two inverters by increasing the frequency of the inverter outputting high power and decreasing the frequency of the inverter outputting low power. When the frequencies of the two inverters are synchronized in this way, the power output from the two inverters can be maintained stably.

[0184] After performing step S870, the induction heating device (100) may proceed to step S820 and repeat the above-described process until the ratio value (R1) is included in the set ratio value (α).

[0185] The order of the flowchart illustrated in FIG. 8 may be changed. For example, after performing step S870, step S860 may be performed. Therefore, the flowchart of the control method of the induction heating device (100) according to one embodiment of the present disclosure is not limited to that illustrated in FIG. 8, and each step of the flowchart illustrated in FIG. 8 may be performed by the processor (310) of the induction heating device (100). In addition, the flowchart of FIG. 8 may include an operation of controlling the frequency of the first inverter (301_1) and the second inverter (301_2) to satisfy the output (Power) between each operation. The flowchart of FIG. 8 identifies a state in which the cooking vessel (104) is placed on a plurality of working coils in step S810, and then controls the command power (P ref ) may include an operation of controlling the frequency and duty of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) to achieve an output (Power) that satisfies the condition.

[0186] Fig. 9 is a diagram showing the relationship between the power and frequency output from two inverters in an induction heating device (100) according to one embodiment of the present disclosure. Fig. 9 is a diagram showing a power waveform when the duty of a switching element of an inverter outputting high power is reduced.

[0187] Point 901 illustrated in FIG. 9 is a case where the ratio value (R1) between the first power (P1) and the second power (P2) exceeds or is less than the set ratio value (α), thereby reducing the duty of the first inverter (301_1) that outputs high power. Accordingly, at point 902, the ratio value (R1) between the first power (P1) and the second power (P2) is included in the set ratio value (α), so that the distribution of the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2) becomes uniform. At this time, the frequencies of the first inverter (301_1) and the second inverter (301_2) can be controlled to satisfy the output (Power). Output satisfaction is the sum (total power (P)) of the first power (P1) output from the first inverter (301_1) and the second power (P2) output from the second inverter (301_2). total )=P1+P2) is the power corresponding to the command (or command power (P ref )) can represent a state in which the command is 10 stages. For example, if the command is 10 stages, the sum of the first power (P1) and the second power (P2) is the output corresponding to 10 stages (e.g., 2 kW, or the command power (P ref ) can represent a state that satisfies the output.

[0188] Fig. 10 is a flowchart of a control method of an induction heating device (100) according to one embodiment of the present disclosure. Fig. 10 is an example in which a configuration for controlling the frequency of a plurality of inverters is added to the flowchart of Fig. 8 until the output of the plurality of inverters corresponds to the command power.

[0189] In step S1010, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2). For example, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2) using the first current detection unit (410_1) and the second current detection unit (410_2). For this purpose, the induction heating device (100) can read a predetermined value stored in the memory (320). The predetermined value may be a current value corresponding to about 10 to 20% of the capacity of the working coil, but the predetermined value is not limited thereto. For example, the predetermined value may be determined based on the output value of the working coil. The induction heating device (100) compares the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) with a predetermined value, and if the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) are equal to or greater than the predetermined value, it can identify that the cooking vessel (104) is in a state (or situation) placed on a plurality of working coils (210_1, 210_2). In step S1010, the induction heating device (100) can also identify whether the cooking vessel (104) is placed on a plurality of working coils by using methods such as those described in the above-described FIG. 1.

[0190] After the cooking vessel (104) is identified as being placed on a plurality of working coils, in step S1020, the induction heating device (100) can obtain (or detect) power output from each of the plurality of inverters. For example, the plurality of inverters may be a first inverter (301_1) and a second inverter (301_2), but are not limited thereto. The induction heating device (100) can detect the current and voltage output from the first inverter (301_1), and obtain the first power (P1) by multiplying the detected current and voltage. The induction heating device (100) can detect the current and voltage output from the second inverter (301_2), and obtain the second power (P2) by multiplying the detected current and voltage.

[0191] In step S1030, the induction heating device (100) can obtain a ratio value (R1) between the obtained powers. For example, the induction heating device (100) can obtain a ratio value (R1) between the first power (P1) and the second power (P2). For example, when the first power (P1) is 2400 W and the second power (P2) is 1600 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 0.67, and the ratio of P1 and P2 can be expressed as P1:P2=2400:1600=1:0.67. In this case, the second power (P2) corresponds to approximately 67% of the first power (P1). For example, if the first power (P1) is 1200 W and the second power (P2) is 1800 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 1.5, and the ratio of P1 and P2 can be expressed as P1:P2=1200:1800=1:1.5. In this case, the second power (P2) corresponds to approximately 125% of the first power (P1).

[0192] In step S1040, the induction heating device (100) compares the obtained ratio value (R1) with the set ratio value (α). The set ratio value (α) is a value determined based on a state in which the power distribution output from the plurality of inverters is uniform. As described with reference to FIGS. 1 and 2, the set ratio value (α) may be determined based on a ratio value between the power output from the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)) in a situation in which the temperature of the bottom surface of the cooking vessel (104) is uniform. For example, the set ratio value (α) may be at least one of 1, 0.83, and 1.2, but is not limited thereto. When the set ratio value (α) is 1, P1:P2=1:1 based on P1. When the set ratio value (α) is 0.83, P1:P2=1:0.83 based on P1. In this case, P2 corresponds to 83% of P1 based on P1. If the set ratio value (α) is 1.2, P1:P2=1:1.2 based on P1. In this case, P2 corresponds to 120% of P1 based on P1. The set ratio value (α) is a ratio value between powers at which the distribution of power output from multiple inverters can be determined to be uniform, and may represent a value representing P2 based on P1. The set ratio value (α) may be determined in various ways depending on the conditions of the cooking vessel (104) and the multiple working coils (201_1, 201_2), and is therefore not limited to the above-described values.

[0193] In step S1040, if the obtained ratio value (R1) is compared with the set ratio value (α), and the obtained ratio value (R1) exceeds or is less than the set ratio value (α) (if the obtained ratio value (R1) deviates from the set ratio value (α)), in step S1050, the induction heating device (100) can adjust the duty of the switching element included in at least one inverter among the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)).

[0194] In step S1050, for example, the induction heating device (100) can reduce the duty of an inverter that outputs high power. Accordingly, the power output from the inverter that outputs high power can be reduced. The duty of the inverter can be used to adjust the magnitude of the voltage output by the inverter. The higher the duty of the inverter, the higher the voltage output by the inverter, and the lower the duty of the inverter, the lower the voltage output by the inverter. Therefore, when the duty of the inverter is reduced, the voltage output from the inverter decreases, and accordingly, the power output from the inverter also decreases. For example, when the input voltage applied to the inverter is 12 V and the duty is 50%, the power output from the inverter (P = V (12 V) * D (50%)) is 6 W. At this time, when the duty is reduced to 40%, the power output from the inverter (P = V (12 V) * D (40%)) is reduced to 4.8 W. A decrease in the power output (P) from the inverter may indicate a decrease in the output voltage of the inverter.

[0195] In step S1050, for example, the induction heating device (100) may increase the duty of an inverter that outputs low power. Accordingly, the power output from the inverter that outputs low power may increase. When the duty of the inverter is increased, the voltage output from the inverter increases, and accordingly, the power output from the inverter also increases. For example, when the input voltage applied to the inverter is 12 V and the duty is 20%, the power output from the inverter (P = V (12 V) * D (20%)) is 2.4 W. At this time, when the duty is increased to 40%, the power output from the inverter (P = V (12 V) * D (40%)) increases to 4.8 W. An increase in the power (P) output from the inverter may indicate that the output voltage of the inverter increases. In the case of increasing the duty of an inverter outputting low power in step S660, it can be performed when the duties of all of the plurality of inverters are low, but is not limited thereto.

[0196] In step S1050, for example, the induction heating device (100) may increase the duty of an inverter outputting low power while decreasing the duty of an inverter outputting high power. Accordingly, the power output from the inverter outputting low power increases while the power output from the inverter outputting high power decreases, so that the distribution of power output from multiple inverters can be controlled evenly.

[0197] After performing step S1050, the induction heating device (100) can control the frequency of the inverter outputting low power to be synchronized with the frequency of the inverter outputting high power in step S1055. For example, a frequency synchronization operation can be performed to match the frequencies of the two inverters by increasing the frequency of the inverter outputting high power and decreasing the frequency of the inverter outputting low power. When the frequencies of the two inverters are synchronized in this way, the power output from the two inverters can be maintained stably.

[0198] After performing step S1055, the induction heating device (100) may proceed to step S1020 and repeat the above-described process until the ratio value (R1) is included in the set ratio value (α).

[0199] In step S1040, if the detected ratio value (R1) is included in the set ratio value (α), in step S1060, the induction heating device (100) calculates the total sum (e.g., P) of the power output from a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)). total =P1+P2) is the command power (P ref ) can be checked to see if it corresponds to the command power (P ref ) may also be referred to as the reference power. The command power is the power that can be set by the user input and may be the power desired by the user. For example, if the user input is 10 stages, the command power may be 2 kW.

[0200] In step S1060, the total sum of power output from multiple inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) (e.g., P totalIf =P1+P2) corresponds to the command power, in step S1075, the induction heating device (100) can maintain the current state. This is because the power output from the plurality of inverters is evenly distributed and the power output from the plurality of inverters satisfies the command power (output satisfaction state).

[0201] In step S1060, the total sum of power output from multiple inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) (e.g., P total =P1+P2) is the command power (P ref ), the induction heating device (100) can control the frequency of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) in step S1070. The frequency control performed in step S1070 is the sum (e.g., P) of the power output from a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)). total =P1+P2) is the command power (P ref ) can be expressed as something that is performed until it corresponds to something else.

[0202] The order of the flowchart illustrated in FIG. 10 may be changed. For example, after performing step S1055, step S1050 may be performed. Therefore, the flowchart of the control method of the induction heating device (100) according to one embodiment of the present disclosure is not limited to that illustrated in FIG. 10, and each step of the flowchart illustrated in FIG. 10 may be performed by the processor (310) of the induction heating device (100). In addition, the flowchart of FIG. 10 may include an operation of controlling the frequency of the first inverter (301_1) and the second inverter (301_2) to satisfy the output (Power) between each operation. The flowchart of FIG. 10 identifies a state in which the cooking vessel (104) is placed on a plurality of working coils in step S1010, and then controls the command power (P ref) may include an operation of controlling the frequency and duty of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) to achieve an output (Power) that satisfies the condition.

[0203] Fig. 11 is a flowchart of a control method of an induction heating device (100) according to one embodiment of the present disclosure. Fig. 11 is an example in which a configuration capable of securing a phase margin is added to the flowchart of Fig. 10.

[0204] In step S1105, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2). For example, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2) using the first current detection unit (410_1) and the second current detection unit (410_2). For this purpose, the induction heating device (100) can read a predetermined value stored in the memory (320). The predetermined value may be a current value corresponding to about 10 to 20% of the capacity of the working coil, but the predetermined value is not limited thereto. For example, the predetermined value may be determined based on the output value of the working coil. The induction heating device (100) compares the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) with a predetermined value, and if the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) are equal to or greater than the predetermined value, it can identify that the cooking vessel (104) is in a state (or situation) placed on a plurality of working coils (210_1, 210_2). In step S1105, the induction heating device (100) can also identify whether the cooking vessel (104) is placed on a plurality of working coils by using methods as described in the above-described FIG. 1.

[0205] After the cooking vessel (104) is identified as being placed on a plurality of working coils, in step S1110, the induction heating device (100) can obtain (or detect) power output from each of the plurality of inverters. For example, the plurality of inverters may be a first inverter (301_1) and a second inverter (301_2), but are not limited thereto. The induction heating device (100) can detect the current and voltage output from the first inverter (301_1), and obtain the first power (P1) by multiplying the detected current and voltage. The induction heating device (100) can detect the current and voltage output from the second inverter (301_2), and obtain the second power (P2) by multiplying the detected current and voltage.

[0206] In step S1115, the induction heating device (100) can obtain a ratio value (R1) between the obtained powers. For example, the induction heating device (100) can obtain a ratio value (R1) between the first power (P1) and the second power (P2). For example, when the first power (P1) is 2400 W and the second power (P2) is 1600 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 0.67, and the ratio of P1 and P2 can be expressed as P1:P2=2400:1600=1:0.67. In this case, the second power (P2) corresponds to approximately 67% of the first power (P1). For example, if the first power (P1) is 1200 W and the second power (P2) is 1800 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 1.5, and the ratio of P1 and P2 can be expressed as P1:P2=1200:1800=1:1.5. In this case, the second power (P2) corresponds to approximately 125% of the first power (P1).

[0207] In step S1120, the induction heating device (100) compares the obtained ratio value (R1) with the set ratio value (α). The set ratio value (α) is a value determined based on a state in which the power distribution output from the plurality of inverters is uniform. As described with reference to FIGS. 1 and 2, the set ratio value (α) may be determined based on a ratio value between the powers output from the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)) in a situation in which the temperature of the bottom surface of the cooking vessel (104) is uniform. For example, the set ratio value (α) may be at least one of 1, 0.83, and 1.2, but is not limited thereto. When the set ratio value (α) is 1, P1:P2=1:1 based on P1. When the set ratio value (α) is 0.83, P1:P2=1:0.83 based on P1. In this case, P2 corresponds to 83% of P1 based on P1. If the set ratio value (α) is 1.2, P1:P2=1:1.2 based on P1. In this case, P2 corresponds to 120% of P1 based on P1. The set ratio value (α) is a ratio value between powers at which the distribution of power output from multiple inverters can be determined to be uniform, and may represent a value representing P2 based on P1. The set ratio value (α) may be determined in various ways depending on the conditions of the cooking vessel (104) and the multiple working coils (201_1, 201_2), and is therefore not limited to the above-described values.

[0208] In step S1120, if the obtained ratio value (R1) is compared with the set ratio value (α), and the obtained ratio value (R1) exceeds or is less than the set ratio value (α) (if the obtained ratio value (R1) deviates from the set ratio value (α)), in step S1122, the induction heating device (100) can adjust the duty of the switching element included in at least one inverter among the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)).

[0209] In step S1122, for example, the induction heating device (100) can reduce the duty of an inverter that outputs high power. Accordingly, the power output from the inverter that outputs high power can be reduced. The duty of the inverter can be used to adjust the magnitude of the voltage output from the inverter. The higher the duty of the inverter, the higher the voltage output from the inverter, and the lower the duty of the inverter, the lower the voltage output from the inverter. Therefore, when the duty of the inverter is reduced, the voltage output from the inverter becomes lower, and accordingly, the power output from the inverter also decreases. For example, when the input voltage applied to the inverter is 12 V and the duty is 50%, the power output from the inverter (P = V (12 V) * D (50%)) is 6 W. At this time, when the duty is reduced to 40%, the power output from the inverter (P = V (12 V) * D (40%)) is reduced to 4.8 W. A decrease in the power output (P) from the inverter may indicate a decrease in the output voltage of the inverter.

[0210] In step S1122, for example, the induction heating device (100) may increase the duty of an inverter that outputs low power. Accordingly, the power output from the inverter that outputs low power may increase. When the duty of the inverter is increased, the voltage output from the inverter increases, and accordingly, the power output from the inverter also increases. For example, when the input voltage applied to the inverter is 12 V and the duty is 20%, the power output from the inverter (P = V (12 V) * D (20%)) is 2.4 W. At this time, when the duty is increased to 40%, the power output from the inverter (P = V (12 V) * D (40%)) increases to 4.8 W. An increase in the power (P) output from the inverter may indicate that the output voltage of the inverter increases. In the case of increasing the duty of an inverter outputting low power in step S660, it can be performed when the duties of all of the plurality of inverters are low, but is not limited thereto.

[0211] In step S1122, for example, the induction heating device (100) may increase the duty of an inverter outputting low power while decreasing the duty of an inverter outputting high power. Accordingly, the power output from an inverter outputting low power increases while the power output from an inverter outputting high power decreases, so that the distribution of power output from multiple inverters can be controlled evenly.

[0212] After performing step S1122, the induction heating device (100) can control the frequency of the inverter outputting low power to be synchronized with the frequency of the inverter outputting high power in step S1124. For example, a frequency synchronization operation can be performed to match the frequencies of the two inverters by increasing the frequency of the inverter outputting high power and decreasing the frequency of the inverter outputting low power. When the frequencies of the two inverters are synchronized in this way, the power output from the two inverters can be maintained stably.

[0213] After performing step S1124, the induction heating device (100) may proceed to step S1110 and repeat the above-described process until the ratio value (R1) is included in the set ratio value (α).

[0214] In step S1120, if the detected ratio value (R1) is included in the set ratio value (α), in step S1130, the induction heating device (100) detects the phase angle of each inverter. At least one of the detected phase angles (e.g., the first inverter (301_1) or the second inverter (301_2)) is set to the set phase value (θ). limit ) or less, in step S1140, the induction heating device (100) can increase the duty of the corresponding inverter. The set phase value (θ limit ) may be a value determined based on the state that prevents damage to the switching elements included in the inverter according to the ZCS (Zero Current Switching) operation. For example, when the duty of the inverter is 10% or less, the phase angle is the set phase value (θ limit) may be. The phase angle can be defined as the distance between the point where the voltage waveform passes through '0' and the point where the current waveform passes through '0', as shown in (730) of Fig. 7. The ZCS (Zero Current Switching) operation refers to the operation in which the current becomes '0' when the switching element included in the inverter is switched. If the current of the switching element does not become '0' when performing the ZCS (Zero Current Switching) operation, the switching element may be damaged.

[0215] In step S1140, the induction heating device (100) increases the duty of the corresponding inverter (e.g., the first inverter (301_1) or the second inverter (301_2)), and then the operation of the induction heating device (100) proceeds to step S1130. The induction heating device (100) detects a phase angle from all inverters included in the induction heating device (100) and sets the phase value (θ) limit ) may be repeatedly performed until the value is greater than step S1130, step S1135, and step S1140.

[0216] In step S1135, the induction heating device (100) sets the phase value (θ) for all phase angles of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)). limit ) is greater than, the induction heating device (100) outputs the total power (e.g. P) from a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) in step S1145. total =P1+P2) is the command power (P ref ), in step S1155, the induction heating device (100) can maintain the current state. This is because the power output from the plurality of inverters is evenly distributed, the power output from the plurality of inverters satisfies the command power (output satisfaction state), and the phase margin of the plurality of inverters is secured.

[0217] In step S1145, the total sum (P) of power output from multiple inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) total =P1+P2) is the command power (P ref ), the induction heating device (100) can control the frequency of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) in step S1150. The frequency control performed in step S1150 is the sum (P) of the power output from the plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)). total =P1+P2) is the command power (P ref ) can mean that it is performed until it corresponds to the corresponding value.

[0218] The order of the flowchart illustrated in FIG. 11 may be changed. For example, after performing step S1125, step S1120 may be performed. Therefore, the flowchart of the control method of the induction heating device (100) according to one embodiment of the present disclosure is not limited to that illustrated in FIG. 11, and each step of the flowchart illustrated in FIG. 11 may be performed by the processor (310) of the induction heating device (100). In addition, the flowchart of FIG. 11 may include an operation of controlling the frequency of the first inverter (301_1) and the second inverter (301_2) to satisfy the output (Power) between each operation. The flowchart of FIG. 11 identifies a state in which the cooking vessel (104) is placed on a plurality of working coils in step S1105, and then controls the command power (P ref ) may include an operation of controlling the frequency and duty of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) to achieve an output (Power) that satisfies the condition.

[0219] FIG. 12 is a diagram for explaining an example of increasing the duty based on the phase angle detected from multiple inverters described in FIG. 11.

[0220] (1210) illustrated in FIG. 12 is an example in which the duty of an inverter (e.g., the first inverter (301_1)) is reduced as described in FIG. 9. As in (1210) illustrated in FIG. 12, the processor (310) reduces the duty of the inverter (e.g., the first inverter (301_1)) to reduce the power (e.g., the first power (P1)) output from the inverter (e.g., the first inverter (301_1)), and then the phase angle (θ) detected from at least one inverter (e.g., the first inverter (301_1)) among a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) is set to a set phase value (θ). limit ) below, the induction heating device (100) can secure the phase margin of the inverter (e.g., the first inverter (301_1)) by increasing the duty of the inverter (e.g., the first inverter (301_1)) as shown in (1220) of FIG. 12.

[0221] Fig. 13 is a flowchart of a control method of an induction heating device (100) according to one embodiment of the present disclosure. Fig. 13 is an example in which a configuration for determining whether to start an operation of adjusting the duty of a plurality of inverters according to one embodiment of the present disclosure is added to the flowchart of Fig. 11.

[0222] In step S1305, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2). For example, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2) using the first current detection unit (410_1) and the second current detection unit (410_2). For this purpose, the induction heating device (100) can read a predetermined value stored in the memory (320). The predetermined value may be a current value corresponding to about 10 to 20% of the capacity of the working coil, but the predetermined value is not limited thereto. For example, the predetermined value may be determined based on the output value of the working coil. The induction heating device (100) compares the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) with a predetermined value, and if the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) are equal to or greater than the predetermined value, it can identify that the cooking vessel (104) is in a state (or situation) placed on a plurality of working coils (210_1, 210_2). In step S1305, the induction heating device (100) can also identify whether the cooking vessel (104) is placed on a plurality of working coils by using methods as described in the above-described FIG. 1.

[0223] In step S1305, after the induction heating device (100) identifies a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2), in step S1310, the induction heating device (100) can obtain power output from each of the plurality of inverters. The induction heating device (100) may also perform step S1310 as in step 1110 described above.

[0224] In step S1315, the induction heating device (100) detects the total power (e.g., P) output from the plurality of detected inverters (e.g., the first inverter (301_1) and the second inverter (301_2)).total =P1+P2) is the preset reference power (P x ) above, it can be decided to start an operation of adjusting the duty of multiple inverters (e.g., the first inverter (301_1) and the second inverter (301_2)). The reference power (Px) will be described in detail in FIG. 14 to be described later.

[0225] In step S1320, the induction heating device (100) can obtain a ratio value (R1) between the obtained powers. For example, the induction heating device (100) can obtain a ratio value (R1) between the first power (P1) and the second power (P2). For example, when the first power (P1) is 2400 W and the second power (P2) is 1600 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 0.67, and the ratio of P1 and P2 can be expressed as P1:P2=2400:1600=1:0.67. In this case, the second power (P2) corresponds to approximately 67% of the first power (P1). For example, if the first power (P1) is 1200 W and the second power (P2) is 1800 W, the ratio value (R1=P2 / P1) between the first power (P1) and the second power (P2) calculated based on P1 is 1.5, and the ratio of P1 and P2 can be expressed as P1:P2=1200:1800=1:1.5. In this case, the second power (P2) corresponds to approximately 125% of the first power (P1).

[0226] In step S1325, the induction heating device (100) can compare the obtained ratio value (R1) with the set ratio value (α). The set ratio value (α) is a value determined based on a state in which the power distribution output from the plurality of inverters is uniform. As described with reference to FIGS. 1 and 2, the set ratio value (α) can be determined based on a ratio value between the powers output from the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)) in a situation in which the temperature of the bottom surface of the cooking vessel (104) is uniform. For example, the set ratio value (α) may be at least one of 1, 0.83, and 1.2, but is not limited thereto. When the set ratio value (α) is 1, P1:P2=1:1 based on P1. When the set ratio value (α) is 0.83, P1:P2=1:0.83 based on P1. In this case, P2 corresponds to 83% of P1 based on P1. If the set ratio value (α) is 1.2, P1:P2=1:1.2 based on P1. In this case, P2 corresponds to 120% of P1 based on P1. The set ratio value (α) is a ratio value between powers at which the distribution of power output from multiple inverters can be determined to be uniform, and may represent a value representing P2 based on P1. The set ratio value (α) may be determined in various ways depending on the conditions of the cooking vessel (104) and the multiple working coils (201_1, 201_2), and is therefore not limited to the above-described values.

[0227] In step S1325, if the obtained ratio value (R1) is compared with the set ratio value (α), and the obtained ratio value (R1) exceeds or is less than the set ratio value (α) (if the obtained ratio value (R1) deviates from the set ratio value (α)), in step S1330, the induction heating device (100) can adjust the duty of the switching element included in at least one inverter among the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)).

[0228] In step S1330, for example, the induction heating device (100) may reduce the duty of an inverter that outputs high power. Accordingly, the power output from the inverter that outputs high power may be reduced. The duty of the inverter may be used to adjust the magnitude of the voltage output by the inverter. The higher the duty of the inverter, the higher the voltage output by the inverter, and the lower the duty of the inverter, the lower the voltage output by the inverter. Therefore, when the duty of the inverter is reduced, the voltage output from the inverter decreases, and accordingly, the power output from the inverter also decreases. For example, when the input voltage applied to the inverter is 12 V and the duty is 50%, the power output from the inverter (P = V (12 V) * D (50%)) is 6 W. At this time, when the duty is reduced to 40%, the power output from the inverter (P = V (12 V) * D (40%)) is reduced to 4.8 W. A decrease in the power output (P) from the inverter may indicate a decrease in the output voltage of the inverter.

[0229] In step S1330, for example, the induction heating device (100) may increase the duty of an inverter that outputs low power. Accordingly, the power output from the inverter that outputs low power may increase. When the duty of the inverter is increased, the voltage output from the inverter increases, and accordingly, the power output from the inverter also increases. For example, when the input voltage applied to the inverter is 12 V and the duty is 20%, the power output from the inverter (P = V (12 V) * D (20%)) is 2.4 W. At this time, when the duty is increased to 40%, the power output from the inverter (P = V (12 V) * D (40%)) increases to 4.8 W. An increase in the power (P) output from the inverter may indicate that the output voltage of the inverter increases. In the case of increasing the duty of an inverter outputting low power in step S660, it can be performed when the duties of all of the plurality of inverters are low, but is not limited thereto.

[0230] In step S1330, for example, the induction heating device (100) may increase the duty of an inverter outputting low power while decreasing the duty of an inverter outputting high power. Accordingly, the power output from an inverter outputting low power increases while the power output from an inverter outputting high power decreases, so that the distribution of power output from multiple inverters can be controlled evenly.

[0231] After performing step S1330, the induction heating device (100) can control the frequency of the inverter outputting low power to be synchronized with the frequency of the inverter outputting high power in step S1335. For example, a frequency synchronization operation can be performed to match the frequencies of the two inverters by increasing the frequency of the inverter outputting high power and decreasing the frequency of the inverter outputting low power. When the frequencies of the two inverters are synchronized in this way, the power output from the two inverters can be maintained stably.

[0232] After performing step S1335, the induction heating device (100) may proceed to step S1320 and repeat the above-described process until the ratio value (R1) is included in the set ratio value (α).

[0233] In step S1325, if the detected ratio value (R1) is included in the set ratio value (α), in step S1340, the induction heating device (100) can obtain the phase angle of each inverter. At least one of the obtained phase angles (e.g., the first inverter (301_1) or the second inverter (301_2)) is set to the set phase value (θ). limit ) or less, in step S1350, the induction heating device (100) can increase the duty of the corresponding inverter. The set phase value (θ limit ) may be a value determined based on the state that prevents damage to the switching elements included in the inverter according to the ZCS (Zero Current Switching) operation. For example, when the duty of the inverter is 10% or less, the phase angle is the set phase value (θ limit) may be. The phase angle can be defined as the distance between the point where the voltage waveform passes through '0' and the point where the current waveform passes through '0', as shown in (730) of Fig. 7. ZCS operation means an operation in which the current becomes '0' when the switching element included in the inverter is switched. If the current of the switching element does not become '0' when performing the ZCS operation, the switching element may be damaged.

[0234] In step S1350, the induction heating device (100) increases the duty of the corresponding inverter (e.g., the first inverter (301_1) or the second inverter (301_2)), and then the operation of the induction heating device (100) proceeds to step S1340. The induction heating device (100) detects a phase angle from all inverters included in the induction heating device (100) and sets the phase value (θ) limit ) may be repeatedly performed until the step S1340, step S1345, and step S1340 are greater than the step S1340.

[0235] In step S1345, the induction heating device (100) sets the phase value (θ) for all phase angles of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)). limit ) is greater than, the induction heating device (100) outputs the total power (e.g. P) from a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) in step S1355. total =P1+P2) is the command power (P ref ), in step S1365, the induction heating device (100) can maintain the current state. This is because the power output from the plurality of inverters is evenly distributed, the power output from the plurality of inverters satisfies the command power (output satisfaction state), and the phase margin of the plurality of inverters is secured.

[0236] In step S1355, the total sum (P) of power output from multiple inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) total =P1+P2) is the command power (P ref ), the induction heating device (100) can control the frequency of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) in step S1360. The frequency control performed in step S1150 is the sum (P) of the power output from a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)). total =P1+P2) is the command power (P ref ) can mean that it is performed until it corresponds to the corresponding value.

[0237] The order of the flowchart illustrated in FIG. 13 may be changed. For example, step S1330 may be performed after performing step S1335. Therefore, the flowchart of the control method of the induction heating device (100) according to one embodiment of the present disclosure is not limited to that illustrated in FIG. 13, and each step of the flowchart illustrated in FIG. 13 may be performed by the processor (310) of the induction heating device (100). In addition, the flowchart of FIG. 13 may include an operation of controlling the frequency of the first inverter (301_1) and the second inverter (301_2) to satisfy the output (Power) between each operation. The flowchart of FIG. 13 identifies a state in which the cooking vessel (104) is placed on a plurality of working coils in step S1305, and then controls the command power (P ref ) may include an operation of controlling the frequency and duty of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) to achieve an output (Power) that satisfies the condition.

[0238] FIG. 14 is a drawing for explaining the point in time at which an induction heating device (100) according to one embodiment of the present disclosure starts performing an operation to reduce the duty of an inverter.

[0239] The induction heating device (100) of Fig. 14 can start performing an operation to reduce the duty of the inverter at point (1401). Point (1401) is the sum (e.g., P) of the power (e.g., the first power (P1) and the second power (P2)) output from a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)). total =P1+P2) is the reference power (P x ) is the point at which the reference power (P) is reached. x ) is a power corresponding to the low power of the induction heating device (100), and the power output from multiple inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) is evenly distributed, but the command power (P ref ) refers to the power that has not yet reached the reference power (P x ) may be less than 1 kW.

[0240] Fig. 15 is a flowchart of a control method of an induction heating device (100) according to one embodiment of the present disclosure. Fig. 15 illustrates a case where power distribution is determined to be uniform when the power output from multiple inverters is the same.

[0241] In step S1510, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2). For example, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2) using the first current detection unit (410_1) and the second current detection unit (410_2). For this purpose, the induction heating device (100) can read a predetermined value stored in the memory (320). The predetermined value may be a current value corresponding to about 10 to 20% of the capacity of the working coil, but the predetermined value is not limited thereto. For example, the predetermined value may be determined based on the output value of the working coil. The induction heating device (100) compares the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) with a predetermined value, and if the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) are equal to or greater than the predetermined value, it can identify that the cooking vessel (104) is in a state (or situation) placed on a plurality of working coils (210_1, 210_2). In step S1510, the induction heating device (100) can also identify whether the cooking vessel (104) is placed on a plurality of working coils by using methods as described in the above-described FIG. 1.

[0242] In step S1510, after the induction heating device (100) identifies a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2), in step S1520, the induction heating device (100) can obtain power (e.g., first power (P1) and second power (P2)) output from a plurality of inverters (e.g., first inverter (301_1) and second inverter (301_2)). The induction heating device (100) can also obtain power output from a plurality of inverters as in step S620 of FIG. 6.

[0243] In step S1530, if the power obtained (e.g., the first power (P1) and the second power (P2)) are the same, the induction heating device (100) can maintain the current state in step S1550. This is because the distribution of power output from the plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) included in the induction heating device (100) is uniform.

[0244] In step S1530, if the powers obtained (e.g., the first power (P1) and the second power (P2)) are different (or not the same), in step S1540, the induction heating device (100) can adjust the duty of the switching element included in at least one of the plurality of inverters (301_1, 301_2), as in step S660 of FIG. 6 described above. The induction heating device (100) can repeatedly perform steps S1520, S1530, and S1540 described above until the powers output from the plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) have the same value. An operation performed until the power output from multiple inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) has the same value may represent an operation of making the first power (P1) and the second power (P2) the same.

[0245] Each step of the flowchart illustrated in Fig. 15 may be performed by the processor (310) of the induction heating device (100). In addition, the flowchart of Fig. 15 may include an operation of controlling the frequency of the first inverter (301_1) and the second inverter (301_2) to satisfy the output (Power) between each operation. The flowchart of Fig. 15 identifies a state in which the cooking vessel (104) is placed on a plurality of working coils in step S1510, and then the command power (P ref) may also perform an operation of controlling the frequency and duty of multiple inverters (e.g., the first inverter (301_1) and the second inverter (301_2)).

[0246] Fig. 16 is a flowchart of a control method of an induction heating device (100) according to one embodiment of the present disclosure. Fig. 16 is an example performed based on power applied to a plurality of working coils.

[0247] In step S1610, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2). For example, the induction heating device (100) can identify a state in which the cooking vessel (104) is placed on a plurality of working coils (210_1, 210_2) using the first current detection unit (410_1) and the second current detection unit (410_2). For this purpose, the induction heating device (100) can read a predetermined value stored in the memory (320). The predetermined value may be a current value corresponding to about 10 to 20% of the capacity of the working coil, but the predetermined value is not limited thereto. For example, the predetermined value may be determined based on the output value of the working coil. The induction heating device (100) compares the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) with a predetermined value, and if the current values ​​obtained from the first current detection unit (410_1) and the second current detection unit (410_2) are equal to or greater than the predetermined value, it can identify that the cooking vessel (104) is in a state (or situation) placed on a plurality of working coils (210_1, 210_2). In step S1610, the induction heating device (100) can also identify whether the cooking vessel (104) is placed on a plurality of working coils by using methods as described in the above-described FIG. 1.

[0248] In step S1620, the induction heating device (100) can obtain power applied to each of a plurality of working coils (e.g., a first working coil (210_1) and a second working coil (210_2)). In step S1630, the induction heating device (100) can obtain a ratio value (R1) between the obtained powers.

[0249] In step S1640, the induction heating device (100) can compare the obtained ratio value (R1) with the set ratio value (α). The set ratio value (α) is a value determined based on a state in which the power distribution output from the plurality of inverters is uniform. As described in FIGS. 1 and 2, the set ratio value (α) can be determined based on a ratio value between the power output from the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)) in a situation in which the temperature of the bottom surface of the cooking vessel (104) is uniform. For example, the set ratio value (α) may be at least one of 1, 0.83, and 1.2, but is not limited thereto. When the set ratio value (α) is 1, P1:P2=1:1 based on P1. When the set ratio value (α) is 0.83, P1:P2=1:0.83 based on P1. In this case, P2 corresponds to 83% of P1 based on P1. If the set ratio value (α) is 1.2, P1:P2=1:1.2 based on P1. In this case, P2 corresponds to 120% of P1 based on P1. The set ratio value (α) is a ratio value between powers at which the distribution of power output from multiple inverters can be determined to be uniform, and may represent a value representing P2 based on P1. The set ratio value (α) may be determined in various ways depending on the conditions of the cooking vessel (104) and the multiple working coils (201_1, 201_2), and is therefore not limited to the above-described values.

[0250] In step S1640, if the obtained ratio value (R1) is included in the set ratio value (α) as a result of comparing the obtained ratio value (R1) with the set ratio value (α) (if the obtained ratio value (R1) does not deviate from the set ratio value (α)), in step S1650, the induction heating device (100) can operate to maintain the current state because the distribution of the first power (P1) and the second power (P2) is uniform.

[0251] In step S1640, if the obtained ratio value (R1) is compared with the set ratio value (α), and the obtained ratio value (R1) exceeds or is less than the set ratio value (α) (if the obtained ratio value (R1) deviates from the set ratio value (α)), in step S1660, the induction heating device (100) can adjust the duty of the switching element included in at least one inverter among the plurality of inverters (the first inverter (301_1) and the second inverter (301_2)).

[0252] In step S1660, for example, the induction heating device (100) may reduce the duty of an inverter that outputs high power. Accordingly, the power output from the inverter that outputs high power may be reduced. The duty of the inverter may be used to adjust the magnitude of the voltage output from the inverter. The higher the duty of the inverter, the higher the voltage output from the inverter, and the lower the duty of the inverter, the lower the voltage output from the inverter. Therefore, when the duty of the inverter is reduced, the voltage output from the inverter decreases, and accordingly, the power output from the inverter also decreases. For example, when the input voltage applied to the inverter is 12 V and the duty is 50%, the power output from the inverter (P = V (12 V) * D (50%)) is 6 W. At this time, when the duty is reduced to 40%, the power output from the inverter (P = V (12 V) * D (40%)) is reduced to 4.8 W. A decrease in the power output (P) from the inverter may indicate a decrease in the output voltage of the inverter.

[0253] In step S1660, for example, the induction heating device (100) may increase the duty of an inverter that outputs low power. Accordingly, the power output from the inverter that outputs low power may increase. When the duty of the inverter is increased, the voltage output from the inverter increases, and accordingly, the power output from the inverter also increases. For example, when the input voltage applied to the inverter is 12 V and the duty is 20%, the power output from the inverter (P = V (12 V) * D (20%)) is 2.4 W. At this time, when the duty is increased to 40%, the power output from the inverter (P = V (12 V) * D (40%)) increases to 4.8 W. An increase in the power (P) output from the inverter may indicate that the output voltage of the inverter increases. In the case of increasing the duty of an inverter outputting low power in step S1660, it can be performed when the duties of all of the plurality of inverters are low, but is not limited thereto.

[0254] In step S1660, for example, the induction heating device (100) may increase the duty of an inverter outputting low power while decreasing the duty of an inverter outputting high power. Accordingly, the power output from an inverter outputting low power increases while the power output from an inverter outputting high power decreases, so that the distribution of power output from multiple inverters can be controlled evenly.

[0255] After performing step S1660, the induction heating device (100) may proceed to step S1620 and repeat the above-described process until the ratio value (R1) is included in the set ratio value (α).

[0256] Each step of the flowchart illustrated in FIG. 16 may be performed by the processor (310) of the induction heating device (100). In addition, although not described in the flowchart of FIG. 16, the flowchart of FIG. 16 may include an operation of controlling the frequency of the first inverter (301_1) and the second inverter (301_2) to satisfy the output (Power) between each operation. Therefore, the flowchart of the control method of the induction heating device (100) according to one embodiment of the present disclosure is not limited to that illustrated in FIG. 16. The flowchart of FIG. 16 identifies a state in which the cooking vessel (104) is placed on a plurality of working coils in step S1610, and then controls the command power (P ref ) may include an operation of controlling the frequency and duty of a plurality of inverters (e.g., the first inverter (301_1) and the second inverter (301_2)) to achieve an output (Power) that satisfies the condition.

[0257] According to one embodiment of the present disclosure, by uniformly controlling the distribution of power output from inverters corresponding to a plurality of working coils on which a cooking vessel (104) is placed, heat distribution between the corresponding working coils can be uniform. Accordingly, the thermal efficiency of the cooking vessel (104) is improved, so that cooking time can be shortened and uniform cooking results can be obtained. In addition, it is possible to prevent a large current from flowing in the resonance network of some of the working coils (e.g., inner working coil) among the plurality of working coils on which the cooking vessel (104) is placed. Accordingly, damage to the working coil or burnout of the switching element built into the inverter corresponding to the working coil can be prevented.

[0258] The embodiment illustrated in FIG. 6 described above can be modified or configured to perform step S620 without performing step S610. The embodiment illustrated in FIG. 8 can be modified or configured to perform step S820 without performing step S810. The embodiment illustrated in FIG. 10 can be modified or configured to perform step S1020 without performing step S1010. The embodiment illustrated in FIG. 11 can be modified or configured to perform step S1110 without performing step S1105. The embodiment illustrated in FIG. 13 can be modified or configured to perform step S1310 without performing step S1305. The embodiment illustrated in FIG. 15 can be modified or configured to perform step S1520 without performing step S1510. The embodiment illustrated in FIG. 16 can be modified or configured to perform step S1620 without performing step S1610. Accordingly, the induction heating device (100) according to one embodiment illustrated in FIGS. 6, 8, 10, 11, 13, 15, and 16 can obtain (or detect) the power output from each of the plurality of inverters without identifying whether the cooking vessel (104) is placed on each of the plurality of working coils. The induction heating device (100) according to one embodiment illustrated in FIGS. 6, 8, 10, 11, 13, 15, and 16 can also control the duty of the switching element included in the inverter so that the power output from each of the plurality of working coils is evenly distributed, without identifying whether the cooking vessel (104) is placed on each of the plurality of working coils.The induction heating device (100) according to one embodiment illustrated in FIGS. 6, 8, 10, 11, 13, 15, and 16 can control the duty of a switching element included in an inverter so that the power output from the inverter corresponding to each of the plurality of working coils is uniformly distributed, regardless of whether the cooking vessel (104) is placed on a plurality of working coils or not (or regardless of the operation of identifying whether the cooking vessel (104) is placed on a plurality of working coils).

[0259] At least one processor (310) according to one embodiment of the present disclosure may perform an operation of reducing the duty of a switching element included in an inverter outputting higher power among the first inverter (301_1) and the second inverter (302_2) to include the ratio value (R1) in the set ratio value (α).

[0260] At least one processor (310) according to one embodiment of the present disclosure can synchronize the frequency of the inverter outputting high power with the frequency of the inverter outputting low power when reducing the duty of the switching element included in the inverter outputting high power.

[0261] At least one processor (310) according to one embodiment of the present disclosure may increase the duty of a switching element included in an inverter outputting lower power among the first inverter (301_1) and the second inverter (302_2), thereby including the ratio value (R1) in the set phase value (α).

[0262] At least one processor (310) according to one embodiment of the present disclosure may reduce the duty of a switching element included in an inverter outputting higher power among the first inverter (301_1) and the second inverter (302_2), and increase the duty of a switching element included in an inverter outputting lower power among the first inverter (301_1) and the second inverter (302_2), thereby including the ratio value (R1) in the set phase value (α).

[0263] A set ratio value (α) according to one embodiment of the present disclosure may be determined based on a ratio value between a first power (P1) and a second power (P2) obtained when a difference value between a temperature value at a first position (L1) and a temperature value at a second position (L2) of a bottom surface of a cooking vessel (104) is equal to or less than a set temperature value while the cooking vessel (104) is placed on a first working coil (210_1) and a second working coil (210_2).

[0264] At least one processor (310) according to one embodiment of the present disclosure may stop the operation of adjusting the duty of the switching element when the ratio value (R1) is included in the set ratio value (α) after adjusting the duty of the switching element.

[0265] At least one processor (310) according to one embodiment of the present disclosure can obtain a first phase angle using a waveform of a current supplied from a first inverter (301_1) to a first working coil (210_1) and a waveform of a voltage supplied from the first inverter (301_1) to the first working coil (210_1). At least one processor (310) can obtain a second phase angle using a waveform of a current supplied from a second inverter (301_2) to a second working coil (210_2) and a waveform of a voltage supplied from the second inverter (301_2) to the second working coil (210_2). At least one processor (310) can increase a duty of a switching element included in an inverter for which a phase angle less than or equal to the set phase value (θlimit) is obtained when at least one of the first phase angle and the second phase angle is less than or equal to a set phase value (θlimit).

[0266] At least one processor (310) according to one embodiment of the present disclosure obtains a phase angle using a waveform of an output voltage and a waveform of an output current of an inverter that outputs high power, and sets the obtained phase angle to a set phase value (θ). limit) below, the duty of the switching element included in the inverter outputting high power can be increased.

[0267] At least one processor (310) according to one embodiment of the present disclosure is configured to: calculate a sum (P) between a first power (P1) and a second power (P2) total ) is set to power (P x ) or more, an operation of adjusting the duty of the switching element can be performed using the ratio value (R1) and the set ratio value (α).

[0268] The step of adjusting the duty of the switching element according to one embodiment of the present disclosure may include a step of reducing the duty of the switching element included in an inverter outputting higher power among the first inverter (301_1) and the second inverter (301_2), thereby including the ratio value (R1) in the set ratio value (α).

[0269] The step of reducing the duty of a switching element included in an inverter outputting high power according to one embodiment of the present disclosure may include a step of synchronizing the frequency of the inverter outputting high power and the frequency of the inverter outputting low power when reducing the duty of the switching element included in the inverter outputting high power.

[0270] The step of adjusting the duty of the switching element according to one embodiment of the present disclosure may include a step of increasing the duty of the switching element included in the inverter outputting lower power among the first inverter (301_1) and the second inverter (302_2), thereby including the ratio value (R1) in the set phase value (α).

[0271] The step of adjusting the duty of a switching element according to one embodiment of the present disclosure includes the step of reducing the duty of a switching element included in an inverter outputting high power among the first inverter (301_1) and the second inverter (302_2); and the step of increasing the duty of a switching element included in an inverter outputting low power among the first inverter (301_1) and the second inverter (302_2), so that the ratio value (R1) can be included in the set phase value (α).

[0272] A method according to one embodiment of the present disclosure may include a step of stopping an operation of adjusting the duty of the switching element when, after adjusting the duty of the switching element, the ratio value (R1) is included in the set ratio value (α).

[0273] A method according to one embodiment of the present disclosure comprises the steps of: obtaining a first phase angle by using a waveform of a current supplied from a first inverter (301_1) to a first working coil (210_1) and a waveform of a voltage supplied from the first inverter (301_1) to the first working coil (210_1); obtaining a second phase angle by using a waveform of a current supplied from a second inverter (301_2) to a second working coil (210_2) and a waveform of a voltage supplied from the second inverter (301_2) to the second working coil (210_2); and setting a phase value (θ) for which at least one of the first phase angle and the second phase angle is set. limit ) is less than or equal to the set phase value (θ limit ) may include a step of increasing the duty of a switching element included in an inverter in which a phase angle less than or equal to 0 is detected.

[0274] A method according to one embodiment of the present disclosure comprises the steps of: obtaining a phase angle using a waveform of an output voltage and a waveform of an output current of an inverter that outputs high power; and obtaining a phase value (θ) where the obtained phase angle is set. limit ) below, a step of increasing the duty of a switching element included in an inverter that outputs high power may be included.

[0275] A method according to one embodiment of the present disclosure comprises: a sum (P) between a first power (P1) and a second power (P2) total ) may include a step of performing an operation of adjusting the duty of the switching element using the ratio value (R1) and the set ratio value (α) when the set power (Px) is greater than or equal to the set power (Px).

[0276] An induction heating device (100) including a plurality of working coils according to one embodiment of the present disclosure may include a first inverter (301_1) that supplies current to a first working coil (210_1) among the plurality of working coils, a second inverter (302_2) that supplies current to a second working coil (210_2) among the plurality of working coils, a memory (320) that stores at least one instruction, and at least one processor (310) that executes at least one instruction to control operations of the first inverter (301_1) and the second inverter (301_2). At least one processor (310) can identify a state in which the cooking vessel (104) is placed on the first working coil (210_1) and the second working coil (210_2), and after identifying a state in which the cooking vessel (104) is placed on the first working coil (201_1) and the second working coil (210_2), obtain a first power (P1) output from the first inverter (301_1) and a second power (P2) output from the second inverter (301_2), and when the first power (P1) is different from the second power (P2), adjust the duty of a switching element included in at least one of the first inverter (301_1) and the second inverter (301_2) to make the first power (P1) and the second power (P2) the same.

[0277] A control method of an induction heating device (100) including a plurality of working coils according to one embodiment of the present disclosure may include a step of identifying a state in which a cooking vessel (104) is placed on a plurality of working coils, a step of obtaining a first power (P1) output from a first inverter (301_1) that supplies current to a first working coil (210_1) among the plurality of working coils after the state in which the cooking vessel (104) is placed on the plurality of working coils is identified, a step of obtaining a second power (P2) output from a second inverter (301_2) that supplies current to a second working coil (210_2) among the plurality of working coils, and a step of performing an operation in which, when the first power (P1) and the second power (P2) are different, the duty of a switching element included in at least one of the first inverter (301_1) and the second inverter (301_2) is adjusted to make the first power (P1) and the second power (P2) the same.

[0278] A device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, the term "non-transitory storage medium" simply means a tangible device that does not contain signals (e.g., electromagnetic waves). This term does not distinguish between cases where data is permanently stored in the storage medium and cases where data is temporarily stored. For example, a "non-transitory storage medium" may include a buffer in which data is temporarily stored.

[0279] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

Claims

1. In an induction heating device (100) including a plurality of working coils, A first inverter (301_1) that supplies current to a first working coil (210_1) among the plurality of working coils; A second inverter (302_2) that supplies current to a second working coil (210_2) among the plurality of working coils; A memory (320) storing at least one instruction: and At least one processor (310) for controlling the operation of the first inverter (301_1) and the second inverter (301_2) by executing at least one instruction, At least one processor (310) above, Obtain the first power (P1) output from the first inverter (301_1), Obtain the second power (P2) output from the second inverter (301_2), Obtain a ratio value (R1) between the first power (P1) and the second power (P2), and If the obtained ratio value (R1) exceeds or is less than the set ratio value (α), an operation is performed to adjust the duty of the switching element included in at least one of the first inverter (301_1) and the second inverter (301_2) so that the ratio value (R1) is included in the set ratio value (α). Induction heating device.

2. In the first paragraph, at least one processor (310) An operation is performed to reduce the duty of a switching element included in an inverter outputting a higher power among the first inverter (301_1) and the second inverter (302_2), thereby including the ratio value (R1) in the set ratio value (α). Induction heating device.

3. In the second paragraph, at least one processor (310) When reducing the duty of the switching element included in the inverter outputting the high power, the frequency of the inverter outputting the high power and the frequency of the inverter outputting the low power are synchronized. Induction heating device.

4. In any one of clauses 1 to 3, the at least one processor (310) By increasing the duty of the switching element included in the inverter outputting lower power among the first inverter (301_1) and the second inverter (302_2), the ratio value (R1) is included in the set phase value (α). Induction heating device.

5. In any one of clauses 1 to 4, the at least one processor (310) Reduce the duty of the switching element included in the inverter outputting high power among the first inverter (301_1) and the second inverter (302_2), By increasing the duty of the switching element included in the inverter that outputs lower power among the first inverter (301_1) and the second inverter (302_2), Including the above ratio value (R1) in the above set phase value (α), Induction heating device.

6. In any one of clauses 1 to 5, the set ratio value (α) is determined based on a ratio value between the first power (P1) and the second power (P2) obtained when the difference value between the temperature value of the first position (L1) and the temperature value of the second position (L2) of the bottom surface of the cooking vessel (104) is less than or equal to the set temperature value while the cooking vessel (104) is placed on the first working coil (210_1) and the second working coil (210_2). Induction heating device.

7. In any one of clauses 1 to 6, the at least one processor (310) After adjusting the duty of the switching element, if the ratio value (R1) is included in the set ratio value (α), the operation of adjusting the duty of the switching element is stopped. Induction heating device.

8. In any one of clauses 1 to 7, the at least one processor (310) The first phase angle is obtained by using the waveform of the current supplied from the first inverter (301_1) to the first working coil (210_1) and the waveform of the voltage supplied from the first inverter (301_1) to the first working coil (210_1). The second phase angle is obtained by using the waveform of the current supplied from the second inverter (301_2) to the second working coil (210_2) and the waveform of the voltage supplied from the second inverter (301_2) to the second working coil (210_2). If at least one of the first phase angle and the second phase angle is less than or equal to the set phase value (θlimit), the duty of the switching element included in the inverter that has obtained the phase angle less than or equal to the set phase value (θlimit) is increased. Induction heating device.

9. In any one of clauses 1 to 7, the at least one processor (310) The phase angle is obtained by using the waveform of the output voltage and the waveform of the output current of the inverter that outputs high power. The phase angle obtained above is set to the phase value (θ limit ) below, increasing the duty of the switching element included in the inverter outputting the high power. Induction heating device.

10. In any one of clauses 1 to 9, the at least one processor (310) The sum (P) between the first power (P1) and the second power (P2) total ) is set to power (P) x ) or more, an operation of adjusting the duty of the switching element is performed using the ratio value (R1) and the set ratio value (α). Induction heating device.

11. A method for controlling an induction heating device (100) including a plurality of working coils, A step of obtaining a first power (P1) output from a first inverter (301_1) that supplies current to a first working coil (210_1) among the plurality of working coils; A step of obtaining a second power (P2) output from a second inverter (301_2) that supplies current to a second working coil (210_2) among the plurality of working coils; A step of obtaining a ratio value (R1) between the first power (P1) and the second power (P2); and Including a step of adjusting the duty of a switching element included in at least one of the first inverter (301_1) and the second inverter (301_2) so that the ratio value (R1) is included in the set ratio value (α) when the ratio value (R1) exceeds or is less than the set ratio value (α). A method for controlling an induction heating device.

12. In the 11th paragraph, the step of adjusting the duty of the switching element is as follows: A step of reducing the duty of a switching element included in an inverter outputting higher power among the first inverter (301_1) and the second inverter (301_2) so as to include the ratio value (R1) in the set ratio value (α). A method for controlling an induction heating device.

13. In the 12th paragraph, the step of reducing the duty of the switching element included in the inverter outputting the high power includes the step of synchronizing the frequency of the inverter outputting the high power and the frequency of the inverter outputting the low power when reducing the duty of the switching element included in the inverter outputting the high power. A method for controlling an induction heating device.

14. In any one of clauses 11 to 13, the step of adjusting the duty of the switching element comprises: Including a step of increasing the duty of a switching element included in an inverter outputting lower power among the first inverter (301_1) and the second inverter (302_2) so that the ratio value (R1) is included in the set phase value (α). A method for controlling an induction heating device.

15. In any one of clauses 11 to 14, the step of adjusting the duty of the switching element comprises: A step of reducing the duty of a switching element included in an inverter that outputs high power among the first inverter (301_1) and the second inverter (302_2); and Including a step of increasing the duty of a switching element included in an inverter outputting lower power among the first inverter (301_1) and the second inverter (302_2), Including the above ratio value (R1) in the above set phase value (α), A method for controlling an induction heating device.

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