KR20160146376A - Induction heat cooking apparatus and control method thereof - Google Patents

Abstract

The present invention relates to an induction heating cooker, which comprises: a coil for generating an induction magnetic field on a load; an inverter for transferring power to the coil by using input power; a first detection unit connected to a first side of the coil, and detecting first current; and a control unit for detecting information related to a state of the load based on the detected first current, and controlling the inverter based on the detected information.

Description

TECHNICAL FIELD [0001] The present invention relates to an induction heating cooker,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction heating cooker and, more particularly, to an electromagnetic induction heating cooker using currents on both sides based on a coil and a control method thereof.

The induction heating cooker induces a high frequency current through a working coil or a heating coil, and when the strong magnetic force line generated by the induction heating coil passes through the cooking vessel, the eddy current flows and the container itself is heated Is an electric cooking apparatus that performs a cooking function.

The basic heating principle of the induction heating cooker is as follows. When a current is applied to the heating coil, the cooking vessel, which is a magnetic body, generates heat by induction heating, and the cooking vessel itself is heated by the generated heat, .

The inverter used in the induction heating electric cooker serves to switch the voltage applied to the heating coil so that a high frequency current flows through the heating coil. The inverter drives a switching element, typically an IGBT (Insulated Gate Bipolar Transistor), so that a high frequency current flows through the heating coil to form a high frequency magnetic field in the heating coil.

Generally, an induction heating cooker performs output control using a current (secondary side current) after passing through a rectifying circuit or a bridge circuit. In this case, the secondary side current is influenced by the external environment such as the pole change of the AC power source, the induced electromotive force generated by the secondary side magnetic force lines, and the characteristics of the load, and the variation width is large. Therefore, there is a problem that the secondary side current is not suitable for use in controlling the output of the cooker.

An object of the present invention is to provide an induction heating cooker capable of performing output control without being affected by changes in the external environment and a control method thereof.

Another object of the present invention is to provide an induction heating cooker capable of detecting the state of a load present on a coil and a control method thereof.

Another object of the present invention is to provide an induction heating cooker and a control method thereof capable of detecting whether or not the load is swallowed.

An induction heating cooker according to the present invention includes a coil for generating an induction magnetic field with respect to a load, an inverter for transmitting power to the coil by using an input power source, a first coil connected to a first side of the coil, And a control unit for detecting information related to the state of the load based on the detected first current and controlling the output of the inverter based on the detected information.

In an embodiment, the control unit may determine that the load is in a boil state if the change amount of the first current is equal to or less than a first reference value for a predetermined time, and based on the determination result, And the inverter is controlled to control the inverter.

The control unit may further include an output unit for outputting information related to an operation state of the induction heating cooker, wherein when the load is determined to be in a boil state, the control unit controls the output unit to output information related to the boil state .

The controller may control the output unit such that, when the output of the inverter decreases, information related to the reduced output amount is output.

In an embodiment, the control unit may determine whether a load is present on the coil if the detected first current is equal to or greater than a reference current value, and to shut off the output of the inverter based on the determination result .

In one embodiment of the present invention, the resonance unit generates a resonance voltage corresponding to an input voltage applied to the coil. The first side of the coil is a side of the coil on which the resonance unit is provided.

[0028] In an embodiment, the apparatus may further include an input part receiving an output frequency and a second detection part connected to a second side different from the first side, the second detection part detecting a second current, , The control unit changes the output of the inverter, calculates a change amount of the second current according to an output change of the inverter, compares the calculated change amount of the second current with a second reference value, And controls the output of the inverter based on the detected information.

In an embodiment, the control unit reduces or cuts the output of the inverter based on the detected second current when the material of the load is determined to be aluminum.

In the embodiment, it is preferable to further include a rectifying unit for rectifying the input power source, and the second side is a side where the rectifying unit is installed at both ends of the coil.

The apparatus of claim 1, further comprising an input for receiving a user input to perform an operation mode for detecting a state of a load, wherein the controller, when the user input is applied, Is controlled.

Further, a method of controlling an induction heating cooker according to the present invention includes the steps of detecting a first current at a first side of a coil, detecting information related to the state of the load based on the detected first current, And controlling the output of the inverter based on the received information.

In an embodiment, the method further comprises a step of determining that the load is in a boiling state when the amount of change of the first current is equal to or less than a first reference value for a predetermined time, and reducing the output of the inverter .

The method may further include the step of outputting information related to the boiling state when it is determined that the load is in the boiling state.

The method may further include determining that a load is present on the coil when the detected first current is equal to or greater than the reference current value, and disconnecting the output of the inverter.

The method of claim 1, further comprising: receiving an output frequency; detecting a second current at a second side different from the first side; changing an output of the inverter based on the input frequency; The method comprising the steps of: calculating a change amount of the second current according to an output change of an inverter; comparing information of a change amount of the calculated second current with a second reference value to detect information related to the material of the load; And controlling the output of the inverter based on the material.

According to the present invention, the output control is performed using the primary side current before passing through the rectifying circuit, so that accurate output control can be performed even when the external environment changes.

Further, the induction heating cooker according to the present invention can more accurately and quickly detect the condition of the load. In particular, the induction heating cooker according to the present invention can more accurately and quickly detect whether the load is in a boil state.

Further, the induction heating cooker according to the present invention achieves the effect of increasing the heat efficiency and reducing the power consumption by performing the output control according to the state of the detected load.

FIG. 1A is a block diagram conceptually showing an induction heating cooker according to embodiments of the present invention. FIG.
FIG. 1B is a circuit diagram showing the first current detector of the induction heating cooker according to the embodiments of the present invention in more detail.
2 is a flowchart illustrating a method of controlling an induction heating cooker according to an embodiment of the present invention.
3 is a flowchart illustrating a method of controlling an induction heating cooker according to another embodiment of the present invention.
4 is a flowchart illustrating a method of controlling an induction heating cooker according to another embodiment of the present invention.

The techniques disclosed herein apply to an Induction Heat Cooking Apparatus. However, the technology disclosed in this specification is not limited thereto, and can be applied to an induction heating system, a wireless power transmission system, and the like, including all the coils to which the technical idea of the present invention can be applied.

It is noted that the technical terms used herein are used only to describe specific embodiments and are not intended to limit the invention. It is also to be understood that the technical terms used herein are to be interpreted in a sense generally understood by a person skilled in the art to which the present invention belongs, Should not be construed to mean, or be interpreted in an excessively reduced sense. Further, when a technical term used herein is an erroneous technical term that does not accurately express the spirit of the present invention, it should be understood that technical terms that can be understood by a person skilled in the art are replaced. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.

Also, the singular forms "as used herein include plural referents unless the context clearly dictates otherwise. In the present application, the term "comprising" or "comprising" or the like should not be construed as necessarily including the various elements or steps described in the specification, Or may be further comprised of additional components or steps.

Furthermore, suffixes "module" and " part "for components used in the present specification are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

Furthermore, terms including ordinals such as first, second, etc. used in this specification can be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or similar elements throughout the several views, and redundant description thereof will be omitted.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention, and should not be construed as limiting the scope of the present invention with reference to the accompanying drawings.

In the following FIG. 1A, the detailed configuration of the induction heating cooker 100 according to the present invention will be described.

1A, the induction heating cooker 100 includes a rectifier 110, an inverter 120, a coil 103, a resonator 130, a controller 140, a driving unit 150, an input unit 160, And an output unit 170. [0029] FIG. Also, the induction heating cooker 100 may include first and second current detection units 101 and 102.

Specifically, the inverter 120 may include a switching device (not shown) for switching the input power source. A coil 103 driven by an output voltage of the switching element may be connected to a connection point of the switching elements connected in series. Thus, the inverter 120 can transmit electric power to the coil 103 by using the input power source. The other side of the coil 103 may be connected to the resonator 130.

The coil 103 can generate an induction magnetic field with respect to the load 1000 by using the output voltage transmitted from the inverter 120. More specifically, the coil 103 can generate an induction magnetic field for the container of the load 1000. Therefore, the power consumed in the coil 103 of the induction heating cooker 100 according to the present invention may be different depending on the container characteristics of the load 1000 raised against the coil 103. [

In the following description, the induction heating cooker 100 including one coil is described, but the present invention is not limited thereto. Although not shown in FIG. 1A, a plurality of coils may be connected to the inverter 120 in parallel.

Although not shown in FIG. 1A, a flat plate (not shown) may be installed on the coil 103 so that the load 1000 may be placed thereon. A heating area (not shown) for guiding the user may be displayed on the flat plate.

Driving of the switching elements included in the inverter 120 is performed by the driving unit 150. When the switching elements are alternately operated by the switching time outputted from the driving unit 150, . Since the closing / opening time of the switching element applied from the driving unit 150 is controlled to be gradually compensated, the voltage supplied to the coil 103 can be changed from a low voltage to a high voltage.

The driving unit 150 may receive a control signal related to the output of the coil from the control unit 140. The control unit 140 may generate a control signal related to the output of the coil and transmit the control signal to the driving unit 150 based on the user input applied to the input unit 160.

In addition, the rectifying unit 110 can receive a used power source AC input from the outside, and can rectify the applied commercial power source to a DC voltage. For example, the rectifying unit 110 may include a bridge circuit (not shown), a half bridge circuit, and the like.

For example, the rectifying section 110 may include first to fourth diodes. In this case, the first diode and the third diode are connected to each other in series, and the second diode and the fourth diode may be connected in series. In addition, the contacts of the first and third diodes and the contacts of the second and fourth diodes may both be connected to a commercial power source.

The resonance unit 130 may include a resonance capacitor corresponding to the coil 103. Thus, the resonance unit 130 can generate a resonance voltage corresponding to the input voltage applied to the coil 103. The resonant capacitor may be formed of at least one capacitor element.

The input unit 160 may include a plurality of operation buttons for inputting various commands related to the operation of the induction heating cooker 100. For example, the input unit 160 may be formed as a touch panel, and at least one input button may be variably displayed.

Specifically, the input unit 160 includes an input for turning on or off the power of the induction heating cooker 100, an input for setting the output frequency of the coil 103, an input for selecting at least one of the plurality of coils, And an input for setting an operation time of the operation unit 103.

In particular, the input unit 160 may receive a user input so that a specific function of detecting the state of the load 1000 is performed. For example, the input unit 160 may include a function of detecting whether or not the load 1000 is boiling, a function of detecting the presence or absence of the load 1000, and a function of detecting information related to the material of the load 1000 The user input may be input so that at least one is performed.

The output unit 170 may display information related to the operation state of the induction heating cooker 100, information related to the load 1000, and the like.

For example, the information related to the operating state of the induction heating cooker 100 may include an output level of the coil 103, an operation time set for the coil 103, an output cutoff for the coil 103, And information related to at least one of whether to perform the specific function to be detected.

For example, the information associated with the load 1000 may include at least one of whether the load 1000 is boiling, the current temperature of the load 1000, the presence or absence of the load 1000 and the material of the load 1000 And < / RTI >

The control unit 140 may use at least one of the information related to the first current detected by the first current detecting unit 101 and the information related to the second current detected by the second current detecting unit 102, The output can be controlled.

Specifically, referring to FIG. 1A, the first current detection unit 101 may be connected to the first side of the coil. The first side may be defined relative to the coil 103. For example, the first side may be defined as the side of the coil 103 where the resonance portion 130 is installed. On the other hand, the first side may be defined relative to the rectifying part 110. For example, the first side may be defined as the opposite side of the rectifying part 110 to which the commercial power is connected.

Referring to FIG. 1A, the second current detection unit 102 may be connected to the second side of the coil. The second side may be defined relative to the coil 103. For example, the second side may be defined as the side on which the rectifying part 110 is installed at both ends of the coil 103. [ On the other hand, the second side may be defined relative to the rectifying part 110. For example, the second side may be defined as a side to which a commercial power source is connected to the rectifying unit 110. [

Hereinafter, the currents detected respectively on the first and second sides of the coil defined above are defined as first and second currents.

In the following description, the current flowing on the side where the resonance part 130 is provided is defined as a first current, and the current flowing on the side to which the commercial power is connected with reference to the rectification part 110 is defined as a second current. However, the configuration of the present invention is not limited to this, and the detection positions of the first and second currents may be variously defined.

The first and second current detectors 101 and 102 can detect information associated with the first and second currents, respectively. For example, the information associated with the first and second currents may include the frequency, current value, etc. of the first and second currents.

The first and second current detectors 101 and 102 may each include an AD converter (not shown). The AD converter may convert analog information associated with the first and second currents to digital information. The control unit 140 can detect information related to the operation state of the induction heating cooker 100 based on the converted digital information.

Specifically, the control unit 140 can detect information related to the state of the load 1000 based on the first current detected by the first current detecting unit 101. For example, information relating to the state of the load 1000 may include information such as whether the load 1000 is boiling, the current temperature of the load 1000, the presence or absence of the load 1000, And information relating to at least one of the materials. Similarly, the control unit 140 can detect information related to the state of the load 1000, based on the second current detected by the second current detecting unit 102. [

Although not shown in FIGS. 1A and 1B, the induction heating cooker 100 includes a sensor (not shown) for sensing information related to a calorific value of the rectifying unit 110, the inverter 120, the coil 103, Time). In addition, the sensor may sense the temperature of the cooking zone or the temperature of the load 1000.

1B, the detailed circuit of the first current detecting unit 101 of the induction heating cooker according to the embodiments of the present invention will be described in more detail.

1B, the first current detector 101 may include at least one of a first current transformer 111 and a first AD converter 121. [

The first current transformer 111 may be connected to the first side of the coil, as shown in FIG. 1B. Referring to FIG. 1A, the first current transformer 111 may be connected to one side of the resonator 130. The first AD converter 121 converts the analog information applied from the first current transformer 111 into digital information and transmits the digital information to the controller 140.

Although not shown in FIG. 1B, the second current detector 102 may include at least one of a second current transformer (not shown) and a second AD converter (not shown).

2, an embodiment of a method of controlling an induction heating cooker according to the present invention will be described.

Referring to FIG. 2, the first current detector 101 may detect a first current flowing to the first side of the coil (S210).

1A, the first current detecting unit 101 is connected to the opposite side of the opposite ends of the coil 103 connected to the rectifying unit 110 or the inverter 120, so that the first current detecting unit 101 can detect the first current .

Specifically, the first current detecting unit 101 can detect the first current at predetermined time intervals. The first AD converter 121 of the first current detection unit 101 can convert the analog information of the detected first current into digital information. Thus, the first current detector 101 can transmit the digital information related to the first current to the controller 140. [

In addition, the controller 140 may determine whether the amount of change of the first current during a predetermined time interval is equal to or less than a first reference value (S220).

The controller 140 controls the input unit 160 such that the user input for detecting the information related to the state of the load 1000 is applied to the input unit 160, The amount of change can be calculated. Thereafter, the control unit 140 may calculate the amount of change of the first current every predetermined time interval, and compare the calculated amount of change with the first reference value.

For example, the control unit 140 may calculate the frequency change amount of the first current for a predetermined time. Also, the controller 140 may calculate the peak value change amount of the first current for a predetermined time. The first reference value may be set differently when the control unit 140 calculates the change amount of the frequency and when the change amount of the peak value is calculated.

In one embodiment, the first reference value may be set in proportion to a predetermined time interval. In another embodiment, the controller 140 may set the first reference value based on the user input applied to the input 160.

For example, the predetermined time interval may be changed by user input applied to the input unit 160. In another example, the control unit 140 controls the operation of the induction heating cooker 100 based on the information related to the amount of heat generation of at least one of the rectifying unit 110, the inverter 120, the resonator unit 130 and the coil 103 of the induction heating cooker 100 The preset time interval can be reset. In another example, the control unit 140 may reset the predetermined time interval based on the temperature of the cooking area sensed by the sensor or the temperature of the load 1000. [

The control unit 140 may determine that the load 1000 is in a boil state if the amount of change of the first current is less than the first reference value for a predetermined time at step S230.

Specifically, the control unit 140 may determine that the load 1000 is in a boiling state when the frequency change amount of the first current is less than the first reference value for a predetermined time. The control unit 140 may determine that the load 1000 is in a boiling state when the amount of change in the peak value of the first current is less than the first reference value for a predetermined time.

The control unit 140 periodically calculates the amount of change of the first current. If the rate of change of the first current is lower than the predetermined rate of change, the controller 140 can determine that the load 1000 is in a boil state.

The control unit 140 may control the inverter 120 to reduce or cut off the output of the inverter 120 or the coil 103 if it is determined that the load 1000 is in a boil state ).

Specifically, the control unit 140 may control the output of the inverter 120 to reduce or cut off the output of the coil 103 if it is determined that the load 1000 is in a boil state. For example, the control unit 140 may reduce the output of the coil 103 to a minimum level when it is determined that the load 1000 is in a boil state.

The control unit 140 may control the output unit 170 to output information related to the boiling state of the load 1000 when it is determined that the load 1000 is in a boil state at operation S250.

The control unit 140 may control the output unit 170 to output information related to a change in output of the coil 103 when it is determined that the load 1000 is in a boil state. That is, the control unit 140 can control the output unit 170 to output information related to the reduced amount of output when the output of the coil 103 is determined as the load 1000 is determined to be in the boiling state.

Specifically, the information related to the boiling state of the load 1000 may include information related to the elapsed time from the time when it is determined that boiling has occurred, and the temperature of the load 1000 determined to boil.

The information related to the output change of the coil 103 may include information related to the output level of the current coil 103 and whether the output of the coil 103 is blocked.

On the other hand, if it is determined that the load 1000 is in a boil state, the control unit 140 may control the output unit 170 to output warning information. For example, the warning information may be at least one of image, voice, and text information.

According to the configuration of the present invention as described above, it is possible to detect whether or not the load 1000 is in a boil state, that is, whether or not the liquid inside the container located above the coil 103 is saturated. Particularly, according to the configuration of the present invention, in detecting whether the load 1000 is in the boil state, since the first current flowing to the coil is used for the coil, the load 1000 Can be detected.

Although not shown in FIG. 2, when the load 140 is operating in an operation mode for determining whether the load 1000 is in a boil state, the controller 140 receives a second current from the second current detector 102 Information can be received. The control unit 140 may determine whether the load 1000 is in a boil state by considering the first and second currents together.

Specifically, the control unit 140 can determine that the load 1000 is in a boil state when the amount of change of the first current and the amount of change of the second current are both equal to or less than a specific reference value. However, the control unit 140 may compare different reference values with respect to the change amount of the first current and the change amount of the second current, and detect the information related to the state of the load 1000.

On the other hand, the control unit 140 may detect information related to the state of the load 1000 based on the amount of change of the second current.

In the following FIG. 3, another embodiment of the control method of the induction heating cooker according to the present invention will be described.

Referring to FIG. 3, the first current detector 101 may detect a first current flowing to the first side of the coil (S310).

The controller 140 may determine whether the detected first current is equal to or greater than the reference current value (S320).

Specifically, the control unit 140 can determine whether the detected first current is equal to or greater than the reference current value, based on the table information related to the reference current value.

In this case, the table information may be composed of a plurality of reference current values corresponding to the output frequency or the output level applied to the input unit 160.

That is, the controller 140 may determine whether the detected first current is equal to or greater than the reference current value according to the applied output frequency or output level.

In one embodiment, the controller 140 may use the average value of the first current for a predetermined time interval to determine whether the detected first current is greater than or equal to the reference current value.

If the detected first current is equal to or greater than the reference current value, the controller 140 may determine that the load 1000 exists on the coil 103 (S331).

The step S331 of determining whether or not the load 1000 exists is the same as the step S230 of determining whether the load 1000 is in a boil state or not, 2 < / RTI > current.

The control unit 140 may control the inverter to maintain the output of the coil 103 or the inverter 120 when it is determined that the load 1000 is present (S341).

The controller 140 may determine that the load 1000 does not exist on the coil 103 if the detected first current is less than the reference current value (S332).

The control unit 140 may control the inverter to shut off the output of the coil 103 or the inverter 120 when it is determined that the load 1000 does not exist (S342).

In addition, the control unit 140 may control the output unit 170 to output notification information indicating that the load 1000 does not exist. For example, the notification information may include image information or audio information.

In the following FIG. 4, another embodiment of the control method of the induction heating cooker according to the present invention will be described.

Referring to FIG. 4, the input unit 160 may receive a user input related to an output frequency or an output level (S410).

Specifically, the input unit 160 may receive a user input for adjusting the output of the coil or the inverter. For example, the input unit 160 may include a plurality of buttons corresponding to a plurality of numbers, respectively, and may receive user inputs applied to any one of the plurality of buttons.

Although not shown in FIG. 4, the input unit 160 may receive a user input to operate the operation mode of the induction heating cooker 100 for detecting the material of the load 1000.

Further, the second current detecting unit 102 can detect the second current flowing to the second side of the coil (S420). Also, the controller 140 may gradually increase the output of the inverter 120 based on the input output frequency (S430).

Specifically, the second current detection unit 102 can detect the second current at a plurality of points of time while the output of the inverter 120 or the coil increases. For example, the second current detecting section 102

In one embodiment, the second current detector 102 detects the second current when operating the operating mode of the induction cooker 100 to detect the material of the load 1000, And may transmit relevant information to the control unit 140.

Accordingly, the control unit 140 can calculate the amount of change of the second current according to the output change of the inverter 120 (S440). In addition, the controller 140 may determine whether the calculated amount of change of the second current is equal to or greater than a second reference value (S450).

Specifically, the control unit 140 can detect the information related to the material of the load by comparing the calculated change amount of the second current with the second reference value. For example, the control unit 140 can determine that the material of the load 1000 is aluminum when the calculated amount of change of the second current is equal to or greater than the second reference value.

The control unit 140 may control the inverter 120 to reduce or cut off the output of the coil 103 when the calculated amount of change of the second current is equal to or greater than the second reference value (S461).

That is, the controller 140 can control the inverter 120 to reduce or cut off the output of the coil 103 if it is determined that the material of the load 1000 is aluminum.

The control unit 140 may control the inverter to maintain the output of the inverter 120 when the calculated amount of change of the second current is equal to or less than the second reference value (S462).

According to the present invention, the output control is performed using the primary side current before passing through the rectifying circuit, so that accurate output control can be performed even when the external environment changes.

Further, the induction heating cooker according to the present invention can more accurately and quickly detect the condition of the load. In particular, the induction heating cooker according to the present invention can more accurately and quickly detect whether the load is in a boil state.

Further, the induction heating cooker according to the present invention achieves the effect of increasing the heat efficiency and reducing the power consumption by performing the output control according to the state of the detected load.

While the preferred embodiments of the present invention have been described with reference to the accompanying drawings, it is to be understood that the scope of the present invention should not be construed as being limited to the embodiments and / or drawings, do. It is to be expressly understood that improvements, changes and modifications apparent to those skilled in the art are also within the scope of the present invention.

Claims (15)

A coil for generating an induction magnetic field with respect to the load;
An inverter for transmitting electric power to the coil using an input power source;
A first detector connected to a first side of the coil, the first detector detecting a first current;
Detecting information related to the state of the load based on the detected first current,
And a controller for controlling the inverter based on the detected information. The method according to claim 1,
Wherein,
And determines that the load is in a boil when the amount of change of the first current is less than a first reference value for a predetermined time,
And controls the inverter to reduce the output of the coil based on the determination result. 3. The method of claim 2,
Further comprising an output unit for outputting information related to an operation state of the induction heating cooker,
Wherein,
And controls the output unit so that information related to the boiling state is output when it is determined that the load is in a boiling state. The method of claim 3,
Wherein,
And controls the output unit so that, when the output of the coil decreases, information related to the reduced output amount is output. The method according to claim 1,
Wherein,
Determining whether a load is present on the coil if the detected first current is greater than or equal to a reference current value,
And the output of the coil is cut off based on a result of the determination. The method according to claim 1,
Further comprising: a resonance unit generating a resonance voltage corresponding to an input voltage applied to the coil,
Wherein the first side of the coil is a side on which the resonance portion is provided at both ends of the coil. The method according to claim 1,
An input part for receiving the output frequency and
Further comprising a second detecting portion connected to a second side different from the first side and detecting a second current,
Wherein,
Changing an output of the coil based on the input output frequency,
Calculates a change amount of the second current according to an output change of the inverter,
Comparing the calculated change amount of the second current with a second reference value to detect information related to the material of the load,
And controls the inverter based on the detected information. 8. The method of claim 7,
Wherein,
Wherein the control unit reduces or blocks the output of the coil when the material of the load is determined to be aluminum based on the detected second current. 8. The method of claim 7,
Further comprising a rectifying section for rectifying the input power source,
And the second side is a side on which the rectifying part is provided at both ends of the coil. The method according to claim 1,
Further comprising an input part for inputting a user input so that an operation mode for detecting the state of the load is performed,
Wherein,
And controls the first current detection unit to detect the first current when the user input is applied. Detecting a first current at a first side of the coil;
Detecting information related to the state of the load based on the detected first current, and
And controlling the inverter based on the detected information. 12. The method of claim 11,
When the amount of change of the first current is equal to or less than a first reference value for a predetermined time,
Determining that the load is in a boiling state and
Further comprising the step of reducing the output of the coil. 13. The method of claim 12,
Further comprising the step of outputting information related to the boiling state when the load is determined to be in a boiling state. 12. The method of claim 11,
If the detected first current is equal to or greater than the reference current value,
Determining that there is a load on the coil; and
Further comprising the step of cutting off the output of the coil. 12. The method of claim 11,
Receiving an output frequency;
Detecting a second current at a second side different from the first side;
Changing an output of the coil based on the input frequency;
Calculating a change amount of the second current according to an output change of the coil;
Comparing the calculated change amount of the second current with a second reference value to detect information related to the material of the load;
Further comprising the step of controlling the inverter based on the detected material of the load.

Images