KR20160040079A - Induction heat cooking apparatus and method for driving the same - Google Patents

Abstract

An induction heat cooking apparatus according to the present invention includes a rectifying part which rectifies an input voltage and outputs a DC voltage; switching elements which switch the DC voltage outputted by the rectifying part; heating coils which heat a cooking container by the control of the switching elements; and a control part which controls the switching elements to simultaneously drive at least two heating coils connected in parallel among the heating coils. So, minimum switching elements can be used to control the induction heat cooking apparatus.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention 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 including a plurality of switching elements and a plurality of resonance circuits and a driving method thereof.

Generally, an induction heating cooker causes a high frequency current to flow through a working coil or a heating coil, and when a strong magnetic force line generated by the induction heating cooker passes through a cooking vessel, eddy current flows and the container itself is heated And performs the cooking function by the method described above.

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 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.

When two heating coils are provided in the induction heating cooker, two inverters formed of four switching elements are required to operate the two heating coils.

1 is a view for explaining an induction heating cooker according to the prior art.

1 shows an induction heating cooker including two inverters and two heating coils.

1, the induction heating cooker includes a rectifying section 10, a first inverter 20, a second inverter 30, a first heating coil 40, a second heating coil 50, a first resonance capacitor (60) and a second resonant capacitor (70).

The first and second inverters 20 and 30 have first and second heating coils 40 and 50 driven by the output voltage of the switching device, Connected to the connection point of the serially connected switching elements. The other side of the first and second heating coils 40 and 50 is connected to the resonant capacitors 60 and 70.

The driving of the switching element is performed by a driving part, and the switching elements are alternately operated by the switching time outputted from the driving part to apply a high frequency voltage to the heating coil. Since the on / off time of the switching element to be applied to the driving unit rotor is controlled to be gradually compensated, the voltage supplied to the heating coil changes from a low voltage to a high voltage.

However, in such an induction heating cooker, two inverter circuits including four switching elements must be included in order to operate two heating coils, thereby increasing the product volume and raising the product price .

In addition, when the number of heating coils increases to three or more, there is a problem that a large number of switching elements are required depending on the number of heating coils.

An embodiment of the present invention is to provide an electromagnetic induction heating cooker capable of controlling an electromagnetic induction heating cooker equipped with a plurality of heating coils with a minimum number of switching elements and a control method thereof.

An embodiment of the present invention is to provide an electromagnetic induction heating cooker capable of driving a plurality of heating coils together with a minimum number of switching elements in an electromagnetic induction heating cooker provided with a plurality of heating coils and a control method thereof.

An electromagnetic induction heating cooker according to the present invention includes a plurality of switching elements; A plurality of heating coils heating the cooking vessel according to the control of the plurality of switching elements; And a controller for controlling the plurality of switching elements to simultaneously drive at least two heating coils connected in parallel among the plurality of heating coils.

The embodiments of the present invention can provide an electromagnetic induction heating cooker and a control method thereof that can control an electromagnetic induction heating cooker provided with a plurality of heating coils with a minimum number of switching elements.

The embodiments of the present invention can provide an electromagnetic induction heating cooker and a control method thereof that can drive a plurality of heating coils together with a minimum number of switching elements in an electromagnetic induction heating cooker provided with a plurality of heating coils.

1 is a view for explaining an induction heating cooker according to the prior art.
2 is a view for explaining a structure of an electromagnetic induction heating cooker according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a control unit for controlling a switching device in an embodiment of the present invention. FIG. 4 is a diagram illustrating a gate driver for operating a switching device in an embodiment of the present invention. Figure 2 illustrates a switching mode power supply in an example.
Figs. 6 and 7 are views showing signals for driving respective heating coils in the embodiment of the present invention. Fig.
8 is a diagram showing signals for driving a plurality of heating coils in a time division manner in the embodiment of the present invention.
9 is a diagram showing signals for driving a plurality of heating coils in a duty control manner in the embodiment of the present invention.
10 is a diagram showing signals for driving two heating coils in a parallel driving manner in the embodiment of the present invention.
11 is a diagram showing signals for driving three heating coils in a parallel driving manner in the embodiment of the present invention.
12 is a view for explaining a structure of an electromagnetic induction heating cooker according to another embodiment of the present invention.
FIG. 13 is a view showing a control unit for controlling a switching device in another embodiment of the present invention, FIG. 14 is a view showing a gate driver for operating a switching device in the embodiment of the present invention, and FIG. Mode power supply in an embodiment.
Figs. 16 and 17 are views showing signals for driving respective heating coils in another embodiment of the present invention. Fig.
18 is a diagram showing signals for driving a plurality of heating coils in a time division manner in another embodiment of the present invention.
19 is a diagram showing signals for driving a plurality of heating coils in a duty control manner in another embodiment of the present invention.
20 is a diagram showing signals for driving two heating coils in a parallel driving manner in another embodiment of the present invention.
21 is a diagram showing signals for driving three heating coils in a parallel driving manner in another embodiment of the present invention.
22 is a view for explaining the structure of an electromagnetic induction heating cooker according to another embodiment of the present invention.
FIG. 23 is a view illustrating a control unit for controlling a switching device according to another embodiment of the present invention, FIG. 24 is a view illustrating a gate driver for operating a switching device according to another embodiment of the present invention, and FIG. 25 is a diagram illustrating a switching mode power supply according to another embodiment of the present invention.
Figs. 26 and 27 are diagrams showing signals for driving respective heating coils in another embodiment of the present invention. Fig.
28 is a diagram showing signals for driving a plurality of heating coils in a time division manner in another embodiment of the present invention.
29 is a diagram showing signals for driving a plurality of heating coils in a duty control manner in another embodiment of the present invention.
30 is a diagram showing signals for driving two heating coils in a parallel driving manner in another embodiment of the present invention.

Hereinafter, an electromagnetic induction heating cooker and a control method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view for explaining a structure of an electromagnetic induction heating cooker according to an embodiment of the present invention.

Referring to FIG. 2, the electromagnetic induction heating cooker includes a rectifying unit 110 to which commercial AC power is input from the outside and rectifies the AC power to a DC power source, a rectifying unit 110 to which both ends of the rectifying unit 110 and the sub- A second switching element 122, a third switching element 123, a fourth switching element 124, a fifth switching element 125, and a second switching element 125, which are connected in series to each other and are switched according to a control signal, A first resonant capacitor 161 having one end connected to a contact point between the first switching device 121 and the second switching device 122 and connected to one end and the other end of the rectifying part 110, One end of the rectifying part 110 is connected to the contact between the second switching device 122 and the third switching device 123 and the other end of the rectifying part 110 is connected to the first heating coil 141, And the other end between the third resonant capacitor 163 and the fourth resonant capacitor 164 connected to the other end And a fifth resonant capacitor 165 having one end connected to a contact point between the third switching device 123 and the fourth switching device 124 and connected to the other end of the rectifying part 110, A third heating coil 143 having one end connected to a contact point between the fourth switching device 124 and the fifth switching device 125 and connected to the other end of the rectifying part 110; And a fourth heating coil 144 whose other end is connected between the resonant capacitors 166.

Further, although not shown, a control unit for controlling the switching operation of the switching elements 121, 122, 123, 124, and 125 is further included.

Although four heating coils are illustrated in the embodiment, the number of the heating coils may be three or more.

In the embodiment, when the number of the heating coils is N, N + 1 switching elements may be provided, and it is possible to drive the heating coils while minimizing the number of switching elements.

The first switching device 121 has one end connected to the positive power supply terminal and the other end connected to the second switching device 122. The second switching element 122 has one end connected to the first switching element 122 and the other end connected to the third switching element 123. The third switching device 123 has one end connected to the second switching device 122 and the other end connected to the fourth switching device 124. The fourth switching device 124 has one end connected to the third switching device 123 and the other end connected to the fifth switching device 125. The fifth switching device 125 has one end connected to the fourth switching device 124 and the other end connected to a negative power terminal.

The smoothing capacitor 190 may further include a smoothing capacitor 190 connected to both ends of the rectifying unit 110. The smoothing capacitor 190 reduces the ripple of the DC voltage output from the rectifying unit 110. [

Although the first heating coil 141 is connected between the first resonant capacitor 161 and the second resonant capacitor 162 in the embodiment, the first resonant capacitor 161 may not be provided have.

In the embodiment, the second heating coil 142 is connected between the third resonant capacitor 163 and the fourth resonant capacitor 164, but the third resonant capacitor 163 is not provided .

In the embodiment, the third heating coil 143 is connected to the fifth resonant capacitor 165, but in a manner similar to the first heating coil 141 or the second heating coil 142, It is also possible to connect between the additional resonance capacitor (not shown) and the fifth resonance capacitor 165.

Also, in the embodiment, it is illustrated that the fourth heating coil 144 is connected to the sixth resonant capacitor 166, but in a manner similar to the first heating coil 141 or the second heating coil 142, It is also possible to connect between the sixth resonant capacitor 166 and an additional resonant capacitor not shown.

An anti-parallel diode may be connected to the switching elements 121, 122, 123, 124, and 125, and an auxiliary resonance capacitor connected in parallel to the anti-parallel diode may be connected to minimize the switching loss of the switching elements.

FIG. 3 is a view illustrating a control unit for controlling a switching device according to an embodiment of the present invention. FIG. 4 is a diagram illustrating a gate driver for operating a switching device according to an embodiment of the present invention. Mode power supply according to an embodiment of the present invention.

3, 4 and 5, the controller 180 receives inputs G1, G2, G3, G4 and G5 of the first, second, third, fourth and fifth gate drivers 191, 192, 193, 194 and 195 for driving the switching elements 121, G5 and GD5 of the gate drivers 191, 192, 193, 191 and 195 are connected to the gates of the switching elements 121, 122, 123, 124 and 125. The gates G1, GD2, GD3, GD4 and GD5 of the gate drivers 191, As shown in FIG. 5, independent power sources of the multiple output SMPS are used as the power supplies to the gate drivers 191, 192, 193, 194, and 195.

Therefore, a signal of the controller 180 is applied to the gate drivers 191, 192, 193, 194, and 195 to control the respective switching elements 121, 122, 123, 124, and 125 by driving the semiconductor switches.

The current transformer 170 may be provided between the ground of the switching elements 121, 122, 123, 124 and 125 connected in series and the ground of the first, second, third and fourth heating coils 141, 142, 143 and 144, The control unit 180 measures the current flowing through the first, second, third and fourth heating coils 141, 142, 143 and 144 so that the current value is inputted to the controller 180 through the analog-to-digital converter (ADC) do. The controller 180 controls the switching elements 121, 122, 123, 124, and 125 based on the current value.

Figs. 6 and 7 are views showing signals for driving respective heating coils in the embodiment of the present invention. Fig.

As shown in FIGS. 6 and 7, the controller 180 controls the currents flowing through the first, second, third, and fourth heating coils 141, 142, 143, and 144 by controlling the switching elements 121, 122, 123,

The control unit 180 causes the first switching device 121 to be in a closed state for half a period of resonance when the first heating coil 141 is to be driven, 122, 123, 124, 125 to be in the open state. Then, the first switching device 121 is brought into the open state and the second, third, fourth, and fifth switching devices 122, 123, 124, and 125 are controlled to be in the closed state during the half period of the remaining resonance.

The input voltage is applied to the first heating coil 141 and the first and second resonant capacitors 161 and 162 during the half period of the resonance through the above operation, The current rises. The input voltage is applied to the first heating coil 141 and the first and second resonant capacitors 161 and 162 during the half period of the rest of the resonance, Direction current is increased.

As the operation is repeated, the eddy current is induced in the cooking container placed on the first heating coil 141, so that the electromagnetic induction heating cooker operates.

7, when the controller 180 desires to drive the second heating coil 142, the first switching device 121 and the second switching device 122 are closed for half a period of the resonance, State, and controls the third, fourth, and fifth switching elements 123, 124, and 125 to be in an open state. The first switching device 121 and the second switching device 122 are brought into the open state and the third, fourth, and fifth switching devices 123, 124, and 125 are controlled to be in the closed state during the half period of the remaining resonance .

During the half period of the resonance through the above operation, the input voltage is applied to the second heating coil 142 and the third and fourth resonant capacitors 163 and 164 so that resonance starts and the second heating coil 142 The current rises. During the half period of the remaining resonance, the input voltage is applied to the second heating coil 142 and the third and fourth resonant capacitors 163 and 164 in reverse, thereby starting resonance, Direction current is increased.

As the operation is repeated, the eddy current is induced in the cooking container placed on the second heating coil 142, and the electromagnetic induction heating cooker is operated.

Although not shown, when the third heating coil 143 is to be driven, the first, second and third switching devices 121, 122 and 123 are brought into a closed state during a half period of resonance, (124, 125) to be in the open state. During the half period of the remaining resonance, the first, second and third switching devices 121, 122 and 123 are brought into the open state and the fourth and fifth switching devices 124 and 125 are controlled to be in the closed state.

When the fourth heating coil 144 is to be driven, the first, second, third, and fourth switching devices 121, 122, 123, and 124 are closed for half a period of the resonance, and the fifth switching devices 125 To be in an open state. During the half period of the remaining resonance, the first, second, third, and fourth switching devices 121, 122, 123, and 124 are brought into the open state and the fifth switching devices 125 are controlled to be in the closed state.

In this way, the control unit 180 can drive the heating coil by controlling the switching elements.

As described above, the electromagnetic induction heating cooker according to the embodiment includes a plurality of heating coils and a minimum number of switching elements for driving the plurality of heating coils, thereby reducing the size of the electromagnetic induction heating cooker and reducing the production cost.

8 is a diagram showing signals for driving a plurality of heating coils in a time division manner in the embodiment of the present invention.

8, when the first, second, and third heating coils 141, 142, and 143 are to be driven, the controller 180 first drives the first heating coil 141, and then the second heating coils 142 And finally drives the third heating coil 143. In this case, By repeating this cycle, all of the first, second, and third heating coils 141, 142, and 143 can be driven.

First, when the control unit 180 desires to drive the first heating coil 141, the first switching device 121 is closed for half a period of resonance, and the second, third, Thereby controlling the switching elements 122, 123, 124, and 125 to be in an open state. Then, the first switching device 121 is brought into the open state and the second, third, fourth, and fifth switching devices 122, 123, 124, and 125 are controlled to be in the closed state during the half period of the remaining resonance.

The input voltage is applied to the first heating coil 141 and the first and second resonant capacitors 161 and 162 during the half period of the resonance through the above operation, The current rises. The input voltage is applied to the first heating coil 141 and the first and second resonant capacitors 161 and 162 during the half period of the rest of the resonance, Direction current is increased.

As the operation is repeated, the eddy current is induced in the cooking container placed on the first heating coil 141, so that the electromagnetic induction heating cooker operates.

Next, when the controller 180 desires to drive the second heating coil 142, the first switching device 121 and the second switching device 122 are brought into the closed state during the half period of the resonance, And controls the third, fourth, and fifth switching elements 123, 124, and 125 to be in an open state. The first switching device 121 and the second switching device 122 are brought into the open state and the third, fourth, and fifth switching devices 123, 124, and 125 are controlled to be in the closed state during the half period of the remaining resonance .

During the half period of the resonance through the above operation, the input voltage is applied to the second heating coil 142 and the third and fourth resonant capacitors 163 and 164 so that resonance starts and the second heating coil 142 The current rises. During the half period of the remaining resonance, the input voltage is applied to the second heating coil 142 and the third and fourth resonant capacitors 163 and 164 in reverse, thereby starting resonance, Direction current is increased.

As the operation is repeated, the eddy current is induced in the cooking container placed on the second heating coil 142, and the electromagnetic induction heating cooker is operated.

Similarly, when the third heating coil 143 is to be driven, the first, second and third switching devices 121, 122 and 123 are brought into a closed state for half a period of resonance, and the fourth and fifth switching devices 124 and 125 To be in an open state. During the half period of the remaining resonance, the first, second and third switching devices 121, 122 and 123 are brought into the open state and the fourth and fifth switching devices 124 and 125 are controlled to be in the closed state.

When all of the first, second, and third heating coils 141, 142, and 143 are driven in the above-described manner, all of the first, second, and third heating coils 141, 142, and 143 can be driven by driving again from the first heating coils 141 .

9 is a diagram showing signals for driving a plurality of heating coils in a duty control manner in the embodiment of the present invention.

9, when the controller 180 drives all of the first, second and third heating coils 141, 142 and 143, the use of the first, second and third heating coils 141, 142, 143 (for example, All of the first, second and third heating coils 141, 142 and 143 can be driven by the duty control in accordance with the cooking capacity of the large capacity cooking vessel or the small capacity cooking vessel, Reduction can be compensated. Each of the first, second, and third heating coils 141, 142, and 143 may vary in power through frequency control. If the output range is limited due to frequency limitation, the duty can be compensated through such duty control.

9, the first heating coil 141 repeats four resonance cycles, the second heating coil 142 repeats two resonance cycles, and the third heating coil 143 repeats the resonance cycle four times, Repeat one resonance cycle.

Accordingly, the first, second, and third heating coils 141, 142, and 143 may have different powers and be driven together according to their use or needs of the user.

10 is a diagram showing signals for driving two heating coils in a parallel driving manner in the embodiment of the present invention.

10, when the control unit 180 simultaneously drives the third and fourth heating coils 143 and 144, the fourth switching device 124 is closed, and during the half period of the resonance, 1,2,3 switching elements 121, 122 and 123 to be in the closed state and the fifth switching element 125 to be in the open state. Then, the first, second and third switching elements 121, 122 and 123 are brought into the open state and the fifth switching element 125 is controlled in the closed state during the half period of the remaining resonance.

Since the fourth switching device 124 is in the closed state, the third heating coil 143 and the fourth heating coil 144 are connected in parallel.

Accordingly, during the half period of the resonance through the above operation, the input voltage is applied to the third and fourth heating coils 143 and 144 and the fifth and sixth resonant capacitors 165 and 166, thereby starting resonance, The currents in the four heating coils 143 and 144 rise. The input voltage is applied to the third and fourth heating coils 143 and 144 and the fifth and sixth resonant capacitors 165 and 166 during a half period of the other resonance, The current in the opposite direction to the currents 143 and 144 rises.

In this case, the third and fourth heating coils 143 and 144 operated by the parallel driving method may have the same capacity. In the embodiment, the third and fourth heating coils 143 and 144 each have a capacity of 2.4 kW .

In addition, the third and fourth heating coils 143 and 144 operated by the parallel driving method are preferably formed to have a smaller capacity than the first and second heating coils 141 and 142, respectively.

As the operation is repeated, the eddy current is induced in the cooking vessel placed on the third and fourth heating coils 143 and 144, so that the electromagnetic induction heating cooker operates.

11 is a diagram showing signals for driving three heating coils in a parallel driving manner in the embodiment of the present invention.

11, when the control unit 180 simultaneously drives the second, third, and fourth heating coils 142, 143, and 144, the third and fourth switching devices 123 and 124 are brought into a closed state, And controls the first and second switching devices 121 and 122 to be in the closed state and the fifth switching device 125 to be in the open state during the half period. Then, the first and second switching elements 121 and 122 are opened and the fifth switching element 125 is closed during a half period of the remaining resonance.

Since the third and fourth switching devices 123 and 124 are in the closed state, the second heating coil 142, the third heating coil 143, and the fourth heating coil 144 are connected in parallel.

Accordingly, during the half period of the resonance through the above operation, the input voltages are applied to the second, third, and fourth heating coils 142, 143, 144 and the third, fourth, fifth, and sixth resonant capacitors 163, 164, 165, 166, The currents in the second, third, and fourth heating coils 142, 143, and 144 rise. The input voltage is applied to the second, third, and fourth heating coils 142, 143, 144 and the third, fourth, fifth, and sixth resonant capacitors 163, 164, 165, 166 during a half period of the other resonance, Second, third, and fourth heating coils 142, 143, and 144.

In this case, the second, third, and fourth heating coils 142, 143, and 144 operated by the parallel driving method may have the same capacity. In the embodiment, the third and fourth heating coils 143 and 144 have a capacity of 2.4 kW And the second heating coil 142 in Fig. 2 is also assumed to have a capacity of 2.4 kW.

In addition, the second, third, and fourth heating coils 142, 143, and 144 operated by the parallel driving method are preferably formed to have a smaller capacity than the first heating coils 141, respectively.

As the operation is repeated, the eddy current is induced in the cooking container placed on the second, third, and fourth heating coils 142, 143, and 144 to operate the electromagnetic induction heating cooker.

12 to 21 are views for explaining an electromagnetic induction heating cooker and a control method thereof according to another embodiment of the present invention.

12 is a view for explaining a structure of an electromagnetic induction heating cooker according to another embodiment of the present invention.

Referring to FIG. 12, the electromagnetic induction heating cooker includes a rectifying part 210 for receiving a commercial AC power from the outside and rectifying the AC power to a DC power source, a rectifying part 210 for rectifying the AC power to both ends A second switching element 222, a third switching element 223 and a fourth switching element 224 which are connected in series to each other and are switched in accordance with a control signal, The other end is connected between the first resonance capacitor 261 and the second resonance capacitor 262, one end of which is connected to the contact point between the first switching device 221 and the second switching device 222 and is connected to one end and the other end of the rectifying part 210, A third resonant capacitor 263 having one end connected to a contact point between the second switching device 222 and the third switching device 223 and connected to the other end of the rectifying part 210, A second heating coil 242 connected between the other end of the third switching device 223, A fourth one end is connected to a contact point between the switching device 224 and includes a third heating coil 243 which is connected between the other end of the fourth resonance capacitor 264 is connected to the other end of the holding portion 210. The

Further, although not shown, a control unit for controlling the switching operation of the switching elements 221, 222, 223, and 224 is further included. In the embodiment, three heating coils are provided.

In the embodiment, when the number of the heating coils is N, N + 1 switching elements may be provided, and it is possible to drive the heating coils while minimizing the number of switching elements.

The first switching device 221 has one end connected to the positive power supply terminal and the other end connected to the second switching device 222. The second switching device 222 has one end connected to the first switching device 221 and the other end connected to the third switching device 223. The third switching device 223 has one end connected to the second switching device 222 and the other end connected to the fourth switching device 224. The fourth switching device 224 has one end connected to the third switching device 223 and the other end connected to a negative power terminal.

The smoothing capacitor 290 may further include a smoothing capacitor 290 connected to both ends of the rectifying unit 210. The smoothing capacitor 290 may reduce the ripple of the DC voltage output from the rectifying unit 210. [

Although the first heating coil 241 is connected between the first resonant capacitor 261 and the second resonant capacitor 262 in the embodiment, the first resonant capacitor 261 may not be provided have.

Further, in the embodiment, the second heating coil 242 is connected to the third resonant capacitor 263, but in a manner similar to the first heating coil 241, an additional resonant capacitor (not shown) 3 resonator capacitor 263. In this case,

In the embodiment, the third heating coil 243 is connected to the fourth resonant capacitor 264, but in a manner similar to the first heating coil 241, additional resonant capacitors (not shown) 4 resonant capacitor 264. [0060]

An anti-parallel diode may be connected to the switching elements 221, 222, 223, and 224, and an auxiliary resonance capacitor connected in parallel to the anti-parallel diode may be connected to minimize the switching loss of the switching elements.

FIG. 13 is a view illustrating a control unit for controlling a switching device according to another embodiment of the present invention, FIG. 14 is a view illustrating a gate driver for operating a switching device according to another embodiment of the present invention, and FIG. FIG. 4 is a diagram illustrating a switching mode power supply according to another embodiment of the present invention. FIG.

13 to 15, the controller 280 is connected to the inputs G1, G2, G3 and G4 of the first, second, third and fourth gate drivers 291, 292, 293 and 294 for driving the switching elements 221, 222, And the outputs GD1, GD2, GD3 and GD4 of the gate drivers 291, 292, 293 and 294 are connected to the gate terminals of the switching elements 221, 222, 223 and 224. As shown in FIG. 15, the power source supplied to the gate drivers 291, 292, 293 and 294 is an independent power source of the multiple output SMPS.

Therefore, a signal from the controller 280 is applied to the gate drivers 291, 292, 293, and 294 to drive the semiconductor switches to control the respective switching elements 221, 222, 223, and 224.

A current transformer 270 may be provided between the ground of the switching elements 221, 222, 223 and 224 connected in series and the ground of the first, second and third heating coils 241, 242 and 243, The currents flowing through the first, second, and third heating coils 241, 242, and 243 are measured and input to the controller 280 through the analog-to-digital converter (ADC) The control unit 280 controls the switching devices 221, 222, 223, and 224 based on the current value.

Figs. 16 and 17 are views showing signals for driving respective heating coils in another embodiment of the present invention. Fig.

As shown in FIGS. 16 and 17, the controller 280 controls the currents flowing through the first, second, and third heating coils 241, 242, and 243 by controlling the switching elements 221, 222, 223, and 224.

When the control unit 280 intends to drive the first heating coil 241, the first switching device 221 is closed for half a period of resonance, and the second, third, and fourth switching devices 222, 223, and 224 are controlled to be in an open state. Then, the first switching device 221 is brought into the open state and the second, third, and fourth switching devices 222, 223, and 224 are controlled to be in the closed state during the half period of the remaining resonance.

During the half period of the resonance through the above operation, an input voltage is applied to the first heating coil 241 and the first and second resonance capacitors 261 and 262, thereby starting resonance, The current rises. The input voltage is applied to the first heating coil 241 and the first and second resonant capacitors 261 and 262 in a half period of the other resonance, and resonance starts to be applied to the first heating coil 241 and the first heating coil 241 Direction current is increased.

As the operation is repeated, the eddy current is induced in the cooking container placed on the first heating coil 241, so that the electromagnetic induction heating cooker operates.

17, when the control unit 280 intends to drive the second heating coil 242, the first switching device 221 and the second switching device 222 are closed for half a period of resonance, State, and controls the third and fourth switching devices 223 and 224 to be in an open state. The first switching device 221 and the second switching device 222 are brought into the open state and the third and fourth switching devices 223 and 224 are controlled to be in the closed state during the half period of the remaining resonance.

Through the above operation, an input voltage is applied to the second heating coil 242 and the third resonant capacitor 263 during the half period of the resonance, so that resonance starts and the current of the second heating coil 242 . An input voltage is applied to the second heating coil 242 and the third resonant capacitor 263 in reverse during a half period of the other resonance so as to start resonance so that the current in the opposite direction to the second heating coil 242 .

As the operation is repeated, the eddy current is induced in the cooking container placed on the second heating coil 242, so that the electromagnetic induction heating cooker operates.

Although it is not shown, when the third heating coil 243 is to be driven, the first, second and third switching devices 221, 222 and 223 are brought into a closed state during a half of the resonance period, and the fourth switching devices 224 Is in the open state. The first, second, and third switching devices 221, 222, and 223 are brought into the open state and the fourth switching devices 224 are controlled to be in the closed state during the half period of the remaining resonance.

Thus, the control unit 280 can drive the heating coil by controlling the switching elements.

As described above, the electromagnetic induction heating cooker according to the embodiment includes a plurality of heating coils and a minimum number of switching elements for driving the plurality of heating coils, thereby reducing the size of the electromagnetic induction heating cooker and reducing the production cost.

18 is a diagram showing signals for driving a plurality of heating coils in a time division manner in another embodiment of the present invention.

18, when the first, second, and third heating coils 241, 242, 243 are to be driven, the controller 280 first drives the first heating coil 241, and then the second heating coils 242 And drives the third heating coil 243 finally. By repeating this cycle, all of the first, second, and third heating coils 241, 242, and 243 can be driven.

First, when the control unit 280 attempts to drive the first heating coil 241, the first switching device 221 is closed for half a period of resonance, and the second, third, 222, 224 and 224 to be in the open state. Then, the first switching device 221 is brought into the open state and the second, third, and fourth switching devices 222, 223, and 224 are controlled to be in the closed state during the half period of the remaining resonance.

During the half period of the resonance through the above operation, an input voltage is applied to the first heating coil 241 and the first and second resonance capacitors 261 and 262, thereby starting resonance, The current rises. The input voltage is applied to the first heating coil 241 and the first and second resonant capacitors 261 and 262 in a half period of the other resonance, and resonance starts to be applied to the first heating coil 241 and the first heating coil 241 Direction current is increased.

As the operation is repeated, the eddy current is induced in the cooking container placed on the first heating coil 241, so that the electromagnetic induction heating cooker operates.

Next, when the control unit 280 intends to drive the second heating coil 242, the first switching device 221 and the second switching device 222 are brought into a closed state during half the resonance period, And controls the third and fourth switching elements 223 and 224 to be in an open state. The first switching device 221 and the second switching device 222 are brought into the open state and the third and fourth switching devices 223 and 224 are controlled to be in the closed state during the half period of the remaining resonance.

Through the above operation, an input voltage is applied to the second heating coil 242 and the third resonant capacitor 263 during the half period of the resonance, so that resonance starts and the current of the second heating coil 242 . An input voltage is applied to the second heating coil 242 and the third resonant capacitor 263 in reverse during a half period of the other resonance so as to start resonance so that the current in the opposite direction to the second heating coil 242 .

As the operation is repeated, the eddy current is induced in the cooking container placed on the second heating coil 242, so that the electromagnetic induction heating cooker operates.

Similarly, when the third heating coil 243 is to be driven, the first, second, and third switching devices 221, 222, and 223 are brought into a closed state for half a period of resonance, and the fourth switching devices 224 are opened . The first, second, and third switching devices 221, 222, and 223 are brought into the open state and the fourth switching devices 224 are controlled to be in the closed state during the half period of the remaining resonance.

When all of the first, second, and third heating coils 241, 242, and 243 are driven in the above-described manner, all of the first, second, and third heating coils 241, 242, and 243 can be driven by driving again from the first heating coil 241 .

19 is a diagram showing signals for driving a plurality of heating coils in a duty control manner in another embodiment of the present invention.

19, when the controller 280 drives all of the first, second and third heating coils 241, 242 and 243, the use of the first, second and third heating coils 241, 242, 243 (for example, All of the first, second and third heating coils 241, 242 and 243 can be driven by duty control in accordance with a large-capacity cooking vessel or a small-capacity cooking vessel, Reduction can be compensated. Each of the first, second, and third heating coils 241, 242, and 243 is power-controlled through frequency control. If the output range is limited due to the frequency limitation, the duty can be compensated through the duty control.

19, the first heating coil 241 repeats four resonance cycles, the second heating coil 242 repeats two resonance cycles, and the third heating coil 243 repeats the resonance cycle four times, Repeat one resonance cycle.

Accordingly, the first, second, and third heating coils 241, 242, and 243 may have different powers and be driven together according to their use or needs of the user.

20 is a diagram showing signals for driving two heating coils in a parallel driving manner in another embodiment of the present invention.

Referring to FIG. 20, when the control unit 280 simultaneously drives the second and third heating coils 242 and 243, the third switching device 223 is brought into a closed state. During the half period of the resonance, 1,2 switching elements 221 and 222 to be in the closed state and the fourth switching element 224 to be in the open state. Then, the first and second switching devices 221 and 222 are brought into the open state and the fourth switching device 224 is controlled in the closed state during the half period of the remaining resonance.

Since the third switching device 223 is in a closed state, the second heating coil 242 and the third heating coil 243 are connected in parallel.

Accordingly, during the half period of the resonance through the above-described operation, the input voltage is applied to the second and third heating coils 242 and 243 and the third and fourth resonant capacitors 263 and 264, thereby starting resonance, The currents in the three heating coils 242 and 243 rise. The input voltage is applied to the second and third heating coils 242 and 243 and the third and fourth resonant capacitors 263 and 264 during the half period of the other resonance, The currents in the opposite direction to the currents 242 and 243 rise.

At this time, the second and third heating coils 242 and 243 operated by the parallel driving method can be formed with the same capacity. In the embodiment, the second and third heating coils 242 and 243 have a capacity of 1.8 kW .

In addition, the second and third heating coils 242 and 243 operated by the parallel driving method are preferably formed to have a smaller capacity than the first heating coils 241, respectively.

As the operation is repeated, the eddy current is induced in the cooking vessel placed on the second and third heating coils 242 and 243, and the electromagnetic induction heating cooker is operated.

21 is a diagram showing signals for driving three heating coils in a parallel driving manner in another embodiment of the present invention.

21, when the control unit 280 simultaneously drives the first, second, and third heating coils 241, 242, and 243, the second and third switching devices 222 and 223 are brought into a closed state, And controls the first switching devices 221 to be in the closed state and the fourth switching device 224 to be in the open state during the half period. Then, the first switching devices 221 and the fourth switching devices 224 are controlled to be in the open state and the closed state, respectively, during the half period of the remaining resonance.

The first heating coil 241, the second heating coil 242, and the third heating coil 243 are connected in parallel to each other in the state where the first, second, third, and fourth switching devices 222, do.

Accordingly, during the half period of the resonance through the above operation, the input voltages are applied to the first, second, and third heating coils 241, 242, 243 and the first, second, third, and fourth resonance capacitors 261, 262, 263, 264, The currents in the first, second, and third heating coils 241, 242, and 243 are increased. The input voltage is applied to the first, second, and third heating coils 241, 242, 243 and the first, second, third, and fourth resonance capacitors 261, 262, 263, 264 in reverse during half of the remaining resonance, The current in the opposite direction rises in the first, second, and third heating coils 241, 242, and 243.

In this case, the first, second, and third heating coils 241, 242, and 243 operated by the parallel driving method may have the same capacity. In the embodiment, the second and third heating coils 242 and 243 have a capacity of 1.8 kW And that the first heating coil 241 in Fig. 12 also has a capacity of 1.8 kW.

As the operation is repeated, the eddy current is induced in the cooking vessel placed on the first, second, and third heating coils 241, 242, and 243 so that the electromagnetic induction heating cooker operates.

22 to 30 are views for explaining an electromagnetic induction heating cooker and a control method thereof according to still another embodiment of the present invention.

22 is a view for explaining the structure of an electromagnetic induction heating cooker according to another embodiment of the present invention.

Referring to FIG. 22, the electromagnetic induction heating cooker includes a rectifying unit 310 for receiving a commercial AC power from the outside and for rectifying the AC power to a DC power source, a rectifying unit 310 for rectifying the AC power to both ends A second switching device 322 and a third switching device 323 which are connected in series to each other and are switched in accordance with a control signal and the first switching device 321 and the second switching device 322, A first heating coil 341 whose one end is connected to a contact between the first resonance capacitor 322 and the other end connected between the first resonance capacitor 361 and the second resonance capacitor 362 connected to one end and the other end of the rectification part 310, And a third resonant capacitor 363 having one end connected to the contact point between the second switching device 322 and the third switching device 323 and the other end connected to the other end of the rectifying unit 310, A heating coil 342 is included.

Further, although not shown, a control unit for controlling the switching operation of the switching elements 321, 322, and 323 is further included. In the embodiment, three heating coils are provided.

In the embodiment, when the number of the heating coils is N, N + 1 switching elements may be provided, and it is possible to drive the heating coils while minimizing the number of switching elements.

The first switching device 321 has one end connected to the positive power supply terminal and the other end connected to the second switching device 322. The second switching device 322 has one end connected to the first switching device 321 and the other end connected to the third switching device 323. The third switching device 323 has one end connected to the second switching device 322 and the other end connected to the negative power terminal.

The smoothing capacitor 390 may further include a smoothing capacitor 390 connected to both ends of the rectifying unit 310. The smoothing capacitor 390 may reduce the ripple of the DC voltage output from the rectifying unit 310. [

Although the first heating coil 341 is connected between the first resonant capacitor 361 and the second resonant capacitor 362 in the embodiment, the first resonant capacitor 361 may not be provided have.

Also, in the embodiment, it is illustrated that the second heating coil 342 is connected to the third resonant capacitor 363. However, in a manner similar to the first heating coil 341, an additional resonant capacitor (not shown) 3 resonator capacitor 363. The resonant capacitor 363 may be connected to the ground.

An anti-parallel diode may be connected to the switching elements 321, 322, and 323, and an auxiliary resonance capacitor connected in parallel to the anti-parallel diode may be connected to minimize the switching loss of the switching elements.

FIG. 23 is a view illustrating a control unit for controlling a switching device according to another embodiment of the present invention, FIG. 24 is a view illustrating a gate driver for operating a switching device according to another embodiment of the present invention, and FIG. 25 is a diagram illustrating a switching mode power supply according to another embodiment of the present invention.

23 to 25, the controller 380 is connected to the inputs G1, G2 and G3 of the first, second and third gate drivers 391, 392 and 393 for driving the switching elements 321, 322 and 323, The outputs GD1, GD2 and GD3 of the drivers 391, 392 and 393 are connected to the gate terminals of the switching elements 321, 322 and 323, respectively. As shown in FIG. 23, the power source supplied to the gate drivers 391, 392 and 393 is an independent power source of the multiple output SMPS.

Accordingly, a signal from the controller 380 is applied to the gate drivers 391, 392, and 393 to drive the semiconductor switches to control the respective switching elements 321, 322, and 323.

The current transformer 370 may be provided between the ground of the switching elements 321, 322 and 323 connected in series and the ground of the first and second heating coils 341 and 342, The currents flowing through the heating coils 341 and 342 are measured and inputted to the controller 380 via an analog-to-digital converter (ADC) provided in the controller 380. The controller 380 controls the switching elements 321, 322 and 323 based on the current value.

Figs. 26 and 27 are diagrams showing signals for driving respective heating coils in another embodiment of the present invention. Fig.

As shown in FIGS. 26 and 27, the controller 380 controls the currents flowing through the first and second heating coils 341, 342 and 343 by controlling the switching elements 321, 322 and 323.

When the controller 380 intends to drive the first heating coil 341, the first switching device 321 is brought to a closed state during a half-period of resonance, and the second and third switching devices 322, Is in an open state. Then, the first switching device 321 is brought into the open state and the second and third switching devices 322 and 323 are controlled in the closed state during the half period of the remaining resonance.

Through the above operation, an input voltage is applied to the first heating coil 341 and the first and second resonant capacitors 361 and 362 during the half period of the resonance, so that resonance starts and the first heating coil 341 The current rises. The input voltage is reversely applied to the first heating coil 341 and the first and second resonant capacitors 361 and 362 during the half period of the rest of the resonance so as to start resonance and to reverse the first heating coil 341 Direction current is increased.

As the operation is repeated, the eddy current is induced in the cooking container placed on the first heating coil 341, so that the electromagnetic induction heating cooker operates.

27, when the control unit 380 intends to drive the second heating coil 342, the first switching device 321 and the second switching device 322 are closed for half a period of resonance, State, and controls the third switching devices 323 to be in an open state. The first switching device 321 and the second switching device 322 are brought into the open state and the third switching devices 323 are brought into the closed state during the half period of the remaining resonance.

Through the above operation, an input voltage is applied to the second heating coil 342 and the third resonant capacitor 363 during the half period of the resonance, so that resonance starts and the current of the second heating coil 342 . The input voltage is applied to the second heating coil 342 and the third resonant capacitor 363 in the half period of the rest of the resonance, and thereby resonance starts to generate a current in the opposite direction of the second heating coil 342 .

As the operation is repeated, the eddy current is induced in the cooking vessel placed on the second heating coil 342, so that the electromagnetic induction heating cooker operates.

Thus, the control unit 380 can drive the heating coil by controlling the switching elements.

As described above, the electromagnetic induction heating cooker according to the embodiment includes a plurality of heating coils and a minimum number of switching elements for driving the plurality of heating coils, thereby reducing the size of the electromagnetic induction heating cooker and reducing the production cost.

28 is a diagram showing signals for driving a plurality of heating coils in a time division manner in another embodiment of the present invention.

28, when the controller 380 drives the first and second heating coils 341 and 342, the controller 380 first drives the first heating coil 341 and then drives the second heating coil 342 . By repeating this cycle, all of the first and second heating coils 341 and 342 can be driven.

First, when the control unit 380 intends to drive the first heating coil 341, the first switching device 321 is brought into a closed state during half a period of resonance, and the second and third switching devices 322, and 323 are in an open state. Then, the first switching device 321 is brought into the open state and the second and third switching devices 322 and 323 are controlled in the closed state during the half period of the remaining resonance.

Through the above operation, an input voltage is applied to the first heating coil 341 and the first and second resonant capacitors 361 and 362 during the half period of the resonance, so that resonance starts and the first heating coil 341 The current rises. The input voltage is reversely applied to the first heating coil 341 and the first and second resonant capacitors 361 and 362 during the half period of the rest of the resonance so as to start resonance and to reverse the first heating coil 341 Direction current is increased.

As the operation is repeated, the eddy current is induced in the cooking container placed on the first heating coil 341, so that the electromagnetic induction heating cooker operates.

Next, when the controller 380 intends to drive the second heating coil 342, the first switching device 321 and the second switching device 322 are brought into the closed state during the half period of the resonance, And controls the third switching elements 323 to be in the open state. The first switching device 321 and the second switching device 322 are brought into the open state and the third switching devices 323 are brought into the closed state during the half period of the remaining resonance.

Through the above operation, an input voltage is applied to the second heating coil 342 and the third resonant capacitor 363 during the half period of the resonance, so that resonance starts and the current of the second heating coil 342 . The input voltage is applied to the second heating coil 342 and the third resonant capacitor 363 in the half period of the rest of the resonance, and thereby resonance starts to generate a current in the opposite direction of the second heating coil 342 .

As the operation is repeated, the eddy current is induced in the cooking vessel placed on the second heating coil 342, so that the electromagnetic induction heating cooker operates.

When all of the first and second heating coils 341 and 342 are driven in the above-described manner, the first and second heating coils 341 and 342 can be driven again by driving the first heating coils 341 again.

29 is a diagram showing signals for driving a plurality of heating coils in a duty control manner in another embodiment of the present invention.

29, when the control unit 380 drives all of the first and second heating coils 341 and 342, the use of the first and second heating coils 341 and 342 (for example, The first and second heating coils 341 and 342 can be driven in accordance with the duty control according to the time-division driving method, and the power reduction can be compensated by driving in the time division manner . The power of each of the first and second heating coils 341 and 342 is controlled through frequency control. If the output range is limited due to the frequency limitation, the first and second heating coils 341 and 342 can be compensated through the duty control.

As shown in Fig. 29, the first heating coil 341 repeats four resonance cycles, and the second heating coil 342 repeats two resonance cycles.

Accordingly, the first and second heating coils 341 and 342 may have different powers and may be driven together according to their use or needs of the user.

30 is a diagram showing signals for driving two heating coils in a parallel driving manner in another embodiment of the present invention.

30, when the control unit 380 simultaneously drives the first and second heating coils 341 and 342, the second switching device 322 is brought into a closed state, and during the half period of the resonance, 1 switching elements 321 to be in the closed state and controls the third switching element 323 to be in the open state. Then, the first switching devices 321 are opened and the third switching devices 323 are closed during a half period of the remaining resonance.

Since the second switching device 322 is in the closed state, the first heating coil 341 and the second heating coil 342 are connected in parallel.

Accordingly, the input voltage is applied to the first and second heating coils 341 and 342 and the first, second and third resonant capacitors 361, 362 and 363 during the half period of the resonance through the above operation, The current rises in the first and second heating coils 341 and 342. The input voltage is applied to the first and second heating coils 341 and 342 and the first, second and third resonant capacitors 361, 362 and 363 during the half period of the rest of the resonance, The current in the opposite direction to the heating coils 341 and 342 rises.

In this case, the first and second heating coils 341 and 342 operated by the parallel driving method may have the same capacity. In the embodiment, the first and second heating coils 341 and 342 have a capacity of 1.8 kW .

As the operation is repeated, the eddy current is induced in the cooking vessel placed on the first and second heating coils 341 and 342, and the electromagnetic induction heating cooker is operated.

110: rectification part 121, 122, 123, 124, 125:
141, 142, 143, 144:
161, 162, 163, 164, 165, 166: resonant capacitor
180:

Claims (16)

A rectifier for rectifying an input voltage to output a DC voltage;
A plurality of switching elements for switching a DC voltage outputted through the rectifying part;
A plurality of heating coils heating the cooking vessel according to the control of the plurality of switching elements; And
And a controller for controlling the plurality of switching elements to simultaneously drive at least two heating coils connected in parallel among the plurality of heating coils. The method according to claim 1,
And at least one switching element among the plurality of switching elements is disposed between the at least two heating coils. The method according to claim 1,
Wherein the at least two heating coils have the same capacity. The method according to claim 1,
Wherein the at least two heating coils have a smaller capacity than the other heating coils among the plurality of heating coils. The method according to claim 1,
Wherein the plurality of switching elements includes a first switching element, a second switching element, a third switching element, a fourth switching element, and a fifth switching element, and the plurality of heating coils includes a first switching element, A second heating coil connected between the second switching device and the third switching device, a third heating coil connected between the third switching device and the fourth switching device, a fourth switching device connected to the fourth heating device, And a fourth heating coil connected between the first and second switching elements. 6. The method of claim 5,
The control unit closes the fourth switching device to drive the third heating coil and the fourth heating coil in parallel, and causes the first, second, and third switching devices to be in a closed state during half the resonance period, 5 switching elements to be in the open state, and the first, second and third switching elements to be in the open state and the fifth switching element to be in the closed state during the half period of the remaining resonance. 6. The method of claim 5,
Wherein the control unit closes the third and fourth switching devices to drive the second heating coil, the third heating coil, and the fourth heating coil in parallel, and turns the first and second switching devices in a closed state And the fifth switching device is brought into the open state, and the first and second switching devices are brought into the open state and the fifth switching device is brought into the closed state during the half period of the remaining resonance. The method according to claim 1,
Wherein the plurality of switching elements includes a first switching element, a second switching element, a third switching element, and a fourth switching element, and the plurality of heating coils includes a first switching element connected between the first switching element and the second switching element, A second heating coil connected between the second switching device and the third switching device, and a third heating coil connected between the third switching device and the fourth switching device. 9. The method of claim 8,
Wherein the control unit closes the third switching device to drive the second heating coil and the third heating coil in parallel and causes the first and second switching devices to be in a closed state for half a period of resonance, To bring the element into an open state and to cause the first and second switching elements to be in an open state and to control the fourth switching element to be in a closed state during a half period of the remaining resonance. 9. The method of claim 8,
Wherein the control unit closes the second and third switching devices to drive the first heating coil, the second heating coil, and the third heating coil in parallel, and turns off the first switching device during the half period of resonance And causes the fourth switching element to be in the open state and the first switching element to be in the open state and the fourth switching element to be in the closed state for half of the remaining resonance. The method according to claim 1,
Wherein the plurality of switching elements includes a first switching element, a second switching element, and a third switching element, the plurality of heating coils includes a first heating coil connected between the first switching element and the second switching element, And a second heating coil connected between the second switching element and the third switching element. 12. The method of claim 11,
Wherein the control unit closes the second switching device to drive the first heating coil and the second heating coil in parallel and causes the first switching device to be in a closed state for half a period of resonance, To be in the open state and to cause the first switching element to be in the open state and the third switching element to be in the closed state for half of the remaining resonance. A rectifier for rectifying an input voltage to output a DC voltage;
A plurality of switching elements for switching a DC voltage outputted through the rectifying part;
A plurality of heating coils heating the cooking vessel according to the control of the plurality of switching elements;
A current converter for sensing a current value flowing through the plurality of heating coils; And
And a controller for controlling the plurality of switching elements according to a current value sensed through the current converter,
The control unit
Wherein at least two heating coils connected in parallel among the plurality of heating coils are simultaneously driven to control the plurality of switching elements. 14. The method of claim 13,
Wherein the current converter is installed between a ground of the plurality of switching elements and a ground of the plurality of heating coils. 14. The method of claim 13,
Wherein the control unit controls the plurality of switching elements to drive the plurality of heating coils by at least one of a time division method, a duty control method, and a parallel driving method. 14. The method of claim 13,
Further comprising a resonance capacitor connected in series to each of the plurality of heating coils.

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