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WO2020197022A1 - Low electromagnetic induction heating electric stove - Google Patents

Low electromagnetic induction heating electric stove Download PDF

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Publication number
WO2020197022A1
WO2020197022A1 PCT/KR2019/014237 KR2019014237W WO2020197022A1 WO 2020197022 A1 WO2020197022 A1 WO 2020197022A1 KR 2019014237 W KR2019014237 W KR 2019014237W WO 2020197022 A1 WO2020197022 A1 WO 2020197022A1
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WO
WIPO (PCT)
Prior art keywords
signal
electric stove
reference signal
output
ref1
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
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PCT/KR2019/014237
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French (fr)
Korean (ko)
Inventor
안순철
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Individual
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Individual
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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/06—Control, e.g. of temperature, of power
    • H05B6/062—Control, e.g. of temperature, of power for cooking plates or the like
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/04—Sources of current
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B2213/00—Aspects relating both to resistive heating and to induction heating, covered by H05B3/00 and H05B6/00
    • H05B2213/05—Heating plates with pan detection means

Definitions

  • the present invention relates to an induction heating electric stove with a small emission of electromagnetic waves.
  • Increasing the operating frequency of the resonant circuit is considered a good way to reduce the amount of electromagnetic waves generated in the electric stove, but increasing the operating frequency makes it difficult to use the existing IGBT as a switching device.
  • a FET can be used as a switching device. Even when using a FET, according to the present inventors, several problems have emerged as important problems.
  • the output control using the frequency control method would be more suitable than the output control using the conventional PWM method.
  • the conventional detection method of the output power level that can be applied to the frequency control method has a problem such as a problem such as an overshoot because the detection speed is low.
  • the present invention is to provide a low electromagnetic wave induction heating electric range capable of significantly improving the detection speed of the output power level.
  • the present invention is to provide a low electromagnetic induction heating electric stove that can significantly improve the recognition accuracy or recognition speed of the presence or absence of a container.
  • the electric stove is a frequency control for controlling the output of the electric stove by controlling the operating frequency of the resonance circuit 10 Adopt the method
  • a first comparison unit 20 outputting a result of comparing a sensing signal obtained by sensing a current flowing through the inductor L of the resonance circuit 10 with a first comparison reference signal V_REF1; And outputting the first comparison reference signal V_REF1 to the first comparison unit 20 and varying the voltage level of the first comparison reference signal V_REF1, and an output signal from the first comparison unit 20 It characterized in that it comprises a; control unit 30 for receiving and controlling the input.
  • the voltage level of the first comparison reference signal V_REF1 may be set differently for each operating frequency in order to determine the presence or absence of a container.
  • control unit 30 determines that there is a container when a pulse train appears in the output signal from the first comparison unit 20, and If there is no pulse train in the output signal, it can be determined that there is no courage.
  • the first comparison reference signal for determining the presence or absence of the container ( The voltage level of V_REF1 is set to be large, and as the operating frequency for controlling the output of the electric stove is further from the resonance frequency of the resonance circuit 10, the first comparison reference signal V_REF1 for determining the presence or absence of the container The voltage level of) may be set small.
  • the control unit 30 receives the output signal from the first comparison unit 20 while sequentially varying the voltage level of the first comparison reference signal V_REF1
  • the actual power level of the resonant circuit 10 is determined, and it may be determined whether the actual power level of the resonant circuit 10 has reached the expected power level.
  • the control unit 30 receives the output signal from the first comparison unit 20 while sequentially varying the voltage level of the first comparison reference signal V_REF1
  • the actual power level of the resonant circuit 10 is determined, and the operating frequency of the resonant circuit 10 is changed according to a difference between the determined actual power level and the expected power level, thereby forming a real-time feedback loop.
  • a CT for outputting a sensing signal obtained by sensing a current flowing through the inductor L of the resonance circuit 10; further comprising, the first comparison unit 20, A rectifier 22 rectifying and outputting the sensing signal output from the CT; And a comparator 21 that outputs a result according to a relative magnitude between the first comparison reference signal and the signal from the rectifier 22 in the form of a binary pulse signal.
  • the second comparison unit outputs a result of comparing the sensing signal obtained by sensing the current flowing through the inductor L of the resonance circuit 10 and the second comparison reference signal V_REF2 (60); wherein the control unit 30 outputs the second comparison reference signal V_REF2 having a fixed voltage level to the second comparison unit 60, and the second comparison unit 60 Whether or not the inductor L is connected may be determined based on an output signal from.
  • the resonance circuit 10 includes: a first capacitor C1 having one end connected to a DC voltage source rectifying commercial power; A second capacitor C2 having one end connected to the other end of the first capacitor C1 and the other end connected to the ground; And the inductor L having one end connected to a node to which the first capacitor C1 and the second capacitor C2 are connected.
  • the first FET (Q1) having a drain and a source connected to one end of the first capacitor (C1) and the other end of the inductor (L), respectively;
  • a second FET Q2 having a drain and a source connected to the other end of the inductor L and the other end of the second capacitor C2, respectively;
  • a gate driver 40 that outputs ON/OFF signals to the gates of the first FET Q1 and the second FET Q2 under control from the controller 30.
  • noise immunity can be achieved without a smoothing circuit as in the prior art, and further, compared to the conventional method, the delay time of the feedback loop for adjusting the output power level and the delay for determining the presence or absence of a container There is an advantage in that time is reduced.
  • FIG. 1 is a circuit diagram showing a main electrical circuit in an induction heating type electric stove according to an embodiment of the present invention.
  • FIG. 2 is a circuit diagram showing a main electrical circuit in an induction heating type electric stove according to a modified embodiment of the present invention.
  • FIG. 3 is a signal timing diagram for explaining the setting and detection of output power in the operation of the induction heating type electric stove according to an embodiment of the present invention.
  • FIG. 4 is a signal timing diagram for explaining container recognition in the operation of an induction heating type electric stove according to an embodiment of the present invention.
  • FIG. 1 is a circuit diagram showing a main electrical circuit in an induction heating type electric stove according to an embodiment of the present invention.
  • the induction heating type electric stove employs a frequency control method for controlling the output of the electric stove by controlling the operating frequency of the resonance circuit 10.
  • the induction heating type electric stove includes a resonance circuit 10, a first comparison unit 20, a control unit 30, a gate driver 40, a switching unit 50, and the like. do.
  • One embodiment of the present invention is a half bridge drive method, and the resonance circuit 10 includes two capacitors and a single inductor.
  • One end of the first capacitor C1 is connected to a DC voltage source (DC PWR) that rectifies AC commercial power (for example, 220V AC), and the second capacitor C2 is connected to the other end of the first capacitor C1.
  • DC PWR DC voltage source
  • the second capacitor C2 is connected to the other end of the first capacitor C1.
  • One end is connected and the other end is connected to ground.
  • the inductor L has one end connected to the node to which the first capacitor C1 and the second capacitor C2 are connected, and the other end connected to the switching unit 50. Specifically, the switching unit 50 The first FET Q1 and the second FET Q2 are connected to nodes connected to each other. In the electric stove, the inductor L faces the place where the container is placed, and is usually constructed directly below the top plate of the electric stove.
  • the switching unit 50 is for sequentially forming a connection channel to a direct current voltage source (DC PWR) or a ground with respect to the tartan of the inductor L, the first FET (Q1) and the second FET (Q2), It includes resistors R1 and R2 connected between their gates and the gate driver 40.
  • DC PWR direct current voltage source
  • Q1 and R2 connected between their gates and the gate driver 40.
  • the first FET Q1 has a drain and a source connected to one end of the first capacitor C1, that is, a DC voltage source (DC PWR) and the other end of the inductor L, and the second FET Q2 is an inductor L A drain and a source are connected to the other end of and to the other end of the second capacitor C2, that is, to ground.
  • DC PWR DC voltage source
  • third capacitor (C3) and fourth capacitor (C4) are for reducing the switching noise of the first FET (Q1) and the second FET (Q2), the fifth capacitor (C5) is a direct current voltage source (DC PWR) It is to remove the ripple of the.
  • the gate driver 40 generates timing signals to the gates of the first FET Q1 and the second FET Q2 under control from the controller 30. In particular, in order to control the output power level of the electric range, the operating frequency of the resonance circuit 10 is precisely controlled. To this end, the gate driver 40 turns on the first FET (Q1) and the second FET (Q2). Each outputs a signal that precisely controls the timing, turn-off timing, and ON/OFF frequency.
  • the driver 40 shifts the voltage level to drive the gates of the first FET (Q1) and the second FET (Q2), the logic signal input from the control unit is, for example, 3.3 ⁇ 5V level, the output signal is It is 9 ⁇ 15V level. Accordingly, the gate driver 40 may be supplied with two types of power (for example, Vcc: 3.3 to 5V, Vdd: 9 to 15V).
  • the CT outputs a sensing signal that senses the current flowing through the inductor L of the resonance circuit 10 and provides it to the first comparator 20. Specifically, the CT outputs a sensing signal that is inserted between the connection point between the first FET (Q1) and the second FET (Q2) and the inductor (L) and senses the current flowing through this path, for example 1000: It can have a current ratio of 1.
  • the first comparison unit 20 outputs a result of comparing the sensing signal obtained by sensing the current flowing through the inductor L of the resonance circuit 10 with the first comparison reference signal V_REF1 from the control unit 30.
  • the first comparison unit 20 calculates the result according to the relative magnitude between the rectifier 22 that outputs the sensing signal output by the CT by full-wave rectification or half-wave rectification, and the first comparison reference signal and the signal from the rectifier 22. It includes a comparator 21 that outputs in the form of a binary pulse signal.
  • the sensing signal that senses the current flowing through the inductor (L) is a signal that has both negative and positive voltages based on the ground, and rectifies it through the rectifier 22 to produce a signal with only one voltage (positive voltage). Change.
  • the comparator 21 may be implemented as an OP AMP.
  • the signal from the rectifier 22 is applied to the + input of the OP AMP, the first comparison reference signal V_REF1 from the control unit 30 is applied as the-input of the OP AMP, and the output of the OP AMP is applied to the control unit 30. Is entered.
  • the resonance circuit 10 may reach a very high maximum voltage, for example, but the first comparator 20 and the control unit 30 may operate at a low DC power voltage such as 5V.
  • the first comparison unit 20 compares the size of the sensing signal and the size of the first comparison reference signal from the control unit, and outputs the level of the DC power supply voltage (for example, 5V) when the determined one is larger. If not, the ground level is output.
  • the level of the DC power supply voltage for example, 5V
  • the control unit 30 outputs a first comparison reference signal V_REF1 to the first comparison unit 20, outputs a signal for controlling the gate driver 40, and controls other components not shown constituting the electric stove.
  • I/O devices can be used to perform input/output from users.
  • a command for determining the output power level may be received from a user using a touch pad and a switch.
  • the output power level command from the user may be a command having a plurality of levels such as levels 1 to 9 levels.
  • the control unit 30 outputs the first comparison reference signal V_REF1, but does not fix the voltage level of the first comparison reference signal V_REF1 but varies according to the situation, and the control unit 30 is implemented by a microprocessor, a microcontroller, etc.
  • a digital analog converter may be included inside and outside to change the voltage level of the first comparison reference signal V_REF1.
  • the control unit 30 receives the output signal from the first comparison unit 20 and uses it for control. In particular, the control unit 30 controls the gate driver 40 and thus the first FET (Q1) and the second FET (Q2). Use. The control unit 30 receives an output signal from the first comparison unit 20 and uses it to control the operation of the resonance circuit 10 and the operating frequency.
  • the control unit 30 determines whether a container is placed on the top plate of the microwave oven. In order to determine the presence or absence of the container, the control unit 30 sets the voltage level of the first comparison reference signal V_REF1 to be different for each operating frequency. For example, if the output power level is designed in 9 stages, the operating frequency is 9 and the voltage level of the first comparison reference signal V_REF1 is also 9 stages.
  • the controller 30 determines that there is a container, and if the pulse train does not appear in the output signal from the first comparison unit 20, it determines that there is no container. In determining whether or not a pulse train appears, if there are more than a predetermined number of pulses at a predetermined time, it may be considered that the pulse train appears.
  • the voltage level of the first comparison reference signal V_REF1 for determining the presence or absence of a container may be specifically set as follows.
  • the voltage level of the first comparison reference signal V_REF1 for judging the presence or absence of a container is set larger, and the output of the electric stove is controlled.
  • the voltage level of the first comparison reference signal V_REF1 for determining the presence or absence of a container is set to be smaller as the operating frequency is further away from the resonance frequency of the resonance circuit 10.
  • the electric stove of the induction heating method according to an embodiment of the present invention is set and compared with the expected power level and the actual power level to feed back the resonance circuit.
  • the control unit 30 sequentially varies the voltage level of the first comparison reference signal V_REF1 and receives the output signal from the first comparison unit 20 to determine the actual power level of the resonance circuit 10, and the resonance circuit It is determined whether the actual power level of (10) has reached the expected power level.
  • the control unit 30 generates a pulse train from the output signal from the first comparison unit 20 each time the first comparison reference signal V_REF1 applied to the first comparison unit 20 is at a plurality of voltage levels. Seeing whether it appears, it is possible to detect the output power level of the resonance circuit 10 (that is, the electric stove). In this case, the controller 30 may sequentially determine the voltage level of the first comparison reference signal V_REF1 for search in the search process by employing a binary search algorithm.
  • the control unit 30 sequentially varies the voltage level of the first comparison reference signal V_REF1 and receives the output signal from the first comparison unit 20 to determine the actual power level of the resonant circuit 10.
  • a real-time feedback loop is formed by controlling the operating frequency of the resonant circuit 10 to change according to the difference between the power level and the expected power level.
  • the feedback loop constitutes a closed loop along the path of the control unit 30-the gate drive 40-FETs (Q1, Q2)-the resonance circuit 10-the first comparator 20-the control unit 30.
  • a smoothing circuit is interposed in the feedback loop for noise immunity, thereby adding more time for charge accumulation, resulting in adding an integral factor to the feedback loop. Accordingly, there is a problem in that a delay time is required and it is difficult to induce an overshoot or to control a feedback to avoid an overshoot.
  • noise immunity can be achieved even without a smoothing circuit as in the prior art, and further, the delay time of the feedback loop for adjusting the output power level and the presence or absence of a container compared to the conventional method. There is an advantage in that the delay time for judgment is reduced.
  • FIG. 2 is a circuit diagram showing a main electrical circuit in an induction heating type electric stove according to a modified embodiment of the present invention.
  • the modified embodiment differs in that the second comparison unit 60 is additionally configured, and other configurations are similar to those of the embodiment described with reference to FIG. 1.
  • the second comparison unit 60 outputs a result of comparing the sensing signal obtained by sensing the current flowing through the inductor L of the resonance circuit 10 with the second comparison reference signal V_REF2, and the controller 30 A second comparison reference signal V_REF2 having a fixed voltage level is output to the comparison unit 60, and it is determined whether or not the inductor L is connected based on the output signal from the second comparison unit 60.
  • the second comparator 60 may share the rectifier 22 of the first comparator 20 to use the output from the rectifier 22 or may be configured separately, or sensing directly from the CT without the rectifier 22 You can also use signals.
  • the comparator 61 of the second comparator 60 converts the result according to the relative magnitude between the second comparison reference signal having a fixed voltage level and the sensing signal (a signal obtained by rectifying the sensing signal is also included) to a binary pulse signal. Output in the form.
  • the second comparison reference signal V_REF2 output from the control unit 30 is a very low minimum voltage level, and the control unit 30 is a pulse train in the output signal of the second comparison unit 60, that is, the output signal of the comparator 61 It is determined whether or not the inductor L is connected according to whether appears.
  • the comparator 61 may be implemented as an OP AMP.
  • the signal from the rectifier 22 is applied to the + input of the OP AMP, the second comparison reference signal (V_REF2) from the control unit 30 is applied as the-input of the OP AMP, and the output of the OP AMP is applied to the control unit 30. Is entered.
  • the second comparison unit 60 compares the size of the sensing signal with the size of the second comparison reference signal from the control unit, and outputs the level of the DC power voltage (for example, 5V) when the determined one is larger. If not, the ground level is output.
  • the level of the DC power voltage for example, 5V
  • 3 is a signal timing diagram for explaining the setting and detection of output power in the operation of the induction heating type electric stove according to an embodiment of the present invention.
  • 4 is a signal timing diagram for explaining container recognition in the operation of an induction heating type electric stove according to an embodiment of the present invention.
  • the user can set the output power level of the electric stove using an I/O device (not shown), and the control unit 30 receives the input. For example, if the output power level is set to 9 stages, which is the highest stage, by the user, the resonance circuit is controlled to operate at the operating frequency corresponding to the 9 stages. Starting from the operating frequency corresponding to, it can be changed sequentially to reach the operating frequency of 9 steps.
  • the output power level applied to the resonance circuit differs from each other depending on the characteristics of the resonance that the output may be unstable when uncontrolled, and the material of the container, the size of the container, and the relative position of the inductor and the container. can do.
  • the output power level becomes excessive, which can increase the failure or fatigue of the components of the microwave oven.
  • the step is raised to reach the highest operating frequency, and even at the same highest step, a small deviation is made in the final frequency set according to the situation, and the target step is made by referring to the output power level according to the operating frequency setting in the following steps. Refer to the setting of operating frequency.
  • step 7-step 8-step 9 is sequentially changed, but the actual output power level according to the operating frequency setting in step 7 and step 8 is detected and used for fine setting of the operating frequency in step 9.
  • step 9 it is assumed that the operating frequency corresponding to the output power of step 8 is set and the actual output power level is sensed accordingly.
  • the control unit 30 outputs a pulse signal of a low voltage, for example, 5V level so that the gate driver 40 can output a switching signal corresponding to the operating frequency f 8 , and such a pulse signal is [1/operation frequency (f 8 )] or a signal with a guard band in this period or a similar signal.
  • the gate driver 40 amplifies the current and voltage signals based on the pulse signal from the control unit 30 to respond to the high voltage applied to the FETs Q1 and Q2.
  • the CT, the first comparison unit 20 and the control unit 30 are used to detect the exact actual output power level.
  • the sensing signal sensed using the CT becomes a half-wave rectified or full-wave rectified sensing signal using the rectifier 22 (refer to the V_S signal in Fig. 3), and the sensing signal is at the set output power level (eg, step 8).
  • the voltage of the signal V_REF1 applied from the control unit 30 to the first comparator 20, specifically the comparator 21, in order to determine whether it has reached or at what level, is initially V1 (1/ You can start with 2).
  • V_REF1 applied to the comparator 21 is then maximum.
  • V2 increased by 1/4 of the voltage level may be applied.
  • V3 increased by 1/8 may be applied again, and even at this time, a pulse train as shown in Fig. 3(c) appears at the output of the comparator 21. Therefore, V4 can be applied again, and if the pulse train does not appear at this time, the voltage reduced by 1/16 can be sequentially detected in the order of application.
  • the output power level may be determined after being applied by adding up to the increment of the minimum resolution, and may be determined as the last applied voltage level or a voltage level before or after it.
  • the actual output power level can be detected according to the output power level set in this way. For example, when the actual output power level of 8 steps is higher than the set output power level, an operation corresponding to the output power level of 9 steps Taking this into account when setting the frequency, feedback is applied so that the operating frequency is farther from the resonant frequency.
  • the preceding step may be omitted.
  • the voltage level of the first comparison reference signal V_REF1 is set differently for each operating frequency in order to determine the presence or absence of a container, and the control unit 30 provides an output signal from the first comparison unit 20. If the pulse train appears in, it is determined that there is a container, and if the pulse train does not appear in the output signal from the first comparison unit 20, it is determined that there is no container. At this time, the first comparison reference signal V_REF1 may be different from the voltage used for detection of the output power level, and the detection of the output power level and the presence or absence of a container are performed at different times.
  • the sensing signal V_S is compared with the sensing signal V_S to determine the output signal V_OUT1 from the comparator 21.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Induction Heating Cooking Devices (AREA)

Abstract

In an induction heating electric stove having a resonant circuit (10), according to the present invention, the electric stove comprises: a first comparison unit (20) which adopts a frequency control method of controlling the output of the electric stove by controlling the operating frequency of the resonant circuit (10), and outputs a result of comparing a sensing signal sensing a current flowing through an inductor (L) of the resonant circuit (10) with a first comparison reference signal (V_REF1); and a control unit (30) which outputs the first comparison reference signal (V_REF1) by means of the first comparison unit (20), varies the voltage level of the first comparison reference signal (V_REF1), and receives and controls an output signal from the first comparison unit (20).

Description

저전자파 유도가열 전기렌지Low electromagnetic induction heating electric stove

본 발명은 전자파의 발산이 작은 유도가열 전기렌지에 관한 것이다.The present invention relates to an induction heating electric stove with a small emission of electromagnetic waves.

가스렌지에 비하여 전기렌지의 장점이 부각되면서, 최근 가정용으로 전기렌지의 사용비율이 높아지는 추세이나, 전기렌지에서 전자파 발생 문제은 또다른 해결과제가 되었다.As the advantages of electric stoves are highlighted compared to gas stoves, the rate of use of electric stoves for home use has recently increased, but the problem of generating electromagnetic waves in electric stoves has become another challenge.

전기렌지에서 전자파의 발생량을 줄이기 위해서 공진회로의 동작 주파수를 높이는 것이 좋은 방안으로 생각되나, 동작 주파수를 높이는 것은 스위칭소자로서 기존 IGBT의 사용을 어렵게 한다.Increasing the operating frequency of the resonant circuit is considered a good way to reduce the amount of electromagnetic waves generated in the electric stove, but increasing the operating frequency makes it difficult to use the existing IGBT as a switching device.

대안으로 FET를 스위칭 소자로 사용할 수 있는데, FET를 사용하는 경우에도 본 발명자에 의하면 몇가지 해결과제가 중요한 문제로 대두되었다.As an alternative, a FET can be used as a switching device. Even when using a FET, according to the present inventors, several problems have emerged as important problems.

먼저, 종래 PWM 방식을 이용한 출력 조절보다는 주파수 제어 방식을 이용한 출력 조절이 더 적당할 것으로 생각되었다. 그런데, 주파수 제어 방식에 적용될 수 있는 기존 출력 파워레벨의 감지 방식은 감지 속도가 느려서 오버슈트 등의 문제가 있는 등 그 제어가 어려운 문제가 있는 것으로 파악되었다.First, it was thought that the output control using the frequency control method would be more suitable than the output control using the conventional PWM method. However, it has been found that the conventional detection method of the output power level that can be applied to the frequency control method has a problem such as a problem such as an overshoot because the detection speed is low.

또한, 전기 렌지위에 용기가 올려져 있는 지를 감지할 필요가 있는 데 주파수 제어 방식을 적용할 때 용기 유무의 인식 정확도가 떨어지고 인식 속도도 떨어지는 문제가 있는 것으로 파악되었다.In addition, it is necessary to detect whether a container is placed on the electric stove, but when the frequency control method is applied, it has been found that there is a problem in that the recognition accuracy of the presence or absence of the container is lowered and the recognition speed is also lowered.

본 발명은 출력 파워레벨의 감지 속도를 대폭 향상시킬 수 있는 저전자파 유도가열 전기렌지를 제공하기 위한 것이다.The present invention is to provide a low electromagnetic wave induction heating electric range capable of significantly improving the detection speed of the output power level.

또한 본 발명은 용기 유무의 인식 정확도 또는 인식 속도를 대폭 향상시킬 수 있는 저전자파 유도가열 전기렌지를 제공하기 위한 것이다.In addition, the present invention is to provide a low electromagnetic induction heating electric stove that can significantly improve the recognition accuracy or recognition speed of the presence or absence of a container.

본 발명의 일 양상에 따른 공진회로(10)를 구비하는 유도가열방식의 전기렌지에 있어서, 상기 전기렌지는 상기 공진 회로(10)의 동작 주파수를 제어함으로써 상기 전기렌지의 출력을 제어하는 주파수 제어 방식을 채용하되,In an induction heating type electric stove having a resonance circuit 10 according to an aspect of the present invention, the electric stove is a frequency control for controlling the output of the electric stove by controlling the operating frequency of the resonance circuit 10 Adopt the method,

상기 공진회로(10)의 인덕터(L)에 흐르는 전류를 센싱한 센싱 신호와 제 1 비교기준 신호(V_REF1)를 비교한 결과를 출력하는 제 1 비교부(20); 및 상기 제 1 비교부(20)로 상기 제 1 비교기준 신호(V_REF1)를 출력하되 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨을 가변하며, 상기 제 1 비교부(20)로부터의 출력 신호를 입력받아 제어하는 제어부(30);를 포함하는 것을 특징으로 한다.A first comparison unit 20 outputting a result of comparing a sensing signal obtained by sensing a current flowing through the inductor L of the resonance circuit 10 with a first comparison reference signal V_REF1; And outputting the first comparison reference signal V_REF1 to the first comparison unit 20 and varying the voltage level of the first comparison reference signal V_REF1, and an output signal from the first comparison unit 20 It characterized in that it comprises a; control unit 30 for receiving and controlling the input.

상기한 유도가열방식의 전기렌지에 있어서, 용기 유무를 판단하기 위하여 상기 동작 주파수 별로 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨이 서로 다르게 설정되어 있을 수 있다.In the electric stove of the induction heating method, the voltage level of the first comparison reference signal V_REF1 may be set differently for each operating frequency in order to determine the presence or absence of a container.

상기한 유도가열방식의 전기렌지에 있어서, 상기 제어부(30)는, 상기 제 1 비교부(20)로부터의 출력 신호에서 펄스열이 나타나면 용기가 있는 것으로 판단하고 상기 제 1 비교부(20)로부터의 출력 신호에서 펄스열이 나타나지 않으면 용기가 없는 것으로 판단할 수 있다.In the electric stove of the induction heating method described above, the control unit 30 determines that there is a container when a pulse train appears in the output signal from the first comparison unit 20, and If there is no pulse train in the output signal, it can be determined that there is no courage.

상기한 유도가열방식의 전기렌지에 있어서, 상기 전기렌지의 출력을 제어하기 위한 상기 동작 주파수가 상기 공진 회로(10)의 공진 주파수에 가까울수록 상기 용기 유무의 판단을 위한 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨은 크게 설정되며, 상기 전기렌지의 출력을 제어하기 위한 상기 동작 주파수가 상기 공진 회로(10)의 공진 주파수로부터 멀수록 상기 용기 유무의 판단을 위한 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨은 작게 설정될 수 있다.In the induction heating type electric stove described above, as the operating frequency for controlling the output of the electric stove is closer to the resonance frequency of the resonance circuit 10, the first comparison reference signal for determining the presence or absence of the container ( The voltage level of V_REF1 is set to be large, and as the operating frequency for controlling the output of the electric stove is further from the resonance frequency of the resonance circuit 10, the first comparison reference signal V_REF1 for determining the presence or absence of the container The voltage level of) may be set small.

상기한 유도가열방식의 전기렌지에 있어서, 상기 제어부(30)는 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨을 순차적으로 가변하면서 상기 제 1 비교부(20)로부터의 출력 신호를 입력받아 상기 공진회로(10)의 실제 파워레벨을 결정하며, 상기 공진회로(10)의 실제 파워레벨이 예상 파워레벨에 도달하였는지를 판단할 수 있다.In the electric stove of the induction heating method described above, the control unit 30 receives the output signal from the first comparison unit 20 while sequentially varying the voltage level of the first comparison reference signal V_REF1 The actual power level of the resonant circuit 10 is determined, and it may be determined whether the actual power level of the resonant circuit 10 has reached the expected power level.

상기한 유도가열방식의 전기렌지에 있어서, 상기 제어부(30)는 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨을 순차적으로 가변하면서 상기 제 1 비교부(20)로부터의 출력 신호를 입력받아 상기 공진회로(10)의 실제 파워레벨을 결정하며, 결정된 실제 파워레벨과 예상 파워레벨의 차이에 따라 상기 공진 회로(10)의 동작 주파수가 변경되도록 제어함으로써 실시간 피드백 루프를 형성할 수 있다.In the electric stove of the induction heating method described above, the control unit 30 receives the output signal from the first comparison unit 20 while sequentially varying the voltage level of the first comparison reference signal V_REF1 The actual power level of the resonant circuit 10 is determined, and the operating frequency of the resonant circuit 10 is changed according to a difference between the determined actual power level and the expected power level, thereby forming a real-time feedback loop.

상기한 유도가열방식의 전기렌지에 있어서, 상기 공진회로(10)의 인덕터(L)에 흐르는 전류를 센싱한 센싱 신호를 출력하는 CT;를 더 포함하며, 상기 제 1 비교부(20)는, 상기 CT가 출력하는 센싱 신호를 정류하여 출력하는 정류기(22); 상기 제 1 비교기준 신호와 상기 정류기(22)로부터의 신호 사이의 상대적 크기에 따른 결과를 이진펄스신호 형태로 출력하는 비교기(21);를 포함하여 구성될 수 있다.In the electric stove of the induction heating method described above, a CT for outputting a sensing signal obtained by sensing a current flowing through the inductor L of the resonance circuit 10; further comprising, the first comparison unit 20, A rectifier 22 rectifying and outputting the sensing signal output from the CT; And a comparator 21 that outputs a result according to a relative magnitude between the first comparison reference signal and the signal from the rectifier 22 in the form of a binary pulse signal.

상기한 유도가열방식의 전기렌지에 있어서, 상기 공진회로(10)의 인덕터(L)에 흐르는 전류를 센싱한 센싱 신호와 제 2 비교기준 신호(V_REF2)를 비교한 결과를 출력하는 제 2 비교부(60);를 더 포함하며, 상기 제어부(30)는 상기 제 2 비교부(60)로 전압 레벨이 고정된 상기 제 2 비교기준 신호(V_REF2)를 출력하며, 상기 제 2 비교부(60)로부터의 출력 신호에 의해 상기 인덕터(L)의 연결 여부를 판단할 수 있다.In the electric stove of the induction heating method described above, the second comparison unit outputs a result of comparing the sensing signal obtained by sensing the current flowing through the inductor L of the resonance circuit 10 and the second comparison reference signal V_REF2 (60); wherein the control unit 30 outputs the second comparison reference signal V_REF2 having a fixed voltage level to the second comparison unit 60, and the second comparison unit 60 Whether or not the inductor L is connected may be determined based on an output signal from.

상기한 유도가열방식의 전기렌지에 있어서, 상기 공진회로(10)는, 상용 전력을 정류한 직류 전압원에 일단이 연결되는 제 1 커패시터(C1); 상기 제 1 커패시터(C1)의 타단에 그 일단이 연결되고 타단은 접지에 연결되는 제 2 커패시터(C2); 상기 제 1 커패시터(C1) 및 상기 제 2 커패시터(C2)가 접속되는 노드에 그 일단이 연결되는 상기 인덕터(L);를 포함하여 구성될 수 있다.In the electric stove of the induction heating method, the resonance circuit 10 includes: a first capacitor C1 having one end connected to a DC voltage source rectifying commercial power; A second capacitor C2 having one end connected to the other end of the first capacitor C1 and the other end connected to the ground; And the inductor L having one end connected to a node to which the first capacitor C1 and the second capacitor C2 are connected.

상기한 유도가열방식의 전기렌지에 있어서, 상기 제 1 커패시터(C1)의 일단과 상기 인덕터(L)의 타단에 드레인 및 소스가 각각 연결되는 제 1 FET(Q1); 상기 인덕터(L)의 타단과 상기 제 2 커패시터(C2)의 타단에 드레인 및 소스가 각각 연결되는 제 2 FET(Q2); 상기 제어부(30)로부터의 제어에 따라 상기 제 1 FET(Q1) 및 상기 제 2 FET(Q2)의 게이트로 ON/OFF 신호를 출력하는 게이트 드라이버(40);를 포함하여 구성될 수 있다.In the induction heating type electric stove, the first FET (Q1) having a drain and a source connected to one end of the first capacitor (C1) and the other end of the inductor (L), respectively; A second FET Q2 having a drain and a source connected to the other end of the inductor L and the other end of the second capacitor C2, respectively; And a gate driver 40 that outputs ON/OFF signals to the gates of the first FET Q1 and the second FET Q2 under control from the controller 30.

본 발명에 따르면, 종래와 같은 평활회로가 없어도 노이즈 면역성(Noise Immunity)을 달성할 수 있으며, 나아가 종래의 방식에 비하여 출력 파워레벨의 조정을 위한 피드백 루프의 지연 시간과 용기유무의 판단을 위한 지연시간이 저감되는 장점이 있다.According to the present invention, noise immunity can be achieved without a smoothing circuit as in the prior art, and further, compared to the conventional method, the delay time of the feedback loop for adjusting the output power level and the delay for determining the presence or absence of a container There is an advantage in that time is reduced.

또한, 본 발명에 따르면, 피드백 루프에서의 지연 시간이 저감됨으로써 종래 오버슈트의 문제를 저감하며 보다 빠르고 정확하게 사용자에 의해 설정된 출력 파워레벨로 도달할 수 있는 효과가 있다.In addition, according to the present invention, by reducing the delay time in the feedback loop, there is an effect of reducing the problem of conventional overshoot and reaching the output power level set by the user more quickly and accurately.

도 1은 본 발명의 일 실시예에 따른 유도가열방식의 전기렌지에서 주요 전기적 회로를 도시한 회로도이다.1 is a circuit diagram showing a main electrical circuit in an induction heating type electric stove according to an embodiment of the present invention.

도 2는 본 발명의 변형 실시예에 따른 유도가열방식 전기렌지에서 주요 전기적 회로를 도시한 회로도이다.2 is a circuit diagram showing a main electrical circuit in an induction heating type electric stove according to a modified embodiment of the present invention.

도 3은 본 발명의 일 실시예에 따른 유도가열방식의 전기렌지의 동작에서 출력 파워의 설정 및 감지를 설명하기 위한 신호 타이밍도이다.3 is a signal timing diagram for explaining the setting and detection of output power in the operation of the induction heating type electric stove according to an embodiment of the present invention.

도 4는 본 발명의 일 실시예에 따른 유도가열방식의 전기렌지의 동작에서 용기 인식을 설명하기 위한 신호 타이밍도이다.4 is a signal timing diagram for explaining container recognition in the operation of an induction heating type electric stove according to an embodiment of the present invention.

도 1은 본 발명의 일 실시예에 따른 유도가열방식의 전기렌지에서 주요 전기적 회로를 도시한 회로도이다.1 is a circuit diagram showing a main electrical circuit in an induction heating type electric stove according to an embodiment of the present invention.

본 발명의 일 실시예에 따른 유도가열방식의 전기렌지는 공진 회로(10)의 동작 주파수를 제어함으로써 전기렌지의 출력을 제어하는 주파수 제어 방식을 채용한다.The induction heating type electric stove according to an embodiment of the present invention employs a frequency control method for controlling the output of the electric stove by controlling the operating frequency of the resonance circuit 10.

본 발명의 일 실시예에 따른 유도가열방식의 전기렌지는 공진회로(10), 제 1 비교부(20), 제어부(30), 게이트 드라이버(40) 및 스위칭부(50) 등을 포함하여 구성된다. The induction heating type electric stove according to an embodiment of the present invention includes a resonance circuit 10, a first comparison unit 20, a control unit 30, a gate driver 40, a switching unit 50, and the like. do.

본 발명의 일 실시예는 Half Bridge 드라이브 방식으로서, 공진회로(10)는 두개의 커패시터와 단일의 인덕터를 포함한다. 제 1 커패시터(C1)는 교류 상용 전력(예를 들면 220V 교류)을 정류한 직류 전압원(DC PWR)에 그 일단이 연결되며, 제 2 커패시터(C2)는 제 1 커패시터(C1)의 타단에 그 일단이 연결되고 타단은 접지에 연결된다.One embodiment of the present invention is a half bridge drive method, and the resonance circuit 10 includes two capacitors and a single inductor. One end of the first capacitor C1 is connected to a DC voltage source (DC PWR) that rectifies AC commercial power (for example, 220V AC), and the second capacitor C2 is connected to the other end of the first capacitor C1. One end is connected and the other end is connected to ground.

인덕터(L)는 제 1 커패시터(C1) 및 제 2 커패시터(C2)가 접속되는 노드에 그 일단이 연결되고 타단은 스위칭부(50)에 연결되는 데, 구체적으로 보면 스위칭부(50)에서 제 1 FET(Q1) 및 제 2 FET(Q2)가 서로 연결되는 노드에 연결된다. 전기 렌지에서 인덕터(L)는 용기가 올려지는 곳에 대향하여 통상 전기 렌지의 상판 직하방에 구성된다.The inductor L has one end connected to the node to which the first capacitor C1 and the second capacitor C2 are connected, and the other end connected to the switching unit 50. Specifically, the switching unit 50 The first FET Q1 and the second FET Q2 are connected to nodes connected to each other. In the electric stove, the inductor L faces the place where the container is placed, and is usually constructed directly below the top plate of the electric stove.

스위칭부(50)는 인덕터(L)의 타탄에 대하여 전기적으로 직류 전압원(DC PWR) 또는 접지로의 연결 채널을 순차 형성하기 위한 것으로서, 제 1 FET(Q1) 및 제 2 FET(Q2)와, 이들의 게이트와 게이트 드라이버(40) 사이에 연결되는 저항(R1, R2)을 포함하여 구성된다.The switching unit 50 is for sequentially forming a connection channel to a direct current voltage source (DC PWR) or a ground with respect to the tartan of the inductor L, the first FET (Q1) and the second FET (Q2), It includes resistors R1 and R2 connected between their gates and the gate driver 40.

제 1 FET(Q1)는 제 1 커패시터(C1)의 일단, 즉 직류 전압원(DC PWR)과 인덕터(L)의 타단에 드레인 및 소스가 각각 연결되며, 제 2 FET(Q2)는 인덕터(L)의 타단과 제 2 커패시터(C2)의 타단, 즉 접지에 드레인 및 소스가 각각 연결된다.The first FET Q1 has a drain and a source connected to one end of the first capacitor C1, that is, a DC voltage source (DC PWR) and the other end of the inductor L, and the second FET Q2 is an inductor L A drain and a source are connected to the other end of and to the other end of the second capacitor C2, that is, to ground.

기타 제 3 커패시터(C3) 및 제 4 커패시터(C4)는 제 1 FET(Q1) 및 제 2 FET(Q2)의 스위칭 노이즈를 저감하기 위한 것이며, 제 5 커패시터(C5)는 직류 전압원(DC PWR)의 리플을 제거하기 위한 것이다.Other third capacitor (C3) and fourth capacitor (C4) are for reducing the switching noise of the first FET (Q1) and the second FET (Q2), the fifth capacitor (C5) is a direct current voltage source (DC PWR) It is to remove the ripple of the.

게이트 드라이버(40)는 제어부(30)로부터의 제어에 따라 제 1 FET(Q1) 및 제 2 FET(Q2)의 게이트로 타이밍 신호를 발생시킨다. 특히, 전기렌지의 출력 파워레벨을 조절하기 위하여 공진회로(10)의 동작 주파수를 정밀하게 제어하는 데, 이를 위하여 게이트 드라이버(40)는 제 1 FET(Q1) 및 제 2 FET(Q2)의 턴온 시점 및 턴오프 시점과 ON/OFF 주파수를 정밀하게 제어하는 신호를 각각 출력한다.The gate driver 40 generates timing signals to the gates of the first FET Q1 and the second FET Q2 under control from the controller 30. In particular, in order to control the output power level of the electric range, the operating frequency of the resonance circuit 10 is precisely controlled. To this end, the gate driver 40 turns on the first FET (Q1) and the second FET (Q2). Each outputs a signal that precisely controls the timing, turn-off timing, and ON/OFF frequency.

드라이버(40)는 제 1 FET(Q1) 및 제 2 FET(Q2)의 게이트를 구동하기위해 전압 레벨을 쉬프트하는 데, 제어부로부터 입력되는 로직 신호는 예를 들면 3.3~5V 레벨이며, 출력 신호는 9~15V 레벨이다. 따라서 게이트 드라이버(40)는 2가지 전원이 공급될 수 있다(예를 들면, Vcc: 3.3~5V, Vdd : 9~15V).The driver 40 shifts the voltage level to drive the gates of the first FET (Q1) and the second FET (Q2), the logic signal input from the control unit is, for example, 3.3 ~ 5V level, the output signal is It is 9~15V level. Accordingly, the gate driver 40 may be supplied with two types of power (for example, Vcc: 3.3 to 5V, Vdd: 9 to 15V).

CT는 공진회로(10)의 인덕터(L)에 흐르는 전류를 센싱한 센싱 신호를 출력하여 제 1 비교부(20)로 제공한다. 구체적으로 보면 CT는 제 1 FET(Q1) 및 제 2 FET(Q2) 사이의 연결점과 인덕터(L) 사이에서 삽입되고 이 경로상에 흐르는 전류를 센싱한 센싱신호를 출력하며, 예를 들면 1000:1의 전류비를 가질 수 있다.The CT outputs a sensing signal that senses the current flowing through the inductor L of the resonance circuit 10 and provides it to the first comparator 20. Specifically, the CT outputs a sensing signal that is inserted between the connection point between the first FET (Q1) and the second FET (Q2) and the inductor (L) and senses the current flowing through this path, for example 1000: It can have a current ratio of 1.

제 1 비교부(20)는 공진회로(10)의 인덕터(L)에 흐르는 전류를 센싱한 센싱 신호와 제어부(30)로부터의 제 1 비교기준 신호(V_REF1)를 비교한 결과를 출력한다. 제 1 비교부(20)는 CT가 출력하는 센싱 신호를 전파정류 또는 반파정류하여 출력하는 정류기(22)와, 제 1 비교기준 신호와 정류기(22)로부터의 신호 사이의 상대적 크기에 따른 결과를 이진펄스신호 형태로 출력하는 비교기(21)를 포함하여 구성된다.The first comparison unit 20 outputs a result of comparing the sensing signal obtained by sensing the current flowing through the inductor L of the resonance circuit 10 with the first comparison reference signal V_REF1 from the control unit 30. The first comparison unit 20 calculates the result according to the relative magnitude between the rectifier 22 that outputs the sensing signal output by the CT by full-wave rectification or half-wave rectification, and the first comparison reference signal and the signal from the rectifier 22. It includes a comparator 21 that outputs in the form of a binary pulse signal.

인덕터(L)에 흐르는 전류를 센싱한 센싱 신호는 그라운드를 기준으로 음의 전압 및 양의 전압을 모두 가진 신호이며 이를 정류기(22)를 통하여 정류함으로써 한쪽의 전압(양의 전압)만을 가진 신호로 바꾼다. The sensing signal that senses the current flowing through the inductor (L) is a signal that has both negative and positive voltages based on the ground, and rectifies it through the rectifier 22 to produce a signal with only one voltage (positive voltage). Change.

예를 들어 비교기(21)는 OP AMP로써 구현될 수 있다. 정류기(22)로부터의 신호는 OP AMP의 + 입력으로 인가되고 제어부(30)로부터의 제 1 비교기준 신호(V_REF1)는 OP AMP의 - 입력으로 인가되며, OP AMP의 출력은 제어부(30)로 입력된다. For example, the comparator 21 may be implemented as an OP AMP. The signal from the rectifier 22 is applied to the + input of the OP AMP, the first comparison reference signal V_REF1 from the control unit 30 is applied as the-input of the OP AMP, and the output of the OP AMP is applied to the control unit 30. Is entered.

공진회로(10)는 예를 들어 매우 높은 최고 전압에까지 이를 수 있으나, 제 1 비교부(20)와 제어부(30) 등은 5V와 같이 낮은 직류 전원전압에서 동작될 수 있다.The resonance circuit 10 may reach a very high maximum voltage, for example, but the first comparator 20 and the control unit 30 may operate at a low DC power voltage such as 5V.

제 1 비교부(20)는 센싱 신호의 크기와 제어부로부터의 제 1 비교기준 신호의 크기를 비교하여 정해진 어느 한쪽이 더 큰 경우에는 직류 전원전압의 레벨(예를 들면 5V)을 출력하며, 그렇지 않는 경우 그라운드 레벨을 출력한다. The first comparison unit 20 compares the size of the sensing signal and the size of the first comparison reference signal from the control unit, and outputs the level of the DC power supply voltage (for example, 5V) when the determined one is larger. If not, the ground level is output.

제어부(30)는 제 1 비교부(20)로 제 1 비교기준 신호(V_REF1)를 출력하고 게이트 드라이버(40)를 제어하는 신호를 출력하며, 전기렌지를 구성하는 비도시된 기타 구성요소를 제어하고 I/O 장치를 이용해 사용자로부터의 입출력을 수행할 수도 있다. 예를 들어, 터치패드 및 스위치 등을 이용해 사용자로부터 출력 파워레벨을 정하는 명령을 수신할 수 있다. 예를 들어 사용자로부터의 출력 파워레벨 명령은 1단계 내지 9단계의 레벨 등 복수의 단계를 가지는 명령일 수 있다.The control unit 30 outputs a first comparison reference signal V_REF1 to the first comparison unit 20, outputs a signal for controlling the gate driver 40, and controls other components not shown constituting the electric stove. I/O devices can be used to perform input/output from users. For example, a command for determining the output power level may be received from a user using a touch pad and a switch. For example, the output power level command from the user may be a command having a plurality of levels such as levels 1 to 9 levels.

제어부(30)는 제 1 비교기준 신호(V_REF1)를 출력하되 제 1 비교기준 신호(V_REF1)의 전압 레벨을 고정시키지 않고 상황에 따라 가변하며, 제어부(30)는 마이크로프로세서, 마이크로 컨트롤러 등으로 구현될 수 있으며, 제 1 비교기준 신호(V_REF1)의 전압 레벨 가변을 위해 내·외부에 DAC(Digital Analog Converter)를 포함할 수도 있다. The control unit 30 outputs the first comparison reference signal V_REF1, but does not fix the voltage level of the first comparison reference signal V_REF1 but varies according to the situation, and the control unit 30 is implemented by a microprocessor, a microcontroller, etc. In addition, a digital analog converter (DAC) may be included inside and outside to change the voltage level of the first comparison reference signal V_REF1.

제어부(30)는 제 1 비교부(20)로부터의 출력 신호를 입력받아 제어에 이용하는 데, 특히 게이트 드라이버(40)의 제어, 따라서 제 1 FET(Q1) 및 제 2 FET(Q2)의 제어에 이용한다. 제어부(30)는 제 1 비교부(20)로부터의 출력 신호를 입력받아 공진회로(10)의 동작과 동작 주파수의 제어에 이용한다.The control unit 30 receives the output signal from the first comparison unit 20 and uses it for control. In particular, the control unit 30 controls the gate driver 40 and thus the first FET (Q1) and the second FET (Q2). Use. The control unit 30 receives an output signal from the first comparison unit 20 and uses it to control the operation of the resonance circuit 10 and the operating frequency.

제어부(30)는 전자 렌지의 상판위에 용기가 올려져 있는지를 판단하게 되는 데, 용기 유무를 판단하기 위하여 동작 주파수 별로 제 1 비교기준 신호(V_REF1)의 전압 레벨이 서로 다르게 되도록 설정한다. 예를 들어, 출력 파워레벨이 총 9 단계로 설계되어 있다면, 동작 주파수를 9 가지로 하고 제 1 비교기준 신호(V_REF1)의 전압 레벨도 9 단계로 한다.The control unit 30 determines whether a container is placed on the top plate of the microwave oven. In order to determine the presence or absence of the container, the control unit 30 sets the voltage level of the first comparison reference signal V_REF1 to be different for each operating frequency. For example, if the output power level is designed in 9 stages, the operating frequency is 9 and the voltage level of the first comparison reference signal V_REF1 is also 9 stages.

그리고 제어부(30)는 제 1 비교부(20)로부터의 출력 신호에서 펄스열이 나타나면 용기가 있는 것으로 판단하고 제 1 비교부(20)로부터의 출력 신호에서 펄스열이 나타나지 않으면 용기가 없는 것으로 판단한다. 펄스열이 나타나는지 여부를 판단함에 있어서, 정해진 시간에 정해진 갯수 이상의 펄스가 있으면 펄스열이 나타난 것으로 할 수 있다. In addition, if the pulse train appears in the output signal from the first comparison unit 20, the controller 30 determines that there is a container, and if the pulse train does not appear in the output signal from the first comparison unit 20, it determines that there is no container. In determining whether or not a pulse train appears, if there are more than a predetermined number of pulses at a predetermined time, it may be considered that the pulse train appears.

용기 유무를 판단하기 위한 제 1 비교기준 신호(V_REF1)의 전압 레벨은 구체적으로 다음과 같이 설정될 수 있다.The voltage level of the first comparison reference signal V_REF1 for determining the presence or absence of a container may be specifically set as follows.

전기렌지의 출력을 제어하기 위한 동작 주파수가 공진 회로(10)의 공진 주파수에 가까울수록 용기 유무의 판단을 위한 제 1 비교기준 신호(V_REF1)의 전압 레벨은 크게 설정되며, 전기렌지의 출력을 제어하기 위한 동작 주파수가 공진 회로(10)의 공진 주파수로부터 멀수록 용기 유무의 판단을 위한 제 1 비교기준 신호(V_REF1)의 전압 레벨은 작게 설정된다.As the operating frequency for controlling the output of the electric stove is closer to the resonance frequency of the resonance circuit 10, the voltage level of the first comparison reference signal V_REF1 for judging the presence or absence of a container is set larger, and the output of the electric stove is controlled. The voltage level of the first comparison reference signal V_REF1 for determining the presence or absence of a container is set to be smaller as the operating frequency is further away from the resonance frequency of the resonance circuit 10.

그리고 본 발명의 일 실시예에 따른 유도가열방식의 전기렌지는 설정되어 예상되는 예상 파워레벨과 실제 파워레벨을 비교하여 공진회로에 대하여 피드백한다.In addition, the electric stove of the induction heating method according to an embodiment of the present invention is set and compared with the expected power level and the actual power level to feed back the resonance circuit.

제어부(30)는 제 1 비교기준 신호(V_REF1)의 전압 레벨을 순차적으로 가변하면서 제 1 비교부(20)로부터의 출력 신호를 입력받아 공진회로(10)의 실제 파워레벨을 결정하며, 공진회로(10)의 실제 파워레벨이 예상 파워레벨에 도달하였는지를 판단한다. The control unit 30 sequentially varies the voltage level of the first comparison reference signal V_REF1 and receives the output signal from the first comparison unit 20 to determine the actual power level of the resonance circuit 10, and the resonance circuit It is determined whether the actual power level of (10) has reached the expected power level.

이때 제어부(30)는 제 1 비교부(20)에 인가되는 제 1 비교기준 신호(V_REF1)가 복수의 전압 레벨에 있을 때의 각각마다, 제 1 비교부(20)로부터의 출력 신호에서 펄스열이 나타나는지를 보고, 공진회로(10)(즉 전기렌지)의 출력 파워레벨을 감지할 수 있다. 이때 제어부(30)는 이진 탐색 알고리즘을 채용하여 탐색과정에서 탐색용 제 1 비교기준 신호(V_REF1)의 전압 레벨을 순차 결정할 수 있다.At this time, the control unit 30 generates a pulse train from the output signal from the first comparison unit 20 each time the first comparison reference signal V_REF1 applied to the first comparison unit 20 is at a plurality of voltage levels. Seeing whether it appears, it is possible to detect the output power level of the resonance circuit 10 (that is, the electric stove). In this case, the controller 30 may sequentially determine the voltage level of the first comparison reference signal V_REF1 for search in the search process by employing a binary search algorithm.

제어부(30)는 제 1 비교기준 신호(V_REF1)의 전압 레벨을 순차적으로 가변하면서 제 1 비교부(20)로부터의 출력 신호를 입력받아 공진회로(10)의 실제 파워레벨을 결정하며, 결정된 실제 파워레벨과 예상 파워레벨의 차이에 따라 공진 회로(10)의 동작 주파수가 변경되도록 제어함으로써 실시간 피드백 루프를 형성한다. 피드백 루프는 제어부(30) - 게이트 드라이브(40) - FET(Q1,Q2) - 공진회로(10) - 제 1 비교부(20) - 제어부(30)의 경로를 따른 폐루프를 구성한다.The control unit 30 sequentially varies the voltage level of the first comparison reference signal V_REF1 and receives the output signal from the first comparison unit 20 to determine the actual power level of the resonant circuit 10. A real-time feedback loop is formed by controlling the operating frequency of the resonant circuit 10 to change according to the difference between the power level and the expected power level. The feedback loop constitutes a closed loop along the path of the control unit 30-the gate drive 40-FETs (Q1, Q2)-the resonance circuit 10-the first comparator 20-the control unit 30.

종래 출력 파워레벨의 감지 방식에서는 노이즈 면역성(Noise Immunity)을 위하여 피드백 루프에 평활회로가 개재됨으로써 전하 축적을 위한 시간이 더 부가하게 되고 이는 피드백 루프에 적분요소를 부가하게 되는 결과를 초래한다. 이에 따라 지연시간이 더 필요하며 자칫 오버슈트를 불러오거나 오버슈트를 피하기 위한 피드백 제어를 어렵게 하는 문제가 있다. In the conventional output power level detection method, a smoothing circuit is interposed in the feedback loop for noise immunity, thereby adding more time for charge accumulation, resulting in adding an integral factor to the feedback loop. Accordingly, there is a problem in that a delay time is required and it is difficult to induce an overshoot or to control a feedback to avoid an overshoot.

본 발명의 일 실시예에 따르면, 종래와 같은 평활회로가 없어도 노이즈 면역성(Noise Immunity)을 달성할 수 있으며, 나아가 종래의 방식에 비하여 출력 파워레벨의 조정을 위한 피드백 루프의 지연 시간과 용기유무의 판단을 위한 지연시간이 저감되는 장점이 있다.According to an embodiment of the present invention, noise immunity can be achieved even without a smoothing circuit as in the prior art, and further, the delay time of the feedback loop for adjusting the output power level and the presence or absence of a container compared to the conventional method. There is an advantage in that the delay time for judgment is reduced.

그리고 피드백 루프에서의 지연 시간이 저감됨으로써 종래 오버슈트의 문제를 저감하며 보다 빠르고 정확하게 사용자에 의해 설정된 출력 파워레벨로 도달할 수 있는 효과가 있다.In addition, by reducing the delay time in the feedback loop, there is an effect of reducing the problem of conventional overshoot and reaching the output power level set by the user more quickly and accurately.

도 2는 본 발명의 변형 실시예에 따른 유도가열방식 전기렌지에서 주요 전기적 회로를 도시한 회로도이다.2 is a circuit diagram showing a main electrical circuit in an induction heating type electric stove according to a modified embodiment of the present invention.

변형 실시예에서는 제 2 비교부(60)가 추가 구성되는 점이 서로 다르며, 기타의 구성은 도 1로써 설명된 실시예의 구성과 유사하다.The modified embodiment differs in that the second comparison unit 60 is additionally configured, and other configurations are similar to those of the embodiment described with reference to FIG. 1.

제 2 비교부(60)는 공진회로(10)의 인덕터(L)에 흐르는 전류를 센싱한 센싱 신호와 제 2 비교기준 신호(V_REF2)를 비교한 결과를 출력하며, 제어부(30)는 제 2 비교부(60)로 전압 레벨이 고정된 제 2 비교기준 신호(V_REF2)를 출력하고, 제 2 비교부(60)로부터의 출력 신호에 의해 인덕터(L)의 연결 여부를 판단한다.The second comparison unit 60 outputs a result of comparing the sensing signal obtained by sensing the current flowing through the inductor L of the resonance circuit 10 with the second comparison reference signal V_REF2, and the controller 30 A second comparison reference signal V_REF2 having a fixed voltage level is output to the comparison unit 60, and it is determined whether or not the inductor L is connected based on the output signal from the second comparison unit 60.

제 2 비교부(60)는 제 1 비교부(20)의 정류기(22)를 공유하여 정류기(22)로부터의 출력을 이용하거나 별도 구성할 수도 있으며, 또는 정류기(22)없이 바로 CT로부터의 센싱신호를 이용할 수도 있다. The second comparator 60 may share the rectifier 22 of the first comparator 20 to use the output from the rectifier 22 or may be configured separately, or sensing directly from the CT without the rectifier 22 You can also use signals.

제 2 비교부(60)의 비교기(61)는 고정된 전압 레벨을 가지는 제 2 비교기준 신호와 센싱 신호(센싱 신호를 정류한 신호도 이에 포함된다) 사이의 상대적 크기에 따른 결과를 이진펄스신호 형태로 출력한다. 제어부(30)가 출력하는 제 2 비교기준 신호(V_REF2)는 매우 낮은 최소한의 전압 레벨로서, 제어부(30)는 제 2 비교부(60)의 출력 신호, 즉 비교기(61)의 출력 신호에서 펄스열이 나타나는지에 따라 인덕터(L)의 연결 여부를 판단한다.The comparator 61 of the second comparator 60 converts the result according to the relative magnitude between the second comparison reference signal having a fixed voltage level and the sensing signal (a signal obtained by rectifying the sensing signal is also included) to a binary pulse signal. Output in the form. The second comparison reference signal V_REF2 output from the control unit 30 is a very low minimum voltage level, and the control unit 30 is a pulse train in the output signal of the second comparison unit 60, that is, the output signal of the comparator 61 It is determined whether or not the inductor L is connected according to whether appears.

예를 들어 비교기(61)는 OP AMP로써 구현될 수 있다. 정류기(22)로부터의 신호는 OP AMP의 + 입력으로 인가되고 제어부(30)로부터의 제 2 비교기준 신호(V_REF2)는 OP AMP의 - 입력으로 인가되며, OP AMP의 출력은 제어부(30)로 입력된다. For example, the comparator 61 may be implemented as an OP AMP. The signal from the rectifier 22 is applied to the + input of the OP AMP, the second comparison reference signal (V_REF2) from the control unit 30 is applied as the-input of the OP AMP, and the output of the OP AMP is applied to the control unit 30. Is entered.

제 2 비교부(60)는 센싱 신호의 크기와 제어부로부터의 제 2 비교기준 신호의 크기를 비교하여 정해진 어느 한쪽이 더 큰 경우에는 직류 전원전압의 레벨(예를 들면 5V)을 출력하며, 그렇지 않는 경우 그라운드 레벨을 출력한다. The second comparison unit 60 compares the size of the sensing signal with the size of the second comparison reference signal from the control unit, and outputs the level of the DC power voltage (for example, 5V) when the determined one is larger. If not, the ground level is output.

이하 본 발명에 따른 유도가열방식의 전기렌지의 동작에 대하여 설명하되 이미 설명된 내용에 대해서는 간략히 설명되거나 생략될 수 있다. Hereinafter, the operation of the electric stove of the induction heating method according to the present invention will be described, but the already described contents may be briefly described or omitted.

도 3은 본 발명의 일 실시예에 따른 유도가열방식의 전기렌지의 동작에서 출력 파워의 설정 및 감지를 설명하기 위한 신호 타이밍도이다. 도 4는 본 발명의 일 실시예에 따른 유도가열방식의 전기렌지의 동작에서 용기 인식을 설명하기 위한 신호 타이밍도이다.3 is a signal timing diagram for explaining the setting and detection of output power in the operation of the induction heating type electric stove according to an embodiment of the present invention. 4 is a signal timing diagram for explaining container recognition in the operation of an induction heating type electric stove according to an embodiment of the present invention.

사용자는 I/O 장치(미도시)를 이용하여 전기렌지의 출력 파워레벨을 설정할 수 있으며, 제어부(30)는 이를 입력받는다. 예를 들어 사용자에 의해 출력 파워레벨이 최고 단계인 9 단계로 설정된 경우, 9 단계에 대응하는 동작주파수로 공진회로가 동작하도록 제어하게 되는 데, 바로 9 단계에 대응하는 동작 주파수로 하기 보다는 아래 단계에 대응하는 동작 주파수로부터 시작하여 순차 변경하여 9 단계의 동작주파수에 이르도록 할 수 있다.The user can set the output power level of the electric stove using an I/O device (not shown), and the control unit 30 receives the input. For example, if the output power level is set to 9 stages, which is the highest stage, by the user, the resonance circuit is controlled to operate at the operating frequency corresponding to the 9 stages. Starting from the operating frequency corresponding to, it can be changed sequentially to reach the operating frequency of 9 steps.

동일한 9 단계의 동작주파수로 설정하더라도 공진의 특성상 비제어시 출력이 불안정할 수 있는 점과, 용기의 재질, 용기의 크기, 인덕터와 용기의 상대적 위치 등에 따라 공진회로에 걸리는 출력 파워레벨은 서로 상이할 수 있다. 특히 동일한 9 단계의 동작주파수로 설정했는데도 출력 파워레벨이 과도해져서 전자렌지의 구성 부품에 고장이나 피로를 증가시킬 수 있다.Even if the operating frequency of the same 9 steps is set, the output power level applied to the resonance circuit differs from each other depending on the characteristics of the resonance that the output may be unstable when uncontrolled, and the material of the container, the size of the container, and the relative position of the inductor and the container. can do. In particular, even if the operating frequency is set to the same 9 steps, the output power level becomes excessive, which can increase the failure or fatigue of the components of the microwave oven.

따라서 단계를 높여가면서 최고 단계의 동작주파수에 이르도록 하고 동일한 최고 단계라 하더라도 상황에 따라 최종 설정되는 주파수에 미세 편차를 두며, 아래 단계의 동작주파수 설정에 따른 출력 파워레벨을 참조하여 목표로 하는 단계의 동작주파수 설정에 참조한다. Therefore, the step is raised to reach the highest operating frequency, and even at the same highest step, a small deviation is made in the final frequency set according to the situation, and the target step is made by referring to the output power level according to the operating frequency setting in the following steps. Refer to the setting of operating frequency.

예를 들어 7 단계 - 8 단계 - 9 단계의 동작주파수를 순차 변경하되, 7 단계 및 8 단계의 동작 주파수 설정에 따른 실제 출력 파워레벨을 감지하여 9 단계의 동작 주파수의 미세 설정에 이용한다.For example, the operating frequency of step 7-step 8-step 9 is sequentially changed, but the actual output power level according to the operating frequency setting in step 7 and step 8 is detected and used for fine setting of the operating frequency in step 9.

예를 들어 9 단계로 가는 과정 도중, 8 단계의 출력 파워에 대응하는 동작 주파수를 설정하고 그에 따른 실제 출력 파워레벨을 감지하는 경우를 상정해본다. For example, in the process of going to step 9, it is assumed that the operating frequency corresponding to the output power of step 8 is set and the actual output power level is sensed accordingly.

제어부(30)는 게이트 드라이버(40)가 동작 주파수(f8)에 해당하는 스위칭 신호를 출력할 수 있도록 저전압, 예를 들면 5V 레벨의 펄스 신호를 출력하며, 이러한 펄스 신호는 [1/동작 주파수(f8)]의 주기 또는 이러한 주기에 가드 밴드를 가진 신호나 그 유사한 신호일 수 있다.The control unit 30 outputs a pulse signal of a low voltage, for example, 5V level so that the gate driver 40 can output a switching signal corresponding to the operating frequency f 8 , and such a pulse signal is [1/operation frequency (f 8 )] or a signal with a guard band in this period or a similar signal.

그리고 게이트 드라이버(40)는 제어부(30)로부터의 펄스 신호에 기반하여 신호를 전류 및 전압 증폭하여 FET(Q1,Q2)에 걸리는 고전압에 대응할 수 있도록 한다.In addition, the gate driver 40 amplifies the current and voltage signals based on the pulse signal from the control unit 30 to respond to the high voltage applied to the FETs Q1 and Q2.

그리고 FET(Q1,Q2)의 스위칭에 의해 공진회로의 출력 파워레벨을 높이는 과정이라면 동작 주파수가 공진 주파수에 더욱 가까이 다가 가게 되며, 공진회로에서 오실레이션되는 전류 및 전압의 크기가 증대된다. 정확한 실제 출력 파워레벨을 감지하기 위하여 CT, 제 1 비교부(20) 및 제어부(30)를 이용한다. And if the process of increasing the output power level of the resonant circuit by switching of the FETs (Q1, Q2), the operating frequency becomes closer to the resonant frequency, and the magnitude of the current and voltage oscillated in the resonant circuit increases. The CT, the first comparison unit 20 and the control unit 30 are used to detect the exact actual output power level.

CT를 이용하여 센싱된 센싱 신호는 정류기(22)를 이용하여 반파정류 또는 전파정류된 센싱 신호가 되며(도 3의 V_S 신호 참조), 이러한 센싱 신호가 설정된 출력 파워레벨(예: 8 단계)에 도달하였는지 또는 어느 정도레벨인지를 판단하기 위하여 제어부(30)로부터 제 1 비교부(20), 구체적으로 비교기(21)에 인가되는 신호(V_REF1)의 전압은 처음 V1(가능한 최대 전압크기의 1/2)부터 시작할 수 있다. The sensing signal sensed using the CT becomes a half-wave rectified or full-wave rectified sensing signal using the rectifier 22 (refer to the V_S signal in Fig. 3), and the sensing signal is at the set output power level (eg, step 8). The voltage of the signal V_REF1 applied from the control unit 30 to the first comparator 20, specifically the comparator 21, in order to determine whether it has reached or at what level, is initially V1 (1/ You can start with 2).

비교기(21)에서 센싱신호(V_S)와 전압(v=V1)이 비교되어 도 3(b)에 도시된 것과 같은 펄스열이 나타나면, 그 다음으로 비교기(21)에 인가되는 신호(V_REF1)는 최대 전압크기의 1/4만큼 증가한 V2가 인가될 수 있다. 이 경우에도 비교기(21)의 출력에는 펄스열이 나타날 것이므로 다시 1/8만큼 증가한 V3가 인가될 수 있으며 이때에도 비교기(21)의 출력에는 펄스열이 도 3(c)에 도시된 것과 같은 펄스열이 나타나므로 다시 V4가 인가될 수 있으며 이때 펄스열이 나타나지 않으면 다시 1/16만큼 감소한 전압 등이 인가되는 순서로 해서 순차 감지할 수 있다.When the sensing signal V_S and the voltage (v=V1) are compared in the comparator 21 and a pulse train as shown in FIG. 3(b) appears, the signal V_REF1 applied to the comparator 21 is then maximum. V2 increased by 1/4 of the voltage level may be applied. Even in this case, since a pulse train will appear at the output of the comparator 21, V3 increased by 1/8 may be applied again, and even at this time, a pulse train as shown in Fig. 3(c) appears at the output of the comparator 21. Therefore, V4 can be applied again, and if the pulse train does not appear at this time, the voltage reduced by 1/16 can be sequentially detected in the order of application.

출력 파워레벨은 최소 해상도의 증가분까지 더하여 인가된 후 결정될 수 있으며, 마지막 인가된 전압레벨 또는 그 전후의 전압레벨로 결정될 수 있다. The output power level may be determined after being applied by adding up to the increment of the minimum resolution, and may be determined as the last applied voltage level or a voltage level before or after it.

이와 같은 방식으로 설정된 출력 파워레벨에 따라 실제의 출력 파워레벨이 감지될 수 있으며, 예를 들면 8 단계의 실제 출력파워레벨이 설정된 출력파워레벨보다 높은 경우, 9 단계의 출력파워레벨에 대응하는 동작주파수를 설정할 때 이를 참작하여 동작주파수가 공진주파수로부터 더 멀리 있도록 피드백을 가한다.The actual output power level can be detected according to the output power level set in this way. For example, when the actual output power level of 8 steps is higher than the set output power level, an operation corresponding to the output power level of 9 steps Taking this into account when setting the frequency, feedback is applied so that the operating frequency is farther from the resonant frequency.

상기한 과정에서 출력 파워레벨이 어느 정도 예상되므로 앞단계는 생략될 수도 있다.Since the output power level is expected to some extent in the above process, the preceding step may be omitted.

이와 같은 출력 파워레벨의 감지를 위하여 레벨변경-감지의 반복적인 과정이 필요함에도, 본 발명에 따르면 이와 같은 과정은 매우 빠른 시간에 완료될 수 있으며, 설정후 감지까지 걸리는 지연 시간이 최소화될 수 있다.Although a repetitive process of level change-sensing is required to detect such an output power level, according to the present invention, such a process can be completed in a very fast time, and a delay time taken to detection after setting can be minimized. .

한편, 출력 파워레벨이 정해지기 이전 또는 이후에도 용기가 전기렌지위에 올려져 있는지를 감지할 필요가 있다.On the other hand, it is necessary to detect whether the container is placed on the electric stove before or after the output power level is determined.

본 발명의 일 실시예에 따르면 용기 유무를 판단하기 위하여 동작 주파수 별로 제 1 비교기준 신호(V_REF1)의 전압 레벨이 서로 다르게 설정되며, 제어부(30)는 제 1 비교부(20)로부터의 출력 신호에서 펄스열이 나타나면 용기가 있는 것으로 판단하고 제 1 비교부(20)로부터의 출력 신호에서 펄스열이 나타나지 않으면 용기가 없는 것으로 판단한다. 이때 제 1 비교기준 신호(V_REF1)는 출력 파워레벨의 감지를 위해 사용되는 전압과는 상이할 수 있으며, 출력 파워레벨의 감지와 용기 유무의 감지는 시간을 달리해서 진행된다. According to an embodiment of the present invention, the voltage level of the first comparison reference signal V_REF1 is set differently for each operating frequency in order to determine the presence or absence of a container, and the control unit 30 provides an output signal from the first comparison unit 20. If the pulse train appears in, it is determined that there is a container, and if the pulse train does not appear in the output signal from the first comparison unit 20, it is determined that there is no container. At this time, the first comparison reference signal V_REF1 may be different from the voltage used for detection of the output power level, and the detection of the output power level and the presence or absence of a container are performed at different times.

예를 들면, 출력 파워레벨이 1단계 ~ 9단계로 되어 있으면 제 1 비교기준 신호(V_REF1)의 전압 레벨은 9 가지로 미리 정해져 있을 수 있다(도 4(a)에서 v=V1 ~ V9). 예를 들어 출력 파워레벨이 제 n 단계로 설정된 경우, v=Vn (도 3에서 설명되는 V1 ~ V4와는 다른 전압일 수 있다)의 전압을 가지는 제 1 비교기준 신호(V_REF1)가 비교기(21)로 인가되고 이와 센싱 신호(V_S)가 비교되어 비교기(21)로부터의 출력 신호(V_OUT1)가 정해질 수 있다.For example, if the output power level is in steps 1 to 9, the voltage level of the first comparison reference signal V_REF1 may be preset as 9 types (v=V1 to V9 in FIG. 4(a)). For example, when the output power level is set to the nth step, the first comparison reference signal V_REF1 having a voltage of v=Vn (which may be a different voltage from V1 to V4 described in FIG. 3) is the comparator 21 And the sensing signal V_S is compared with the sensing signal V_S to determine the output signal V_OUT1 from the comparator 21.

출력 신호(V_OUT1)에서 펄스열이 나타나면(도 4(a) 참조) 용기가 있는 것으로 판단하며, 출력 신호(V_OUT1)에서 펄스열이 나타나지 않으면(도 4(b) 참조) 용기가 없는 것으로 판단한다.If a pulse train appears in the output signal V_OUT1 (see FIG. 4(a)), it is determined that there is a container, and if the pulse train does not appear in the output signal V_OUT1 (see FIG. 4(b)), it is determined that there is no container.

Claims (6)

공진회로(10)를 구비하는 유도가열방식의 전기렌지에 있어서, In an induction heating type electric stove having a resonance circuit 10, 상기 전기렌지는 상기 공진 회로(10)의 동작 주파수를 제어함으로써 상기 전기렌지의 출력을 제어하는 주파수 제어 방식을 채용하되,The electric stove adopts a frequency control method of controlling the output of the electric stove by controlling the operating frequency of the resonance circuit 10, 상기 공진회로(10)의 인덕터(L)에 흐르는 전류를 센싱한 센싱 신호와 제 1 비교기준 신호(V_REF1)를 비교한 결과를 출력하는 제 1 비교부(20); 및A first comparison unit 20 outputting a result of comparing a sensing signal obtained by sensing a current flowing through the inductor L of the resonance circuit 10 with a first comparison reference signal V_REF1; And 상기 제 1 비교부(20)로 상기 제 1 비교기준 신호(V_REF1)를 출력하되 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨을 가변하며, 상기 제 1 비교부(20)로부터의 출력 신호를 입력받아 제어하는 제어부(30);를 포함하며,The first comparison reference signal V_REF1 is output to the first comparison unit 20, but the voltage level of the first comparison reference signal V_REF1 is varied, and the output signal from the first comparison unit 20 is Includes; a control unit 30 for receiving and controlling the input, 용기 유무를 판단하기 위하여 상기 동작 주파수 별로 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨이 서로 다르게 설정되어 있으며,In order to determine the presence or absence of a container, the voltage level of the first comparison reference signal V_REF1 is set differently for each operating frequency, 상기 제 1 비교부(20)로부터의 출력 신호에서 펄스열이 나타나면 용기가 있는 것으로 판단하고 상기 제 1 비교부(20)로부터의 출력 신호에서 펄스열이 나타나지 않으면 용기가 없는 것으로 판단하되, 펄스열이 나타나는지 여부를 판단함에 있어서 정해진 시간에 정해진 갯수 이상의 펄스가 있으면 펄스열이 나타난 것으로 하며,If a pulse train appears in the output signal from the first comparator 20, it is determined that there is a container, and if the pulse train does not appear in the output signal from the first comparator 20, it is determined that there is no container. In judging, if there are more than a set number of pulses at a set time, it is assumed that a pulse train appears 상기 제어부(30)는 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨을 순차적으로 가변하면서 상기 제 1 비교부(20)로부터의 출력 신호를 입력받아 상기 공진회로(10)의 실제 파워레벨을 결정하며, 상기 공진회로(10)의 실제 파워레벨이 예상 파워레벨에 도달하였는지를 판단하고, 결정된 실제 파워레벨과 예상 파워레벨의 차이에 따라 상기 공진 회로(10)의 동작 주파수가 변경되도록 제어함으로써 실시간 피드백 루프를 형성하는 것을 특징으로 하는,The control unit 30 receives an output signal from the first comparison unit 20 while sequentially varying the voltage level of the first comparison reference signal V_REF1 and determines the actual power level of the resonance circuit 10 And, by determining whether the actual power level of the resonance circuit 10 has reached the expected power level, and controlling the operating frequency of the resonance circuit 10 to change according to the difference between the determined actual power level and the expected power level, real-time feedback Characterized in that to form a loop, 유도가열방식의 전기렌지.Electric stove with induction heating method. 청구항 1에 있어서,The method according to claim 1, 상기 전기렌지의 출력을 제어하기 위한 상기 동작 주파수가 상기 공진 회로(10)의 공진 주파수에 가까울수록 상기 용기 유무의 판단을 위한 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨은 크게 설정되며,As the operating frequency for controlling the output of the electric stove is closer to the resonance frequency of the resonant circuit 10, the voltage level of the first comparison reference signal V_REF1 for determining the presence or absence of the container is set higher, 상기 전기렌지의 출력을 제어하기 위한 상기 동작 주파수가 상기 공진 회로(10)의 공진 주파수로부터 멀수록 상기 용기 유무의 판단을 위한 상기 제 1 비교기준 신호(V_REF1)의 전압 레벨은 작게 설정되는,As the operating frequency for controlling the output of the electric stove is further from the resonance frequency of the resonance circuit 10, the voltage level of the first comparison reference signal V_REF1 for determining the presence or absence of the container is set to be smaller, 유도가열방식의 전기렌지.Electric stove with induction heating method. 청구항 1에 있어서,The method according to claim 1, 상기 공진회로(10)의 인덕터(L)에 흐르는 전류를 센싱한 센싱 신호를 출력하는 CT;를 더 포함하며,CT for outputting a sensing signal sensing the current flowing through the inductor (L) of the resonance circuit 10; further includes, 상기 제 1 비교부(20)는, The first comparison unit 20, 상기 CT가 출력하는 센싱 신호를 정류하여 출력하는 정류기(22);A rectifier 22 rectifying and outputting the sensing signal output from the CT; 상기 제 1 비교기준 신호와 상기 정류기(22)로부터의 신호 사이의 상대적 크기에 따른 결과를 이진펄스신호 형태로 출력하는 비교기(21);를 포함하여 구성되는,Comparator 21 for outputting a result according to the relative magnitude between the first comparison reference signal and the signal from the rectifier 22 in the form of a binary pulse signal; 유도가열방식의 전기렌지.Electric stove with induction heating method. 청구항 1에 있어서,The method according to claim 1, 상기 공진회로(10)의 인덕터(L)에 흐르는 전류를 센싱한 센싱 신호와 제 2 비교기준 신호(V_REF2)를 비교한 결과를 출력하는 제 2 비교부(60);를 더 포함하며,A second comparison unit 60 outputting a result of comparing the sensing signal obtained by sensing the current flowing through the inductor L of the resonance circuit 10 with the second comparison reference signal V_REF2; and 상기 제어부(30)는 상기 제 2 비교부(60)로 전압 레벨이 고정된 상기 제 2 비교기준 신호(V_REF2)를 출력하며, 상기 제 2 비교부(60)로부터의 출력 신호에 의해 상기 인덕터(L)의 연결 여부를 판단하는,The control unit 30 outputs the second comparison reference signal V_REF2 having a fixed voltage level to the second comparison unit 60, and the inductor () by the output signal from the second comparison unit 60 L) to determine whether to connect, 유도가열방식의 전기렌지.Electric stove with induction heating method. 청구항 1에 있어서,The method according to claim 1, 상기 공진회로(10)는,The resonance circuit 10, 상용 전력을 정류한 직류 전압원에 일단이 연결되는 제 1 커패시터(C1);A first capacitor C1 having one end connected to a DC voltage source rectifying commercial power; 상기 제 1 커패시터(C1)의 타단에 그 일단이 연결되고 타단은 접지에 연결되는 제 2 커패시터(C2);A second capacitor C2 having one end connected to the other end of the first capacitor C1 and the other end connected to the ground; 상기 제 1 커패시터(C1) 및 상기 제 2 커패시터(C2)가 접속되는 노드에 그 일단이 연결되는 상기 인덕터(L);를 포함하여 구성되는,The inductor L having one end connected to a node to which the first capacitor C1 and the second capacitor C2 are connected; 유도가열방식의 전기렌지.Electric stove with induction heating method. 청구항 5에 있어서,The method of claim 5, 상기 제 1 커패시터(C1)의 일단과 상기 인덕터(L)의 타단에 드레인 및 소스가 각각 연결되는 제 1 FET(Q1);A first FET Q1 having a drain and a source connected to one end of the first capacitor C1 and the other end of the inductor L; 상기 인덕터(L)의 타단과 상기 제 2 커패시터(C2)의 타단에 드레인 및 소스가 각각 연결되는 제 2 FET(Q2);A second FET Q2 having a drain and a source connected to the other end of the inductor L and the other end of the second capacitor C2, respectively; 상기 제어부(30)로부터의 제어에 따라 상기 제 1 FET(Q1) 및 상기 제 2 FET(Q2)의 게이트로 ON/OFF 신호를 출력하는 게이트 드라이버(40);를 포함하여 구성되는, A gate driver 40 for outputting an ON/OFF signal to the gates of the first FET (Q1) and the second FET (Q2) under control from the controller 30; 유도가열방식의 전기렌지.Electric stove with induction heating method.
PCT/KR2019/014237 2019-03-27 2019-10-28 Low electromagnetic induction heating electric stove Ceased WO2020197022A1 (en)

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JPH06176862A (en) * 1992-12-08 1994-06-24 Hitachi Home Tec Ltd Induction heating cooker
KR19990058258A (en) * 1997-12-30 1999-07-15 구자홍 Electro-induction heating cooker with dual half bridge with multiple loads
KR20030027222A (en) * 2001-09-18 2003-04-07 권용재 Apparatus for detecting cooking vessel of induction heating type cooker
JP2010182561A (en) * 2009-02-06 2010-08-19 Panasonic Corp Induction heating cooking device
KR101946872B1 (en) * 2018-07-11 2019-02-11 주식회사 네오스타이엘씨 Pot detection method and module of portable induction heater
KR102028066B1 (en) * 2019-03-27 2019-10-02 안순철 Electric range of induction heating type radiating low elctromagnetic wave

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06176862A (en) * 1992-12-08 1994-06-24 Hitachi Home Tec Ltd Induction heating cooker
KR19990058258A (en) * 1997-12-30 1999-07-15 구자홍 Electro-induction heating cooker with dual half bridge with multiple loads
KR20030027222A (en) * 2001-09-18 2003-04-07 권용재 Apparatus for detecting cooking vessel of induction heating type cooker
JP2010182561A (en) * 2009-02-06 2010-08-19 Panasonic Corp Induction heating cooking device
KR101946872B1 (en) * 2018-07-11 2019-02-11 주식회사 네오스타이엘씨 Pot detection method and module of portable induction heater
KR102028066B1 (en) * 2019-03-27 2019-10-02 안순철 Electric range of induction heating type radiating low elctromagnetic wave

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