Patent Grant
11979963
This application is a U.S. National Stage Application under 35 U.S.C. ยง 371 of PCT Application No. PCT/KR2018/002283, filed Feb. 23, 2018, which claims priority to Korean Patent Application No. 10-2017-0026814, filed Feb. 28, 2017, whose entire disclosures are hereby incorporated by reference.
The present disclosure relates to an induction-heating cooking apparatus that includes a sensing circuit for controlling an output of a heating coil, and more specifically, to an induction-heating cooking apparatus capable of enhancing accuracy in measuring electric currents of a heating coil by simply modifying a circuit.
In general, an induction-heating cooking apparatus is an electric cooking device that cooks food with the method in which high-frequency currents flow through a working coil or a heating coil, and when a strong magnetic line of force, generated as a result, passes through a cooking container, eddy currents flow such that the container itself is heated.
According to a basic theory of heating of the induction-heating cooking apparatus, as electric currents are supplied to a heating coil, a cooking container that is a magnetic substance generates heat through induction heating, and the cooking container itself is heated by the generated heat to cook food.
The configuration of a circuit of a conventional induction-heating cooking apparatus is described as follows with reference to
A driving circuit 10 used for an induction-heating electric cooking apparatus switches voltages that are supplied to a heating coil (Coil) such that high-frequency currents flow through the heating coil (Coil). The driving circuit 10 drives a switch unit 7 comprised of usual insulate gate bipolar transistors (IGBT) such that high-frequency currents flow through the heating coil and a high-frequency magnetic field is formed in the heating coil (Coil).
Specifically, the driving circuit 10 of the induction-heating electric cooking apparatus includes an alternating-current-power supplying unit 1 that is supplied with usual alternating current power, a rectifying unit 2 that rectifies the alternating current power, a filter 3 that filters the power rectified by the rectifying unit 2, and a switch unit 7 that is supplied with the power filtered by the filter 3, that drives switching devices and that supplies high-output power to a heating coil.
A sensor 20 is connected with the alternating-current-power supplying unit 1 and senses voltages or electric currents output from the alternating-current-power supplying unit 1. A control unit 30 calculates voltages or electric currents supplied to the heating coil (Coil) on the basis of voltages or electric currents measured by the sensor 20, and generates control signals for controlling operations of a switch driving unit 40 on the basis of the calculated voltages or electric currents. The switch driving unit 40 controls on/off operations of the switch unit 7 on the basis of the control signals received from the control unit 30.
In this case, electric currents flowing through the heating coil (Coil) have to be accurately sensed to precisely control an output of the heating coil (Coil). However, in a conventional sensing method, calculation of an output of a heating coil (Coil) lacks accuracy. Additionally, the convention sensing method is not appropriate to sense voltages or electric currents of a plurality of heating coils.
Further, a method of directly measuring electric currents or voltages flowing through a heating coil (Coil) at a node in which the heating coil (Coil) is placed may be used. However, with the method, constituting a circuit incurs huge costs.
The objective of the present disclosure is to provide an induction-heating cooking apparatus that may enhance accuracy in controlling an output of a heating coil by exactly sensing the output of the heating coil with a simple change in the structure of a circuit at low costs.
Another objective of the present disclosure is to provide an induction-heating cooking apparatus that may enhance accuracy in measuring outputs of a plurality of heating coils by exactly sensing the outputs of the plurality of heating coils with a simple change in the structure of a circuit at low costs.
Objectives of the present disclosure are not limited to what has been described. Additionally, other objectives and advantages that have not been mentioned may be clearly understood from the following description and may be more clearly understood from embodiments. Further, it will be understood that the objectives and advantages of the present disclosure may be realized via means and a combination thereof that are described in the appended claims.
An induction-heating cooking apparatus according to an embodiment includes a power supplying unit that supplies alternating current power, a rectifying unit that rectifies the alternating current power supplied by the power supplying unit, a filter that filters the power rectified by the rectifying unit, a first driving unit that includes a first switch unit supplying the power filtered by the filter to a first heating coil, and first sensing resistance disposed between the filter and the first switch unit, a sensor that measures electric currents flowing through the first sensing resistance, and a control unit that calculates an output of the first heating coil on the basis of the electric currents measured by the sensor.
An induction-heating cooking apparatus according to another embodiment includes a power supplying unit that supplies alternating current power, a rectifying unit that rectifies the alternating current power supplied by the power supplying unit, a filter that filters the power rectified by the rectifying unit, a first driving unit that supplies the filtered power to a first heating coil, wherein the first driving unit includes a first capacitor connected between one side of the first heating coil and one side of the filter, a second capacitor connected between one side of the first heating coil and the other side of the filter, a first switch connected between the other side of the first heating coil and one side of the first capacitor, a second switch connected between the other side of the first heating coil and one side of the second capacitor, and first sensing resistance connected between the other side of the filter and one side of the second capacitor.
The induction-heating cooking apparatus according to the present disclosure includes a circuit structure in which sensing resistance is added between a filter and a switch unit and electric currents flowing through the sensing resistance is measured, thereby making a circuit smaller than a circuit using a resonance CT sensor and reducing manufacturing costs. Additionally, electric currents flowing through sensing resistance and an output of a heating coil have linearity. Accordingly, the output of a heating coil may be accurately sensed by measuring electric currents flowing through the sensing resistance. By doing so, a sensing circuit that ensures high credibility and high efficiency in controlling a high-output induction may be implemented at a low cost.
Further, the induction-heating cooking apparatus according to the present disclosure includes a circuit structure in which sensing resistance is added to each of the plurality of heating coils and electric currents flowing through the sensing resistance is measured. Accordingly, outputs of the plurality of heating coils may be accurately sensed. By doing so, the outputs of the plurality of heating coils may be controlled accurately and independently, and a circuit required for sensing outputs of the plurality of heating coils may be simplified. Thus, the induction-heating cooking apparatus according to the present disclosure may enhance user convenience and reduce costs.
Terms and words used in this specification and the appended claims should not be interpreted as those defined in commonly used dictionaries. The terms and words should be interpreted on the basis of the meaning and concept in accordance with the technical spirit of the present invention according to the principle that the inventor can properly define the concept of terms so as to best describe the invention. The embodiments set forth in this specification, and the elements illustrated in the drawings are presented only as preferred embodiments and do not represent the technical spirit of the present invention entirely. It should be understood that there may be various equivalents and modifications capable of replacing the embodiments and elements at the time when this application is filed.
Below, an induction-heating cooking apparatus according to embodiments is described with reference to the attached drawings.
Referring to
The driving circuit 110 supplies high-frequency power to the heating coil (Coil). As electric currents are supplied to the heating coil (Coil), a cooking container on the heating coil (Coil) that is a magnetic substance generates heat by induction heating, and by the generated heat, the cooking container itself is heated. Thus, food is cooked.
The heating coil (Coil) may include a dual heating coil that is separated into and comprised of an inner coil and an outer coil, and a single heating coil. However, the present disclosure is not limited to what has been described.
Specifically, the driving circuit 110 includes an alternating-current-power supplying unit 111, a rectifying unit 112, a filter 113 and a driving unit 115.
The alternating-current-power supplying unit 111 supplies usual alternating current power.
The rectifying unit 112 may rectify alternating current power supplied by the alternating-current-power supplying unit 111. The rectifying unit 112 may include at least one or more diodes, but the present disclosure is not limited to what has been described.
The filter 113 may filer the power rectified by the rectifying unit 112. The filter 113 may include at least one capacitor, but the present disclosure is not limited to what has been described. The filter 113 may supply an input voltage (Vin) to the driving unit 115.
The driving unit 115 supplies power to the heating coil (Coil). The driving unit 115 includes sensing resistance (R1), a switch unit 117 including a plurality of switching devices (S1, and S2), and a plurality of capacitors (C1, and C2). The driving unit 115 operates as an inverter that controls operations of the heating coil (Coil).
Specifically, the driving unit 115 is connected with an output terminal of the filter 113, and includes first and second switching devices (S1, and S2) that are connected in series, and first and second capacitors (C1, and C2) that are connected in parallel respectively with the first and second switching devices (S1, and S2). The first and second switching devices (S1, and S2) may include an insulated gate bipolar transistor (IGBT), but the present disclosure is not limited to what has been described.
The induction-heating cooking apparatus that is configured as described above receives alternating current power, rectifies and smoothes the input alternating current power, and supplies direct current power to the driving unit 115. In this case, high-frequency currents flow through the heating coil (Coil) by increasing the speed at which the first and second switching devices (S1, and S2) of the driving unit 115 alternately operate, thereby generating a high-frequency magnetic flux.
In this case, the first and second capacitors (C1, and C2), connected in parallel respectively with the first and second switching devices (S1, and S2), may reduce switching losses that are generated when the first and second switching devices (S1, and S2) perform switching operations.
Additionally, the driving unit 115 includes sensing resistance (R1). First sensing resistance (R1) may be connected between one end of the filter 113 and one end of the second capacitor (C2).
The sensor 120 may measure electric currents flowing through the sensing resistance (R1). However, the present disclosure is not limited to what has been described, and the sensor 120 may measure voltages and electric currents of both ends of the sensing resistance (R1). The sensor 120 may deliver measured data to the control unit 130.
The control unit 130 may calculate an output of the heating coil (Coil) on the basis of the data measured by the sensor 120. A method of calculating an output of the heating coil (Coil) on the basis of data measured by the sensor 120 is specifically described with reference to
The control unit 130 may deliver control signals to the switch driving unit 140 on the basis of the calculated output of the heating coil (Coil). Though not explicitly illustrated in the drawing, the control unit 130 may generate control signals to adjust an output of the heating coil (Coil) according to a value that is input by a user or that is previously input. The generated control signals are delivered to the switch driving unit 140.
The switch driving unit 140 may control operations of the first and second switching devices (S1, and S2) on the basis of the control signals received from the control unit 130.
Additionally, the driving circuit 110 of the induction-heating cooking apparatus of the present disclosure may further include a third sensing resistance (Ra). Though not explicitly illustrated in the drawing, the sensor 120 may measure electric currents flowing through the third sensing resistance (Ra) or voltages of both ends of the third sensing resistance (Ra). The sensor 120 supplies measured data to the control unit 130, and the control unit 130 may calculate input currents and voltages on the basis of the received data. However, the present disclosure is not limited to what has been described.
Referring to
The differential amplifier 123 may receive electric currents flowing through both ends of the sensing resistance (R1 or Ra), or voltages at both ends of the sensing resistance (R1 or Ra), and may compare and amplify signals received at both of the ends.
The RC filter 124 receives an output of the differential amplifier 123. The RC filter 124 may remove noise ingredients included in a value received from the differential amplifier 123.
The micom (or processor) 125 may receive signal values from which noise ingredients are removed from the RC filter 124, and may measure values of electric currents or voltages flowing through the sensing resistance (R1) on the basis of the signal values.
In this case, values of electric currents or voltages flowing through the sensing resistance (R1) may be expressed as ADC. For example, when a 5V voltage is supplied to both ends of the sensing resistance (R1), value of ADC may be 1024, and when a 1V voltage is supplied to both ends of the sensing resistance (R1), value of ADC may be 100, and when a 0V voltage is supplied to both ends of the sensing resistance (R1), value of ADC may be 0. However, the present disclosure is not limited to what has been described.
Data measured by the sensor 120 may be delivered to the control unit 130. Though not explicitly illustrated in the drawing, the sensor 120 of the present disclosure may measure voltages at both ends of both sensing resistances (Ra and R1), and electric currents flowing through both ends of the sensing resistances (Ra and R1).
Additionally, the sensor 120 included in the induction-heating cooking apparatus according to a few different embodiments may include RC filters 121, 122 that are respectively disposed at input terminals of the differential amplifier 123. The RC filters 121, 122 may extract high-frequency ingredients of signals input to the differential amplifier 123, or may extract the largest value among values of input signals and may deliver the largest value to the differential amplifier 123. However, the present disclosure is not limited to what has been described.
Referring to
Specifically, the primary currents (Ia) are half-wave rectified waveforms of the input currents (Iin). The input currents (Iin) are rectified while passing through the rectifying unit 112, and as a result, have the same waveform as the primary currents (Ia).
In this case, RMS values of the input currents (Iin) and the primary currents (Ia) are the same, and the primary currents (Ia) may be substituted for the input currents (Iin).
By doing so, the control unit 130 may accurately calculate the input currents (Iin) by measuring the primary currents (Ia) through the sensor 120.
Referring to
Specifically, a peak value of the secondary currents (I1) is half the peak value of the resonance currents (Ir), and frequencies of the secondary currents (I1) are two times as much as frequencies of the resonance currents (Ir). That is, the secondary currents (I1) and the resonance currents (Ir) have linearity, and the secondary currents (I1) include peak current information on a resonance load of the heating coil (Coil).
Thus, when a peak value of the secondary currents (I1) is learned, a peak value and an RMS value of the resonance currents (Ir) may be calculated. That is, the secondary currents (I1) may be substituted for the resonance currents (Ir).
Accordingly, the sensor 120 measures magnitude of the secondary currents (I1), and delivers the measured value of the secondary currents (I1) to the control unit 130. Next, the control unit 130 may calculate resonance currents (Ir) using the received data of the secondary currents (I1), and on the basis of the calculated resonance currents, may calculate an output of the heating coil (Coil).
By doing so, the control unit 130 may accurately calculate the resonance currents (Ir) by measuring the secondary currents (I1) through the sensor 120.
That is, the induction-heating cooking apparatus of the present disclosure may accurately sense an output of the heating coil by measuring electric currents flowing through the sensing resistance. By doing so, a sensing circuit that ensures high credibility and high efficiency in controlling a high-output induction may be implemented at a low cost.
The size and the manufacturing costs of the sensing circuit of the induction-heating cooking apparatus according to the present disclosure may be smaller and lower than those of a circuit of an induction-heating cooking apparatus to which a conventional method for measuring resonance currents using a resonance CT sensor is applied.
For convenience of description, details identical with those of the above-described embodiments are not described, but differences are described.
Referring to
The driving circuit 210 of the present disclosure includes an alternating-current-power supplying unit 211, a rectifying unit 212, a filter 213, a first driving unit 215 and a second driving unit 216. The first driving unit 215 includes a circuit substantially the same as the circuit of the driving unit 115 that is described above with reference to
The second driving unit 216 includes components substantially the same as those of the first driving unit 215 and may operate in a way substantially the same as the first driving unit 215.
Specifically, the first driving unit 215 includes first sensing resistance (R1), a first switch unit 217 including a plurality of switching devices (S1, and S2), and a plurality of capacitors (C1, and C2). The first driving unit 215 operates as a first inverter that controls operations of a first heating coil (Coil 1).
Likewise, the second driving unit 216 includes second sensing resistance (R2), a second switch unit 218 including a plurality of switches (S3, and S4), and a plurality of capacitors (C3, and C4). The second driving unit 216 operates as a second inverter that controls operations of a second heating coil (Coil 2).
In this case, the second driving unit 216 may be connected in parallel with the first driving unit 215.
The sensor may measure electric currents flowing through the first sensing resistance (R1) and the second sensing resistance (R2). However, the present disclosure is not limited to what has been described, and the sensor may measure voltages and electric currents of both ends of the first sensing resistance (R1) and the second sensing resistance (R2). The control unit may calculate outputs of the first heating coil (Coil 1) and the second heating coil (Coil 2) respectively on the basis of data measured by the sensor. A method of calculating outputs of the first heating coil (Coil 1) and the second heating coil (Coil 2) may be the same as the method that is described above with reference to
By doing so, the induction-heating cooking apparatus according to the present disclosure may accurately sense outputs of a plurality of heating coils by measuring electric currents flowing through sensing resistance corresponding to each of the plurality of heating coils. Accordingly, outputs of the plurality of heating coils may be controlled accurately and independently, and a circuit required for sensing the outputs of the plurality of heating coils may be simplified, thereby enhancing user convenience and reducing costs.
The embodiments are provided as examples only to describe the invention and are not intended to limit the present disclosure. The scope of the present disclosure should be defined according to the appended claims rather than the detailed description set forth herein. Further, the meaning and scope of the appended claims and various modifications and equivalents thereof should be construed as being included within the technical spirit of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2017-0026814 | Feb 2017 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2018/002283 | 2/23/2018 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2018/159963 | 9/7/2018 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 20030155349 | Matsuo | Aug 2003 | A1 |
| 20050247703 | Ryu | Nov 2005 | A1 |
| 20090129131 | Hosemans | May 2009 | A1 |
| 20110120989 | Schilling | May 2011 | A1 |
| 20110285210 | Lemmens | Nov 2011 | A1 |
| 20140014647 | Brosnan | Jan 2014 | A1 |
| 20160178422 | Humpal | Jun 2016 | A1 |
| Number | Date | Country |
|---|---|---|
| 2744299 | Jun 2014 | EP |
| 2004-227839 | Aug 2004 | JP |
| 2007-214143 | Aug 2007 | JP |
| 2007214143 | Aug 2007 | JP |
| 2008210743 | Sep 2008 | JP |
| 2013-206644 | Oct 2013 | JP |
| 10-2005-0103704 | Nov 2005 | KR |
| 10-2011-0092069 | Aug 2011 | KR |
| 2011009069 | Dec 2011 | KR |
| 20110092069 | Dec 2011 | KR |
| WO-2007076043 | Jul 2007 | WO |
| Entry |
|---|
| International Search Report (with English translation) and Written Opinion dated Jun. 18, 2018 issued in Application No. PCT/KR2018/002283. |
| Number | Date | Country | |
|---|---|---|---|
| 20200059996 A1 | Feb 2020 | US |
