Induction heating cooking apparatus and control method thereof

Abstract

An induction heating cooking apparatus and a control method thereof are provided. A vessel can be effectively heated by using a plurality of heating coils regardless of a position of the vessel. By connecting a plurality of heating coils to a smaller amount of inverters through relays, only a heating coil on which a vessel is placed, among the plurality of heating coils, can be heated. Also, by connecting the heating coils in series, a current flowing in the heating coil can be lowered, and thus, a rated current of the inverter can be lowered. Also, by connecting relays and heating coils such that a larger amount of heating coils are operated, while minimizing the amount of inverters, manufacturing cost can be reduced, operation efficiency can be increased, and stability of the cooking apparatus can be enhanced.

What is claimed is: 
     
       1. An induction heating cooking apparatus, comprising:
 a heater including a plurality of heating coils that forms a plurality of heating regions and that heats a vessel placed in each of the plurality of heating regions, respectively; 
 a plurality of inverters that supplies a drive voltage to one or more of the plurality of heating coils; 
 a sensor that senses a current of the plurality of heating coils and outputs a current value; 
 a controller that compares the current value with a predetermined reference current value, detects one or more of the plurality of heating regions in which the vessel is placed based on a comparison result and controls the plurality of inverters according to a control command; and 
 a plurality of relays that connects the one or more of the plurality of heating coils corresponding to the one or more of the plurality of heating regions detected by the controller and one or more of the plurality of inverters based on respective opening and closing signals, wherein the plurality of heating coils connectable to a same inverter of the plurality of inverters, among the plurality of heating coils corresponding to the detected one or more of the plurality of heating regions, are connected in series to each other by the plurality of relays. 
 
     
     
       2. The induction heating cooking apparatus of  claim 1 , wherein a number of the plurality of inverters is less than a number of the plurality of heating coils. 
     
     
       3. The induction heating cooking apparatus of  claim 2 , wherein each of the plurality of inverters is connected to some of the plurality of heating coils in order to supply the drive voltage thereto. 
     
     
       4. The induction heating cooking apparatus of  claim 1 , wherein each of the plurality of inverters is one of a half-bridge type inverter, a full-bridge type inverter, or a Class E type inverter. 
     
     
       5. The induction heating cooking apparatus of  claim 1 , wherein each of the plurality of heating coils is a flat litz wire type heating coil. 
     
     
       6. The induction heating cooking apparatus of  claim 5 , wherein the flat litz wire type heating coil is formed by compressing a circular litz wire type heating coil. 
     
     
       7. The induction heating cooking apparatus of  claim 6 , wherein the heater further includes a plurality of resonance capacitors connected to the plurality of heating coils to generate a resonance. 
     
     
       8. An induction heating cooking apparatus, comprising:
 a converter that converts an input voltage from a commercial AC power source into a DC voltage and outputs the DC voltage; 
 a smoothing device that smoothes the DC voltage output from the converter; 
 heater including a plurality of heating coils that forms a plurality of heating regions and that heats a vessel placed in each of the plurality of heating regions, respectively, and a plurality of resonance capacitors connected to the plurality of heating coils to generate a resonance; 
 a plurality of inverters that converts the smoothed DC voltage from the smoothing device into a drive voltage based on a control signal, and supplies the drive voltage to one or more of the plurality of heating coils; 
 an input that receives a control command with respect to the heater; 
 a sensor that senses a current of the plurality of heating coils and outputs a current value; 
 a controller that compares the current value with a predetermined reference current value, detects one or more of the plurality of heating regions in which the vessel is placed based on a comparison result, and generates the control signal for controlling the plurality of inverters according to the control command; and 
 a plurality of relays that connects the one or more of the plurality of heating coils corresponding to the one or more of the plurality of heating regions detected by the controller and one or more of the plurality of inverters, based on respective opening and closing signals, wherein the plurality of heating coils connectable to a same inverter of the plurality of inverters, among the plurality of heating coils corresponding to the detected one or more of the plurality of heating regions, are connected in series to each other by the plurality of relays. 
 
     
     
       9. The induction heating cooking apparatus of  claim 8 , wherein the heater comprises:
 a first coil device including two or more heating coils of the plurality of heating coils driven by a first inverter of the plurality of inverters, connected in series, and forming a first heating region of the plurality of heating regions; 
 a second coil device including two or more heating coils of the plurality of heating coils driven by a second inverter of the plurality of inverters, connected in series, and forming a second heating region of the plurality of heating regions; and 
 a third coil device including one or more heating coils of the plurality of heating coils driven by the first inverter or the second inverter and connected to the first coil device or the second coil device in series or directly connected to the first inverter or the second inverter to form a third heating region of the plurality of heating regions. 
 
     
     
       10. The induction heating cooking apparatus of  claim 8 , wherein each of the plurality of heating coils is a flat litz wire type heating coil. 
     
     
       11. The induction heating cooking apparatus of  claim 10 , wherein the flat litz wire type coil is formed by compressing a circular litz wire type heating coil. 
     
     
       12. A method for controlling an induction heating cooking apparatus including a heater including a plurality of heating coils that forms a plurality of heating regions and that heats a vessel placed in each of the plurality of heating regions, respectively, a plurality of inverters that supplies a drive voltage to one or more of the plurality of heating coils, and a plurality of relays, the method comprising:
 sensing a current of the plurality of heating coils and outputting a current value; 
 comparing the current value with a predetermined reference current value; 
 detecting one or more of the plurality of heating regions in which the vessel is placed based on a comparison result; 
 connecting one or more of the plurality of heating coils corresponding to the one or more of the plurality of heating regions and one or more of the plurality of inverters by the plurality of relays; 
 receiving a control command; and 
 driving a corresponding one or more of the plurality of inverters according to the control command, wherein the plurality of heating coils connectable to a same inverter of the plurality of inverters, among the plurality of heating coils corresponding to the detected one or more of the plurality of heating regions, are connected in series to each other by the plurality of relays. 
 
     
     
       13. The induction heating cooking apparatus of  claim 1 , wherein each of the plurality of inverters includes a switching device. 
     
     
       14. The induction heating cooking apparatus of  claim 13 , wherein the switching device is a high frequency semiconductor. 
     
     
       15. The induction heating cooking apparatus of  claim 13 , wherein the switching device is one of a bipolar junction transistor (BJT), a metal oxide semiconductor field effect transistor (MOSFET), or an insulated gate bipolar transistor (IGBT). 
     
     
       16. The induction heating cooking apparatus of  claim 13 , wherein the switching device of each of the plurality of inverters is switched based on a drive signal from a respective drive of a plurality of drives. 
     
     
       17. The induction heating cooking apparatus of  claim 16 , wherein the plurality of drives receives a control signal from the controller, respectively, to regulate heating of the plurality of heating coils according to the control command.