Search

KR-102961268-B1 - INDUCTION HEATING TYPE COOKTOP

KR102961268B1KR 102961268 B1KR102961268 B1KR 102961268B1KR-102961268-B1

Abstract

The present disclosure is intended to provide a cooktop capable of heating both magnetic and non-magnetic containers at high output, and the driving method of the inverter can be changed according to the type of cooking container.

Inventors

  • 김의성
  • 문현욱
  • 박경호
  • 김양경

Assignees

  • 엘지전자 주식회사

Dates

Publication Date
20260508
Application Date
20210305

Claims (10)

  1. Working coil; An inverter comprising a plurality of switching elements driven to flow current through the above-mentioned working coil; A container identification unit that determines the type of cooking container; It includes a control unit that changes the driving method of the inverter according to the type of the cooking vessel, The above control unit If the type of the above cooking vessel is a magnetic material, the driving method of the inverter is changed so that it operates in a region above the resonance frequency, and If the type of the above cooking vessel is a non-magnetic material, the driving method of the inverter is changed so that it operates in a region below the resonance frequency, and If the operating frequency is above the resonance frequency, the output is adjusted by varying the operating frequency, and When the operating frequency is below the resonance frequency, the output is controlled by varying the duty cycle of the plurality of switching elements. Induction heating cooktop.
  2. delete
  3. delete
  4. In claim 1, The above control unit Adjusting the duty of the plurality of switching elements when operating in a region below the resonant frequency Induction heating cooktop.
  5. In claim 4, The above control unit Adjusting the duty of the first switching element among the plurality of switching elements to be smaller than the duty of the second switching element among the plurality of switching elements. Induction heating cooktop.
  6. In claim 5, The duty cycle of the first switching element is 50% or less. Induction heating cooktop.
  7. In claim 5, The second switching element is positioned closer to the heat dissipation fan than the first switching element. Induction heating cooktop.
  8. In claim 1, The above control unit When the above operating frequency is below the above resonance frequency, the output is controlled by varying the duty cycle according to the heating level. Induction heating cooktop.
  9. In claim 8, If the operating frequency is below the resonance frequency, the operating frequency is a fixed frequency. Induction heating cooktop.
  10. In claim 1, The above plurality of switching elements are SiC elements. Induction heating cooktop.

Description

Induction Heating Type Cooktop The present disclosure relates to an induction heating type cooktop, and more specifically, to an induction heating type cooktop capable of heating both magnetic and non-magnetic materials. Various types of cooking appliances are used to heat food in homes and restaurants. Traditionally, gas ranges using gas as fuel have been widely used, but recently, devices that heat cooking vessels using electricity instead of gas are becoming more popular. Methods of heating an object using electricity are broadly divided into resistance heating and induction heating. Resistance heating is a method of heating by transferring heat generated when an electric current is passed through a metal resistance wire or a non-metallic heating element, such as silicon carbide, to a cooking vessel through radiation or conduction. Induction heating, on the other hand, is a method of heating the cooking vessel itself by generating eddy currents in a cooking vessel made of metal components using a magnetic field generated around a coil when high-frequency power of a predetermined magnitude is applied to the coil. Meanwhile, in this induction heating method, there is a problem in that the output power varies depending on the material of the cooking vessel even when the same current is applied to the coil. Specifically, non-magnetic vessels have lower resistivity than magnetic vessels due to lower permeability, and consequently, the output of non-magnetic vessels is smaller than that of magnetic vessels. Accordingly, a method to increase output for non-magnetic containers as well as magnetic containers is required. In other words, a cooktop capable of heating both magnetic and non-magnetic containers with high output is required. FIG. 1 is a perspective view showing a cooktop and a cooking vessel according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view of a cooktop and a cooking vessel according to an embodiment of the present disclosure. FIG. 3 is a diagram showing a circuit of a cooktop according to an embodiment of the present disclosure. FIG. 4 is a drawing showing the output characteristics of a cooktop according to an embodiment of the present disclosure. Figure 5 is a diagram showing the operating section in the inverter of an induction heating type cooktop using SiC elements. Figure 6 is a diagram illustrating the electrical operation characteristics of an inverter according to the type of cooking vessel. Figure 7 is a table showing the losses according to the type of cooking vessel heated by an induction heating cooktop using SiC elements. FIG. 8 is a control block diagram of a cooktop according to an embodiment of the present disclosure. FIG. 9 is a flowchart illustrating the operation method of a cooktop according to an embodiment of the present disclosure. FIG. 10 is a drawing showing the operating frequency of a cooktop according to an embodiment of the present disclosure as the driving method of the inverter is changed. FIG. 11 is an example showing the operation waveform of an inverter when the cooking vessel is a non-magnetic material in a cooktop according to an embodiment of the present disclosure. FIG. 12 is a drawing showing an example of the arrangement of a plurality of switching elements according to an embodiment of the present disclosure. FIG. 13 is a graph showing the temperatures of a plurality of switching elements when the first switching element is positioned closer to the heat dissipation fan than the second switching element in a cooktop according to an embodiment of the present disclosure. FIG. 14 is a graph showing the temperatures of a plurality of switching elements when the second switching element is positioned closer to the heat dissipation fan than the first switching element in a cooktop according to an embodiment of the present disclosure. Hereinafter, embodiments related to the present disclosure will be described in more detail with reference to the drawings. The suffixes "module" and "part" for components used in the following description are assigned or used interchangeably solely for the ease of drafting the specification and do not have distinct meanings or roles in themselves. Hereinafter, an induction heating type cooktop and a method of operation thereof according to an embodiment of the present disclosure will be described. For convenience of explanation, the “induction heating type cooktop” will be referred to as the “cooktop.” FIG. 1 is a perspective view showing a cooktop and a cooking vessel according to an embodiment of the present disclosure, and FIG. 2 is a cross-sectional view of a cooktop and a cooking vessel according to an embodiment of the present disclosure. A cooking vessel (1) can be positioned on top of a cooktop (10), and the cooktop (10) can heat the cooking vessel (1) positioned on top. First, explain how the cooktop (10) heats the cooking vessel (1). As illustrated in FIG. 1, the cooktop (10) can generate a