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KR-102961272-B1 - INDUCTION HEATING TYPE COOKTOP

KR102961272B1KR 102961272 B1KR102961272 B1KR 102961272B1KR-102961272-B1

Abstract

The present disclosure relates to an induction heating type cooktop with a variable dead time, comprising a working coil, an inverter including a plurality of switching elements driven to flow current through the working coil, and a control unit for controlling the duty of the plurality of switching elements, wherein the dead time during which all of the plurality of switching elements are turned off can be varied.

Inventors

  • 정경훈
  • 김의성
  • 문현욱

Assignees

  • 엘지전자 주식회사

Dates

Publication Date
20260508
Application Date
20210309

Claims (10)

  1. Working coil; An inverter comprising a plurality of switching elements driven to flow current through the above-mentioned working coil; It includes a control unit for controlling the duty of the plurality of switching elements, and The dead time during which all of the above-mentioned plurality of switching elements are turned off is variable, and The above control unit The dead time is adjusted based on the driving frequency of the above inverter, and Calculating the preset ratio according to the above driving frequency as the above dead time Induction heating cooktop.
  2. delete
  3. In claim 1, The above control unit A period corresponding to the above driving frequency is obtained, and a preset ratio of the obtained period is set as the above dead time. Induction heating cooktop.
  4. In claim 1, The above control unit Calculate the dead time whenever the above driving frequency changes Induction heating cooktop.
  5. In claim 1, The above control unit If the calculated dead time is less than or equal to a preset minimum dead time, the dead time is set to the preset dead time. Induction heating cooktop.
  6. In claim 1, The above control unit If the calculated dead time exceeds the preset minimum dead time, the dead time is set to the above calculated dead time. Induction heating cooktop.
  7. In claim 1, The above control unit Adjusting the above dead time according to the type of cooking container Induction heating cooktop.
  8. In claim 7, The above control unit If the above cooking container is the first container, the dead time is set to the first value, and If the above cooking container is the second container, the dead time is set to the second value. Induction heating cooktop.
  9. In claim 8, When the first container is a magnetic material and the second container is a non-magnetic material, the first value is greater than the second value. Induction heating cooktop.
  10. In claim 1, The above control unit The dead time is varied so that the dead time decreases as the driving frequency of the inverter increases. 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 illustrating the output characteristics of a cooktop according to the driving frequency for each type of cooking vessel. Figure 6 is a graph showing the drop voltage of an internal diode according to the gate voltage of a SiC device. FIG. 7 is a drawing showing the dead time section and the reverse current generation section of an inverter according to an embodiment of the present disclosure. FIG. 8 is a control block diagram of a cooktop according to one embodiment of the present disclosure. FIG. 9 is a flowchart illustrating a method of operation of a cooktop according to a first embodiment of the present disclosure. FIGS. 10 and 11 are drawings for explaining an example of a method for a cooktop to calculate dead time according to a first embodiment of the present disclosure. FIG. 12 is a flowchart illustrating a method of operation of a cooktop according to a second 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 magnetic field (20) such that at least a portion of it passes through the cooking vessel (1). At this time, if the material of the cooking vessel (1) contains an electrical resistance component, the magnetic field (20) can induce an eddy current (30) in the cooking vessel (1). This eddy current (30) heats the cooking vessel (1) itself, and since this heat is transmitted through conduction or radiation to the interior of the cooking vessel (1), the contents of the cooking vessel (1) can be cooked. Meanwhile, if the material of the cooking vessel (1) does not contain an electrical resistance component, eddy current (30) is not generated. Therefore, in this case, the cooktop (10) cannot heat the cookin