CN113271696A - Electromagnetic induction heating circuit, control method thereof and electromagnetic heating equipment - Google Patents

Electromagnetic induction heating circuit, control method thereof and electromagnetic heating equipment Download PDF

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Publication number
CN113271696A
CN113271696A CN202110714147.7A CN202110714147A CN113271696A CN 113271696 A CN113271696 A CN 113271696A CN 202110714147 A CN202110714147 A CN 202110714147A CN 113271696 A CN113271696 A CN 113271696A
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China
Prior art keywords
heating
type
resonant
switching device
heating assembly
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CN202110714147.7A
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Chinese (zh)
Inventor
张博超
龚辉平
陈和辉
符招永
陈定武
李硕勇
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Gree Electric Appliances Inc of Zhuhai
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Gree Electric Appliances Inc of Zhuhai
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Priority to CN202110714147.7A priority Critical patent/CN113271696A/en
Publication of CN113271696A publication Critical patent/CN113271696A/en
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    • 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
    • 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
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H05B6/12—Cooking devices
    • 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
    • H05B6/36—Coil arrangements
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B40/00—Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Induction Heating Cooking Devices (AREA)

Abstract

The application relates to an electromagnetic induction heating circuit, a control method thereof and electromagnetic heating equipment, wherein a first type resonance heating assembly and a second type resonance heating assembly are arranged at the same time, more than two heating coils are arranged in the second type resonance heating assembly at the same time, the coupling of each heating coil and the first type resonance heating assembly is not completely the same, and a first type switching device is used for adjusting the heating power of the first type resonance heating assembly. When the first type of resonant heating assembly heats with the power lower than the preset power threshold value, the controller can control the heating coil which is coupled with the first type of resonant heating assembly in the second type of resonant heating assembly to be connected into the circuit. Due to the existence of the heating coil, the back voltage and the current value of the first type of switching device are kept at large values, and finally the first type of resonant heating assembly is kept at the power lower than the preset power threshold value for heating, so that low-power continuous heating is realized.

Description

Electromagnetic induction heating circuit, control method thereof and electromagnetic heating equipment
Technical Field
The present disclosure relates to the field of magnetic induction technologies, and in particular, to an electromagnetic induction heating circuit, a control method thereof, and an electromagnetic heating apparatus.
Background
IH (Induction heating) heating is a method of heating an article to be heated in an appliance by heating the appliance by electromagnetic Induction. With the rapid development of scientific technology, the heating mode is applied to equipment such as electric cookers and the like, and the household appliance of the type is popular with users due to the advantages of quick heating, large firepower, more power saving and good heat convection.
In the equipments such as the rice cooker heated by IH, an Insulated Gate Bipolar Transistor (IGBT) is generally used to control the resonance of an LC parallel circuit to generate eddy current for heating, and the circuit topology and components determine that the heating power cannot be too low. Therefore, conventional IH heating has difficulty in achieving low power continuous heating.
Disclosure of Invention
In view of the above, it is necessary to provide an electromagnetic induction heating circuit, a control method thereof, and an electromagnetic heating apparatus, aiming at the problem that the conventional IH heating apparatus is difficult to perform low-power continuous heating.
An electromagnetic induction heating circuit comprising: a first type of resonant heating assembly; the second type of resonance heating assembly is provided with more than two heating coils, and the coupling of each heating coil and the first type of resonance heating assembly is not completely the same; the first type of switching device is connected with the first type of resonant heating component, and forms a heating branch with the first type of resonant heating component to be connected to a power supply; the second-class resonance heating assembly and the first-class switching device are respectively connected with the controller, and the controller is used for controlling a heating coil of the second-class resonance heating assembly to be connected with a heating coil which is coupled with the first-class resonance heating assembly to be heated when the first-class resonance heating assembly is judged to run at a power smaller than a preset power threshold value, so that low-power continuous heating is realized.
In one embodiment, the electromagnetic induction heating circuit further comprises a second type switching device, the second type switching device is connected with the second type resonant heating assembly, the second type switching device and the second type resonant heating assembly form another heating branch circuit to be connected to a power supply, and the second type switching device is connected with the controller.
In one embodiment, the first resonant heating assembly comprises a first resonant capacitor and a first heating coil, the first switching device comprises a first switching device, a first end of the first resonant capacitor is connected with a first end of the first heating coil, a common end of the first resonant capacitor is connected with a first end of the first switching device, a second end of the first switching device is connected with a power supply and the second switching device, a control end of the first switching device is connected with the controller, and a second end of the first resonant capacitor is connected with a second end of the first heating coil, and a common end of the first resonant capacitor is connected with the power supply and the second resonant heating assembly.
In one embodiment, the first type resonant heating assembly further comprises a first switching device, the second end of the first heating coil is connected to the first end of the first switching device, the second end of the first switching device is connected to the second end of the first resonant capacitor, and the control end of the first switching device is connected to the controller.
In one embodiment, the second type resonant heating assembly includes a second resonant capacitor, a gating device and two or more heating coils, the second type switching device includes a second switching device, a first end of each heating coil and a first end of the second resonant capacitor are connected to each other, a common end of each heating coil is connected to the first end of the second switching device, a second end of the second switching device is connected to the first type switching device and a power supply, a control end of the second switching device is connected to the controller, a second end of each heating coil is connected to the gating device, the gating device is connected to the second end of the second resonant capacitor and the first type resonant heating assembly, and the gating device is connected to the controller.
In one embodiment, the second type of resonant heating assembly includes more than two heating coils, switching devices with the same number as the heating coils, and resonant capacitors with the same number as the heating coils, the second type of switching device includes switching devices with the same number as the heating coils, a first end of any one of the heating coils is correspondingly connected with a first end of one of the resonant capacitors, a first end of each of the resonant capacitors is correspondingly connected with a first end of one of the switching devices, a second end of each of the switching devices is respectively connected with the first type of switching device and a power supply, a control end of each of the switching devices is respectively connected with the controller, a second end of any one of the heating coils is correspondingly connected with a first end of one of the switching devices, and a second end of each of the switching devices and a second end of each of the resonant capacitors are connected with each other, and the common end is connected with the first type resonance heating component and the power supply, and the control end of each switch device is respectively connected with the controller.
In one embodiment, the number of the heating coils is two.
In one embodiment, the electromagnetic induction heating circuit further comprises a rectifying device, a first terminal of the rectifying device and a second terminal of the rectifying device are respectively connected with a power supply, a third terminal of the rectifying device is connected with the first resonant heating assembly and the second resonant heating assembly, and a fourth terminal of the rectifying device is connected with the first switching device and the second switching device.
In one embodiment, the electromagnetic induction heating circuit further includes a first filter circuit and a second filter circuit, a first end of the rectifying device is connected to the first end of the first filter circuit, a second end of the rectifying device is connected to the second end of the first filter circuit, a third end of the first filter circuit and a fourth end of the first filter circuit are respectively connected to a power supply, a first end of the second filter circuit is connected to the third end of the rectifying device, a second end of the second filter circuit is connected to the fourth end of the rectifying device, a third end of the second filter circuit is connected to the first resonant heating assembly and the second resonant heating assembly, and a fourth end of the second filter circuit is connected to the first switching device and the second switching device.
In one embodiment, the electromagnetic induction heating circuit further includes a fuse and a voltage dependent resistor, the third end of the first filter circuit is connected to the first end of the fuse and the first end of the voltage dependent resistor, the second end of the fuse is connected to the live wire of the power supply, and the second end of the voltage dependent resistor is connected to the fourth end of the first filter circuit and the neutral wire of the power supply.
A control method of the electromagnetic induction heating circuit as described above, comprising: acquiring the power of the first type of resonant heating component; judging whether the power is smaller than a preset power threshold value or not; and when the power is smaller than the preset power threshold value, controlling a heating coil of the second type of resonance heating assembly to be connected with a heating coil which is coupled with the first type of resonance heating assembly to heat so as to realize low-power continuous heating.
In one embodiment, after determining whether the power is less than a preset power threshold, the method further includes: and when the power is greater than or equal to the preset power threshold value, controlling a heating coil of the second type of resonance heating assembly to be connected with a heating coil coupled with the first type of resonance heating assembly for heating so as to realize high-power continuous heating.
In one embodiment, the controlling of the heating coil of the second type of resonant heating assembly, the heating coil coupled with the first type of resonant heating assembly is switched in for heating, and the controlling includes: and controlling a gating device of the second type of resonant heating assembly to gate the heating coil of the second type of resonant heating assembly, and connecting the heating coil coupled with the first type of resonant heating assembly to a small heating coil for heating.
In one embodiment, the controlling of the heating coil of the second type of resonant heating assembly, the heating coil coupled with the first type of resonant heating assembly is switched in for heating, and the controlling includes: and controlling the conduction of a switching device corresponding to the heating coil coupled with the first type of resonant heating assembly in the heating coil of the second type of resonant heating assembly.
In one embodiment, before the step of controlling the heating coil of the second type of resonant heating assembly to be switched in and heated by the heating coil coupled with the first type of resonant heating assembly when the power is smaller than the preset power threshold, the method further includes: and acquiring the coupling size of each heating coil in the second type of resonant heating assembly and the first type of resonant heating assembly.
An electromagnetic heating device comprises the electromagnetic induction heating circuit, and the controller is used for heating control according to the method.
In one embodiment, the electromagnetic heating is a rice cooker.
The electromagnetic induction heating circuit, the control method thereof and the electromagnetic heating equipment are simultaneously provided with the first type resonance heating assembly and the second type resonance heating assembly, the second type resonance heating assembly is simultaneously provided with more than two heating coils, the coupling of each heating coil and the first type resonance heating assembly is not completely the same, and the first type switching device is used for adjusting the heating power of the first type resonance heating assembly. By the arrangement mode, a plurality of parts can be controlled to be heated simultaneously, and multi-section heating control is realized; and when the first type of resonant heating assembly heats with the power lower than the preset power threshold, the controller can control a heating coil which is coupled with the first type of resonant heating assembly in the second type of resonant heating assembly to be connected into the circuit. Due to the existence of the heating coil, the back voltage and the current value of the first type of switching device are kept at large values, and finally the first type of resonant heating assembly is kept at the power lower than the preset power threshold value for heating, so that low-power continuous heating is realized.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic diagram of an exemplary electromagnetic induction heating circuit;
FIG. 2 is a schematic diagram of an electromagnetic induction heating circuit according to another embodiment;
FIG. 3 is a schematic diagram of an electromagnetic induction heating circuit according to yet another embodiment;
FIG. 4 is a schematic diagram of an electromagnetic induction heating circuit according to yet another embodiment;
FIG. 5 is a schematic diagram of an electromagnetic induction heating circuit according to another embodiment;
FIG. 6 is a schematic diagram of an electromagnetic induction heating circuit according to yet another embodiment;
FIG. 7 is a schematic diagram of an electromagnetic induction heating circuit according to yet another embodiment;
FIG. 8 is a schematic diagram of an electromagnetic induction heating circuit according to yet another embodiment;
FIG. 9 is a schematic diagram of an electromagnetic induction heating circuit according to yet another embodiment;
FIG. 10 is a flowchart illustrating a method for controlling the electromagnetic induction heating circuit according to an embodiment;
fig. 11 is a flowchart illustrating a control method of the electromagnetic induction heating circuit according to another embodiment.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Referring to fig. 1, an electromagnetic induction heating circuit includes: a first type of resonant heating assembly 10; a second type resonance heating assembly 20 provided with two or more heating coils, each of which is not completely coupled to the first type resonance heating assembly 10; the first-type switching device 30 is connected with the first-type resonant heating component 10, and forms a heating branch with the first-type resonant heating component 10 to be connected to a power supply; the second type resonance heating assembly 20 and the first type switching device 30 are respectively connected to a controller (not shown), and the controller is used for judging that when the first type resonance heating assembly 10 operates at a power smaller than a preset power threshold value, controlling a heating coil of the second type resonance heating assembly 20 to be connected with a heating coil coupled with the first type resonance heating assembly 10 to heat, so as to realize low-power continuous heating.
Specifically, the resonance heating subassembly is promptly can carry out the energy storage under the circular telegram circumstances, and through the resonance under the outage circumstances, produces the electric current of alternation, according to Faraday's electromagnetic induction law to produce the magnetic field that changes, this magnetic field acts on the utensil that holds the article of waiting to heat such as pan, produces the vortex, realizes the subassembly of the article heating of waiting to heat. The first type switching device 30 is used for power regulation of the first type resonant heating assembly 10, and the first type switching device 30 is enabled to perform heating operation at different powers by controlling the on-time and the off-time of the first type switching device 30.
In the scheme of the embodiment, when the first type resonant heating assembly 10 operates at a power lower than the preset power threshold, the controller controls the heating coil coupled with the first type resonant heating assembly 10 in the second type resonant heating assembly 20 to be switched on for heating, and due to the existence of the heating coil, the back pressure and the current value of the first type switching device 30 are both kept at a large value, so that low-power heating is maintained. The scheme reduces the impact on the power grid and the influence on other electric equipment, and can be realized by selecting devices with lower withstand voltage, thereby effectively reducing the cost.
In one embodiment, whether the first type of resonant heating assembly 10 is operated at low power or at high power is distinguished by a preset power threshold, and when the heating power of the first type of resonant heating assembly 10 is greater than the preset power threshold, it is considered to be operated at high power, and when the heating power of the first type of resonant heating assembly 10 is less than the preset power threshold, it is considered to be operated at low power.
It should be noted that the magnitude of the preset power threshold may be set differently in different types of devices. For example, in one embodiment, when the electromagnetic induction heating circuit is applied to an electric rice cooker, the preset power threshold may be set to 800W, that is, when the operation power of the first type resonant heating assembly 10 is greater than 800W, the electric rice cooker is considered to be operated with high power heating, and when the operation power of the first type resonant heating assembly 10 is less than 800W, the electric rice cooker is considered to be operated with low power heating.
Accordingly, in another embodiment, when the operation power of the first type resonant heating assembly 10 is greater than the preset power threshold, that is, when the first type resonant heating assembly 10 operates at high power, the controller may control the heating coil coupled to the first type resonant heating assembly 10 in the second type resonant heating assembly 20 to be switched on, so as to achieve high-power continuous heating. In this case, the back voltage and the current of the first type switching device 30 can be kept small, the stress on the first type switching device 30 is small, the loss is relatively small, and therefore the first type resonant heating assembly 10 can be controlled to be in a continuous high-power heating state.
Further, in one embodiment, when the first type resonant heating assembly 10 is operated at a power less than the preset power threshold and the small coupled heating coil of the second type resonant heating assembly 20 coupled to the first type resonant heating assembly 10 is controlled to be connected, the small coupled heating coil is relative to the coupling of each coil of the second type resonant heating assembly 20 to the first type resonant heating assembly 10. In order to achieve low-power continuous heating, an analysis is carried out in conjunction with the coupling of all heating coils to the first type of resonant heating assembly 10, wherein the heating coil with the relatively smaller coupling is selected to be switched in. Specifically, which heating coil is used may be selected differently according to the actual use scenario, as long as the heating coil not coupled the most is not available.
In one embodiment, the smaller the coupling of the selected heating coil to the first type of resonant heating assembly 10, the better. For example, in a more detailed embodiment, the heating coil with the smallest coupling with the first type resonant heating assembly 10 among all the heating coils of the second type resonant heating assembly 20 can be directly selected to be connected, so as to realize the low-power continuous heating control; and directly selecting the heating coil which is coupled with the first type resonant heating assembly 10 to be connected, and realizing high-power continuous heating control.
It can be understood that, when the first type switching device 30 is connected to the first type resonant heating component 10 and forms a heating branch with the first type resonant heating component 10 to be connected to a power supply, the first type resonant heating component 10 may be connected to the power supply, and the first type switching device 30 is grounded to form a closed loop; or the first resonant heating component 10 is grounded, and the first switching device 30 is connected with the power supply to form a closed loop; it is also possible that the resonant heating assembly 10 of the first type is connected to the positive (or negative) terminal of the power supply and the switching device 30 of the first type is connected to the negative (or positive) terminal of the power supply to form a closed loop, and the specific connection is selected according to the power supply and the specific form of the switching device 30 of the first type. Fig. 1 shows a first type resonant heating element 10 and a first type switching device 30 connected to respective ends of a power supply.
Referring to fig. 2, in an embodiment, the electromagnetic induction heating circuit further includes a second type switching device 40, the second type switching device 40 is connected to the second type resonant heating element 20, forms another heating branch with the second type resonant heating element 20 and is connected to a power supply, and the second type switching device 40 is connected to a controller (not shown).
Specifically, the second type of switching device 40 is used to power-condition the second type of resonant heating assembly 20, and the specific type of the second type of switching device 40 is not unique depending on the structure of the second type of resonant heating assembly 20. Since only one heating coil coupled to the first type resonant heating assembly 10 is connected to the circuit when the first type resonant heating assembly 10 operates at a power less than the preset power threshold, in one embodiment, only one switching device may be provided to perform power control of the heating coil, and one heating coil may be connected to the circuit in the second type resonant heating assembly 20 by gating. In another embodiment, it is also possible that the second type switching device 40 includes more than two switching devices, and one switching device is provided for each heating coil in the second type resonant heating assembly 20 for corresponding power control.
It can be understood that, when the second type switching device 40 is connected to the second type resonant heating assembly 20 and forms another heating branch with the second type resonant heating assembly 20 to be connected to the power supply, the second type resonant heating assembly 20 may be connected to the power supply, and the second type switching device 40 is grounded to form a closed loop; or the second type resonant heating component 20 is grounded, and the second type switching device 40 is connected with a power supply to form a closed loop; it is also possible that the second type resonant heating assembly 20 is connected to the positive (or negative) terminal of the power supply and the second type switching device 40 is connected to the negative (or positive) terminal of the power supply to form a closed loop, and the specific connection is selected according to the specific form of the power supply and the second type switching device 40. Fig. 2 shows the second type resonant heating element 20 and the second type switching device 40 connected to two ends of the power supply respectively.
Referring to fig. 3, in an embodiment, the first resonant heating element 10 includes a first resonant capacitor C1 and a first heating coil L1, the first switching device 30 includes a first switching device, a first terminal of the first resonant capacitor C1 is connected to a first terminal of the first heating coil L1, a common terminal of the first resonant capacitor C1 is connected to a first terminal of the first switching device, a second terminal of the first switching device is connected to the power supply and the second switching device 40, a control terminal of the first switching device is connected to a controller (not shown), a second terminal of the first resonant capacitor C1 is connected to a second terminal of the first heating coil L1, and the common terminal of the first resonant capacitor C1 is connected to the power supply and the second resonant heating element 20.
Specifically, the specific type of the first type resonant heating assembly 10 is not exclusive, and in this embodiment, the first type resonant heating assembly 10 has a structure in which only one first heating coil L1 is provided, and accordingly, only one first switching device is required to achieve the power adjustment of the first heating coil L1. At the moment, the first heating coil L1 is connected in parallel with the first resonant capacitor C1, the first resonant capacitor C1 is connected in parallel and then connected to the first switching device, and when the first switching device is switched on, a power supply flows in through the first switching device to store energy for the first heating coil L1; after the first switching device is turned off, the first heating coil L1 resonates with the first resonant capacitor C1 to generate a varying current, based on faraday's law of electromagnetic induction, to generate a varying magnetic field, which acts on a pot or the like containing a hot article to be cooked to generate an eddy current, thereby achieving a heating operation.
Further, in an embodiment, referring to fig. 4, the first resonant heating element 10 further includes a first switching device K1, a second terminal of the first heating coil L1 is connected to a first terminal of the first switching device K1, a second terminal of the first switching device K1 is connected to a second terminal of the first resonant capacitor C1, and a control terminal of the first switching device K1 is connected to a controller (not shown).
Specifically, in the embodiment, a first switch device K1 is provided at a second end of the first heating coil L1, and the first switch device K1 controls whether the first heating coil L1 is switched into a circuit for heating. By the scheme, when the first heating coil L1 is not required to perform heating operation, the first heating coil L1 can be disconnected through the first switching device K1, the working reliability of the electromagnetic induction heating circuit can be effectively improved, and meanwhile, the safety performance of the first type resonance heating assembly 10 can also be improved due to the existence of the first switching device K1. After the first switching device K1 controls the first heating coil L1 to be switched off, only the heating coils of the second type of resonant heating assembly 20 are switched on for heating, and different heating power adjustments can be realized by controlling the number of the heating coils of the second type of resonant heating assembly 20 switched on the electromagnetic induction heating circuit. Through the scheme, only one heating coil can be connected in for heating, and further lower-power heating control can be realized.
It should be noted that the specific type of the first switch device K1 is not exclusive, and may be other types of devices having a switch function, such as a power switch tube or a relay, as long as the device can be turned on or off under different control signals of the controller.
Referring to fig. 3 or 4, in an embodiment, the second type resonant heating assembly 20 includes a second resonant capacitor C2, a gating device K and two or more heating coils L, the second type switching device 40 includes a second switching device, a first end of each heating coil L and a first end of the second resonant capacitor C2 are connected to each other, a common end of the second switching device is connected to the first end of the second switching device, a second end of the second switching device is connected to the first type switching device 30 and the power supply, a control end of the second switching device is connected to a controller (not shown), a second end of each heating coil L is connected to the gating device K, the gating device K is connected to the second end of the second resonant capacitor C2 and the first type resonant heating assembly 10, and the gating device K is connected to the controller.
Specifically, the specific structure of the second type resonant heating assembly 20 is not exclusive, as long as the corresponding heating coil L is switched on under the control of the controller to perform multi-stage heating according to the operating state of the first type resonant heating assembly 10. In the scheme of this embodiment, the gating device K is used to perform the selection operation of the access circuit of the heating coils L, and at this time, different heating coils L share one resonant capacitor C, that is, the second resonant capacitor C2, and share one switching device 40 of the second type, that is, the second switching device. The controller controls the corresponding heating coil to be connected into the circuit through the gating device K according to the working state of the first type resonant heating assembly 10, and then the heating coil L and the second resonant capacitor C2 are heated under the control of the second switching device. Through the scheme, the number of the second switching devices and the number of the resonant capacitors C can be effectively reduced, so that the circuit size is effectively reduced, and the circuit cost is reduced.
In the embodiment shown in fig. 3, the first type resonant heating assembly 10 is not provided with the first switching device K1, and the heating operation of the first heating coil L1 is achieved only by the control of the first switching device. In the embodiment shown in fig. 4, the first type resonant heating module 10 is provided with the first switching device K1, and the first heating coil L1 is controlled by the first switching device K1 and the first switching device to realize the heating operation, in both cases, the second type resonant heating module 20 can be heated by means of the common resonant capacitor C and the second type switching device 40.
It is to be understood that in the gating control scheme of the second type resonant heating assembly 20 using the gating device K for the heating coils, the number of the heating coils is not exclusive as long as it is ensured that the coupling of the respective heating coils with the first type resonant heating assembly 10 (specifically, the first heating coil L1 in the first type resonant heating assembly 10) is not identical. For example, in a more detailed embodiment, the number of heating coils is two.
Specifically, in this embodiment, two heating coils are connected to the gating device K, the coupling sizes of the two heating coils and the first type resonant heating assembly 10 are different, and the controller controls the gating device K to realize connection control of the two heating coils. When the first type of resonant heating assembly 10 runs at low power, the heating coil with the smaller coupling is selected to be switched on, so that low-power continuous heating is realized; and when the first type of resonant heating assembly 10 runs at high power, the heating coil with larger coupling is selected to be connected, and high-power continuous heating control is realized. The low power continuous heating is controlled in a similar manner to the high power continuous heating when there are other numbers of heating coils as long as the coupling of the heating coil accessed at the low power heating to the first type resonant heating assembly 10 is smaller than the coupling of the heating coil accessed at the high power heating to the first type resonant heating assembly 10.
Referring to fig. 5, in one embodiment, the second type resonant heating assembly 20 includes more than two heating coils L, switching devices K2 having the same number as the heating coils L, and resonant capacitors C having the same number as the heating coils L, the second type switching devices 40 include switching devices 41 having the same number as the heating coils L, a first end of any one of the heating coils L is correspondingly connected to a first end of one of the resonant capacitors C, first ends of the resonant capacitors C are respectively correspondingly connected to a first end of one of the switching devices 41, second ends of the switching devices 41 are respectively connected to the first type switching devices 30 and the power source, control ends of the switching devices 41 are respectively connected to the controller (not shown), a second end of any one of the heating coils L is respectively correspondingly connected to a first end of one of the switching devices K2, second ends of the switching devices K2 and second ends of the resonant capacitors C are connected to each other, and a common end is connected to the first type resonant heating assembly 10 and the power source, the control terminals of the switching devices K2 are connected to a controller.
Specifically, the two or more heating coils L in the second type resonant heating assembly 20 may also be in a form not passing through the common resonant capacitor C, at this time, each heating coil L is correspondingly connected in parallel with one resonant capacitor C, each heating coil L realizes corresponding heating power control through one switching device 41, and meanwhile, each heating coil L is further provided with a switching device K2 alone to perform control operation on whether the heating coil L is connected to the electromagnetic induction heating circuit. In the embodiment shown in fig. 5, the first type resonant heating assembly 10 is a resonant heating assembly of a type in which the first heating coil L1 is connected and controlled by the first switching device K1, and it is understood that in other embodiments, the first type resonant heating assembly 10 may be a resonant heating assembly in which the first heating coil L1 is directly connected to the second end of the first resonant capacitor C1 and the power supply.
It is understood that the specific type of the switching device K2 is not exclusive, and any type can be used as long as the control of whether the corresponding heating coil L is connected to the circuit or not can be realized according to the control signal of the controller. For example, in one embodiment, the switching device K2 may be implemented using a power switch or a relay, similar to the first switching device K1.
The scheme of this embodiment, each heating element's access all need switch on through a switching device K2 who corresponds with it and realize, and each heating element all corresponds a resonance electric capacity C, when carrying out the multistage heating, can realize more accurate heating control, and can select at least one heating element to insert electromagnetic induction heating circuit in the second resonance heating element according to actual demand to effectively improve electromagnetic induction heating circuit's operational reliability.
Similarly, in the case of the second type resonant heating assembly 20 in which each heating coil L corresponds to one resonant capacitor C, the number of the heating coils L is not unique, as long as the coupling between each heating coil L and the first type resonant heating assembly 10 (specifically, the first heating coil L1 in the first type resonant heating assembly 10) is not completely the same. For example, in a more detailed embodiment, the number of heating coils L is two.
In this embodiment, the two heating coils L are respectively connected with a switching device K2, the coupling sizes of the two heating coils L and the first type resonant heating assembly 10 are different, and the controller realizes the access control of the two heating coils L by controlling the on-off of the switching device K2. When the first type resonant heating assembly 10 runs at low power, the switching device K2 corresponding to the heating coil L with the coupling smaller is selected to be switched on, so that low-power continuous heating is realized; when the first type resonant heating assembly 10 operates at high power, the switching device K2 corresponding to the heating coil L with large coupling is selected to be turned on, so as to realize high-power continuous heating control.
It should be noted that the specific types of the switching device 41, the first switching device and the second switching device are not exclusive, and may be controlled to be turned on and off so that the corresponding heating coils are heated at different powers. For example, in one embodiment, the switching device 41, the first switching device, and the second switching device are all power switching tubes. Further, in a more detailed embodiment, the switching device 41, the first switching device, and the second switching device are all IGBTs (Insulated Gate Bipolar transistors).
Referring to fig. 6, in an embodiment, the electromagnetic induction heating circuit further includes a rectifying device 50, a first terminal of the rectifying device 50 and a second terminal of the rectifying device 50 are respectively connected to the power supply, a third terminal of the rectifying device 50 is connected to the first resonant heating assembly 10 and the second resonant heating assembly 20, and a fourth terminal of the rectifying device 50 is connected to the first switching device 30 and the second switching device 40.
Specifically, the rectifying device 50 is a device for converting an accessed ac power into a dc power to supply power. Through the rectifying device 50, the ac power input to the first end of the rectifying device 50 and the second end of the rectifying device 50 can be converted into the dc power, so that the electromagnetic induction heating circuit is applied to the ac power scene, such as various household appliances. It is understood that the specific type of rectifying device 50 is not exclusive, as long as it can convert the ac power to dc power for heating. For example, in one embodiment, the rectifying device 50 may specifically employ a bridge rectifying device 50.
Further, referring to fig. 7, in an embodiment, the electromagnetic induction heating circuit further includes a first filter circuit 60 and a second filter circuit 70, a first end of the rectifying device 50 is connected to the first end of the first filter circuit 60, a second end of the rectifying device 50 is connected to the second end of the first filter circuit 60, a third end of the first filter circuit 60 and a fourth end of the first filter circuit 60 are respectively connected to the power supply, a first end of the second filter circuit 70 is connected to the third end of the rectifying device 50, a second end of the second filter circuit 70 is connected to the fourth end of the rectifying device 50, a third end of the second filter circuit 70 is connected to the first resonant heating element 10 and the second resonant heating element 20, and a fourth end of the second filter circuit 70 is connected to the first switching device 30 and the second switching device 40.
Specifically, in the solution of the present embodiment, the filter circuits are disposed on both sides of the rectifying device 50, and after the interference components in the ac power supply are filtered by the first filter circuit 60, the ac power supply is transmitted to the rectifying device for rectifying operation. Meanwhile, a second filter circuit 70 is further disposed on the output side of the rectifier device 50 to ensure that no interference component exists in the dc power output from the rectifier device 50 to the heating coil. Through the design of the first filter circuit 60 and the second filter circuit 70, the working reliability of the electromagnetic induction heating circuit can be effectively improved. It should be noted that the specific form of the first filter circuit 60 and the second filter circuit 70 is not exclusive, and in one embodiment, the first filter circuit 60 is an EMC filter circuit, that is, an electromagnetic compatibility filter circuit, and the second filter circuit 70 may be implemented by an RC filter circuit or the like.
Further, referring to fig. 8, in an embodiment, the electromagnetic induction heating circuit further includes a fuse F and a voltage dependent resistor Z, a third terminal of the first filter circuit 60 is connected to the first terminal of the fuse F and the first terminal of the voltage dependent resistor Z, a second terminal of the fuse F is connected to the live wire of the power supply, and a second terminal of the voltage dependent resistor Z is connected to the fourth terminal of the first filter circuit 60 and the neutral wire of the power supply.
Specifically, the fuse F is a current fuse, and mainly plays a role in overload protection, and when the current rises to a certain height and heat abnormally, the fuse F itself fuses to cut off the current, thereby protecting the safe operation of the circuit. The voltage dependent resistor Z is a resistor device with nonlinear volt-ampere characteristics, and is mainly used for clamping voltage when a circuit bears overvoltage, and absorbing redundant current to protect a sensitive device. Through the design of the fuse F and the piezoresistor Z, the safety performance of the electromagnetic induction heating circuit can be effectively improved.
The electromagnetic induction heating circuit is provided with a first type resonance heating assembly 10 and a second type resonance heating assembly 20 at the same time, the second type resonance heating assembly 20 is provided with more than two heating coils at the same time, the coupling of each heating coil and the first type resonance heating assembly 10 is not completely the same, and the first type switching device 30 is used for adjusting the heating power of the first type resonance heating assembly 10. By the arrangement mode, a plurality of parts can be controlled to be heated simultaneously, and multi-section heating control is realized; and when the first type resonant heating assembly 10 heats with the power lower than the preset power threshold, the controller controls the heating coil coupled with the first type resonant heating assembly 10 in the second type resonant heating assembly 20 to be connected into the circuit. Due to the existence of the heating coil, the back voltage and the current value of the first type switching device 30 are kept at large values, and finally the first type resonant heating assembly 10 is kept at the power lower than the preset power threshold value for heating, so that low-power continuous heating is realized.
Referring to fig. 10, a control method of the electromagnetic induction heating circuit includes steps S100, S200, and S300.
And S100, acquiring the power of the first type of resonant heating component. Step S200, judging whether the power is smaller than a preset power threshold value. And step S300, when the power is smaller than a preset power threshold value, controlling a heating coil of the second type of resonance heating assembly to be connected with a heating coil which is coupled with the first type of resonance heating assembly to heat so as to realize low-power continuous heating.
The structure of electromagnetic induction heating circuit is as described in each embodiment and the figure, specifically, electromagnetic induction heating circuit's structure is as described in each embodiment and the figure, and the resonance heating subassembly can carry out the energy storage promptly under the circular telegram condition, and through the resonance under the outage condition, produces the electric current of alternation, according to Faraday's law of electromagnetic induction to produce the magnetic field that changes, this magnetic field acts on the utensil that holds the article of waiting to heat such as pan, produces the vortex, realizes the subassembly of waiting to heat the article heating. The first type switching device 30 is used for power regulation of the first type resonant heating assembly 10, and the first type switching device 30 is enabled to perform heating operation at different powers by controlling the on-time and the off-time of the first type switching device 30.
When the first type resonant heating assembly 10 operates at a power lower than a preset power threshold value, the controller controls a heating coil coupled with the first type resonant heating assembly 10 in the second type resonant heating assembly 20 to be switched on for heating, and due to the existence of the heating coil, the back voltage and the current value of the first type switching device 30 are kept at large values, so that low-power heating is maintained. The scheme reduces the impact on the power grid and the influence on other electric equipment, and can be realized by selecting devices with lower withstand voltage, thereby effectively reducing the cost.
It will be appreciated that the manner in which the controller derives power from the first type of resonant heating assembly 10 is not exclusive. In one embodiment, the controller may directly obtain the corresponding power according to a control instruction issued by a user in combination with an actual usage scenario of the electromagnetic induction heating circuit. For example, in one embodiment, when the electromagnetic induction heating circuit is used in an electric cooker, the controller may obtain the current power of the electromagnetic induction heating circuit according to an operation mode selection instruction or the like sent by a user to the electric cooker. After obtaining the power of the first resonant heating assembly 10, the controller directly compares and analyzes with a preset power threshold.
It should be noted that the magnitude of the preset power threshold may be set differently in different types of devices. For example, in one embodiment, when the electromagnetic induction heating circuit is applied to an electric rice cooker, the preset power threshold may be set to 800W, that is, when the operation power of the first type resonant heating assembly 10 is greater than 800W, the electric rice cooker is considered to be operated with high power heating, and when the operation power of the first type resonant heating assembly 10 is less than 800W, the electric rice cooker is considered to be operated with low power heating.
Referring to fig. 11, in an embodiment, after step S200, step S400 is further included.
And step S400, when the power is greater than or equal to the preset power threshold value, controlling a heating coil of the second type of resonance heating assembly to be connected with a heating coil coupled with the first type of resonance heating assembly for heating so as to realize high-power continuous heating.
Specifically, when the operating power of the first type resonant heating assembly 10 is greater than the preset power threshold, that is, when the first type resonant heating assembly 10 operates at a high power, the controller may control the heating coil of the second type resonant heating assembly 20, which is coupled to the first type resonant heating assembly 10, to be switched on, so as to achieve high-power continuous heating. In this case, the back voltage and the current of the first type switching device 30 can be kept small, the stress on the first type switching device 30 is small, the loss is relatively small, and therefore the first type resonant heating assembly 10 can be controlled to be in a continuous high-power heating state.
In one embodiment, the control of the heating coil of the second type of resonant heating assembly, which is coupled with the first type of resonant heating assembly and is switched in for heating, comprises: and the gating device for controlling the second type of resonant heating assembly gates the heating coil of the second type of resonant heating assembly, and the heating coil coupled with the first type of resonant heating assembly is connected in for heating.
Specifically, in the embodiment, the second resonant heating assembly 20 includes a second resonant capacitor C2, a gating device K, and two or more heating coils L, the second switching device 40 includes a second switching device, a first end of each heating coil L and a first end of the second resonant capacitor C2 are connected to each other, a common end of the second switching device is connected to a first end of the second switching device, a second end of the second switching device is connected to the first switching device 30 and the power supply, a control end of the second switching device is connected to a controller (not shown), a second end of each heating coil L is connected to the gating device K, the gating device K is connected to a second end of the second resonant capacitor C2 and the first resonant heating assembly 10, and the gating device K is connected to the controller.
The gating device K is used to perform the selection operation of the access circuit of the heating coils L, at which time different heating coils L share one resonant capacitor C, i.e. the second resonant capacitor C2, and share one switching device 40 of the second type, i.e. the second switching device. The controller controls the corresponding heating coil to be connected into the circuit through the gating device K according to the working state of the first type resonant heating assembly 10, and then the heating coil L and the second resonant capacitor C2 are heated under the control of the second switching device. Through the scheme, the number of the second switching devices and the number of the resonant capacitors C can be effectively reduced, so that the circuit size is effectively reduced, and the circuit cost is reduced.
In one embodiment, the control of the heating coil of the second type of resonant heating assembly, which is coupled with the first type of resonant heating assembly and is switched in for heating, comprises: and controlling the conduction of a switching device corresponding to the heating coil coupled with the first type of resonant heating assembly in the heating coil of the second type of resonant heating assembly.
Specifically, in the embodiment, the second type resonant heating assembly 20 includes more than two heating coils L, switching devices K2 with the same number as the heating coils L, and resonant capacitors C with the same number as the heating coils L, the second type switching device 40 includes switching devices 41 with the same number as the heating coils L, a first end of any heating coil L is correspondingly connected to a first end of a resonant capacitor C, a first end of each resonant capacitor C is correspondingly connected to a first end of a switching device 41, a second end of each switching device 41 is respectively connected to the first type switching device 30 and the power supply, a control end of each switching device 41 is respectively connected to the controller (not shown), a second end of any heating coil L is correspondingly connected to a first end of a switching device K2, a second end of each switching device K2 and a second end of each resonant capacitor C are connected to each other, and a common end is connected to the first type resonant heating assembly 10 and the power supply, the control terminals of the switching devices K2 are connected to a controller.
More than two heating coils L in the second type resonant heating assembly 20 may also be in a form not passing through the common resonant capacitor C, at this time, each heating coil L is correspondingly connected in parallel with one resonant capacitor C, each heating coil L realizes corresponding heating power control through one switching device 41, and meanwhile, each heating coil L is also separately provided with a switching device K2 to perform control operation on whether the heating coil L is connected to the electromagnetic induction heating circuit. In the embodiment shown in fig. 5, the first type resonant heating assembly 10 is a resonant heating assembly of a type in which the first heating coil L1 is connected and controlled by the first switching device K1, and it is understood that in other embodiments, the first type resonant heating assembly 10 may be a resonant heating assembly in which the first heating coil L1 is directly connected to the second end of the first resonant capacitor C1 and the power supply.
Further, in one embodiment, the controller is further configured to implement power regulation of the first type resonant heating assembly 10 by controlling a duty cycle of the first type switching device 30; and/or the controller is further configured to effect power regulation of the second type resonant heating assembly 20 by controlling the duty cycle of the second type switching device 40. That is, the controller controls the on-time and the off-time of the first type switching device 10 to make the first type resonant heating assembly 10 operate at the corresponding power, and controls the on-time and the off-time of the second type switching device 20 to make the second type resonant heating assembly 20 operate at the corresponding power.
It should be noted that, in one embodiment, before step S300, the method further comprises: and acquiring the coupling size of each heating coil in the second type of resonant heating assembly and the first type of resonant heating assembly.
Specifically, in the scheme of this embodiment, before the controller performs the type analysis of the heating coil L that needs to be connected in the second type resonant heating assembly 20 in combination with the power of the first type resonant heating assembly 10, the coupling size between each heating coil L in the second type resonant heating assembly 20 and the first type resonant heating assembly 10 is also obtained first, that is, the coupling between each heating coil L and the first heating coil L1 is obtained, so that the controller realizes the type selection operation of the heating coil L in combination with the power of the first type resonant heating assembly 10.
It is understood that, in the solution of the present embodiment, the coupling magnitude may specifically refer to a coupling value of each heating coil L with the first type resonant heating assembly 10; the coupling magnitude relationship between each heating coil L and the first type resonant heating assembly 10 may also be, that is, it is not necessary to know the specific value of the coupling between the heating coil L and the first type resonant heating assembly 10, and it is only necessary to know which heating coil L is coupled with the first type resonant heating assembly 10 in turn from large to small in the heating coil L.
The manner of obtaining the coupling magnitude between each heating coil L in the second type resonant heating assembly and the first type resonant heating assembly 10 is not unique, and in one embodiment, since the relative position of each heating coil L in the second type resonant heating assembly 20 is already set when the electromagnetic heating device applying the electromagnetic induction heating circuit is shipped from a factory, and in the case that other conditions are substantially consistent, the coupling magnitude relationship between each heating coil L and the first type resonant heating assembly 10 is basically determined, at this time, the coupling magnitude relationship between each heating coil L and the first type resonant heating assembly 10 can be set in a preset manner in the controller, and the coupling magnitude relationship between each heating coil L and the first type resonant heating assembly 10 can be directly called when heating control is performed. In other embodiments, the controller obtains the coupling magnitude relation between each heating coil L and the first type resonant heating assembly 10, or obtains the coupling value between each heating coil L and the first type resonant heating assembly 10 by obtaining the relative position between each heating coil L and the first type resonant heating assembly 10, the magnetic medium information around each heating coil L, and the like for analysis.
It should be noted that the relationship between the step of obtaining the coupling magnitude between each heating coil in the second type resonant heating assembly and the first type resonant heating assembly and the steps S100 and S200 is not exclusive, and the step may be performed before the step S100, between the step S100 and the step S200, or after the step S200, as long as the step is performed before the step S300 or the step S400 performs the access selection of the heating coil L according to the heating.
The control method of the electromagnetic induction heating circuit is simultaneously provided with the first type resonance heating assembly 10 and the second type resonance heating assembly 20, the second type resonance heating assembly 20 is simultaneously provided with more than two heating coils, the coupling of each heating coil and the first type resonance heating assembly 10 is not completely the same, and the first type switching device 30 is used for adjusting the heating power of the first type resonance heating assembly 10. By the arrangement mode, a plurality of parts can be controlled to be heated simultaneously, and multi-section heating control is realized; and when the first type resonant heating assembly 10 heats with the power lower than the preset power threshold, the controller controls the heating coil coupled with the first type resonant heating assembly 10 in the second type resonant heating assembly 20 to be connected into the circuit. Due to the existence of the heating coil, the back voltage and the current value of the first type switching device 30 are kept at large values, and finally the first type resonant heating assembly 10 is kept at the power lower than the preset power threshold value for heating, so that low-power continuous heating is realized.
An electromagnetic heating device comprises the electromagnetic induction heating circuit, and a controller is used for heating control according to the method.
Specifically, the resonance heating subassembly is promptly can carry out the energy storage under the circular telegram circumstances, and through the resonance under the outage circumstances, produces the electric current of alternation, according to Faraday's electromagnetic induction law to produce the magnetic field that changes, this magnetic field acts on the utensil that holds the article of waiting to heat such as pan, produces the vortex, realizes the subassembly of the article heating of waiting to heat. The first-type switching device 30 is used for power regulation of the first-type resonant heating assembly 10, and the first-type switching device 30 is enabled to perform heating operation at different powers by controlling the on-time and the off-time of the first-type switching device 30; the second type of switching device 40 is used for power conditioning the second type of resonant heating element 20, and the specific type of the second type of switching device 40 is not exclusive according to the structure of the second type of resonant heating element 20.
Since only one heating coil coupled to the first resonant heating assembly 10 in the second resonant heating assembly 20 is connected to the circuit when the first resonant heating assembly 10 operates at a power less than the preset power threshold, in one embodiment, only one second switching device 40 may be provided for power control, and one heating coil in the second resonant heating assembly 20 is connected to the circuit in a gating manner. In another embodiment, it is also possible that the second type switching device 40 includes more than two switching devices, and one switching device is provided for each heating coil in the second type resonant heating assembly 20 for corresponding power control.
In the scheme of the embodiment, when the first type resonant heating assembly 10 operates at a power lower than the preset power threshold, the controller controls the heating coil, which is coupled with the first type resonant heating assembly 10 and is smaller, of the second type resonant heating assembly 20 to be connected, and due to the existence of the heating coil, the back pressure and the current value of the first type switching device 30 are kept at larger values, so that low-power heating is maintained. The scheme reduces the impact on the power grid and the influence on other electric equipment, and can be realized by selecting devices with lower withstand voltage, thereby effectively reducing the cost.
It should be noted that the specific type of electromagnetic heating device is not exclusive, as long as it is a device that heats by electromagnetic induction. For example, in one embodiment, it may be an electromagnetic heating type home appliance. Further, the electromagnetic heating type household electrical appliance is an electric cooker.
Specifically, through setting up above-mentioned electromagnetic induction heating circuit in electric rice cooker for electric rice cooker can realize the multistage heating function, thereby guarantees that the rice homogeneity that the culinary art obtained is higher, the taste is better. In addition, because the low-power continuous heating can be realized, the effect of slow stewing with slow fire can also be realized, the rice cooker is not easy to overflow when a user cooks porridge, and the cooking reliability of the rice cooker is effectively improved.
It should be noted that the arrangement of the heating coils in the resonant heating assemblies in the rice cooker is not exclusive, and in a more detailed embodiment, please refer to fig. 9, the first type resonant heating assembly 10 includes a first heating coil L1, the second type resonant heating assembly 20 includes two heating coils, and the electromagnetic induction heating circuit includes a rectifying device 50, a first filter circuit 60, a second filter circuit 70, a fuse F and a voltage dependent resistor Z.
At this time, the first heating coil L1 may be disposed at the bottom of the inner container, one heating coil of the second type resonant heating unit 20 may be disposed at the R-corner of the inner container, and the other heating coil of the second type resonant heating unit 20 may be disposed at the top side of the inner container. The two heating coils are not equally coupled with the first heating coil L1, and only the heating coil with the smaller coupling with the first heating coil L1 is connected with the two heating coils in the second type of resonant heating assembly 20 at the same time, so that the low-power continuous heating operation of the electric cooker is realized according to the rectified and filtered direct current.
The electromagnetic heating device is provided with the first type resonance heating assembly 10 and the second type resonance heating assembly 20 at the same time, the second type resonance heating assembly 20 is provided with more than two heating coils at the same time, the coupling of each heating coil and the first type resonance heating assembly 10 is not completely the same, and the first type switching device 30 is used for adjusting the heating power of the first type resonance heating assembly 10. By the arrangement mode, a plurality of parts can be controlled to be heated simultaneously, and multi-section heating control is realized; and when the first type resonant heating assembly 10 heats with the power lower than the preset power threshold, the controller controls the heating coil coupled with the first type resonant heating assembly 10 in the second type resonant heating assembly 20 to be connected into the circuit. Due to the existence of the heating coil, the back voltage and the current value of the first type switching device 30 are kept at large values, and finally the first type resonant heating assembly 10 is kept at the power lower than the preset power threshold value for heating, so that low-power continuous heating is realized.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (18)

1. An electromagnetic induction heating circuit, comprising:
a first type of resonant heating assembly;
the second type of resonance heating assembly is provided with more than two heating coils, and the coupling of each heating coil and the first type of resonance heating assembly is not completely the same;
the first type of switching device is connected with the first type of resonant heating component, and forms a heating branch with the first type of resonant heating component to be connected to a power supply;
the second-class resonance heating assembly and the first-class switching device are respectively connected with the controller, and the controller is used for controlling a heating coil of the second-class resonance heating assembly to be connected with a heating coil which is coupled with the first-class resonance heating assembly to be heated when the first-class resonance heating assembly is judged to run at a power smaller than a preset power threshold value, so that low-power continuous heating is realized.
2. The electromagnetic induction heating circuit of claim 1, further comprising a second type switching device, wherein the second type switching device is connected to the second type resonant heating component, forms another heating branch with the second type resonant heating component and is connected to a power supply, and the second type switching device is connected to the controller.
3. The electromagnetic induction heating circuit of claim 2, wherein the first resonant heating assembly comprises a first resonant capacitor and a first heating coil, the first switching device comprises a first switching device, a first end of the first resonant capacitor is connected to a first end of the first heating coil and a common end is connected to a first end of the first switching device, a second end of the first switching device is connected to a power supply and the second switching device, a control end of the first switching device is connected to the controller, and a second end of the first resonant capacitor is connected to a second end of the first heating coil and a common end is connected to the power supply and the second resonant heating assembly.
4. The electromagnetic induction heating circuit of claim 3, wherein the first type of resonant heating assembly further comprises a first switching device, the second end of the first heating coil is connected to the first end of the first switching device, the second end of the first switching device is connected to the second end of the first resonant capacitor, and the control end of the first switching device is connected to the controller.
5. The electromagnetic induction heating circuit according to any one of claims 2 to 4, wherein the second type resonant heating assembly comprises a second resonant capacitor, a gating means and two or more heating coils, the second type switching device comprises a second switching device, a first end of each heating coil and a first end of the second resonant capacitor are connected to each other, a common terminal is connected to a first end of the second switching device, a second end of the second switching device is connected to the first type switching device and a power supply, a control terminal of the second switching device is connected to the controller, a second end of each heating coil is connected to the gating means, the gating means is connected to a second end of the second resonant capacitor and the first type resonant heating assembly, and the gating means is connected to the controller.
6. The electromagnetic induction heating circuit according to claim 5, wherein the number of the heating coils is two.
7. The electromagnetic induction heating circuit according to any one of claims 2 to 4, wherein the second type of resonant heating assembly comprises more than two heating coils, the same number of switching devices as the heating coils, and the same number of resonant capacitors as the heating coils, and the second type of switching devices comprises the same number of switching devices as the heating coils;
the first end of any heating coil is correspondingly connected with the first end of one resonant capacitor, the first end of each resonant capacitor is correspondingly connected with the first end of one switching device, the second end of each switching device is connected with the first type of switching device and the power supply, the control end of each switching device is connected with the controller, the second end of any heating coil is correspondingly connected with the first end of one switching device, the second end of each switching device and the second end of each resonant capacitor are connected with each other, the common end of each switching device is connected with the first type of resonant heating assembly and the power supply, and the control end of each switching device is connected with the controller.
8. The electromagnetic induction heating circuit according to claim 7, wherein the number of the heating coils is two.
9. The electromagnetic induction heating circuit according to any one of claims 2 to 4, further comprising a rectifying device, wherein a first terminal of the rectifying device and a second terminal of the rectifying device are respectively connected to a power supply, a third terminal of the rectifying device is connected to the first resonant heating assembly and the second resonant heating assembly, and a fourth terminal of the rectifying device is connected to the first switching device and the second switching device.
10. The electromagnetic induction heating circuit according to claim 9, further comprising a first filter circuit and a second filter circuit, wherein a first terminal of the rectifying device is connected to a first terminal of the first filter circuit, a second terminal of the rectifying device is connected to a second terminal of the first filter circuit, a third terminal of the first filter circuit and a fourth terminal of the first filter circuit are respectively connected to a power supply, a first terminal of the second filter circuit is connected to a third terminal of the rectifying device, a second terminal of the second filter circuit is connected to a fourth terminal of the rectifying device, a third terminal of the second filter circuit is connected to the first resonant heating element and the second resonant heating element, and a fourth terminal of the second filter circuit is connected to the first switching device and the second switching device.
11. The electromagnetic induction heating circuit of claim 10, further comprising a fuse and a varistor, wherein the third terminal of the first filter circuit is connected to the first terminal of the fuse and the first terminal of the varistor, the second terminal of the fuse is connected to the hot wire of the power supply, and the second terminal of the varistor is connected to the fourth terminal of the first filter circuit and the neutral wire of the power supply.
12. A method of controlling an electromagnetic induction heating circuit as set forth in any one of claims 1 to 11, comprising:
acquiring the power of the first type of resonant heating component;
judging whether the power is smaller than a preset power threshold value or not;
and when the power is smaller than the preset power threshold value, controlling a heating coil of the second type of resonance heating assembly to be connected with a heating coil which is coupled with the first type of resonance heating assembly to heat so as to realize low-power continuous heating.
13. The control method according to claim 12, wherein after determining whether the power is less than a preset power threshold, the method further comprises:
and when the power is greater than or equal to the preset power threshold value, controlling a heating coil of the second type of resonance heating assembly to be connected with a heating coil coupled with the first type of resonance heating assembly for heating so as to realize high-power continuous heating.
14. The control method of claim 12, wherein the controlling of the heating coil of the second type of resonant heating assembly, the heating coil coupled with the first type of resonant heating assembly being switched in for heating, comprises:
and controlling a gating device of the second type of resonant heating assembly to gate the heating coil of the second type of resonant heating assembly, and connecting the heating coil coupled with the first type of resonant heating assembly to a small heating coil for heating.
15. The control method of claim 12, wherein the controlling of the heating coil of the second type of resonant heating assembly, the heating coil coupled with the first type of resonant heating assembly being switched in for heating, comprises:
and controlling the conduction of a switching device corresponding to the heating coil coupled with the first type of resonant heating assembly in the heating coil of the second type of resonant heating assembly.
16. The control method according to claim 12, wherein before the step of controlling the heating coil of the second type of resonant heating assembly to be switched on for heating by the heating coil coupled with the first type of resonant heating assembly to realize low-power continuous heating when the power is smaller than the preset power threshold, the method further comprises:
and acquiring the coupling size of each heating coil in the second type of resonant heating assembly and the first type of resonant heating assembly.
17. An electromagnetic heating apparatus comprising an electromagnetic induction heating circuit as claimed in any one of claims 1 to 11, said controller being adapted to perform heating control in accordance with the method as claimed in any one of claims 12 to 16.
18. Electromagnetic heating apparatus according to claim 17, wherein said electromagnetic heating apparatus is an electric rice cooker.
CN202110714147.7A 2021-06-25 2021-06-25 Electromagnetic induction heating circuit, control method thereof and electromagnetic heating equipment Pending CN113271696A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110714147.7A CN113271696A (en) 2021-06-25 2021-06-25 Electromagnetic induction heating circuit, control method thereof and electromagnetic heating equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110714147.7A CN113271696A (en) 2021-06-25 2021-06-25 Electromagnetic induction heating circuit, control method thereof and electromagnetic heating equipment

Publications (1)

Publication Number Publication Date
CN113271696A true CN113271696A (en) 2021-08-17

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Application Number Title Priority Date Filing Date
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