CN104244481A - Electromagnetic induction heating device and heating control method thereof - Google Patents

Abstract

The invention discloses a heating control method of an electromagnetic induction heating device, wherein the electromagnetic induction heating device includes a power switch, and the method includes the following steps: S1, real-time detection of the current of the power switch; S2, when the power switch When the average current is greater than or equal to the first current threshold, control the electromagnetic induction heating device to heat with the first current threshold for the first preset time T1, and then reduce the duty cycle of the signal controlling the power switch; S3, When the average current is less than or equal to the second current threshold, after controlling the electromagnetic induction heating device to heat with the second current threshold for a second preset time T2, increase the duty cycle of the signal controlling the power switch, Wherein, the second current threshold is smaller than the first current threshold. The heating control method can effectively reduce the temperature rise of the power switch without increasing the cost and has strong practicability. The invention also discloses an electromagnetic induction heating device.

Description

Heating control method of electromagnetic induction heating device and electromagnetic induction heating device

technical field

The invention relates to the technical field of electromagnetic induction heating, in particular to a heating control method of an electromagnetic induction heating device and an electromagnetic induction heating device.

Background technique

At present, electromagnetic induction heating devices such as induction cookers are mainly implemented by measures such as increasing the radiator, increasing the air volume of the fan, and changing the air duct in the solution to reduce the temperature rise of the IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) of the induction cooker. . Although these methods can also reduce the temperature rise of the IGBT, increasing the radiator and increasing the air volume of the fan will increase the cost, and there is no rule to change the air duct. Different models need to be modified differently, which increases the complexity of the work and the production cost. high.

Contents of the invention

The object of the present invention is to solve at least one of the above-mentioned technical drawbacks.

Therefore, the present invention needs to provide an electromagnetic induction heating device and a heating control method thereof that can effectively reduce the temperature rise of the power switch without increasing the cost.

In order to achieve the above purpose, an embodiment of the present invention proposes a heating control method for an electromagnetic induction heating device, wherein the electromagnetic induction heating device includes a power switch, and the method includes the following steps: S1, real-time detection of the The current of the power switch; S2, calculate the average current of the power switch according to the current of the power switch detected by the preset times, and control the electromagnetic induction heating when the average current is greater than or equal to the first current threshold After the device heats with the first current threshold for the first preset time T1, reduce the duty cycle of the signal controlling the power switch; S3, when the average current is less than or equal to the second current threshold, control the power switch The magnetic induction heating device increases the duty cycle of the signal controlling the power switch after heating with the second current threshold for a second preset time T2, wherein the second current threshold is smaller than the first current threshold.

According to the heating control method of the electromagnetic induction heating device of the embodiment of the present invention, the fluctuation of the heating power of the electromagnetic induction heating device can be realized by controlling and changing the single turn-on time of the power switch when the electromagnetic induction heating device is working, which can effectively reduce the power switch. temperature rise, the control method of the present invention is applicable to any type of electromagnetic induction heating device, and has strong versatility. In addition, the heating control method is simple and easy to implement.

In an embodiment of the present invention, 0 minutes ≤ T1 ≤ 5 minutes, 0 minutes ≤ T2 ≤ 5 minutes.

Wherein, in the steps S2 and S3, the average heating power of the electromagnetic induction heating device is controlled to be within a preset plus or minus deviation range of the rated power.

In an embodiment of the present invention, the preset positive and negative deviation range is 5% to -20%.

In an embodiment of the present invention, the preset times are 5-20 times.

In an embodiment of the present invention, the first current threshold is the current value corresponding to the maximum positive deviation of the rated power, and the second current threshold is the current corresponding to the minimum negative deviation of the rated power value.

In order to achieve the above object, another embodiment of the present invention proposes an electromagnetic induction heating device, including: a power switch; a current detection module, the current detection module is connected to the power switch, and is used to detect the power switch current; a drive module, the drive module is connected to the power switch; a control module, the control module is connected to the drive module and the current detection unit respectively, and the control module is preset according to the current detection module Calculate the average current of the power switch from the current of the power switch detected for the second time, output a first control signal to control the turn-on time of the power switch when the average current is greater than or equal to a first current threshold, and After a control signal maintains the same duty cycle for a first preset time T1, the control module reduces the duty cycle of the first control signal, and outputs a second current threshold when the average current is less than or equal to a second current threshold. control signal to control the turn-on time of the power switch, and after the second control signal maintains the same duty cycle for a second preset time T2, the control module increases the duty cycle of the second control signal , wherein the second current threshold is smaller than the first current threshold.

According to the electromagnetic induction heating device of the embodiment of the present invention, the fluctuation of the heating power of the electromagnetic induction heating device can be realized by controlling the control module to change the single turn-on time of the power switch when the electromagnetic induction heating device is working, which can effectively reduce the power switch. The temperature rise does not need to increase the complexity of the work, which reduces the production cost, and is suitable for any type of electromagnetic induction heating device, and has strong versatility.

In an embodiment of the present invention, 0 minutes ≤ T1 ≤ 5 minutes, 0 minutes ≤ T2 ≤ 5 minutes.

Wherein, the control module controls the average heating power of the electromagnetic induction heating device to be within a preset plus or minus deviation range of the rated power.

In an embodiment of the present invention, the preset positive and negative deviation range is 5% to -20%.

In an embodiment of the present invention, the first current threshold is the current value corresponding to the maximum positive deviation of the rated power, and the second current threshold is the current corresponding to the minimum negative deviation of the rated power value.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

1 is a flowchart of a heating control method of an electromagnetic induction heating device according to an embodiment of the present invention;

Fig. 2 is the flowchart of the heating control method of the induction cooker according to a specific embodiment of the present invention; And

Fig. 3 is a schematic structural diagram of an electromagnetic induction heating device according to an embodiment of the present invention.

Reference signs:

A power switch 10 , a current detection module 20 , a driving module 30 , a control module 40 , and a heating module 50 .

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, components and arrangements of specific examples are described below. Of course, they are only examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in different instances. This repetition is for the purpose of simplicity and clarity and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed. In addition, various specific process and material examples are provided herein, but one of ordinary skill in the art will recognize the applicability of other processes and/or the use of other materials. Additionally, configurations described below in which a first feature is "on" a second feature may include embodiments where the first and second features are formed in direct contact, and may include additional features formed between the first and second features. For example, such that the first and second features may not be in direct contact.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be two The internal communication of each element may be directly connected or indirectly connected through an intermediary. Those skilled in the art can understand the specific meanings of the above terms according to specific situations.

These and other aspects of embodiments of the invention will become apparent with reference to the following description and drawings. In these descriptions and drawings, some specific implementations of the embodiments of the present invention are specifically disclosed to represent some ways of implementing the principles of the embodiments of the present invention, but it should be understood that the scope of the embodiments of the present invention is not limited by this limit. On the contrary, the embodiments of the present invention include all changes, modifications and equivalents coming within the spirit and scope of the appended claims.

The heating control method of the electromagnetic induction heating device and the electromagnetic induction heating device proposed according to the embodiments of the present invention will be described below with reference to the accompanying drawings.

Fig. 1 is a flowchart of a heating control method of an electromagnetic induction heating device according to an embodiment of the present invention. Wherein, as shown in Figure 1, the electromagnetic induction heating device includes a power switch, and the heating control method of the electromagnetic induction heating device includes the following steps:

S1, detecting the current of the power switch in real time.

In one embodiment of the present invention, the power switch may be an IGBT.

S2, calculate the average current of the power switch according to the current of the power switch detected by preset times, when the average current is greater than or equal to the first current threshold, control the electromagnetic induction heating device to heat with the first current threshold after the first preset time T1 , reducing the duty cycle of the signal controlling the power switch. In an example of the present invention, the preset times are 5-20 times.

Wherein, 0 minutes≤T1≤5 minutes, preferably, T1 may be 2 minutes. Moreover, in this step S2, it is necessary to control the average heating power of the electromagnetic induction heating device to be within a preset plus or minus deviation range of the rated power. In an example of the present invention, the preset positive and negative deviation range may be 5% to -20%. For example, the positive deviation of rated power may be 5% of rated power, and the negative deviation of rated power may be -10% of rated power. %.

Further, in an embodiment of the present invention, the first current threshold is the current value corresponding to when the rated power is at the maximum positive deviation, for example, the first current threshold may be the current corresponding to P1=Pe (1+5%) Value, where P1 is the maximum power that the electromagnetic induction heating device can achieve.

S3, when the average current is less than or equal to the second current threshold, control the electromagnetic induction heating device to heat with the second current threshold for the second preset time T2, and increase the duty cycle of the signal controlling the power switch, wherein the second current threshold less than the first current threshold.

Wherein, 0 minutes≤T2≤5 minutes, preferably, T2 may also be 2 minutes. Moreover, in this step S3, it is also necessary to control the average heating power of the electromagnetic induction heating device to be within the preset plus or minus deviation range of the rated power.

Further, in an embodiment of the present invention, the second current threshold is the current value corresponding to when the rated power is at the minimum negative deviation, for example, the second current threshold may be the current corresponding to P2=Pe (1-10%) value, where P2 is the minimum power that the electromagnetic induction heating device can achieve.

Specifically, in one embodiment of the present invention, as shown in FIG. 2, the above-mentioned electromagnetic induction heating device is an induction cooker, and the heating control method of the induction cooker is realized based on the control circuit of the induction cooker, and specifically includes the following steps:

S201, start. Turn on the induction cooker for heating.

S202, detecting the current of the IGBT multiple times, and calculating the average current of the IGBT.

S203. Determine whether the current average current of the IGBT is greater than or equal to a first current value. If yes, execute step S204; if no, execute step S210.

S204. Control the induction cooker to heat at the first current threshold.

S205, judging whether the heating time reaches T1. If yes, execute step S206; if no, return to step S205 to continue judging.

S206, controlling the induction cooker to reduce the power to heat. That is to say, reduce the duty ratio of the signal controlling the IGBT, that is, control the pulse width to the IGBT to gradually decrease to reduce the single turn-on time of the IGBT, so that the heating power of the induction cooker is gradually reduced.

S207, judging whether the current average current of the IGBT is less than or equal to the second current value. If yes, execute step S208; if no, return to step S206.

S208. Control the induction cooker to heat with the second current threshold.

S209, judging whether the heating time reaches T2. If yes, execute step S210; if no, return to step S209 to continue judging.

S210, controlling the heating of the induction cooker by increasing the power. That is to say, increasing the duty ratio of the signal controlling the IGBT means gradually increasing the pulse width of the IGBT to increase the single turn-on time of the IGBT, so that the heating power of the induction cooker is gradually increased. And, repeat the above steps after heating until it is detected that the current average current of the IGBT is greater than or equal to the first current threshold, that is, return to step S203 to continue the judgment.

It should be noted that the heating control method of the present invention can be applied to a variety of electrical appliances using IGBTs as power switches, and is especially suitable for electromagnetic induction heating devices such as electromagnetic cookers, electromagnetic rice cookers, and electromagnetic pressure cookers.

According to the heating control method of the electromagnetic induction heating device of the embodiment of the present invention, the fluctuation of the heating power of the electromagnetic induction heating device can be realized by controlling and changing the single turn-on time of the power switch when the electromagnetic induction heating device is working, which can effectively reduce the power switch. temperature rise. In addition, the heating control method is simple and easy, and is applicable to any type of electromagnetic induction heating device, and has strong versatility, especially applicable to household appliances using electromagnetic heating such as electromagnetic cooker, electromagnetic rice cooker, and electromagnetic pressure cooker.

Fig. 3 is a schematic structural diagram of an electromagnetic induction heating device according to an embodiment of the present invention. As shown in FIG. 3 , the electromagnetic induction heating device includes a power switch 10 , a heating module 50 , a current detection module 20 , a driving module 30 and a control module 40 .

Wherein, the heating module 50 is connected to the power switch 10 , and the current detection module 20 is connected to the power switch 10 for detecting the current of the power switch 10 . The drive module 30 is connected to the power switch 10, the control module 40 is connected to the drive module 30 and the current detection unit 20 respectively, and the control module 40 calculates the average current of the power switch 10 according to the current of the power switch 10 detected by the current detection module 20 preset times, When the average current is greater than or equal to the first current threshold, a first control signal is output to control the turn-on time of the power switch 10, and after the first control signal is maintained at the same duty cycle for a first preset time T1, the control module 40 reduce the duty cycle of the first control signal, and output the second control signal to control the turn-on time of the power switch 10 when the average current is less than or equal to the second current threshold, and maintain the second control signal with the same duty cycle After a preset time T2, the control module 40 increases the duty ratio of the second control signal, wherein the second current threshold is smaller than the first current threshold.

In one embodiment of the present invention, as shown in FIG. 3 , the power switch 10 may be an IGBT, the control module 40 may be a single-chip microcomputer, and the electromagnetic induction heating device may be an induction cooker. The output end of the IGBT drive module is connected to the G pole of the IGBT, the input end is connected to the single-chip microcomputer, the input end of the current detection module 20 is connected to the E pole of the IGBT, the output end is connected to the single-chip microcomputer, and the C pole of the IGBT is connected to the heating module 50 .

When the current detection module 20 detects that the E pole average current of the IGBT is greater than or equal to the first current threshold, the single-chip microcomputer controls the heating module to keep the first current threshold for heating for a period of time T1, and the single-chip microcomputer controls the IGBT drive module to output to the IGBT. The pulse width gradually decreases In order to reduce the IGBT single turn-on time, the power of the induction cooker is gradually reduced;

When the current detection module 20 detects that the E pole average current of the IGBT is less than or equal to the second current threshold, the single-chip microcomputer controls the heating module to keep the second current threshold heating for a period of time T2, and the single-chip microcomputer controls the IGBT drive module to output to the IGBT. The pulse width gradually increases to Increase the one-time turn-on time of the IGBT to gradually increase the power and heat until the current detection module detects that the average current of the E pole of the IGBT is greater than or equal to the first current threshold, thereby performing cycle control.

Wherein, 0 minutes≤T1≤5 minutes, 0 minutes≤T2≤5 minutes, preferably, T1 may be 2 minutes, and T2 may also be 2 minutes. In addition, the control module 40 needs to control the average heating power of the electromagnetic induction heating device to be within a preset plus or minus deviation range of the rated power. In an example of the present invention, the preset positive and negative deviation range may be 5% to -20%. For example, the positive deviation of rated power may be 5% of rated power, and the negative deviation of rated power may be -10% of rated power. %.

Further, in an embodiment of the present invention, the first current threshold is the current value corresponding to when the rated power is at the maximum positive deviation, for example, the first current threshold may be the current corresponding to P1=Pe (1+5%) Value, where P1 is the maximum power that the electromagnetic induction heating device can achieve. The second current threshold is the current value corresponding to the rated power at the minimum negative deviation, for example, the second current threshold can be the current value corresponding to P2=Pe (1-10%), where P2 is the electromagnetic induction heating device The minimum power achievable.

According to the electromagnetic induction heating device of the embodiment of the present invention, when the electromagnetic induction heating device is working, the control module controls and changes the single turn-on time of the power switch to realize the fluctuation of the heating power of the heating module, which can effectively reduce the temperature rise of the power switch , without increasing the complexity of the work, reducing the production cost, and suitable for any type of electromagnetic induction heating device, with strong versatility.

Any process or method descriptions in flowcharts or otherwise described herein may be understood to represent modules, segments or portions of code comprising one or more executable instructions for implementing specific logical functions or steps of the process , and the scope of preferred embodiments of the invention includes alternative implementations in which functions may be performed out of the order shown or discussed, including substantially concurrently or in reverse order depending on the functions involved, which shall It is understood by those skilled in the art to which the embodiments of the present invention pertain.

The logic and/or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium, For use with an instruction execution system, device, or device (such as a computer-based system, a system including a processor, or other systems that can fetch instructions from an instruction execution system, device, or device and execute instructions), or in conjunction with such an instruction execution system, device or equipment used. For the purposes of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use in or in conjunction with an instruction execution system, device or device. More specific examples (non-exhaustive list) of computer-readable media include the following: electrical connection with one or more wires (electronic device), portable computer disk case (magnetic device), random access memory (RAM), Read Only Memory (ROM), Erasable and Editable Read Only Memory (EPROM or Flash Memory), Fiber Optic Devices, and Portable Compact Disc Read Only Memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program can be printed, since the program can be read, for example, by optically scanning the paper or other medium, followed by editing, interpretation or other suitable processing if necessary. The program is processed electronically and stored in computer memory.

It should be understood that various parts of the present invention can be realized by hardware, software, firmware or their combination. In the embodiments described above, various steps or methods may be implemented by software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or combination of the following techniques known in the art: Discrete logic circuits, ASICs with suitable combinational logic gates, Programmable Gate Arrays (PGAs), Field Programmable Gate Arrays (FPGAs), etc.

Those of ordinary skill in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. During execution, one or a combination of the steps of the method embodiments is included.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing module, each unit may exist separately physically, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. If the integrated modules are realized in the form of software function modules and sold or used as independent products, they can also be stored in a computer-readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, and the like.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (11)

1. a heating control method of electromagnetic induction heating device, it is characterized in that, described electromagnetic induction heating device comprises power switch, and described method comprises the steps: S1, detecting the current of the power switch in real time; S2. Calculate the average current of the power switch according to the current of the power switch detected for preset times, and when the average current is greater than or equal to a first current threshold, control the electromagnetic induction heating device to use the first current After the threshold is heated for a first preset time T1, the duty cycle of the signal controlling the power switch is reduced; S3. When the average current is less than or equal to the second current threshold, control the electromagnetic induction heating device to heat at the second current threshold for a second preset time T2, and increase the duty of the signal for controlling the power switch ratio, wherein the second current threshold is smaller than the first current threshold. 2. The heating control method according to claim 1, characterized in that 0 minutes≤T1≤5 minutes, 0 minutes≤T2≤5 minutes. 3. The heating control method according to claim 1, characterized in that, in the steps S2 and S3, the average heating power of the electromagnetic induction heating device is controlled to be within a predetermined range of positive and negative deviations of the rated power. 4. The heating control method according to claim 3, wherein the preset positive and negative deviation range is 5% to -20%. 5. The heating control method according to claim 1, characterized in that, the preset times are 5-20 times. 6. The heating control method according to claim 3, wherein the first current threshold is the current value corresponding to when the rated power is at the maximum positive deviation, and the second current threshold is the rated power The current value corresponding to the minimum negative deviation. 7. An electromagnetic induction heating device, characterized in that it comprises: power switch; A current detection module, the current detection module is connected to the power switch and used to detect the current of the power switch; a drive module, the drive module is connected to the power switch; A control module, the control module is connected to the drive module and the current detection unit respectively, and the control module calculates the average current of the power switch according to the current of the power switch detected by the current detection module for a preset time , outputting a first control signal to control the turn-on time of the power switch when the average current is greater than or equal to a first current threshold, and after the first control signal remains at the same duty cycle for a first preset time T1 , the control module reduces the duty cycle of the first control signal, and outputs a second control signal to control the turn-on time of the power switch when the average current is less than or equal to a second current threshold, and at the second After the two control signals maintain the same duty cycle for a second preset time T2, the control module increases the duty cycle of the second control signal, wherein the second current threshold is smaller than the first current threshold. 8. The electromagnetic induction heating device according to claim 7, characterized in that 0 minutes≤T1≤5 minutes, 0 minutes≤T2≤5 minutes. 9 . The electromagnetic induction heating device according to claim 7 , wherein the control module controls the average heating power of the electromagnetic induction heating device to be within a preset positive and negative deviation range of the rated power. 10 . The electromagnetic induction heating device according to claim 9 , wherein the preset positive and negative deviation range is 5%˜-20%. 11 . 11. The electromagnetic induction heating device according to claim 9, characterized in that, the first current threshold is the current value corresponding to the maximum positive deviation of the rated power, and the second current threshold is the rated power The corresponding current value when the power is at the minimum negative deviation.