Electromagnetic heating control method compatible with sine wave inverter and square wave inverter

Abstract

The invention provides an electromagnetic heating control method compatible with a sine wave and square wave inverter, and the method comprises a voltage detection circuit which is used for collecting an input AC voltage signal; and the rectifying and filtering unit rectifies the input alternating current power supply and then filters the alternating current power supply into a direct current power supply to provide energy for follow-up circuit work. The electromagnetic heating resonance unit comprises an LC oscillation circuit and an IGBT. The IGBT driving circuit is connected with the main control chip and an IGBT of the electromagnetic heating resonance unit; and the main control chip is connected with the voltage detection circuit, the main control chip judges the waveform of the input voltage according to the voltage signal acquired by the voltage detection circuit and outputs a corresponding signal to the IGBT driving circuit, and the IGBT driving circuit drives the electromagnetic heating resonance unit to work according to the voltage type. According to the electromagnetic heating control method compatible with the sine wave inverter and the square wave inverter, the input voltage is detected, so that different control programs are started, and electromagnetic heating equipment can work normally no matter whether a user uses the pure sine wave inverter or the square wave inverter.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic heating control, and particularly relates to an electromagnetic heating control method compatible with sine wave and square wave inverters. Background Art

[0002] For outdoor enthusiasts, to meet the cooking needs of using electromagnetic heating products in the wild outdoors, it is necessary to use an inverter that converts direct current (DC) at low voltage to alternating current (AC) at high voltage to convert the DC power of the energy storage battery into AC power before using household electromagnetic heating products. Currently, the inverters sold on the market that convert DC at low voltage to AC at high voltage are divided into two types: pure sine wave inverters and non-pure sine wave (square wave) inverters. However, the household electromagnetic heating products on the market are all designed with circuit systems based on sine wave alternating current and cannot be matched with non-pure sine wave (square wave) inverters for use. Summary of the Invention

[0003] To make up for the deficiencies in the prior art, the present invention provides an electromagnetic heating control method compatible with sine wave and square wave inverters. By detecting the input voltage, different control programs are started, so that the electromagnetic heating device can work normally regardless of whether the user uses a pure sine wave inverter or a square wave inverter.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] An electromagnetic heating control method compatible with sine wave and square wave inverters, comprising:

[0006] A voltage detection circuit for collecting the input AC voltage signal; providing the information of the input voltage to the main control chip, thereby providing a signal basis for the main control chip to judge the type of the input voltage.

[0007] A rectification and filtering unit that rectifies and filters the input AC power into DC power to provide energy for the subsequent circuit operation.

[0008] An electromagnetic heating resonance unit, including an LC oscillation circuit and an IGBT.

[0009] An IGBT drive circuit, connected to the IGBT of the main control chip and the electromagnetic heating resonance unit; driving the IGBT of the resonance unit to work by receiving and amplifying the output signal of the main control chip.

[0010] The main control chip is connected to the voltage detection circuit. The main control chip judges the waveform of the input voltage according to the voltage signal collected by the voltage detection circuit, and then outputs a corresponding signal to the IGBT drive circuit, and the IGBT drive circuit then drives the electromagnetic heating resonance unit to work according to the voltage type.

[0011] Further, when the main control chip determines that the input voltage waveform is a sine wave, it outputs a sine wave heating signal to the IGBT to drive the electromagnetic heating resonance unit to operate in the sine wave type; when the main control chip determines that the input voltage waveform is a non-sine wave, it outputs a square wave heating signal to the IGBT to drive the electromagnetic heating resonance unit to operate in the square wave type.

[0012] Further, when the main control chip determines that the input voltage waveform is a non-sine wave, it dynamically detects the voltage signal of the voltage detection circuit: if the current voltage is zero voltage, the main control chip turns off the signal output to the IGBT drive circuit, and the electromagnetic heating resonance unit does not work; if the current voltage is high voltage, the main control chip first outputs a first-stage narrow pulse width PPG to the IGBT drive circuit, and after the electromagnetic heating resonance unit operates stably, it outputs a second-stage wide pulse width PPG to the IGBT drive circuit to make the electromagnetic heating resonance unit operate at a constant power.

[0013] Preferably, the first-stage narrow pulse width PPG is a group of drive pulse widths PPG with equal widths.

[0014] Preferably, the first-stage narrow pulse width PPG is a group of drive pulse widths PPG with increasing widths.

[0015] Further, the width of the second-stage wide pulse width PPG is adjustable. The main control chip can adjust the width of the second-stage wide pulse width PPG according to the user's power requirement for the heating cooking utensil, so as to adjust the output power of the electromagnetic heating.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects:

[0017] By detecting the input voltage, the present invention starts different control programs, so that regardless of whether the user uses a pure sine wave inverter or a square wave inverter, the electromagnetic heating device can work normally. It solves the problem that outdoor cooking enthusiasts cannot use flameless electromagnetic heating cooking when using a square wave inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the electromagnetic heating control circuit compatible with sine wave and square wave inverters of the present invention.

[0019] Figure 2 is a flowchart of an electromagnetic heating control method compatible with sine wave and square wave inverters of the present invention.

[0020] Figure 3 is a working voltage waveform diagram of the electromagnetic heating control method of the present invention when the input is a square wave.

[0021] Figure 4 is a relationship diagram between the high voltage waveform of the C pole of the IGBT and the output voltage waveform of the main control chip in an embodiment.

[0022] Figure 5 It is a diagram showing the corresponding relationship between the C - pole high - voltage waveform of the IGBT and the output voltage waveform period of the main control chip in one embodiment.

[0023] Figure 6 It is a diagram showing the relationship between the C - pole high - voltage waveform of the IGBT and the output voltage waveform of the main control chip in another embodiment.

[0024] Figure 7 It is a diagram showing the corresponding relationship between the C - pole high - voltage waveform of the IGBT and the output voltage waveform period of the main control chip in another embodiment. Specific embodiments

[0025] In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from this description, and those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0026] As Figure 1 shown, an electromagnetic heating control circuit compatible with sine - wave and square - wave inverters includes: a rectifier - filter unit 10, an electromagnetic heating resonance unit 20, an IGBT drive circuit 30, a main control chip 40, and a voltage detection circuit 50.

[0027] Among them, the rectifier - filter unit 10 provides direct current after rectification and filtering to the electromagnetic resonance unit 20, providing the energy for the output power of the electromagnetic resonance unit 20. The electromagnetic heating resonance unit 20 is the core circuit of electromagnetic heating, including a resonance inductor 201, a resonance capacitor 202, and an oscillation - control high - speed power switch tube 203 (generally an IGBT).

[0028] The IGBT drive circuit 30 is connected to the main control chip 40 and the oscillation - control high - speed power switch tube 203 of the electromagnetic heating resonance unit 20. The IGBT drive circuit 30 receives the signal (generally PPG) from the main control chip, and after amplification processing, outputs it to the oscillation - control high - speed power switch tube 203 of the electromagnetic heating resonance unit 20.

[0029] The main control chip 40 is connected to the voltage detection circuit 50 and the IGBT drive circuit 30. The main control chip 40 receives the voltage signal detected by the voltage detection circuit 50 and outputs different PPG signals to the IGBT drive circuit 30 according to different voltage types.

[0030] One end of the voltage detection circuit 50 is connected to the AC power supply (L / N), and the other end is connected to the main control chip 40. The voltage detection circuit 50 detects the voltage signal of the input AC power supply (L / N) and outputs the detected voltage signal to the main control chip 40.

[0031] AsFigure 2 As shown in the figure, an electromagnetic heating control method compatible with sine wave and square wave inverters:

[0032] Detect the input voltage S1 and input it into the main control chip 40, enter the judgment program S2, and judge whether it is a square wave. If it is not a square wave, enter the sine wave heating program S3; if it is a square wave, enter the square wave heating program S4. After entering the square wave heating program, the main control chip 40 enters the judgment program S5 to judge whether it is a high voltage. If it is not a high voltage, enter the shutdown PPG program S6; if it is a high voltage, enter the narrow pulse width PPG soft start heating S7. After executing the narrow pulse width PPG soft start heating S7, enter the wide pulse width PPG constant power heating S8. After executing the wide pulse width PPG constant power heating S8, enter the judgment program S5 again to execute the next cycle judgment program.

[0033] As Figure 3 shown, when the input voltage of the L / N AC power supply is AC square wave 3-1, the rectified voltage is DC square wave 3-2. The main control chip 40 enters the square wave heating program S4, and the main control chip 40 outputs the PPG voltage waveform 3-3 to the IGBT drive circuit. The oscillation control of the electromagnetic resonance unit 20 outputs a high voltage waveform 3-4 at the C pole of the high-speed power switch tube 203 (generally IGBT).

[0034] In the PPG voltage waveform 3-3, in the first stage, the narrow pulse width PPG control program soft starts heating (step S7); in the second stage, the wide pulse width PPG control program runs at constant power heating (step S8).

[0035] As Figure 4 shown, in one embodiment, in the square wave heating program, when it is detected that the current is a high voltage, the narrow pulse width PPG in the first stage is a set of drive pulse widths A1 with equal widths. During the drive pulse width A1 time period, the soft start heating program starts, and the C pole voltage of the IGBT stabilizes at VcL (as Figure 4-1 ).

[0036] The wide pulse width PPG in the second stage is also a set of drive pulse widths B1 with equal widths, and the control program runs at constant power heating. The C pole voltage of the IGBT rises to VcH (as Figure 4-1 ).

[0037] As Figure 5 shown, during the drive pulse width A1 time period, the main control chip outputs a PPG voltage waveform with an equal width b, and the C pole high voltage of the IGBT stabilizes at VcL (as Figure 5-1 ); during the drive pulse width B1 time period, the main control chip outputs a PPG voltage waveform with an equal width d, and the C pole high voltage of the IGBT is VcH (as Figure 5-1 ).

[0038] As Figure 6As shown, in another embodiment, during the square-wave heating program, when the current high voltage is detected, the first-stage narrow pulse-width PPG is a set of driving pulse widths A2 with increasing widths. During the driving pulse-width A2 period, the soft-start heating program is started, and the C-pole voltage of the IGBT rises to Vc (such as Figure 6-1 ).

[0039] The second-stage wide pulse-width PPG is a set of driving pulse widths B2 with equal widths, and the control program runs at constant power heating. The C-pole voltage of the IGBT is stabilized at Vc (such as Figure 6-1 ).

[0040] Such as Figure 7 shown, during the driving pulse-width A2 period, the PPG voltage waveform output by the main control chip is of increasing width, which can be successively: a, a + e, a + 2e, a + 3e....... The C-pole high voltage of the single-cycle IGBT increases successively (such as Figure 7-1 ); when the PPG voltage waveform width a + ne = d, the C-pole high voltage of the single-cycle IGBT rises to Vc. During the driving pulse-width B2 period, the PPG voltage waveform output by the main control chip is of equal width d, and the C-pole high voltage of the single-cycle IGBT is Vc (such as Figure 7-1 ).

[0041] In addition, the main control chip 40 can adjust the total output power of the overall electromagnetic heating control circuit by adjusting the width of the output PPG pulse width d during the wide pulse-width PPG constant power heating stage (step S8).

[0042] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electromagnetic heating control method compatible with sine wave and square wave inverters, characterized in that: A voltage detection circuit, used for collecting input AC voltage signals; Rectification and filtering unit, used to provide power to subsequent circuits; An electromagnetic heating resonance unit, including an LC oscillation circuit and an IGBT; IGBT drive circuit, connecting the main control chip and the IGBT of the electromagnetic heating resonance unit; The main control chip is connected to the voltage detection circuit. The main control chip determines the waveform of the input voltage according to the voltage signal collected by the voltage detection circuit, and then outputs the corresponding signal to the IGBT drive circuit. The IGBT drive circuit then drives the electromagnetic heating resonance unit to work according to different voltage types.

2. The electromagnetic heating control method compatible with sine wave and square wave inverters according to claim 1, characterized in that: When the main control chip determines that the input voltage waveform is a sine wave, it outputs a sinusoidal heating signal to the IGBT, driving the electromagnetic heating resonance unit to work in a sinusoidal type; when the main control chip determines that the input voltage waveform is a non-sinusoidal wave, it outputs a square wave heating signal to the IGBT, driving the electromagnetic heating resonance unit to work in a square wave type.

3. The electromagnetic heating control method compatible with sine wave and square wave inverters according to claim 2, characterized in that: When the main control chip determines that the input voltage waveform is a non-sinusoidal wave, it dynamically detects the voltage signal of the voltage detection circuit: if the current voltage is zero voltage, the main control chip turns off the signal output to the IGBT drive circuit; if the current voltage is high voltage, the main control chip first outputs the first stage narrow pulse width PPG to the IGBT drive circuit, and after the electromagnetic heating resonance unit works stably, it outputs the second stage wide pulse width PPG to the IGBT drive circuit.

4. The electromagnetic heating control method compatible with sine wave and square wave inverters according to claim 3, characterized in that: The narrow pulse width PPG in the first stage is a group of driving pulse width PPGs with equal width.

5. The electromagnetic heating control method compatible with sine wave and square wave inverters according to claim 3, characterized in that: The narrow pulse width PPG in the first stage is a group of driving pulse widths PPG with increasing widths.

6. The electromagnetic heating control method compatible with sine wave and square wave inverters according to claim 4 or 5, characterized in that: The width of the second stage wide pulse width PPG is adjustable.

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