An electromagnetic heating control method compatible with sine wave and square wave inverters

Abstract

The application provides an electromagnetic heating control method compatible with sine wave and square wave inverters, comprising: a voltage detection circuit for collecting input AC voltage signals; a rectification and filtering unit for rectifying and filtering input AC power into DC power to provide energy for subsequent circuit operation; an electromagnetic heating resonance unit comprising an LC oscillation circuit and an IGBT; an IGBT driving circuit connected with a master control chip and the IGBT of the electromagnetic heating resonance unit; and the master control chip connected with the voltage detection circuit, which 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 driving circuit, which drives the electromagnetic heating resonance unit to work according to the voltage type. The electromagnetic heating control method compatible with sine wave and square wave inverters detects the input voltage to start different control programs, so that the electromagnetic heating equipment can work normally regardless of whether the user uses a pure sine wave inverter or a square wave inverter.

Description

TECHNICAL FIELD

[0001] The present application 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

[0002] For outdoor enthusiasts, in order to realize the cooking demand of using electromagnetic heating products in the wild, it is necessary to use an inverter for converting DC low voltage into AC high voltage to convert the DC power of the energy storage battery into AC power, so that the household electromagnetic heating products can be used. The inverters for converting DC low voltage into AC high voltage on the market are divided into pure sine wave inverters and non-pure sine wave (square wave) inverters. However, the household electromagnetic heating products on the market are all circuit systems designed based on sine wave AC power, and cannot match the use of non-pure sine wave (square wave) inverters. SUMMARY

[0003] In order to make up for the deficiencies in the prior art, the present application provides an electromagnetic heating control method compatible with sine wave and square wave inverters, which detects the input voltage to start different control programs, so that the electromagnetic heating equipment can work normally no matter whether the user uses a pure sine wave inverter or a square wave inverter.

[0004] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

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

[0006] A voltage detection circuit is used to collect the input AC voltage signal, and provide the input voltage information for the main control chip, so as to provide a signal basis for the main control chip to judge the input voltage type.

[0007] A rectifier filter unit is used to rectify and filter the input AC power into DC power to provide energy for the subsequent circuit work.

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

[0009] An IGBT driving circuit is connected to the IGBT of the electromagnetic heating resonance unit and the main control chip, and drives 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, and judges 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 driving circuit, and the IGBT driving circuit drives the electromagnetic heating resonance unit to work according to the voltage type.

[0011] Further, the master control chip judges the input voltage waveform as a sine wave, and outputs a sine wave heating signal to the IGBT, so that the electromagnetic heating resonant unit works in a sine wave type; the master control chip judges the input voltage waveform as a non-sine wave, and outputs a square wave heating signal to the IGBT, so that the electromagnetic heating resonant unit works in a square wave type.

[0012] Further, the master control chip judges the input voltage waveform as a non-sine wave, and dynamically detects the voltage signal of the voltage detection circuit; if the current voltage is zero voltage, the master control chip stops the signal output to the IGBT driving circuit, and the electromagnetic heating resonant unit does not work; if the current voltage is high voltage, the master control chip outputs a first stage narrow pulse width PPG to the IGBT driving circuit, and after the electromagnetic heating resonant unit works stably, outputs a second stage wide pulse width PPG to the IGBT driving circuit, so that the electromagnetic heating resonant unit works in a constant power mode.

[0013] Preferably, the first stage narrow pulse width PPG is a group of driving pulse width PPGs with equal width.

[0014] Preferably, the first stage narrow pulse width PPG is a group of driving pulse width PPGs with width increasing.

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

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

[0017] The present application detects the input voltage, so as to start different control programs, and no matter whether the user uses a pure sine wave inverter or a square wave inverter, the electromagnetic heating device can work normally. The problem that an outdoor cooking enthusiast cannot use the electromagnetic heating cooking device in the case of using a square wave inverter is solved. BRIEF DESCRIPTION OF DRAWINGS

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

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

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

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

[0022] Figure 5 is a graph of the C pole high voltage waveform of the IGBT and the output voltage waveform of the master control chip in one embodiment.

[0023] Figure 6 is a graph of the C pole high voltage waveform of the IGBT and the output voltage waveform of the master control chip in another embodiment.

[0024] Figure 7 is a graph of the C pole high voltage waveform of the IGBT and the output voltage waveform of the master control chip in another embodiment. DETAILED DESCRIPTION

[0025] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details set forth in this description. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present application.

[0026] As shown in Figure 1 , an electromagnetic heating control circuit compatible with a sine wave and a square wave inverter includes a rectification filter unit 10, an electromagnetic heating resonant unit 20, an IGBT drive circuit 30, a master control chip 40, and a voltage detection circuit 50.

[0027] The rectification filter unit 10 provides a direct current after rectification filtering to the electromagnetic resonant unit 20, and provides energy for output power of the electromagnetic resonant unit 20. The electromagnetic heating resonant unit 20 is an electromagnetic heating core circuit, including a resonant inductor 201, a resonant 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 master control chip 40 and the oscillation control high-speed power switch tube 203 of the electromagnetic heating resonant unit 20. The IGBT drive circuit 30 receives a signal (generally PPG) of the master control chip, and outputs the signal to the oscillation control high-speed power switch tube 203 of the electromagnetic heating resonant unit 20 through amplification processing.

[0029] The master control chip 40 is connected to the voltage detection circuit 50 and the IGBT drive circuit 30. The master control chip 40 receives a 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] The voltage detection circuit 50 is connected to an alternating current power source (L / N) at one end and to the master control chip 40 at the other end. The voltage detection circuit 50 detects an input alternating current power source (L / N) voltage signal, and outputs a detected voltage signal to the master control chip 40.

[0031] AsFigure 2 An electromagnetic heating control method compatible with sine wave and square wave inverters is shown:

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

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

[0034] In the PPG voltage waveform 3-3, the first stage is a narrow pulse width PPG control program soft start heating (step S7), and the second stage is a wide pulse width PPG control program constant power heating (step S8).

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

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

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

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

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

[0040] As shown in Figure 7 , during the driving pulse width A2 period, the PPG voltage waveform output by the master control chip is of increasing width, which can be a, a+e, a+2e, a+3e, and so on in sequence. The C pole high voltage of the single cycle IGBT is raised in sequence (as shown in Figure 7-1 ). When the width of the PPG voltage waveform is a+ne=d, the C pole high voltage of the single cycle IGBT is raised to Vc. During the driving pulse width B2 period, the PPG voltage waveform output by the master control chip is of equal width d, and the C pole high voltage of the single cycle IGBT is Vc (as shown in Figure 7-1 ).

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

[0042] The above is only a preferred embodiment of the present application, and is not used to limit the present application, although the present application is described in detail with reference to the embodiment. For those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced equivalently, but any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An electromagnetic heating control method compatible with a sine wave and a square wave inverter, characterized by, The electromagnetic heating control circuit used by the application comprises: a voltage detection circuit for collecting input AC voltage signals; a rectification filter unit for providing DC power to the electromagnetic heating resonance unit after rectification and filtering; an electromagnetic heating resonance unit comprising an LC oscillation circuit and an IGBT; an IGBT drive circuit connected to the main control chip and the IGBT of the electromagnetic heating resonance unit; a main control chip connected to the voltage detection circuit, which judges the waveform of the input voltage according to the voltage signals collected by the voltage detection circuit, and then outputs corresponding signals to the IGBT drive circuit, which then drives the electromagnetic heating resonance unit to work under different voltage types; when the main control chip judges 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 work under the sine wave type; when the main control chip judges that the input voltage waveform is a square wave, it outputs a square wave heating signal to the IGBT to drive the electromagnetic heating resonance unit to work under the square wave type; when the main control chip judges that the input voltage waveform is a square wave, it dynamically detects the voltage signal of the voltage detection circuit: if the current voltage is not high, the main control chip closes the signal output to the IGBT drive circuit; if the current voltage is high, the main control chip first outputs a first-stage narrow pulse width PPG to the IGBT drive circuit, and then outputs a second-stage wide pulse width PPG to the IGBT drive circuit after the electromagnetic heating resonance unit stabilizes.

2. The electromagnetic heating control method for a compatible sine wave and square wave inverter according to claim 1, characterized by: The first-stage narrow pulse width PPG is a group of driving pulse width PPGs with equal width.

3. The electromagnetic heating control method for a compatible sine wave and square wave inverter according to claim 1, characterized by: The first-stage narrow pulse width PPG is a group of driving pulse width PPGs with increasing width.

4. The electromagnetic heating control method for a compatible sine wave and square wave inverter according to claim 2 or 3, characterized by: The width of the second-stage wide pulse width PPG is adjustable.

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