CN108419319B - Electromagnetic heating device and driving detection circuit and method of power switch tube of electromagnetic heating device - Google Patents

Electromagnetic heating device and driving detection circuit and method of power switch tube of electromagnetic heating device Download PDF

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CN108419319B
CN108419319B CN201710074229.3A CN201710074229A CN108419319B CN 108419319 B CN108419319 B CN 108419319B CN 201710074229 A CN201710074229 A CN 201710074229A CN 108419319 B CN108419319 B CN 108419319B
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driving
module
voltage
signal
detection
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CN108419319A (en
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江德勇
王云峰
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Foshan Shunde Midea Electrical Heating Appliances Manufacturing Co Ltd
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Foshan Shunde Midea Electrical Heating Appliances Manufacturing Co Ltd
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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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • 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
    • H05B2206/00—Aspects relating to heating by electric, magnetic, or electromagnetic fields covered by group H05B6/00
    • H05B2206/02—Induction heating

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  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Induction Heating Cooking Devices (AREA)
  • Control Of Resistance Heating (AREA)

Abstract

The invention discloses an electromagnetic heating device and a drive detection circuit and a method of a power switch tube thereof, wherein the drive detection circuit comprises: the driving module is connected with the power switch tube and used for outputting a driving signal to the power switch tube so as to drive the power switch tube to be switched on or switched off; the detection module is connected with the driving module and is used for generating a detection signal according to the driving signal output by the driving module; the counting module is used for adjusting a counting value at intervals of preset intervals; and the control chip is connected with the detection module and the counting module and is used for detecting whether the detection signal triggers the interruption or not, resetting the count value of the counting module when the interruption is triggered, acquiring the final count value of the counting module when the detection time reaches the preset detection time, and judging whether the driving module is abnormal or not according to the final count value and the voltage state of the driving signal, so that the abnormal condition of the driving module can be effectively detected, and the potential safety hazard is reduced.

Description

Electromagnetic heating device and driving detection circuit and method of power switch tube of electromagnetic heating device
Technical Field
The invention relates to the technical field of domestic electric appliances, in particular to a driving detection circuit of a power switch tube in an electromagnetic heating device, the electromagnetic heating device and a driving detection method of the power switch tube in the electromagnetic heating device.
Background
The related electromagnetic heating device, such as an electromagnetic oven, generally drives the IGBT tube through a driving circuit, that is, the driving circuit may provide a driving signal to the IGBT tube to control the on or off of the IGBT tube, and if the driving circuit is abnormal, the IGBT tube may be excessively worn, and even the IGBT tube may be heated and burned, which may affect the normal operation of the electromagnetic heating system.
However, the related art does not detect whether or not an abnormality occurs in the drive circuit.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, an object of the present invention is to provide a driving detection circuit for a power switch in an electromagnetic heating device, which can effectively detect an abnormal condition of a driving module and reduce potential safety hazards.
Another object of the present invention is to provide an electromagnetic heating device. Another object of the present invention is to provide a method for detecting the driving of a power switch in an electromagnetic heating device.
In order to achieve the above object, an embodiment of the present invention provides a driving detection circuit for a power switch in an electromagnetic heating device, including: the driving module is connected with the power switch tube and used for outputting a driving signal to the power switch tube so as to drive the power switch tube to be switched on or switched off; the detection module is connected with the driving module and is used for generating a detection signal according to the driving signal output by the driving module; the counting module is used for adjusting a counting value at intervals of a preset interval; and the control chip is connected with the detection module and the counting module and is used for detecting whether the detection signal triggers interruption or not, resetting the count value of the counting module when the interruption is triggered, acquiring the final count value of the counting module when the detection time reaches the preset detection time, and judging whether the driving module is abnormal or not according to the final count value and the voltage state of the driving signal.
According to the drive detection circuit of the power switch tube in the electromagnetic heating device provided by the embodiment of the invention, the detection module generates a detection signal according to the drive signal output by the drive module, the counting module adjusts the counting value at preset intervals, the control chip detects whether the detection signal triggers interruption or not, clears the counting value of the counting module when the interruption is triggered, and judges whether the drive module is abnormal or not according to the final counting value and the voltage state of the drive signal when the detection time reaches the preset detection time, so that the abnormal condition of the drive module can be effectively detected, the phenomenon that the pulse current of the power switch tube is overlarge and the noise is larger due to overhigh drive voltage can be prevented, and the phenomenon that the power switch tube is too large in loss and even is heated and burnt due to overlow drive voltage can be prevented.
In addition, the driving detection circuit for the power switch tube in the electromagnetic heating device proposed by the above embodiment of the present invention may further have the following additional technical features:
according to an embodiment of the present invention, the control chip has an interrupt input terminal, and the detection module includes: the circuit comprises a first resistor, a first capacitor and a second capacitor, wherein one end of the first resistor is connected with the driving module, the other end of the first resistor is connected with the interrupt input end of the control chip, one end of the first capacitor is connected with the other end of the first resistor, and the other end of the first capacitor is grounded.
According to an embodiment of the invention, the detection module further comprises: and the anode of the first diode is connected with the other end of the first resistor, and the cathode of the first diode is connected with a preset power supply.
According to an embodiment of the present invention, the control chip is connected to the driving module, the control chip has a first control output terminal and a second control output terminal, and the driving module includes: the input end of the driving unit is connected with the first control output end, the output end of the driving unit is connected with the control end of the power switch tube, and the driving unit outputs the driving signal to the power switch tube to drive the power switch tube to be switched on or switched off; the output end of the voltage reduction unit is connected with the second control output end, and the output end of the voltage reduction unit is respectively connected with the output end of the driving unit and the control end of the power switch tube so as to reduce the voltage of the driving signal or stop reducing the voltage; the control chip outputs a first control signal to the driving unit through the first control output end and outputs a second control signal to the voltage reduction unit through the second control output end so that the power switching tube works in an amplification state, and outputs the first control signal to the driving unit through the first control output end and outputs a third control signal to the voltage reduction unit through the second control output end so that the power switching tube works in a saturation conduction state.
According to an embodiment of the present invention, the detection module is connected to the voltage reduction unit, and the voltage reduction unit includes: the cathode of the first voltage-stabilizing tube is connected with the output end of the driving unit and the control end of the power switch tube respectively, and the anode of the first voltage-stabilizing tube is connected with the detection module; and a first end of the switch circuit is connected with the anode of the first voltage-regulator tube, a second end of the switch circuit is grounded, a third end of the switch circuit is connected with a second control output end of the control chip, and the switch circuit is switched on or off under the control of the control chip so as to control the first voltage-regulator tube to be switched on or switched off.
According to one embodiment of the present invention, the switching circuit includes: one end of the second resistor is connected with the second control output end; one end of the third resistor is connected with the other end of the second resistor and is provided with a first node, and the other end of the third resistor is grounded; and the collector of the first triode is connected with the anode of the first voltage-regulator tube, the base of the first triode is connected with the first node, and the emitter of the first triode is grounded.
According to an embodiment of the invention, the first control signal is a PPG pulse signal, the second control signal is a high level signal, and the third control signal is a low level signal.
According to an embodiment of the present invention, the driving unit outputs a driving signal of a first driving voltage under the combined action of the first control signal and the second control signal, and outputs a driving signal of a second driving voltage under the combined action of the first control signal and the third control signal, wherein the first driving voltage is smaller than the second driving voltage.
According to an embodiment of the present invention, when the driving module outputs a driving signal of a first driving voltage, the control chip is further configured to determine that the driving module is abnormal when a final count value of the counting module is smaller than a preset threshold; when the driving module outputs a driving signal of a second driving voltage, the control chip is further configured to determine that the driving module is abnormal when the final count value of the counting module is greater than or equal to the preset threshold value.
In order to achieve the above object, another embodiment of the present invention further provides an electromagnetic heating device, including a driving detection circuit of a power switch tube in the electromagnetic heating device.
According to the electromagnetic heating device provided by the embodiment of the invention, the drive detection circuit of the embodiment can effectively detect the abnormal condition of the drive module, prevent the pulse current of the power switch tube from being too large and the noise from being larger due to the overhigh drive voltage, and also prevent the power switch tube from being too large in loss and even heated and burned due to the overlow drive voltage.
In addition, the electromagnetic heating device proposed according to the above embodiment of the present invention may further have the following additional technical features:
according to an embodiment of the present invention, the electromagnetic heating device may be an induction cooker, an electromagnetic pressure cooker or an electromagnetic rice cooker.
In order to achieve the above object, another embodiment of the present invention further provides a method for detecting driving of a power switch in an electromagnetic heating device, including the following steps: generating a detection signal according to a driving signal output by a driving module in the electromagnetic heating device, wherein the driving module outputs the driving signal to the power switch tube to drive the power switch tube to be switched on or switched off; adjusting the count value of the counting module at intervals of a preset interval; detecting whether the detection signal triggers interruption or not, and clearing the count value of the counting module when the interruption is triggered; and when the detection time reaches the preset detection time, acquiring the final count value of the counting module, and judging whether the driving module is abnormal or not according to the final count value and the voltage state of the driving signal.
According to the method for detecting the driving of the power switch tube in the electromagnetic heating device, provided by the embodiment of the invention, the detection signal is generated through the driving signal output by the driving module, the count value of the counting module is adjusted at intervals of a preset interval time, whether the detection signal triggers interruption or not is detected, the count value of the counting module is reset when the interruption is triggered, the final count value of the counting module is obtained when the detection time reaches the preset detection time, and whether the driving module is abnormal or not is judged according to the final count value and the voltage state of the driving signal, so that the abnormal condition of the driving module can be effectively detected, the phenomenon that the pulse current of the power switch tube is overlarge and the noise is larger due to overhigh driving voltage is prevented, and the phenomenon that the power switch tube is too large in loss and even is heated and burnt due to overlow.
In addition, the driving detection method for the power switch tube in the electromagnetic heating device proposed by the above embodiment of the present invention may further have the following additional technical features:
according to an embodiment of the present invention, the determining whether the driving module is abnormal according to the final count value and the voltage state of the driving signal includes: when the driving module outputs a driving signal of a first driving voltage, if the final count value of the counting module is smaller than a preset threshold value, judging that the driving module is abnormal; when the driving module outputs a driving signal of a second driving voltage, if the final count value of the counting module is greater than or equal to the preset threshold value, judging that the driving module is abnormal; wherein the first driving voltage is less than the second driving voltage.
Drawings
FIG. 1 is a block diagram of a driving detection circuit of a power switch tube in an electromagnetic heating device according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of the low power duty cycle heating control of an electromagnetic heating apparatus according to one embodiment of the present invention;
FIG. 3 is an expanded view of the waveforms of discharge phase D1, heating phase D2, and stop phase D3 of FIG. 2;
FIG. 4 is a schematic circuit diagram of a driving detection circuit of a power switch tube in an electromagnetic heating device according to an embodiment of the present invention;
FIG. 5 is a control schematic diagram of a driving module in a driving detection circuit of a power switch tube in an electromagnetic heating apparatus according to an embodiment of the present invention;
FIG. 6 is a schematic waveform diagram of a detection signal generated by a detection module in a driving detection circuit of a power switch tube in an electromagnetic heating device according to an embodiment of the present invention;
FIG. 7 is a schematic view of an electromagnetic heating apparatus according to an embodiment of the present invention;
fig. 8 is a flowchart of a driving detection method of a power switching tube in an electromagnetic heating apparatus according to an embodiment of the present invention;
fig. 9 is a flowchart of a driving detection method of a power switching tube in an electromagnetic heating apparatus according to an embodiment of the present invention; and
fig. 10 is a flowchart of a driving detection method of a power switching tube in an electromagnetic heating apparatus according to another embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
The following describes a drive detection circuit of a power switch tube in an electromagnetic heating device, an electromagnetic heating device having the same, and a drive detection method of a power switch tube in an electromagnetic heating device according to an embodiment of the present invention with reference to the drawings.
Fig. 1 is a block diagram of a driving detection circuit of a power switch tube in an electromagnetic heating device according to an embodiment of the present invention. As shown in fig. 1, the driving detection circuit of the power switch tube in the electromagnetic heating device includes: the device comprises a driving module 10, a detection module 20, a counting module 30 and a control chip 40.
The driving module 10 is connected to the power switch tube 50, and the driving module 10 is configured to output a driving signal to the power switch tube 50 to drive the power switch tube 50 to turn on or off; the detection module 20 is connected to the driving module 10, and the detection module 20 is configured to generate a detection signal according to the driving signal output by the driving module 10.
The counting module 30 is configured to adjust a count value of the counting module 30 at preset intervals. It should be noted that the counting module 30 may have a counting overflow value, and the control chip 40 may control the counting value of the counting module 30 to be maintained as the counting overflow value when the counting value of the counting module 30 exceeds the counting overflow value.
The control chip 40 is connected to the detection module 20 and the counting module 30, and the control chip 40 is configured to detect whether the detection signal triggers the interrupt, clear the count value of the counting module 30 when the interrupt is triggered, obtain the final count value of the counting module 30 when the detection time reaches the preset detection time, and determine whether the driving module 10 is abnormal according to the final count value of the counting module 30 and the voltage state of the driving signal. The preset detection time is greater than the preset interval time, for example, the preset interval time may be 0.1ms (millisecond), and the preset detection time may be greater than or equal to 1 ms.
That is, when the driving abnormality detection is performed on the electromagnetic heating device, the control chip 40 may count the driving abnormality detection time by a timer, after the timer starts, the detecting module 20 may generate a detecting signal according to the voltage state of the driving signal output by the driving module 10, the counting module 30 may adjust the counting value at preset intervals, for example, 0.1ms, for example, by adding 1, meanwhile, the control chip 40 detects whether the detection signal triggers the interrupt, and clears the count value of the counting module 30 when the interrupt is triggered, and the process is repeated, the counting value of the counting module 30 is adjusted, when the counting time of the timer, i.e. the detection time of the driving abnormality detection, reaches a preset detection time, e.g. 1ms, the control chip 40 obtains the final counting value of the counting module 30, and judges whether the driving module 10 is abnormal according to the final count value of the counting module 30 and the voltage state of the driving signal.
In some embodiments of the present invention, the driving detection circuit according to the embodiments of the present invention may detect a driving abnormality of the electromagnetic heating device heated by a plurality of driving voltages, that is, may detect whether a voltage state of the driving signal is abnormal. For example, the driving module 10 may output a driving signal of the first driving voltage V1 or the second driving voltage V2 to the power switch 50, when the driving module 10 outputs the driving signal of the first driving voltage V1, the control chip 40 may determine whether the driving module 10 normally outputs the driving signal of the first driving voltage V1 according to the final count value of the counting module 30, and when the driving module 10 outputs the driving signal of the second driving voltage V2, the control chip 40 may determine whether the driving module 10 normally outputs the driving signal of the second driving voltage V2 according to the final count value of the counting module 30.
The detection module 20 may generate the detection signal according to the voltage state of the driving signal, for example, when the driving module 10 outputs the driving signal of the first driving voltage V1, the detection module 20 may generate the detection signal of the first state, and when the driving module 10 outputs the driving signal of the second driving voltage V2, the detection module 20 may generate the detection signal of the second state. The embodiment of the present invention is described by taking an example in which there is no level change in the detection signal in the first state and a level change (a rising edge, a falling edge, or a double edge) occurs in the detection signal in the second state.
It should be noted that the control chip 40 may have an external interrupt function, for example, the control chip 40 may be interrupted due to a level change of the detection signal, and the control chip 40 may determine whether to clear the count value of the counting module 30 according to an interrupt condition caused by the detection signal.
That is, the control chip 40 may determine whether the level of the detection signal changes, for example, whether a rising edge and/or a falling edge occurs, if the level of the detection signal changes, an interrupt is triggered, the control chip 40 enters an interrupt process to zero the count value of the counting module 30, if the level of the detection signal does not change, the interrupt is not triggered, the control chip 40 does not enter the interrupt process, that is, the count value of the counting module 30 is not cleared, and the count value of the counting module 30 continues to be incremented by 1 every preset interval time. Therefore, when the count value of the counting module 30 is automatically increased by 1 every preset interval time, whether the detection signal triggers the interrupt is judged, for example, the level edge change of the detection signal triggers the interrupt, and the count value of the counting module 30 is cleared in the interrupt program, so that the control chip 40 can judge whether the voltage state of the driving module 10 is abnormal according to the final count value of the counting module 30 when the preset detection time is reached.
Further, according to an embodiment of the present invention, when the driving module 10 outputs the driving signal of the first driving voltage V1, the control chip 40 is further configured to determine that the driving module 10 is abnormal when the final count value of the counting module 30 is smaller than the preset threshold; when the driving module 10 outputs the driving signal of the second driving voltage, the control chip 40 is further configured to determine that the driving module 10 is abnormal when the final count value of the counting module 30 is greater than or equal to the preset threshold, where the first driving voltage, for example, 9V, is less than the second driving voltage, for example, 18V.
Specifically, as shown in fig. 6, the driving signal output by the driving module 10 may be a high-frequency pulse signal, and the frequency of the high-frequency pulse signal may be greater than or equal to 20kHz, that is, the high-low level change occurs at least once every 50us (microseconds) of the driving signal, so as to drive the power switch tube 50 to be turned on and off at least once. Among them, the detection module 20 may generate a first level, e.g., a low level, when the driving signal is at a low level, the detection module 20 may generate a first level when the driving signal is at a high level of the first driving voltage V1, and the detection module 20 may generate a second level, e.g., a high level, when the driving signal is at a high level of the second driving voltage V2.
Thus, when the driving module 10 outputs the driving signal of the first driving voltage V1 to the power switch tube 50, the detection signal of the first state generated by the detection module 20 will be maintained at a low level, i.e. no level change; when the driving module 10 outputs the driving signal of the second driving voltage V2 to the power switch tube 50, the detection signal of the second state generated by the detection module 20 will be at a high-low level, i.e. a level change occurs, and the transition frequency of the high-low level is the same as the frequency of the driving signal.
In this way, the count value of the counting module 30 is automatically increased by 1 every preset interval time, for example, 0.1ms, and the control chip 40 can detect whether the detection signal triggers the interrupt in real time, wherein if the driving module 10 outputs the driving signal of the first driving voltage V1 to the power switch tube 50, the detection signal has no level change and does not trigger the interrupt, and the counting module 30 continues to count; if the driving module 10 outputs the driving signal of the second driving voltage V2 to the power switch tube 50, the level of the detection signal changes, which triggers an interrupt, and the control chip 40 controls the count value of the counting module 30 to be cleared.
The above steps are repeated until a preset detection time is reached, for example, 1ms, and when the preset detection time is reached, the count value of the counting module 30 is adjusted 10 times, wherein if the driving module 10 continuously outputs the driving signal of the first driving voltage V1, the final count value of the counting module 30 after 10 times of adjustment is theoretically 10; if the driving module 10 continuously outputs the driving signal of the second driving voltage V2, the final count value of the counting module 30 after 10 times of adjustment is theoretically less than 5. The control chip 40 can determine whether the voltage state of the driving module 10 is abnormal according to the final count value of the counting module 30
Specifically, when the driving module 10 outputs the driving signal of the first driving voltage V1 to the power switch tube 50, if the final count value of the counting module 30 is greater than or equal to the preset threshold, it indicates that the control chip 40 does not perform zero clearing processing on the count value of the counting module 30, there is no level change in the detection signal, and no interrupt is triggered, at this time, the control chip 40 determines that the driving module 10 is not abnormal, and normally outputs the driving signal of the first driving voltage V1. If the final count value of the counting module 30 is smaller than the preset threshold, it means that the control chip 40 performs zero clearing processing on the count value of the counting module 30, and the detection signal changes in level, triggering an interrupt, at which time the control chip 40 determines that the driving module 10 is abnormal, for example, the driving module 10 outputs a driving signal of the second driving voltage V2.
Under the condition that the driving module 10 outputs the driving signal of the second driving voltage V2 to the power switch tube 50, if the final count value of the counting module 30 is smaller than the preset threshold, the control chip 40 performs zero clearing processing on the count value of the counting module 30, and the detection signal changes in level and triggers an interrupt, at this time, the control chip 40 determines that the driving module 10 is not abnormal, and normally outputs the driving signal of the second driving voltage V2. If the final count value of the counting module 30 is greater than or equal to the preset threshold, it indicates that the control chip 40 does not perform zero clearing processing on the count value of the counting module 30, and the detection signal has no level change and does not trigger an interrupt, at this time, the control chip 40 determines that the driving module 10 is abnormal, for example, the driving module 10 outputs a driving signal of the first driving voltage V1.
Therefore, the power switch tube 50 can be prevented from being driven by the first driving voltage for a long time, the self-generated loss of the power switch tube 50 is prevented from being large, the over-temperature burning of the power switch tube 50 is prevented, the pulse current caused by the fact that the first driving voltage V1 fails to work for the second driving voltage V2 is prevented from being too large, the noise is prevented from being too large, and the over-temperature burning of the power switch tube 50 is prevented.
According to an embodiment of the present invention, the preset threshold may be set according to a preset interval time and a preset detection time, for example, when the preset interval time is 0.1ms and the preset detection time is 1ms, the preset threshold may be 5 (theoretical value is 10).
Therefore, the drive detection circuit of the embodiment of the present invention detects whether the drive module is abnormal by whether the drive signal triggers the interrupt, for example, intelligently identifies whether the state of the drive signal at the first drive voltage V1 or the second drive voltage V2 is normal, so as to effectively detect the abnormal condition of the drive module 10, prevent the pulse current of the power switch tube 50 from being too large and the noise from being large due to the too high drive voltage, and prevent the power switch tube from being too large and even being heated and burned due to the too low drive voltage.
In an embodiment of the present invention, the electromagnetic heating device may implement low-power duty cycle heating by using a plurality of driving voltages, and specifically, the duty cycle may be set in a unit of a half-wave period of the ac mains, where the duty cycle may refer to a ratio of a number of half-waves occupied in the heating stage to a number of half-waves occupied in the entire control period, as shown in fig. 2, the duty cycles are 1/4, 2/4, and 3/4 in sequence, that is, each control period is 4 half-waves, 1 half-wave is heated and heating of 3 half-waves is stopped when the duty cycle is 1/4, 2 half-waves is heated and heating of 2 half-waves is stopped when the duty cycle is 2/4, and 3 half-waves is heated and heating of 1 half-wave is stopped when the duty cycle is 3/4.
In each control cycle, as shown in fig. 2, the operation phase of the electromagnetic heating device includes a discharging phase D1, a heating phase D2 and a stopping phase D3, wherein the intersection points of the discharging phase D1 and the heating phase D2 and the heating phase D2 and the stopping phase D3 may be at a voltage zero crossing point, and the duration of the discharging phase D1 may be greater than or equal to 1 ms.
Specifically, as shown in fig. 3, in the discharging phase D1, the control chip 40 may control the output driving module 10 to output a driving signal of the first driving voltage V1 to the power switch 50, so as to operate the power switch 50 in an amplifying state, and thus release the electric energy stored in the filter capacitor (i.e., C1 in fig. 7) during the stop phase in the previous control period, so that the collector voltage of the power switch 50 is substantially 0V when the heating phase D2 is entered, and the pulse current of the power switch 50 is reduced. In the heating phase D2, the control chip 40 may control the output driving module 10 to output the driving signal of the second driving voltage V2 to the power switch 50, so that the power switch 50 operates in a saturated conducting state, thereby controlling the electromagnetic heating apparatus to perform normal resonant heating. In the stop stage D3, the control chip 40 may control the output driving module 10 to output a third driving voltage, i.e. 0V, to the power switch 50 to drive the power switch 50 to turn off, so as to control the electromagnetic heating apparatus to stop heating.
The driving signal may be a pulse signal, that is, in the discharging phase D1, the control chip 40 may control the driving module 10 to output a plurality of first pulse signals with an amplitude of the first driving voltage V1, and pulse widths of the plurality of first pulse signals may gradually increase from the initial pulse width Y1; during the heating phase D2, the control chip 40 may control the driving module 10 to output a plurality of second pulse signals with the amplitude of the second driving voltage V2.
Specifically, when the current heating power of the electromagnetic heating device is less than the preset power, for example, 1000W, the electromagnetic heating device is controlled to perform low-power heating, and the control chip 40 controls the electromagnetic heating device to perform low-power heating in a duty ratio manner. As shown in fig. 6, in the discharging phase D1, the amplitudes of the plurality of first pulse signals are the first driving voltage V1, and the detection signal generated by the detection module 20 has no level change, e.g., remains at a low level, and does not trigger an interrupt; in the heating stage D2, the amplitudes of the plurality of second pulse signals are the second driving voltage V2, the detection signal generated by the detection module 20 changes in level to trigger the interrupt, and the frequency of the detection signal is equal to the frequency of the driving signal, for example, the frequency of the driving signal is equal, that is, the on frequency of the power switch tube may be greater than or equal to 20KHZ, that is, the power switch tube is turned on at least once every 5Ous, and at least one interrupt occurs to clear the count value of the counting module 30.
Therefore, when the discharging stage D1 is entered, the control chip 40 may control the timer to start timing, the count value of the counting module 30 is automatically increased by 1 every preset interval time, for example, 0.1ms, the detection module 20 may generate a detection signal according to the driving signal, the control chip 40 determines whether the detection signal triggers an interrupt, and clears the count value of the counting module 30 when the interrupt is triggered, when the timing time of the timer reaches the preset detection time, for example, 1ms, the final count value of the counting module 30 is obtained, if the final count value of the counting module 30 is greater than or equal to the preset threshold, for example, 5, it is determined that the interrupt is not triggered, the voltage amplitude of the driving signal is substantially maintained at the first driving voltage V1, and the control chip 40 determines that the driving module 10 is not abnormal. If the final count value of the counting module 30 is smaller than the preset threshold, it indicates that the interrupt is triggered, the voltage amplitude of the driving signal becomes the second driving voltage V2, and the control chip 40 determines that the driving module 10 is abnormal.
When the heating stage D2 is entered, the control chip 40 may control the timer to restart timing, the count value of the counting module 30 is automatically increased by 1 every preset interval time, for example, 0.1ms from zero, the detection module 20 may generate a detection signal according to the driving signal, the control chip 40 determines whether the detection signal triggers an interrupt, and clears the count value of the counting module 30 when the interrupt is triggered, when the timing time of the timer reaches the preset detection time, for example, 1ms, the final count value of the counting module 30 is obtained, if the final count value of the counting module 30 is less than a preset threshold, for example, 5, it is determined that the interrupt is triggered, the voltage amplitude of the driving signal is substantially maintained at the second driving voltage V2, and the control chip 40 determines that the driving module 10 is not abnormal. If the final count value of the counting module 30 is greater than or equal to the preset threshold, it indicates that the interrupt is not triggered, the voltage amplitude of the driving signal is changed to the first driving voltage V1, and the control chip 40 determines that the driving module 10 is abnormal.
As described above, in an embodiment of the present invention, in the heating status, for example, the discharging phase D1 and the heating phase D2, the control chip 40 may detect whether the detection signal triggers the interrupt handler in real time, and clear the count value of the counting module 30 if the interrupt handler is triggered, and keep the count value of the counting module 30 unchanged if the interrupt handler is not triggered. And, the control chip 40 can execute the driving detection main program every preset detection time, for example, 0.1ms, when executing the driving detection main program, the control chip 40 can add 1 to the count value of the counting module 30, and determine whether the preset detection time is reached, if the preset detection time is not reached, exit, wait for the preset interval time and then re-execute the driving detection main program, if the preset detection time is reached, obtain the final count value of the counting module 30 at this time, and determine whether the driving module 10 is abnormal according to the final count value of the counting module 30 at this time.
It should be understood that the main driver detection program is executed once every preset interval, and the interrupt handler is triggered by the level change of the detection signal, and the interrupt handler clears the count value of the count module 30.
In addition, when executing the main driving detection program, the control chip 40 can determine that the driving module 10 is abnormal according to the final count value of the counting module 30 at this time and the voltage state of the driving signal. If the driving module 10 outputs the driving signal of the first driving voltage V1, the control chip 40 determines that the driving module 10 is normal when the final count value of the counting module 30 is greater than or equal to the preset threshold, and determines that the driving module 10 is abnormal when the final count value of the counting module 30 is less than the preset threshold. If the driving module 10 outputs the driving signal of the second driving voltage V2, the control chip 40 determines that the driving module 10 is normal when the final count value of the counting module 30 is smaller than the preset threshold, and determines that the driving module 10 is abnormal when the final count value of the counting module 30 is greater than or equal to the preset threshold.
Also, when the driving detection main program is executed, the control chip 40 determines that the count value of the counting module 30 is greater than or equal to a count overflow value, for example, 50, after controlling the count value of the counting module 30 to add 1, and if the count value of the counting module 30 is greater than or equal to the count overflow value, the control chip 40 may control the count value of the counting module 30 to be maintained as the count overflow value.
The circuit structure of the driving detection circuit of the power switch tube in the electromagnetic heating device according to the embodiment of the present invention will be described in detail with reference to fig. 4 to 6.
According to an embodiment of the present invention, as shown in fig. 4, the control chip 40 has an interrupt input INT, and the detection module 20 includes: a first resistor R1 and a first capacitor C0.
One end of the first resistor R1 is connected to the driving module 10, and the other end of the first resistor R1 is connected to the interrupt input end INT of the control chip 40; one end of the first capacitor C0 is connected to the other end of the first resistor R1, and the other end of the first capacitor C0 is grounded.
Further, the detection module 20 further includes: and a first diode D1, an anode of the first diode D1 being connected to the other end of the first resistor R1, and a cathode of the first diode D1 being connected to a predetermined power VCC.
According to an embodiment of the present invention, as shown in fig. 4, the driving module 10 is connected to a control chip 40, the control chip 40 has a first control output PPG and a second control output EN, and the driving module 10 includes: a driving unit 101 and a voltage dropping unit 102.
The input end of the driving unit 101 is connected to the first control output end PPG, the output end of the driving unit 101 is connected to the control end of the power switch tube 50, and the driving unit 101 outputs a driving signal to the power switch tube 50 to drive the power switch tube 50 to be turned on or turned off; the output end of the voltage reduction unit 102 is connected with the second control output end EN, and the output end of the voltage reduction unit 102 is respectively connected with the output end of the driving unit 101 and the control end of the power switch tube 50 so as to reduce the voltage of the driving signal or stop reducing the voltage; the control chip 40 outputs a first control signal to the driving unit 101 through the first control output end PPG and outputs a second control signal to the voltage reduction unit 101 through the second control output end EN so as to enable the power switch tube 50 to work in an amplification state, and outputs a first control signal to the driving unit 101 through the first control output end PPG and outputs a third control signal to the voltage reduction unit 102 through the second control output end EN so as to enable the power switch tube 50 to work in a saturation conduction state.
According to an embodiment of the present invention, the first control signal may be a PPG (programmable pulse Generator) pulse signal, and, as shown in fig. 5, the second control signal may be a high-level signal and the third control signal may be a low-level signal.
According to an embodiment of the present invention, the driving unit 101 outputs a driving signal of the first driving voltage V1 under the combined action of the first control signal and the second control signal, and the driving unit 101 outputs a driving signal of the second driving voltage V2 under the combined action of the first control signal and the third control signal.
That is, when the control chip 40 outputs a high-level signal to the voltage dropping unit 102, the driving voltage output by the driving unit 101 to the control terminal of the power switch 50 is the first driving voltage V1, and the power switch 50 is in an amplifying state; when the control chip 40 outputs a low-level signal to the voltage dropping unit 102, the driving voltage output by the driving unit 101 to the control terminal of the power switch tube 50 is the second driving voltage V2, and the power switch tube 50 is in a saturated conducting state.
Specifically, as shown in fig. 4, the detection module 20 is connected to a voltage reduction unit 102, and the voltage reduction unit 102 includes: a first voltage regulator tube Z1 and a switch circuit 103, wherein the cathode of the first voltage regulator tube Z1 is connected with the output end of the driving unit 101 and the control end of the power switch tube 50, and the anode of the first voltage regulator tube Z1 is connected with one end of the detection module 20, namely a first resistor R1; the first end of the switch circuit 103 is connected with the anode of the first voltage regulator tube Z1, the second end of the switch circuit 103 is grounded, the third end of the switch circuit 103 is connected with the second control output end EN of the control chip 40, and the switch circuit 103 is turned on or off under the control of the control chip 40 to control the turn-on or turn-off of the first voltage regulator tube Z1.
More specifically, as shown in fig. 4, the switching circuit 103 includes: a second resistor R2, a third resistor R3 and a first triode Q1.
One end of the second resistor R2 is connected with the second control output end EN; one end of the third resistor R3 is connected with the other end of the second resistor R2 and is provided with a first node, and the other end of the third resistor R3 is grounded; the collector of the first triode Q1 is connected to the anode of the first voltage regulator Z1, the base of the first triode Q1 is connected to the first node, and the emitter of the first triode Q1 is grounded.
According to an embodiment of the present invention, as shown in fig. 4, the driving unit 101 includes: the circuit comprises a fourth resistor R4, a fifth resistor R5, a third triode Q3, a fourth triode Q4, a sixth resistor R6, a seventh resistor R7 and a push-pull amplifying circuit 50.
One end of the fourth resistor R4 is connected with the first control output end PPG; one end of a fifth resistor R5 is respectively connected with one end of a fourth resistor R4 and the first control output end PPG, and the other end of the fifth resistor R5 is grounded; the base electrode of the third triode Q3 is connected with the other end of the fourth resistor R4, the emitter electrode of the third triode Q3 is grounded, and the collector electrode of the third triode Q3 is connected with a first preset power supply VDD through a sixth resistor R6; the base electrode of the fourth triode Q4 is connected with the collector electrode of the third triode Q3, the emitter electrode of the fourth triode Q4 is grounded, and the collector electrode of the fourth triode Q4 is connected with a first preset power supply VDD through a seventh resistor R7; a first terminal of the push-pull amplification circuit 50 is connected to a collector of the fourth transistor Q4, and a second terminal of the push-pull amplification circuit 50 is connected to a control terminal of the power switch tube 50.
Specifically, as shown in fig. 4, the push-pull amplification circuit 50 includes: a fifth triode Q5, a sixth triode Q6, an eighth resistor R8, a ninth resistor R9 and a tenth resistor R10.
The base electrode of the fifth triode Q5 is connected with the collector electrode of the fourth triode Q4, and the collector electrode of the fifth triode Q5 is connected with the first preset power supply VDD through the eighth resistor R8; the base electrode of the sixth triode Q6 is connected with the base electrode of the fifth triode Q5, and the collector electrode of the sixth triode Q6 is grounded; one end of a ninth resistor R9 is connected with the emitter of the sixth triode Q6, and the other end of the ninth resistor R9 is connected with the emitter of the fifth triode Q5; one end of the tenth resistor R10 is connected to the emitter of the fifth transistor Q5 and the other end of the ninth resistor R9, respectively, and the other end of the tenth resistor R10 is connected to the control terminal of the power switch 50.
In this case, as shown in fig. 4, the power switch tube 50 may be an IGBT tube. The first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 may all be NPN transistors, and the sixth switch tube Q6 may be PNP transistors.
According to an embodiment of the present invention, as shown in fig. 4, the driving module 10 further includes: a second regulator tube Z2 and an eleventh resistor R11.
The anode of the second voltage-regulator tube Z2 is connected with the emitter of the power switch tube 50 and then grounded, and the cathode of the second voltage-regulator tube Z2 is connected with the control end of the power switch tube 50; an eleventh resistor R11 is connected in parallel with the second regulator tube Z2.
Specifically, as shown in fig. 5, when the PPG pulse signal output by the control chip 40 to the driving unit 101 is at a high level, the high level is input to the base of the third triode Q3 through the fourth resistor R4, so that the third triode Q3 is turned on, the fourth triode Q4 is turned off, the fifth triode Q5 is turned on, and the sixth triode Q6 is turned off, at this time, if the control chip 40 outputs a high level signal to the voltage reduction unit 102, the first triode Q1 is turned on, the first voltage regulator Z1 is turned on, the first driving voltage V1 at a point a is the sum of saturated voltage drops of the first voltage regulator Z1 and the first triode Q1, and the IGBT is turned on in an amplification state; if the control chip 40 outputs a low level signal to the voltage dropping unit 102, the voltage dropping unit 102 stops dropping voltage, the second driving voltage V2 at the point a is the voltage division of the eighth resistor R8, the fifth triode Q5, the tenth resistor R10 and the eleventh resistor R11 on the first preset power supply VDD, the first driving voltage V1 is smaller than the second driving voltage V2, and the IGBT is turned on in a saturated conduction state.
When the PPG pulse signal output by the control chip 40 to the driving module 10 is at a low level, the low level is input to the base of the third triode Q3 through the fourth resistor R4, so that the third triode Q3 is turned off, the fourth triode Q4 is turned on, the fifth triode Q5 is turned off, the sixth triode Q6 is turned on, the voltage at the point a is 0V, and the IGBT is turned off.
Moreover, as shown in fig. 6, when the driving module 10 outputs the driving signal of the first driving voltage V1, the first transistor Q1 is turned on, and the detection signal generated by the detection module 20 will not change in level and will continue to be at a low level, that is, when the voltage at the point a is the first driving voltage V1 and 0V, the level at the point B is at a low level; when the driving module 10 outputs the driving signal of the second driving voltage V2, the first transistor Q1 is turned off, and the detection signal generated by the detection module 20 will change with the driving signal at the same frequency, that is, when the voltage at the point a is the second driving voltage V2, the level at the point B is high level (the high level may be the difference between the regulated voltage values of the second driving voltage V2 and the first voltage regulator Z1), and when the voltage at the point a is 0V, the level at the point B is low level.
Assuming that the frequency of the driving signal is greater than 20kHz, when the driving module 10 outputs the driving signal of the first driving voltage V1, the detection signal received by the interrupt input terminal INT of the control chip 40 will keep the level state unchanged, and the count value of the counting module 30 is increased by 1 every preset time, for example, 0.1 ms; when the driving module 10 outputs the driving signal of the second driving voltage V2, the interrupt input end INT of the control chip 40 receives a high-low level signal with a frequency greater than 20kHz, the control chip 40 determines that the detection signal triggers the interrupt, and clears the count value of the counting module 30 in the interrupt handler. In this way, after the multiple cycles reach the preset detection time, for example, 1ms, the control chip 40 obtains the final count value of the counting module 30, and determines whether the driving module 10 is abnormal according to the final count value of the counting module 30 in combination with the voltage state of the driving signal.
For example, at low power heating (e.g. less than 1000W), the heating is achieved by a duty cycle, e.g. 2/4 duty cycle, i.e. heating 2 half-waves, stopping 2 half-waves. Each control cycle of the heating process is divided into 3 stages, namely a discharging stage D1, a heating stage D2 and a stopping stage D3, wherein in the discharging stage D1, the control chip 40 can control the output driving module 10 to output a driving signal of a first driving voltage V1 to the power switch tube 50 in the heating stage D2, and the control chip 40 can control the output driving module 10 to output a driving signal of a second driving voltage V2 to the power switch tube 50; in the stop stage D3, the control chip 40 can control the output driving module 10 to output the third driving voltage, i.e. 0V, to the power switch tube 50.
In the discharging stage D1, after entering the discharging stage D1, the driving abnormality detection time is counted by the timer, 1 is added to each preset interval time, for example, 0.1ms, of the count value of the counting module 30, and when the driving abnormality detection time does not reach the preset detection time, for example, 1ms, the control chip 40 adjusts the count value of the counting module 40 through the detection signal received by the interrupt input terminal INT (if the driving abnormality detection time is abnormal, an interrupt occurs, and the count value is cleared). After the driving abnormality detection time reaches the preset detection time, for example, 1ms, if the count value is greater than or equal to the preset threshold, for example, 5 (at this time, the theoretical value is 10), it indicates that there is no interruption at this time, and the driving signal of the first driving voltage V1 is normally output or the first voltage regulator tube Z1 is open-circuited, and meanwhile, the abnormal situations of the first voltage regulator tube Z1 short circuit (no heating) and the first triode Q1 abnormality (cut-off) are eliminated. If the count value is less than a predetermined threshold value, for example, 5, it indicates that there may be an abnormal condition where the first regulator tube Z1 is short-circuited and the first transistor Q1 is abnormal (turned off).
In the heating stage D2, after entering the heating stage D2, the driving abnormality detection time is counted by a timer, 1 is added to each preset interval time, for example, 0.1ms, of the count value of the counting module 30, and when the driving abnormality detection time does not reach the preset detection time, for example, 1ms, the control chip 40 adjusts the count value of the counting module 40 through the detection signal received by the interrupt input terminal INT (if normal, interrupt occurs, the count value is cleared, if abnormal, interrupt does not occur, and the count value is not cleared). After the driving abnormality detection time reaches the preset detection time, for example, 1ms, if the count value is smaller than the preset threshold, for example, 5 (at this time, the theoretical value is 10), it indicates that the driving signal of the second driving voltage V1 is normally output, and meanwhile, the abnormal situations that the first voltage regulator tube Z1 is open and the first triode Q1 is abnormal (conductive) are eliminated. If the count value is greater than or equal to the preset threshold value, for example, 5, it indicates that there may be an abnormal situation where the first regulator tube Z1 is open and the first transistor Q1 is abnormal (conducting).
Therefore, whether the driving voltage of the driving module 10 is abnormal or not is judged according to the counting value condition adjusted by the detection signal in the discharging stage D1 and the heating stage D2, namely whether the first voltage-regulator tube Z1 and the first triode Q1 are abnormal or not is judged, so that the abnormal condition of the driving module can be effectively detected, the phenomenon that the pulse current of the power switch tube is overlarge and the noise is large due to overhigh driving voltage is prevented, and the phenomenon that the power switch tube is overlarge in loss and even is heated and burnt due to overlow driving voltage can be prevented.
In summary, according to the driving detection circuit of the power switch in the electromagnetic heating device provided by the embodiment of the invention, the detection module generates the detection signal according to the driving signal output by the driving module, adjusts the count value of the counting module at preset intervals, detects whether the detection signal triggers the interruption or not, and clears the count value of the counting module when the interruption is triggered, so as to obtain the final count value of the counting module when the detection time reaches the preset detection time, and judges whether the driving module is abnormal or not according to the final count value and the voltage state of the driving signal, thereby effectively detecting the abnormal condition of the driving module, preventing the power switch from being over-high in pulse current and high in noise caused by over-high driving voltage, and preventing the power switch from being over-high in loss and even being over-heated and burned due to over-low driving voltage.
In addition, the embodiment of the invention also provides an electromagnetic heating device. Wherein, according to an embodiment of the present invention, the electromagnetic heating device may be an induction cooker, an electromagnetic pressure cooker or an electromagnetic rice cooker.
Fig. 7 is a schematic view of an electromagnetic heating apparatus according to an embodiment of the present invention. As shown in fig. 7, the electromagnetic heating apparatus according to the embodiment of the present invention includes a driving detection circuit 200 of the power switch in the electromagnetic heating apparatus according to the embodiment. Specifically, the driving detection circuit 200 of the power switch tube may include a driving unit 101, a voltage step-down unit 102, a control chip 40, and the like.
As shown in fig. 7, the electromagnetic heating apparatus according to the embodiment of the present invention further includes: a resonant circuit 300 and a supply circuit 400. The resonant circuit 300 comprises a resonant capacitor C2 and a heating coil L2 which are connected in parallel, one end of the resonant capacitor C2 and one end of the heating coil L2 which are connected in parallel are connected with a collector of the power switch tube 50, and an emitter of the power switch tube 50 is grounded; the power supply circuit 400 is connected to the other end of the heating coil L2 and the resonant capacitor C2 in parallel, and the power supply circuit 400 is used to supply power to the resonant circuit 300.
Specifically, the power supply circuit 400 may include a rectifier bridge 401 and a filter module 402, where the rectifier bridge 401 is configured to rectify an AC power input by an AC power source AC to output a rectified dc power; the filtering module 402 includes a filtering capacitor C1 and a filtering inductor L1, and the filtering module 402 is configured to filter the rectified dc power to output a rectified and filtered dc power, and to rectify the filtered dc power and supply the rectified dc power to the resonant circuit 300.
When the electromagnetic heating device stops heating, the collector voltage of the power switch tube 50 is 1.4 times of the AC voltage of the AC power supply due to the existence of the filter capacitor C1. After the electromagnetic heating device starts to heat, the electromagnetic heating device enters a starting stage and a normal heating stage in sequence, in the starting stage, the driving unit 101 of the power switch tube outputs a first driving voltage V1 to the power switch tube 50, the power switch tube 50 is in an amplification state, and the current flowing through the power switch tube 50 is related to V1, so that a smaller first driving voltage V1 is output, and the pulse current at the moment of switching on the power switch tube can be reduced; in the normal heating stage, the driving unit 101 outputs a second driving voltage V2 to the power switch tube 50, the power switch tube 50 is in a saturation conducting state, when the power switch tube 50 is conducted, it is equivalent to a conducting switch, and the electromagnetic heating device performs normal resonance heating on the cookware.
According to the electromagnetic heating device provided by the embodiment of the invention, the drive detection circuit of the embodiment can effectively detect the abnormal condition of the drive module, prevent the pulse current of the power switch tube from being too large and the noise from being larger due to the overhigh drive voltage, and also prevent the power switch tube from being too large in loss and even heated and burned due to the overlow drive voltage.
The embodiment of the invention also provides a driving detection method of the power switch tube in the electromagnetic heating device.
Fig. 8 is a flowchart of a driving detection method of a power switching tube in an electromagnetic heating apparatus according to an embodiment of the present invention. As shown in fig. 8, the method for detecting the driving of the power switch tube in the electromagnetic heating device includes the following steps:
s1: and generating a detection signal according to a driving signal output by a driving module in the electromagnetic heating device, wherein the driving module outputs the driving signal to the power switch tube to drive the power switch tube to be switched on or switched off.
S2: and adjusting the count value of the counting module at preset intervals.
S3: and detecting whether the detection signal triggers the interrupt, and clearing the count value of the counting module when the interrupt is triggered.
S4: and when the preset detection time is reached, acquiring the final count value of the counting module, and judging whether the driving module is abnormal or not according to the final count value of the counting module and the voltage state of the driving signal.
According to an embodiment of the present invention, determining whether the driving module is abnormal according to the final count value of the counting module and the voltage state of the driving signal includes: when the driving module outputs a driving signal of a first driving voltage, if the final count value of the counting module is smaller than a preset threshold value, judging that the driving module is abnormal; when the driving module outputs a driving signal of a second driving voltage, if the final count value of the counting module is greater than or equal to a preset threshold value, judging that the driving module is abnormal; the first driving voltage is smaller than the second driving voltage.
Specifically, as shown in fig. 9, the main driving detection program in the method for detecting the driving of the power switching tube in the electromagnetic heating device according to the embodiment of the present invention includes the following steps:
s101: and judging whether the electromagnetic heating device is in a heating state, such as a discharging stage and a heating stage.
If yes, executing step S102; if not, exiting.
S102: and controlling the counting value of the counting module to be increased by 1.
S103: it is determined whether the count value of the count module is greater than or equal to a count overflow value, such as 50.
If yes, executing step S104; if not, step S105 is performed.
S104: the count value of the count module is controlled to be maintained as a count overflow value.
S105: and judging whether the driving detection time reaches the preset detection time.
If yes, go to step S106; if not, exiting.
S106: whether the driving module outputs the driving signal of the first driving voltage is determined, that is, in the embodiment of fig. 4, whether the control chip outputs the high level signal through the second control output terminal is determined.
If yes, go to step S107; if not, step S108 is performed.
S107: the final count value of the count module is judged to be greater than or equal to a preset threshold value, such as 5.
If yes, go to step S109; if not, step S110 is executed.
S108: the final count value of the counting module is judged to be smaller than a preset threshold value, for example, 5.
If yes, go to step S109; if not, step S110 is executed.
S109: the driving module is normal.
S110: the drive module is abnormal.
Specifically, as shown in fig. 10, in the abnormality detection process, it is determined whether the detection signal triggers an interrupt, and an interrupt handler in the interrupt handling method in the method for detecting the driving of the power switching tube in the electromagnetic heating apparatus according to the embodiment of the present invention includes the following steps:
s201: a detection signal external interrupt, such as a rising edge trigger, is set.
S202: and judging whether the detection signal triggers the interrupt or not.
If yes, go to step S203; if not, exiting.
S203: and clearing the count value of the count module.
Thus, in the heating state, the control flow shown in fig. 9 is executed every preset interval time, and when the preset detection time is reached, whether the driving module is abnormal or not can be judged according to the final count value of the counting module.
In summary, according to the driving detection method for the power switch tube in the electromagnetic heating device provided by the embodiment of the present invention, the detection signal is generated by the driving signal output by the driving module, the count value of the counting module is adjusted at preset intervals, whether the detection signal triggers the interruption is detected, and the count value of the counting module is cleared when the interruption is triggered, so that the final count value of the counting module is obtained when the detection time reaches the preset detection time, and whether the driving module is abnormal is determined according to the final count value and the voltage state of the driving signal, thereby effectively detecting the abnormal condition of the driving module, preventing the power switch tube from being too large in pulse current and loud in noise caused by too high driving voltage, and preventing the power switch tube from being too large in loss and even being heated and burned due to too low driving voltage.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (13)

1. A drive detection circuit of an IGBT tube in an electromagnetic heating device is characterized by comprising:
the driving module is connected with the IGBT tube and used for outputting a driving signal to the IGBT tube so as to drive the IGBT tube to be switched on or switched off;
the detection module is connected with the driving module and is used for generating a detection signal according to the driving signal output by the driving module;
the counting module is used for adjusting a counting value at intervals of a preset interval;
and the control chip is connected with the detection module and the counting module and is used for detecting whether the detection signal triggers interruption or not, resetting the count value of the counting module when the interruption is triggered, acquiring the final count value of the counting module when the detection time reaches the preset detection time, and judging whether the driving module is abnormal or not according to the final count value and the voltage state of the driving signal.
2. The driving detection circuit of the IGBT tube in the electromagnetic heating device according to claim 1, wherein the control chip has an interrupt input terminal, and the detection module includes:
one end of the first resistor is connected with the driving module, the other end of the first resistor is connected with the interrupt input end of the control chip,
and one end of the first capacitor is connected with the other end of the first resistor, and the other end of the first capacitor is grounded.
3. The driving detection circuit of the IGBT tube in the electromagnetic heating device according to claim 2, wherein the detection module further includes:
and the anode of the first diode is connected with the other end of the first resistor, and the cathode of the first diode is connected with a preset power supply.
4. The driving detection circuit of the IGBT tube in the electromagnetic heating device according to claim 2 or 3, wherein the control chip is connected to the driving module, the control chip has a first control output terminal and a second control output terminal, and the driving module includes:
the input end of the driving unit is connected with the first control output end, the output end of the driving unit is connected with the control end of the IGBT tube, and the driving unit outputs the driving signal to the IGBT tube to drive the IGBT tube to be switched on or switched off;
the output end of the voltage reduction unit is connected with the second control output end, and the output end of the voltage reduction unit is respectively connected with the output end of the driving unit and the control end of the IGBT tube so as to reduce the voltage of the driving signal or stop reducing the voltage;
the control chip outputs a first control signal to the driving unit through the first control output end and outputs a second control signal to the voltage reduction unit through the second control output end so that the IGBT tube works in an amplification state, and outputs the first control signal to the driving unit through the first control output end and outputs a third control signal to the voltage reduction unit through the second control output end so that the IGBT tube works in a saturation conduction state.
5. The driving detection circuit of the IGBT tube in the electromagnetic heating device according to claim 4, wherein the detection module is connected with the voltage reduction unit, and the voltage reduction unit comprises:
the cathode of the first voltage-stabilizing tube is connected with the output end of the driving unit and the control end of the IGBT tube respectively, and the anode of the first voltage-stabilizing tube is connected with the detection module;
and a first end of the switch circuit is connected with the anode of the first voltage-regulator tube, a second end of the switch circuit is grounded, a third end of the switch circuit is connected with a second control output end of the control chip, and the switch circuit is switched on or off under the control of the control chip so as to control the first voltage-regulator tube to be switched on or switched off.
6. The driving detection circuit of the IGBT tube in the electromagnetic heating device according to claim 5, characterized in that the switching circuit comprises:
one end of the second resistor is connected with the second control output end;
one end of the third resistor is connected with the other end of the second resistor and is provided with a first node, and the other end of the third resistor is grounded;
and the collector of the first triode is connected with the anode of the first voltage-regulator tube, the base of the first triode is connected with the first node, and the emitter of the first triode is grounded.
7. The driving detection circuit of the IGBT tube in the electromagnetic heating device according to claim 4, wherein the first control signal is a PPG pulse signal, the second control signal is a high level signal, and the third control signal is a low level signal.
8. The driving detection circuit of the IGBT tube in the electromagnetic heating device according to claim 4, wherein the driving unit outputs a driving signal of a first driving voltage under the joint action of the first control signal and the second control signal, and outputs a driving signal of a second driving voltage under the joint action of the first control signal and the third control signal, wherein the first driving voltage is smaller than the second driving voltage.
9. The driving detection circuit of IGBT tube in electromagnetic heating device according to claim 1,
when the driving module outputs a driving signal of a first driving voltage, the control chip is further used for judging that the driving module is abnormal when the final count value of the counting module is smaller than a preset threshold value;
when the driving module outputs a driving signal of a second driving voltage, the control chip is further used for judging that the driving module is abnormal when the final count value of the counting module is greater than or equal to the preset threshold value;
wherein the first driving voltage is less than the second driving voltage.
10. An electromagnetic heating device, characterized by comprising a drive detection circuit of an IGBT tube in the electromagnetic heating device according to any one of claims 1 to 9.
11. The electromagnetic heating device according to claim 10, wherein the electromagnetic heating device is an induction cooker, an electromagnetic pressure cooker or an electromagnetic rice cooker.
12. A method for driving and detecting a power switch tube in an electromagnetic heating device is characterized by comprising the following steps:
generating a detection signal according to a driving signal output by a driving module in the electromagnetic heating device, wherein the driving module outputs the driving signal to the power switch tube to drive the power switch tube to be switched on or switched off;
adjusting the count value of the counting module at intervals of a preset interval;
detecting whether the detection signal triggers interruption or not, and clearing the count value of the counting module when the interruption is triggered;
and when the detection time reaches the preset detection time, acquiring the final count value of the counting module, and judging whether the driving module is abnormal or not according to the final count value and the voltage state of the driving signal.
13. The method for detecting the driving of the power switch tube in the electromagnetic heating device according to claim 12, wherein the determining whether the driving module is abnormal according to the final count value and the voltage state of the driving signal comprises:
when the driving module outputs a driving signal of a first driving voltage, if the final count value of the counting module is smaller than a preset threshold value, judging that the driving module is abnormal;
when the driving module outputs a driving signal of a second driving voltage, if the final count value of the counting module is greater than or equal to the preset threshold value, judging that the driving module is abnormal;
wherein the first driving voltage is less than the second driving voltage.
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