CN211630081U - PFC circuit, circuit board and air conditioner - Google Patents
PFC circuit, circuit board and air conditioner Download PDFInfo
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- CN211630081U CN211630081U CN202020583535.7U CN202020583535U CN211630081U CN 211630081 U CN211630081 U CN 211630081U CN 202020583535 U CN202020583535 U CN 202020583535U CN 211630081 U CN211630081 U CN 211630081U
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- 230000010355 oscillation Effects 0.000 abstract description 8
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The utility model discloses a PFC circuit, circuit board and air conditioner, PFC circuit includes reactor, first rectifier circuit, PFC drive circuit, PFC switch circuit, overcurrent protection circuit and overcurrent blocking circuit; when the circuit works normally, the PFC driving circuit outputs a corresponding PFC driving signal according to the received control signal, and the PFC switching circuit outputs a sampling current signal to the overcurrent protection circuit; if the sampling current signal is larger than the preset reference value due to the short circuit of the reactor or an external reason, the overcurrent protection circuit outputs a driving protection signal, so that the PFC driving circuit stops outputting the PFC driving signal and the PFC switching circuit is turned off; on the other hand, the overcurrent locking circuit is enabled to output a locking signal for locking the control signal; therefore, overcurrent protection can be realized, circuit loop oscillation can be prevented, and the situation that a PFC driving circuit repeatedly outputs a PFC driving signal due to the fact that a sampling current signal is rapidly reduced to be below a preset reference value after a PFC switching circuit is turned off is avoided.
Description
Technical Field
The utility model relates to a PFC circuit technical field, in particular to PFC circuit, circuit board and air conditioner.
Background
A Power Factor Correction (PFC) circuit is generally introduced into existing electronic Power equipment, so that on one hand, the utilization rate of a Power supply to mains supply can be improved when alternating current is converted into direct current through the PFC circuit, and the electric energy loss in the conversion process is reduced, so that energy can be saved; on the other hand, harmonic pollution in the power grid can be reduced through the PFC circuit.
At present, the current transformer is generally arranged in a PFC circuit to detect current so as to realize overcurrent protection of the PFC circuit, and when the current is too large, the overcurrent protection circuit controls a switching tube to be turned off, so that a power device in the circuit is prevented from being damaged. However, after the switch tube is turned off, the current in the PFC circuit will drop rapidly, the overcurrent protection circuit will not operate, and the switch tube is turned on again, resulting in oscillation, which has a large impact on both the PFC circuit and the switch tube.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to solve one of the technical problem that exists among the prior art at least, provide a PFC circuit, circuit board and air conditioner, prevent when can realizing overcurrent protection that circuit loop from vibrating appearing.
According to the utility model discloses a PFC circuit of first aspect embodiment includes:
one end of the reactor is connected with a live wire end of an alternating current power supply;
the input end of the first rectifying circuit is connected with the other end of the reactor;
the PFC driving circuit outputs a corresponding PFC driving signal according to the received control signal;
the controlled end of the PFC switch circuit is connected with the output end of the PFC drive circuit, the input end of the PFC switch circuit is connected with the other end of the reactor, and the PFC switch circuit is also provided with a sampling current output end for outputting a sampling current signal;
the detection end of the over-current protection circuit is connected with the sampling current output end and is used for receiving the sampling current signal, and the output end of the over-current protection circuit is connected with the PFC drive circuit and outputs a drive protection signal when the sampling current signal is larger than a preset reference value; the PFC driving circuit stops outputting the PFC driving signal when receiving the driving protection signal;
the input end of the overcurrent locking circuit is connected with the output end of the overcurrent protection circuit, and the output end of the overcurrent locking circuit outputs a locking signal in a state of receiving the driving protection signal;
the input end of the MCU module is connected with the output end of the overcurrent locking circuit to receive the locking signal, the output end of the MCU module is connected with the PFC driving circuit to output the control signal, and the MCU module stops outputting the control signal when receiving the locking signal.
According to the utility model discloses PFC circuit has following beneficial effect at least: when the circuit works normally, the PFC driving circuit outputs a corresponding PFC driving signal to the PFC switching circuit according to a control signal sent by the MCU module, and the PFC switching circuit outputs a sampling current signal to the overcurrent protection circuit from the sampling current output end; if the sampling current signal is larger than the preset reference value due to the short circuit of the reactor or an external reason, the overcurrent protection circuit outputs a driving protection signal, so that the PFC driving circuit stops outputting the PFC driving signal and the PFC switching circuit is turned off; on the other hand, the overcurrent locking circuit outputs a locking signal to the MCU module, the MCU module stops outputting the control signal after receiving the locking signal, and the PFC driving circuit does not output the PFC driving signal any more; therefore, overcurrent protection can be realized, circuit loop oscillation can be prevented, and the situation that a PFC driving circuit repeatedly outputs a PFC driving signal due to the fact that a sampling current signal is rapidly reduced to be below a preset reference value after a PFC switching circuit is turned off is avoided.
According to some embodiments of the present invention, the PFC drive circuit includes a first signal isolation device, an input of the first signal isolation device serves as the input of the PFC drive circuit and is used to receive the control signal, an output of the first signal isolation device serves as the output of the PFC drive circuit and is used to output the PFC drive signal to the PFC switch circuit. The arrangement of the first signal isolation device can realize the isolation and conversion of the control signal at the input end and the PFC driving signal at the output end.
According to the utility model discloses a some embodiments, PFC switch circuit includes second rectifier circuit, first switch tube and current sampling component, the second rectifier circuit the input positive pole with the other end of reactor is connected, the input negative pole of second rectifier circuit is connected with alternating current power supply's zero line end, the output of second rectifier circuit is connected respectively two switch pins of first switch tube, the control pin of first switch tube is as PFC switch circuit's controlled end, current sampling component establishes ties or connects in parallel second rectifier circuit's output with between the first switch tube, current sampling component's output is as PFC switch circuit's sampling current output. The current sampling element is connected in series or in parallel between the output end of the second rectifying circuit and the first switching tube, so that a current signal in the circuit when the first switching tube is conducted is detected.
Optionally, the current sampling element is one of a non-inductive resistor, a transformer, a voltage-type hall current sensor, and a current-type hall current sensor.
According to some embodiments of the utility model, overcurrent protection circuit includes comparator and second switch tube, the first input of comparator is as overcurrent protection circuit's sense terminal is used for receiving the sampling current signal, the second input of comparator inserts preset reference value, the output of comparator is connected the control pin of second switch tube, a switch pin of second switch tube connects first DC power supply, another switch pin of second switch tube connects the power end of first signal isolation device. The comparator receives the sampling current signal from the first input end, compares the sampling current signal with a preset reference value received by the second input end, controls the second switching tube to be switched off if the sampling current signal is larger than the preset reference value, and the first direct-current power supply cannot supply power to the first signal isolation device, so that the first signal isolation device cannot realize the conversion of the control signal, and the PFC driving circuit stops outputting the PFC driving signal.
According to some embodiments of the utility model, overflow the blocking circuit and include second signal isolation device, the input of second signal isolation device is connected the output of comparator, the output of second signal isolation device does overflow the blocking circuit's output and be used for the output the blocking signal. The second signal isolation device converts the signal output by the comparator into a locking signal when the sampling current signal is greater than the preset reference value, and is used for locking the control signal, so that the situation that the sampling current signal is rapidly reduced below the preset reference value after the PFC switch circuit is turned off, the PFC drive circuit repeatedly outputs the PFC drive signal, and circuit loop oscillation is prevented.
According to some embodiments of the invention, the second signal isolation device is one of an optocoupler, a transformer and a hall current sensor.
According to some embodiments of the invention, the MCU module comprises a first signal isolation device and a second signal isolation device. The locking signal is latched by the latch, so that the reliability of the MCU module for receiving the locking signal is improved.
According to the utility model discloses a some embodiments still include energy storage filter circuit, energy storage filter circuit's input with first rectifier circuit's output is connected. The energy storage filter circuit is used for storing the output electric energy and filtering the output voltage so as to stabilize the output voltage.
According to the utility model discloses a some embodiments, energy storage filter circuit includes first electric capacity and second electric capacity, the output positive pole of first rectifier circuit is connected the one end of first electric capacity, the other end of first electric capacity is connected the one end of second electric capacity and alternating current power supply's zero line end, the other end ground connection of second electric capacity. The energy storage filter circuit is realized by two capacitors which are connected in series, so that voltage-multiplying rectification is realized by the energy storage filter circuit and the first rectification circuit, and the voltage value of the output end of the first rectification circuit is equal to twice of the input end of the first rectification circuit.
According to the utility model provides a circuit board of second aspect embodiment, include according to the utility model discloses the PFC circuit of first aspect embodiment.
According to the utility model discloses circuit board has following beneficial effect at least: when the device normally works, the PFC driving circuit outputs a corresponding PFC driving signal to the PFC switching circuit according to the received control signal, and the PFC switching circuit outputs a sampling current signal to the overcurrent protection circuit from the sampling current output end; if the sampling current signal is larger than the preset reference value due to the short circuit of the reactor or an external reason, the overcurrent protection circuit outputs a driving protection signal, so that the PFC driving circuit stops outputting the PFC driving signal and the PFC switching circuit is turned off; on the other hand, the overcurrent locking circuit is enabled to output a locking signal for locking the control signal; therefore, overcurrent protection can be realized, circuit loop oscillation can be prevented, and the situation that a PFC driving circuit repeatedly outputs a PFC driving signal due to the fact that a sampling current signal is rapidly reduced to be below a preset reference value after a PFC switching circuit is turned off is avoided.
According to the utility model discloses an air conditioner that third aspect embodiment provided, include according to the utility model discloses the circuit board of second aspect embodiment.
According to the utility model discloses air conditioner has following beneficial effect at least: when the device normally works, the PFC driving circuit outputs a corresponding PFC driving signal to the PFC switching circuit according to the received control signal, and the PFC switching circuit outputs a sampling current signal to the overcurrent protection circuit from the sampling current output end; if the sampling current signal is larger than the preset reference value due to the short circuit of the reactor or an external reason, the overcurrent protection circuit outputs a driving protection signal, so that the PFC driving circuit stops outputting the PFC driving signal and the PFC switching circuit is turned off; on the other hand, the overcurrent locking circuit is enabled to output a locking signal for locking the control signal; therefore, overcurrent protection can be realized, circuit loop oscillation can be prevented, and the situation that a PFC driving circuit repeatedly outputs a PFC driving signal due to the fact that a sampling current signal is rapidly reduced to be below a preset reference value after a PFC switching circuit is turned off is avoided.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The present invention will be further described with reference to the accompanying drawings and examples;
fig. 1 is a schematic diagram of functional modules of a PFC circuit according to an embodiment of the present invention;
fig. 2 is a schematic circuit diagram of a PFC circuit according to an embodiment of the present invention.
Detailed Description
This section will describe in detail the embodiments of the present invention, preferred embodiments of the present invention are shown in the attached drawings, which are used to supplement the description of the text part of the specification with figures, so that one can intuitively and vividly understand each technical feature and the whole technical solution of the present invention, but they cannot be understood as the limitation of the protection scope of the present invention.
In the description of the present invention, if there are first and second descriptions for distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the precedence of the indicated technical features.
In the description of the present invention, unless there is an explicit limitation, the words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in combination with the specific contents of the technical solution.
A Power Factor Correction (PFC) circuit is generally introduced into existing electronic Power equipment, so that on one hand, the utilization rate of a Power supply to mains supply can be improved when alternating current is converted into direct current through the PFC circuit, and the electric energy loss in the conversion process is reduced, so that energy can be saved; on the other hand, harmonic pollution in the power grid can be reduced through the PFC circuit.
At present, the current transformer is generally arranged in a PFC circuit to detect current so as to realize overcurrent protection of the PFC circuit, and when the current is too large, the overcurrent protection circuit controls a switching tube to be turned off, so that a power device in the circuit is prevented from being damaged. However, after the switch tube is turned off, the current in the PFC circuit will drop rapidly, the overcurrent protection circuit will not operate, and the switch tube is turned on again, resulting in oscillation, which has a large impact on both the PFC circuit and the switch tube.
Based on this, the embodiment of the utility model provides a PFC circuit, circuit board and air conditioner prevents that circuit loop from appearing shaking when can realize overcurrent protection.
The embodiments of the present invention will be further explained with reference to the drawings.
Referring to fig. 1, an embodiment of a first aspect of the present invention provides a PFC circuit, including:
one end of the reactor L1 is connected with a live wire end of the alternating current power supply;
a first rectifier circuit 100, an input end of the first rectifier circuit 100 being connected to the other end of the reactor L1;
the PFC driving circuit 200 outputs a corresponding PFC driving signal according to the received control signal PFC-PWM;
the controlled end of the PFC switch circuit 300 is connected with the output end of the PFC drive circuit 200, the input end of the PFC switch circuit 300 is connected with the other end of the reactor L1, and the PFC switch circuit 300 is further provided with a sampling current output end for outputting a sampling current signal;
the detection end of the overcurrent protection circuit 400 is connected with the sampling current output end and is used for receiving the sampling current signal, and the output end of the overcurrent protection circuit 400 is connected with the PFC drive circuit 200 and outputs a drive protection signal when the sampling current signal is larger than a preset reference value; the PFC driving circuit 200 stops outputting the PFC driving signal in a state of receiving the driving protection signal;
the input end of the overcurrent blocking circuit 500 is connected with the output end of the overcurrent protection circuit 400, and the output end of the overcurrent blocking circuit 500 outputs a blocking signal PFC-Fault in a state of receiving a driving protection signal;
the input end of the MCU module 600 is connected to the output end of the over-current blocking circuit 500 to receive the blocking signal PFC-Fault, the output end of the MCU module is connected to the PFC driving circuit 200 to output the controlled signal PFC-PWM, and the MCU module stops outputting the controlled signal PFC-PWM when receiving the blocking signal PFC-Fault.
In this embodiment, when the PFC circuit normally works, the PFC driving circuit 200 outputs a corresponding PFC driving signal to the PFC switch circuit 300 according to the control signal PFC-PWM sent by the MCU module 600, and the PFC switch circuit 300 outputs a sampled current signal to the overcurrent protection circuit 400 from a sampled current output terminal; if the sampling current signal is larger than the preset reference value due to the short circuit of the reactor L1 caused by itself or an external factor, the overcurrent protection circuit 400 outputs a driving protection signal, so that the PFC driving circuit 200 stops outputting the PFC driving signal and turns off the PFC switching circuit 300; on the other hand, the overcurrent locking circuit 500 outputs the locking signal PFC-Fault to the MCU module 600, the MCU module 600 stops outputting the control signal PFC-PWM after receiving the locking signal PFC-Fault, and the PFC driving circuit 200 does not output the PFC driving signal any more; therefore, overcurrent protection can be realized, circuit loop oscillation can be prevented, and the situation that the sampling current signal is rapidly reduced below a preset reference value after the PFC switch circuit 300 is turned off, so that the PFC driving circuit 200 repeatedly outputs the PFC driving signal is avoided.
Referring to fig. 2, in some embodiments of the present invention, the PFC driving circuit 200 includes a first signal isolation device U1, an input terminal of the first signal isolation device U1 is used as an input terminal of the PFC driving circuit 200 and is configured to receive the control signal PFC-PWM, and an output terminal of the first signal isolation device U1 is used as an output terminal of the PFC driving circuit 200 and is configured to output the PFC driving signal to the PFC switching circuit 300. The first signal isolation device U1 is provided to isolate and convert the control signal PFC-PWM at the input terminal and the PFC driving signal at the output terminal.
Referring to fig. 2, in some embodiments of the present invention, the PFC switch circuit 300 includes a second rectifier circuit 310, a first switch Q1 and a current sampling element, specifically, the current sampling element in this embodiment selects a non-inductive resistor R1, an input positive terminal of the second rectifier circuit 310 is connected to the other end of the reactor L1, an input negative terminal of the second rectifier circuit 310 is connected to the zero line terminal of the ac power supply, an output positive terminal of the second rectifier circuit 310 is connected to one switch pin of the first switch Q1, another switch pin of the first switch Q1 is connected to one end of the non-inductive resistor R1, and the other end of the non-inductive resistor R1 is connected to the output negative terminal of the second rectifier circuit 310. When the reactor L1 of the PFC circuit is short-circuited by itself or an external factor, and the first switching tube Q1 is turned on, the current in the circuit will rise instantly, which is far beyond the rated value of the circuit, and at this time, a voltage difference much larger than that in normal operation is generated between two ends of the non-inductive resistor R1, and the voltage difference signal is sent to the overcurrent protection circuit 400, so that the PFC driving circuit 200 stops outputting the PFC driving signal.
Specifically, the PFC switch circuit 300 further includes a second resistor R2 and a third resistor R3, the control pin of the first switch Q1 is grounded through the second resistor R2, and the output terminal of the first signal isolation device U1 is connected to the control pin of the first switch Q1 through the third resistor.
It is to be understood that the current sampling element may also be one of a transformer, a voltage-type hall current sensor, and a current-type hall current sensor.
Referring to fig. 2, in some embodiments of the present invention, the overcurrent protection circuit 400 includes a comparator U2 and a second switch tube Q2, a first input terminal of the comparator U2 is used as a detection terminal of the overcurrent protection circuit 400 and is used for receiving a sampling current signal, a second input terminal of the comparator U2 is connected to a preset reference value, an output terminal of the comparator U2 is connected to a control pin of the second switch tube Q2, a switch pin of the second switch tube Q2 is connected to the first dc power supply +15V IGBT, and another switch pin of the second switch tube Q2 is connected to a power terminal of the first signal isolation device U1. After receiving the sampling current signal from the first input end, the comparator U2 compares the sampling current signal with the preset reference value received by the second input end, and if the sampling current signal is greater than the preset reference value, the second switching tube Q2 is controlled to be turned off, and the first direct-current power supply cannot supply power to the first signal isolation device U1, so that the first signal isolation device U1 cannot realize conversion of a control signal PFC-PWM, and the PFC drive circuit 200 stops outputting a PFC drive signal.
Specifically, the overcurrent protection circuit 400 further includes a third switching tube Q3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third inductor C3, a fourth inductor C4, a fifth inductor C5, and a sixth inductor C6; the fourth resistor R4 and the fifth resistor R5 are used for providing a preset reference value for a second input end of the comparator U2, one end of the fourth resistor R4 is connected with a second direct-current power supply, the other end of the fourth resistor R4 is grounded through the fifth resistor R5, and a connection point of the fourth resistor R4 and the fifth resistor R5 is connected to the second input end of the comparator U2; the third inductor C3 is connected in parallel to two ends of the fifth resistor R5, one end of the fourth inductor C4 is connected with the first input end of the comparator U2, and the other end of the fourth inductor C4 is grounded; the second direct current power supply is also connected with a power supply end of the comparator U2 to supply power for the comparator U2; an output end of the comparator U2 is connected to one end of a sixth resistor R6, the other end of the sixth resistor R6 is connected to a control pin of the third switching tube Q3, one end of the fifth inductor C5 and one end of the seventh resistor R7, the other end of the fifth inductor C5, the other end of the seventh resistor R7 and one switch pin of the third switching tube Q3 are grounded, the other switch pin of the third switching tube Q3 is connected to the control pin of the second switching tube Q2 through an eighth resistor, one end of the ninth resistor R9 is connected to the first dc power supply +15V IGBT, the other end of the ninth resistor R9 is connected to the control pin of the second switching tube Q2, and the first dc power supply +15V IGBT is also grounded through the sixth inductor C6.
Referring to fig. 2, in some embodiments of the present invention, the overcurrent locking circuit 500 includes a second signal isolation device U3, an input terminal of the second signal isolation device U3 is connected to an output terminal of the comparator U2, and an output terminal of the second signal isolation device U3 serves as an output terminal of the overcurrent locking circuit 500 and is used for outputting the locking signal PFC-Fault. The second signal isolation device U3 converts the signal output by the comparator U2 when the sampling current signal is greater than the preset reference value into a blocking signal PFC-Fault for blocking the control signal PFC-PWM, so as to prevent the sampling current signal from rapidly decreasing below the preset reference value after the PFC switch circuit 300 is turned off, which may cause the PFC driving circuit 200 to repeatedly output the PFC driving signal, thereby preventing the circuit loop from oscillating.
Specifically, the overcurrent locking circuit 500 further includes an eleventh resistor R11, a twelfth resistor R12 and a thirteenth resistor R13, an output end of the comparator U2 is connected to one end of the thirteenth resistor R13, the other end of the thirteenth resistor R13 is respectively connected to one end of the twelfth resistor R12 and the anode of the input end of the second signal isolation device U3, and the cathode of the input end of the second signal isolation device U3 and the other end of the twelfth resistor R12 are grounded; the +5V third direct-current power supply is connected with the anode of the output end of the second signal isolation device U3 through an eleventh resistor R11, the cathode of the output end of the second signal isolation device U3 is grounded, and the anode of the output end of the second signal isolation device U3 is used as the output end of the overcurrent lockout circuit 500 and used for outputting a lockout signal PFC-Fault.
Illustratively, the second signal isolation device U3 is one of an optocoupler, a transformer, and a hall current sensor.
According to some embodiments of the present invention, a latch may also be provided, and the output of the second signal isolation device U3 is connected to the MCU module 600 through the latch. The latch is arranged to latch the blocking signal PFC-Fault, so that the reliability of the MCU module 600 for receiving the blocking signal PFC-Fault is improved.
Referring to fig. 2, in some embodiments of the present invention, the present invention further includes a tank filter circuit 700, and an input end of the tank filter circuit 700 is connected to an output end of the first rectification circuit 100. The tank filter circuit 700 is used for storing the output electric energy and filtering the output voltage to stabilize the output voltage.
Specifically, the energy storage filter circuit 700 includes a first capacitor C1 and a second capacitor C2, the positive electrode of the output end of the first rectification circuit 100 is connected to one end of the first capacitor C1, the other end of the first capacitor C1 is connected to one end of the second capacitor C2 and the zero line end of the alternating current power supply, and the other end of the second capacitor C2 is grounded. The energy storage filter circuit 700 is implemented by two capacitors connected in series, so as to implement voltage-doubling rectification with the first rectification circuit 100, that is, the voltage value at the output end of the first rectification circuit 100 is equal to twice the voltage value at the input end of the first rectification circuit 100.
According to the utility model provides a circuit board of second aspect embodiment, include according to the utility model discloses the PFC circuit of first aspect embodiment. The function and principle of the circuit board of this embodiment are based on the PFC circuit, so the circuit board of this embodiment has the same beneficial effects as the PFC circuit, and for brevity, the description is not repeated here.
According to the utility model discloses an air conditioner that third aspect embodiment provided, include according to the utility model discloses the circuit board of second aspect embodiment. The operation and principle of the air conditioner of this embodiment are based on the circuit board, so the air conditioner of this embodiment has the same beneficial effects as the circuit board, and for the sake of brevity, the description is not repeated here.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.
Claims (12)
1. A PFC circuit, comprising:
one end of the reactor is connected with a live wire end of an alternating current power supply;
the input end of the first rectifying circuit is connected with the other end of the reactor;
the PFC driving circuit outputs a corresponding PFC driving signal according to the received control signal;
the controlled end of the PFC switch circuit is connected with the output end of the PFC drive circuit, the input end of the PFC switch circuit is connected with the other end of the reactor, and the PFC switch circuit is also provided with a sampling current output end for outputting a sampling current signal;
the detection end of the over-current protection circuit is connected with the sampling current output end and is used for receiving the sampling current signal, and the output end of the over-current protection circuit is connected with the PFC drive circuit and outputs a drive protection signal when the sampling current signal is larger than a preset reference value; the PFC driving circuit stops outputting the PFC driving signal when receiving the driving protection signal;
the input end of the overcurrent locking circuit is connected with the output end of the overcurrent protection circuit, and the output end of the overcurrent locking circuit outputs a locking signal in a state of receiving the driving protection signal;
the input end of the MCU module is connected with the output end of the overcurrent locking circuit to receive the locking signal, the output end of the MCU module is connected with the PFC driving circuit to output the control signal, and the MCU module stops outputting the control signal when receiving the locking signal.
2. The PFC circuit of claim 1, wherein the PFC driving circuit comprises a first signal isolation device, an input of the first signal isolation device being configured to receive the control signal, and an output of the first signal isolation device being configured to output the PFC driving signal to the PFC switching circuit.
3. The PFC circuit according to claim 1, wherein the PFC switch circuit comprises a second rectification circuit, a first switch tube and a current sampling element, wherein an anode of an input end of the second rectification circuit is connected with the other end of the reactor, a cathode of the input end of the second rectification circuit is connected with a zero line end of an alternating current power supply, an output end of the second rectification circuit is respectively connected with two switch pins of the first switch tube, a control pin of the first switch tube is used as a controlled end of the PFC switch circuit, the current sampling element is connected in series or in parallel between an output end of the second rectification circuit and the first switch tube, and an output end of the current sampling element is used as a sampling current output end of the PFC switch circuit.
4. The PFC circuit of claim 3, wherein the current sampling element is one of a non-inductive resistor, a transformer, a voltage-mode Hall current sensor, and a current-mode Hall current sensor.
5. The PFC circuit of claim 2, wherein the over-current protection circuit comprises a comparator and a second switch tube, a first input terminal of the comparator is used as a detection terminal of the over-current protection circuit and is configured to receive the sampled current signal, a second input terminal of the comparator is connected to the preset reference value, an output terminal of the comparator is connected to a control pin of the second switch tube, one switch pin of the second switch tube is connected to the first DC power supply, and another switch pin of the second switch tube is connected to a power supply terminal of the first signal isolation device.
6. The PFC circuit of claim 5, wherein the over-current blocking circuit comprises a second signal isolation device, an input terminal of the second signal isolation device is connected to the output terminal of the comparator, and an output terminal of the second signal isolation device is used as an output terminal of the over-current blocking circuit and is used for outputting the blocking signal.
7. The PFC circuit of claim 6, wherein the second signal isolation device is one of an optocoupler, a transformer, and a Hall current sensor.
8. The PFC circuit of claim 7, comprising a latch, wherein the output of the second signal isolation device is connected to the MCU module via the latch.
9. The PFC circuit of claim 1, further comprising a tank filter circuit having an input connected to the output of the first rectification circuit.
10. The PFC circuit of claim 9, wherein the tank filter circuit comprises a first capacitor and a second capacitor, wherein a positive terminal of an output terminal of the first rectifying circuit is connected to one terminal of the first capacitor, the other terminal of the first capacitor is connected to one terminal of the second capacitor and a neutral terminal of an ac power source, and the other terminal of the second capacitor is grounded.
11. A circuit board, characterized by: comprising a PFC circuit according to any of claims 1 to 10.
12. An air conditioner, characterized in that: comprising the wiring board of claim 11.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020583535.7U CN211630081U (en) | 2020-04-17 | 2020-04-17 | PFC circuit, circuit board and air conditioner |
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| CN202020583535.7U CN211630081U (en) | 2020-04-17 | 2020-04-17 | PFC circuit, circuit board and air conditioner |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114421422A (en) * | 2021-12-31 | 2022-04-29 | 高斯机器人(深圳)有限公司 | Overcurrent protection circuit and electronic device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114421422A (en) * | 2021-12-31 | 2022-04-29 | 高斯机器人(深圳)有限公司 | Overcurrent protection circuit and electronic device |
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