CN217956672U - Short-circuit protection circuit of PFC circuit, PFC circuit and air conditioner - Google Patents
Short-circuit protection circuit of PFC circuit, PFC circuit and air conditioner Download PDFInfo
- Publication number
- CN217956672U CN217956672U CN202221455897.3U CN202221455897U CN217956672U CN 217956672 U CN217956672 U CN 217956672U CN 202221455897 U CN202221455897 U CN 202221455897U CN 217956672 U CN217956672 U CN 217956672U
- Authority
- CN
- China
- Prior art keywords
- circuit
- comparator
- igbt
- short
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Protection Of Static Devices (AREA)
Abstract
The utility model provides a short-circuit protection circuit of PFC circuit, PFC circuit and air conditioner, this short-circuit protection circuit adopts the mode collection that hall sensor inserts the IGBT branch road to flow through the current signal of IGBT, compare this current signal and voltage reference value through the comparator, and output the break-make of the one-way conduction element of high low level control based on the comparative result, thereby whether control IGBT turn-offs, wherein collection and judgement link still less, response speed is faster, can reduce IGBT's damage risk effectively, reduce the service failure rate.
Description
Technical Field
The utility model relates to a PFC circuit technical field particularly, relates to a short-circuit protection circuit, PFC circuit and air conditioner of PFC circuit.
Background
An existing air conditioner is often damaged after sale due to an Insulated Gate Bipolar Transistor (IGBT) in a Power Factor Correction (PFC) circuit, so that the air conditioner cannot operate, and user experience is affected. After the air conditioner controller with the IGBT fault is disassembled and analyzed, the situation that only the IGBT is damaged is found to be very many, other components and parts have no problem, and the air conditioner can normally run after the qualified IGBT is replaced.
The commonly used protection circuit obtains a sampling signal through resistance sampling, then transmits the sampling signal to a chip for judgment after being amplified by an operational amplifier, and then switches off and controls PWM (Pulse Width Modulation) of PFC through the chip.
SUMMERY OF THE UTILITY MODEL
The utility model provides a problem be that the protection mechanism of the IGBT of current PFC circuit delays longer, and IGBT's damage risk is high.
In order to solve the above problems, the present invention provides a short circuit protection circuit of a PFC circuit, which includes a hall sensor sub-circuit, a comparator sub-circuit and a unidirectional conducting sub-circuit; the Hall sensor sub-circuit comprises a Hall sensor, a current input end and a current output end of the Hall sensor are connected in series with a power supply branch of the IGBT, and a signal output end is connected with the comparator sub-circuit; the signal output end outputs a high level under the condition that the collected current is greater than or equal to a set value, and outputs a low level under the condition that the collected current is less than the set value; the comparator sub-circuit comprises a divider resistor and a comparator, a first input end of the comparator is connected with the signal output end, the divider resistor is connected between a second input end of the comparator and working voltage, and an output end of the comparator is connected with the one-way conduction sub-circuit; the output end of the comparator outputs a low level when the high level is greater than or equal to a voltage reference value, and outputs a high level when the low level is less than the voltage reference value; the unidirectional conduction sub-circuit comprises a unidirectional conduction element, the unidirectional conduction element is connected between the output end of the comparator and the control end of the IGBT, and is reversely cut off under the condition that the comparator outputs a high level and is conducted under the condition that the comparator outputs a low level.
The embodiment of the utility model provides an adopt the mode collection of hall sensor access IGBT branch road to flow through the current signal of IGBT, compare this current signal and voltage reference value through the comparator to based on the break-make of comparison result output high-low level control one-way conduction element, thereby whether control IGBT switches off, collection wherein and judgement link still less, response speed is faster, can reduce the damage risk of IGBT effectively, reduces the use failure rate.
Optionally, a current input end of the hall sensor is connected with a first output end of the power supply circuit, and a current output end of the hall sensor is connected with a collector of the IGBT; and the emitter of the IGBT is connected with the second output end of the power supply circuit.
The embodiment of the utility model provides a, in the power supply branch road of connecting into IGBT with hall sensor's current input/output end to effectively accurate current signal who gathers IGBT.
Optionally, the voltage dividing resistor includes a first voltage dividing resistor and a second voltage dividing resistor, and the first voltage dividing resistor and the second voltage dividing resistor are connected in series and connected between the operating voltage and the ground; the second input end of the comparator is connected between the first voltage-dividing resistor and the second voltage-dividing resistor.
The embodiment of the utility model provides a through the resistance that sets up first divider resistance and second divider resistance to change operating voltage through voltage reduction amplitude between them, with the voltage regulation of position between the two to the voltage reference value that is fit for the comparator and uses.
Optionally, the unidirectional conducting element is a diode; and the cathode of the diode is connected with the output end of the comparator, and the anode of the diode is connected with the gate pole of the IGBT.
The embodiment of the utility model provides a under the condition of comparator output low level, IGBT's gate pole is drawn to the low level to effectively turn off IGBT.
Optionally, the hall sensor sub-circuit further comprises a third resistor and a first capacitor; the third resistor is connected in series between the signal output end and the first input end of the comparator, one end of the first capacitor is connected between the third resistor and the first input end of the comparator, and the other end of the first capacitor is grounded.
The embodiment of the utility model provides an in this third resistance and first electric capacity can play protection and noise reduction effect.
Optionally, the first input end of the comparator is an inverting input end, and the second input end of the comparator is a non-inverting input end; the positive power input end of the comparator is connected with working voltage, and the negative power input end of the comparator is grounded.
The embodiment of the utility model provides an in syntropy input, the reverse input of comparator are input voltage reference value, hall sensor's output level respectively, confirm through comparing both that whether electric current sharply increases the trouble such as short circuit appears in the IGBT branch road to and turn off IGBT in time.
Optionally, the comparator sub-circuit further comprises a second capacitance; the second capacitor is connected in parallel with the second voltage-dividing resistor.
The embodiment of the utility model provides an in the comparator sub-circuit can also include the second electric capacity, play the protection and fall the effect of making an uproar.
Optionally, the unidirectional conducting sub-circuit further comprises a fourth resistor; the fourth resistor is connected between the cathode of the diode and the output end of the comparator.
The embodiment of the utility model provides an in one-way conduction sub-circuit can also include the fourth resistance, plays the guard action.
The utility model provides a PFC circuit, including above-mentioned arbitrary one PFC circuit's short-circuit protection circuit.
The utility model provides an air conditioner, including foretell PFC circuit.
The utility model provides a PFC circuit and air conditioner can reach the same technological effect with the short-circuit protection circuit of above-mentioned PFC circuit.
Drawings
Fig. 1 is a schematic structural diagram of a short-circuit protection circuit of a PFC circuit according to an embodiment of the present invention.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.
The embodiment of the utility model provides a to PFC circuit short circuit fault's damage IGBT's problem, provide a protection scheme, based on Hall current sensor detection IGBT's electric current, when short circuit or similar abnormal conditions appear, just trigger protection circuit the first moment, can accomplish the protection (drawing down IGBT's drive signal) in short time, avoid appearing damaging IGBT's the condition, treat the trouble and remove, the PFC circuit can continue normal work.
The embodiment of the utility model provides a short-circuit protection circuit of PFC circuit, including hall sensor sub-circuit, comparator sub-circuit and one-way conduction sub-circuit.
The Hall sensor sub-circuit comprises a Hall sensor, and a current input end and a current output end of the Hall sensor are connected in series with a power supply branch of the IGBT and used for sampling the current change degree flowing through the IGBT. And the signal output end of the Hall sensor is connected with the comparator sub-circuit. Specifically, the signal output end of the hall sensor outputs a high level when the collection current is greater than or equal to a set value, and outputs a low level when the collection current is less than the set value. The acquisition current may be an absolute value of the current or a variation value of the current, for example.
The comparator sub-circuit comprises a divider resistor and a comparator, wherein a first input end of the comparator is connected with a signal output end, the divider resistor is connected between a second input end of the comparator and working voltage, and an output end of the comparator is connected with the one-way conduction sub-circuit. The purpose of the voltage dividing resistor is to divide the operating voltage to obtain a voltage reference value for comparison with the output level of the hall sensor, i.e., the input of the comparator is the voltage reference value and the output level of the hall sensor.
The output end of the comparator outputs a low level when the high level is larger than or equal to the voltage reference value, and outputs a high level when the low level is smaller than the voltage reference value.
The unidirectional conduction sub-circuit comprises a unidirectional conduction element, the unidirectional conduction element is connected between the output end of the comparator and the control end of the IGBT, the unidirectional conduction element is reversely cut off under the condition that the comparator outputs a high level, and the unidirectional conduction sub-circuit is conducted under the condition that the comparator outputs a low level.
The embodiment of the utility model provides a short-circuit protection circuit of PFC circuit adopts the mode collection that hall sensor inserts the IGBT branch road to flow through the current signal of IGBT, through this current signal of comparator and voltage reference value to based on the break-make of comparison result output high-low level control one-way conduction element, thereby control IGBT whether turn-offs, wherein collection and judgement link still less, response speed is faster, can reduce IGBT's damage risk effectively, reduce the service failure rate.
Illustratively, the current input end of the hall sensor is connected with the first output end of the power supply circuit, the current output end of the hall sensor is connected with the collector of the IGBT, and the emitter of the IGBT is connected with the second output end of the power supply circuit. Based on the connection mode, the current input/output end of the Hall sensor is connected into the power supply branch of the IGBT, so that the current signal of the IGBT is effectively and accurately acquired.
Illustratively, the voltage dividing resistor comprises a first voltage dividing resistor and a second voltage dividing resistor, and the first voltage dividing resistor and the second voltage dividing resistor are connected in series and are connected between the working voltage and the ground; the second input end of the comparator is connected between the first voltage-dividing resistor and the second voltage-dividing resistor. The resistance values of the first voltage-dividing resistor and the second voltage-dividing resistor are set, so that the voltage reduction amplitude of the working voltage passing through the first voltage-dividing resistor and the second voltage-dividing resistor is changed, and the voltage at the position between the first voltage-dividing resistor and the second voltage-dividing resistor is adjusted to be a voltage reference value suitable for the comparator.
Illustratively, the unidirectional conducting element may be a diode, a cathode of the diode is connected to the output terminal of the comparator, and an anode of the diode is connected to the gate of the IGBT. In the case where the comparator outputs a low level, the gate of the IGBT is pulled to a low level, thereby effectively turning off the IGBT. It should be noted that other elements having forward on and reverse off performances may also be adopted, and this embodiment is not limited thereto.
Further, the hall sensor sub-circuit may further include a third resistor and a first capacitor; the third resistor is connected in series between the signal output end and the first input end of the comparator, one end of the first capacitor is connected between the third resistor and the first input end of the comparator, and the other end of the first capacitor is grounded. The third resistor and the first capacitor can play a role in protecting and reducing noise.
Specifically, the first input terminal of the comparator is an inverting input terminal, and the second input terminal of the comparator is a homodromous input terminal; the positive power input end of the comparator is connected with working voltage, and the negative power input end of the comparator is grounded. The same-direction input end and the reverse-direction input end of the comparator are respectively used for inputting a voltage reference value and an output level of the Hall sensor, whether the IGBT branch circuit has a current sharp increase fault such as short circuit or not is determined by comparing the voltage reference value and the output level, and the IGBT is turned off in time.
The comparator sub-circuit can also comprise a second capacitor which is connected with the second voltage-dividing resistor in parallel and plays roles of protection and noise reduction.
Furthermore, the unidirectional conducting sub-circuit can further comprise a fourth resistor, and the fourth resistor is connected between the cathode of the diode and the output end of the comparator to play a role in protection.
Referring to fig. 1, the embodiment of the present invention provides a schematic structural diagram of a short-circuit protection circuit of a PFC circuit, showing a power supply circuit 10 and a short-circuit protection circuit 20, where the short-circuit protection circuit 20 is composed of three segments: hall sensor sub-circuit, comparator sub-circuit and one-way conduction sub-circuit.
Fig. 1 shows a rectifier bridge BG1, an inductor L1, an IGBT1, a comparator U1A, a hall current sensor IC1, diodes D1, D2, resistors R1 to R6, and a zener diode ZD1.
The Hall sensor circuit is used for connecting the current part of the Hall sensor IC1 into an IGBT branch circuit in series, the Hall sensor samples the current change degree, when the current is greater than a set value di/dt, OUT1 outputs high level, and when the current is less than the set value di/dt, OUT1 outputs low level;
comparator circuit, R1 and R2 divide the voltage to provide a reference value U for the comparator Datum When the Hall OUT1 outputs a low level or outputs a level lower than a reference value U1, the comparator outputs a high level, and when the Hall OUT1 outputs a level higher than the reference value U1, the comparator outputs a low level;
and the diode D2 is reversely cut off when the comparator outputs a high level, and the diode D2 is forwardly conducted when the comparator outputs a low level, so that the driving gate pole of the IGBT is pulled to the low level, and the IGBT can be effectively turned off.
Under normal operating conditions: current I through IGBT General of The Hall sensor outputs U after passing through the Hall sensor (5 feet in and 4 feet out) out At a low level, U out If the reference voltage is less than the U reference, the output voltage of the comparator U, the comparator is in a high level, the diode D2 is cut off in a reverse direction, and the Vgs voltage (PWM input) of the IGBT is not applied;
in the case of an abnormality such as a short circuit: current through IGBT is from I General rule Increase rapidly to I Short circuit Hall sensor output U out Is at a high level, U out ＞U Datum The comparator output voltage Ucomparator is low level, the diode D2 is conducted in forward direction, the Vgs voltage of the IGBT is pulled down, and meanwhile the main chip receives the U out At low, the PWM is turned off and the IGBT is no longer driven.
Wherein, I General of The current is the current passing through the IGBT when the PFC works normally; i is Short circuit The current passes through the IGBT under the abnormal conditions of short circuit of PFC or strong interference and the like; u shape out The voltage output by the Hall sensor is connected with the inverting input end of the comparator; u shape Datum Dividing voltage of VCC for R2 and R3, and connecting to positive phase input end of comparator; u shape Comparator with a comparator circuit Outputting a voltage for the comparator; vgs is the IGBT gate input voltage, and the chip input PWM is a square wave with alternating high and low levels.
The following describes an execution flow of the short-circuit protection circuit of the PFC circuit:
1. starting an air conditioner;
2. keeping normal operation;
3. and judging whether the IGBT current di/dt reaches a set value or not. If yes, executing step 4, if no, executing step 8;
4. the Hall sensor outputs a high level;
5. the comparator outputs a low level;
6. the diode forward direction conducts the chip to turn off PWM;
vgs of the IGBT is low level, and the IGBT enters a protection state;
8. the Hall sensor outputs a low level;
9. the comparator outputs high level;
10. the diode is turned off in the reverse direction.
The utility model provides an above-mentioned PFC short-circuit protection circuit, short-circuit signal are few through the link, and response speed is faster, can effectual reduction IGBT's fault rate, reduce the number of times of reprocessing after sale, improve user experience and reduce the relevant loss after sale.
The embodiment of the utility model provides a still provide a PFC circuit, including the short-circuit protection circuit of above-mentioned PFC circuit.
The embodiment of the utility model provides an air conditioner is still provided, including above-mentioned PFC circuit. The PFC circuit is one of basic unit circuits of an outdoor unit controller of the variable frequency air conditioner, is usually arranged on a main power loop of an outdoor unit of the variable frequency air conditioner, can improve the power factor of the air conditioner, avoids the adverse effect of factors such as phase difference between current and voltage on the air conditioner, greatly improves the utilization rate of a power grid, and reduces harmonic pollution of the power grid.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present invention, and the scope of the present invention is defined by the appended claims.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present invention, and the scope of the present invention is defined by the appended claims.
Claims (10)
1. A short-circuit protection circuit of a PFC circuit is characterized by comprising a Hall sensor sub-circuit, a comparator sub-circuit and a one-way conduction sub-circuit;
the Hall sensor sub-circuit comprises a Hall sensor, a current input end and a current output end of the Hall sensor are connected in series with a power supply branch of the IGBT, and a signal output end is connected with the comparator sub-circuit; the signal output end outputs a high level under the condition that the collected current is greater than or equal to a set value, and outputs a low level under the condition that the collected current is less than the set value;
the comparator sub-circuit comprises a divider resistor and a comparator, a first input end of the comparator is connected with the signal output end, the divider resistor is connected between a second input end of the comparator and working voltage, and an output end of the comparator is connected with the one-way conduction sub-circuit; the output end of the comparator outputs a low level when the high level is greater than or equal to a voltage reference value, and outputs a high level when the low level is less than the voltage reference value;
the unidirectional conduction sub-circuit comprises a unidirectional conduction element, the unidirectional conduction element is connected between the output end of the comparator and the control end of the IGBT, and is reversely cut off under the condition that the comparator outputs a high level and is conducted under the condition that the comparator outputs a low level.
2. The short-circuit protection circuit of the PFC circuit of claim 1, wherein a current input terminal of the hall sensor is connected to a first output terminal of a power supply circuit, and a current output terminal of the hall sensor is connected to a collector of the IGBT;
and the emitter of the IGBT is connected with the second output end of the power supply circuit.
3. The short-circuit protection circuit of claim 1, wherein the voltage dividing resistor comprises a first voltage dividing resistor and a second voltage dividing resistor, the first voltage dividing resistor and the second voltage dividing resistor are connected in series and connected between the operating voltage and the ground;
the second input end of the comparator is connected between the first voltage-dividing resistor and the second voltage-dividing resistor.
4. The short-circuit protection circuit of the PFC circuit of claim 1, wherein the unidirectional conducting element is a diode; and the cathode of the diode is connected with the output end of the comparator, and the anode of the diode is connected with the gate pole of the IGBT.
5. The short-circuit protection circuit of the PFC circuit of claim 2, wherein the hall sensor sub-circuit further comprises a third resistor and a first capacitor; the third resistor is connected in series between the signal output end and the first input end of the comparator, one end of the first capacitor is connected between the third resistor and the first input end of the comparator, and the other end of the first capacitor is grounded.
6. The short-circuit protection circuit of claim 3, wherein the first input terminal of the comparator is an inverting input terminal, and the second input terminal of the comparator is a non-inverting input terminal;
the positive power input end of the comparator is connected with working voltage, and the negative power input end of the comparator is grounded.
7. The short-circuit protection circuit of a PFC circuit of claim 3, wherein the comparator sub-circuit further comprises a second capacitor;
the second capacitor is connected in parallel with the second divider resistor.
8. The short-circuit protection circuit of the PFC circuit of claim 4, wherein the unidirectional conducting sub-circuit further comprises a fourth resistor; the fourth resistor is connected between the cathode of the diode and the output end of the comparator.
9. A PFC circuit comprising the short circuit protection circuit of any one of claims 1-8.
10. An air conditioner comprising the PFC circuit of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221455897.3U CN217956672U (en) | 2022-06-10 | 2022-06-10 | Short-circuit protection circuit of PFC circuit, PFC circuit and air conditioner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221455897.3U CN217956672U (en) | 2022-06-10 | 2022-06-10 | Short-circuit protection circuit of PFC circuit, PFC circuit and air conditioner |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217956672U true CN217956672U (en) | 2022-12-02 |
Family
ID=84216712
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221455897.3U Active CN217956672U (en) | 2022-06-10 | 2022-06-10 | Short-circuit protection circuit of PFC circuit, PFC circuit and air conditioner |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217956672U (en) |
-
2022
- 2022-06-10 CN CN202221455897.3U patent/CN217956672U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103033769B (en) | Fault detection method of three-phase power supply | |
| CN101414748B (en) | Method for starting control circuit and protecting power supply control chip | |
| US10638551B2 (en) | Electromagnetic heating control circuit and electromagnetic heating device | |
| US8422249B2 (en) | Apparatus for a microinverter particularly suited for use in solar power installations | |
| CN103219705B (en) | The short-circuit protection method of half bridge resonant transformer and device | |
| WO2017088799A1 (en) | Switch-mode power supply and control apparatus of the same | |
| US10644614B2 (en) | Conversion device having a control unit for detecting arm short-circuit | |
| CN103475217A (en) | DC-DC circuit and overcurrent protection method thereof | |
| CN204014137U (en) | Possesses the cooking equipment of overcurrent protection function | |
| EP1995870A1 (en) | Earth-fault detecting method | |
| US20230135870A1 (en) | Method of controlling input voltage | |
| US8674667B2 (en) | Post regulation control circuit | |
| US9515576B2 (en) | Short circuit detection in a capacitor of a DC-bridge and DC-bridge protection | |
| CN217956672U (en) | Short-circuit protection circuit of PFC circuit, PFC circuit and air conditioner | |
| CN114512961A (en) | Self-adaptive protection design method suitable for deep space sampling high-power direct current motor limit condition | |
| CN114123755A (en) | Method for detecting fault of PFC circuit, PFC circuit and air conditioner | |
| CN210007614U (en) | Drive control circuit and household electrical appliance | |
| CN108808627A (en) | A kind of controller | |
| CN208638018U (en) | A kind of controller | |
| CN110932236A (en) | Overcurrent open-phase detection protection circuit and method and compressor comprising circuit | |
| CN205453078U (en) | Current foldback circuit and constant voltage power supply | |
| CN107134754B (en) | Output overvoltage protection method and device of power supply parallel operation system | |
| CN112398384B (en) | Control device for direct current motor | |
| US10602601B2 (en) | Creeping discharge element drive device and creeping discharge element drive method | |
| CN209930129U (en) | PFC protection circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |