Protection circuit and protection method for coping with lightning strike event

Abstract

The present application relates to the technical field of power electronics. Provided are a protection circuit and protection method for coping with a lightning strike event. The protection circuit comprises: a detection unit, a power factor correction unit, a comparison unit, an execution unit and a bus capacitor, wherein one end of the detection unit is connected to a live wire, the other end of the detection unit is connected to a grounding wire of the bus capacitor, and the detection unit is configured to output a voltage detection signal to the comparison unit, the voltage detection signal being used for representing a voltage change rate between the live wire and the grounding wire; the comparison unit is connected to an output end of the detection unit and configured to determine, on the basis of the voltage detection signal and a preset voltage threshold value, whether a lightning strike event has occurred in the power factor correction unit; and an input end of the execution unit is connected to an output end of the comparison unit, an output end of the execution unit is connected to the power factor correction unit, and the execution unit is configured to execute, when a lightning strike event occurs, a protection operation on the power factor correction unit until the lightning strike event is eliminated.

Description

A protection circuit and a protection method for coping with lightning strike event TECHNICAL FIELD

[0001] The present application belongs to the technical field of power electronics, in particular to the field of circuit protection, and more particularly to a protection circuit and a protection method for coping with lightning strike event. BACKGROUND

[0002] With the pursuit of high efficiency and high power density of switching power supply, Totem-pole PFC (Totem-pole Power Factor Corrector) structure or active bridge structure is generally used in the industry to replace the traditional diode rectifier bridge structure as shown in FIG. 1, however, in Totem-pole PFC structure or active bridge structure, lightning strike event is easy to occur, resulting in the destruction of devices due to common. At present, by means of current detection, for example, a current detector is arranged in Totem-pole PFC structure or active bridge structure to determine whether the current is greater than a preset current threshold, so as to determine whether the device is common due to the existence of lightning strike event.

[0003] However, the above-mentioned current detection method is affected by the bandwidth of the current detector in terms of speed; the accuracy is affected by the setting of the preset current threshold, because the common event is only one of the reasons for the increase of current, if the preset current threshold is set too low, it is easy to misjudge, and the increase of current caused by other reasons is judged as a common event; if the preset current threshold is set too high, although it can reduce the probability of misjudgment, the cost is that in the common event, the device will withstand a larger impact. Therefore, there is an urgent need for a protection circuit and a protection method for coping with lightning strike event. SUMMARY

[0004] In view of at least one problem existing in the prior art, the present application provides a protection circuit and a protection method for coping with lightning strike event, which can accurately detect and handle lightning strike event, and improve the safety of the circuit.

[0005] According to a first aspect of the present application, a protection circuit for coping with lightning strike event is provided, comprising a detection unit, a power factor correction unit, a comparison unit, an execution unit and a bus capacitor, wherein:

[0006] One end of the detection unit is connected with a live wire, and the other end of the detection unit is connected with a ground wire of the bus capacitor, for outputting a voltage detection signal to the comparison unit, wherein the voltage detection signal is used to represent the voltage change rate between the live wire and the ground wire;

[0007] The comparison unit is connected with the output end of the detection unit, for determining whether the power factor correction unit occurs lightning strike event according to the voltage detection signal and a preset voltage threshold.

[0008] An output end of the execution unit is connected with an output end of the comparison unit, and an input end of the power factor correction unit is connected with the output end of the execution unit, so as to execute a protection operation on the power factor correction unit until the lightning strike event is eliminated when the lightning strike event occurs.

[0009] In some optional modes of the embodiment, the detection unit comprises a detection capacitor and a detection resistor, and the voltage detection signal is used to represent a detection voltage between the detection resistor, wherein:

[0010] A first end of the detection capacitor is connected with the live wire, and a first end of the detection resistor is connected with a second end of the detection capacitor;

[0011] A second end of the detection resistor is grounded, and an output end of the detection unit is arranged between the second end of the detection capacitor and the first end of the detection resistor.

[0012] In some optional modes of the embodiment, a positive input end of the comparison unit is connected with the output end of the detection unit, so as to receive the voltage detection signal, and a negative input end of the comparison unit is used to input the preset voltage threshold value;

[0013] When the detection voltage is greater than the preset voltage threshold value, the comparison unit is specifically used to determine that the lightning strike event occurs in the power factor correction unit, and outputs a high-level signal to the execution unit;

[0014] When the detection voltage is less than or equal to the preset voltage threshold value, the comparison unit is specifically used to determine that the lightning strike event does not occur in the power factor correction unit, and outputs a low-level signal to the execution unit.

[0015] In some optional modes of the embodiment, the power factor correction unit comprises a first diode, a second diode, an inductor, a first power tube, a second power tube, a third power tube and a fourth power tube, wherein:

[0016] A positive electrode of the first diode is connected with a first end of the inductor and a negative electrode of the second diode;

[0017] A negative electrode of the first diode is connected with a drain electrode of the first power tube, a drain electrode of the third power tube and a first end of the bus capacitor;

[0018] A negative electrode of the second diode, a source electrode of the second power tube, a source electrode of the fourth power tube and a second end of the bus capacitor are grounded;

[0019] A source electrode of the first power tube and a drain electrode of the second power tube are connected with a second end of the inductor.

[0020] a gate of the third power transistor and a gate of the fourth power transistor are connected with an output terminal of the execution unit;

[0021] wherein, a positive pole of the first diode and a first end of the inductor are connected with the live line; a source of the third power transistor and a drain of the fourth power transistor are connected with the zero line.

[0022] In some optional modes of the embodiment, the execution unit is a NOT gate circuit, wherein:

[0023] an input terminal of the NOT gate circuit is connected with an output terminal of the comparison unit, for receiving the high-level signal or the low-level signal; an output terminal of the NOT gate circuit is connected with the gate of the third power transistor and the gate of the fourth power transistor, for outputting a gate control signal to the third power transistor and the fourth power transistor.

[0024] In some optional modes of the embodiment, the execution unit is specifically used for:

[0025] generating the gate control signal according to the high-level signal;

[0026] turning off the third power transistor and the fourth power transistor within a preset time according to the gate control signal, until the lightning strike event is eliminated.

[0027] In some optional modes of the embodiment, the transistor types of the first power transistor, the second power transistor, the third power transistor and the fourth power transistor are NMOS.

[0028] According to a second aspect of the present application, a protection method for coping with lightning strike event based on the foregoing protection circuit is also provided, comprising:

[0029] the detection unit outputs a voltage detection signal to the comparison unit, wherein the voltage detection signal is used to represent a voltage change rate between the live line and the ground line;

[0030] the comparison unit determines whether the power factor correction unit has a lightning strike event according to the voltage detection signal and a preset voltage threshold value;

[0031] when the lightning strike event occurs, the execution unit performs a protection operation on the power factor correction unit until the lightning strike event is eliminated.

[0032] In some optional modes of the embodiment, the comparison unit determines whether the power factor correction unit has a lightning strike event according to the voltage detection signal and a preset voltage threshold value, comprising:

[0033] When the detection voltage corresponding to the voltage detection signal is greater than the preset voltage threshold, the comparison unit determines that the power factor correction unit has a lightning strike event, and outputs a high-level signal to the execution unit;

[0034] When the detection voltage corresponding to the voltage detection signal is less than or equal to the preset voltage threshold, the comparison unit determines that the power factor correction unit does not have a lightning strike event, and outputs a low-level signal to the execution unit.

[0035] In some optional manners of the embodiment, the execution unit performs a protection operation on the power factor correction unit until the lightning strike event is eliminated, and the protection operation includes:

[0036] The execution unit generates a gate control signal according to the high-level signal;

[0037] The execution unit turns off the third power tube and the fourth power tube according to the gate control signal within a preset time until the lightning strike event is eliminated.

[0038] The protection circuit and the protection method for coping with a lightning strike event provided in the application can detect a lightning strike event in time by comparing a detection voltage with a preset voltage threshold, and can turn off a slow bridge arm power tube after the lightning strike event occurs, thereby improving the safety of a circuit. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0040] FIG. 1 is a schematic diagram of a diode rectifier bridge structure in the prior art;

[0041] FIG. 2 is a schematic diagram of a protection circuit for coping with a lightning strike event according to an embodiment of the present application;

[0042] FIG. 3 is a voltage schematic diagram of a positive half cycle and a negative half cycle according to an embodiment of the present application;

[0043] FIG. 4 is a circuit flow schematic diagram of a power factor correction unit in a positive half cycle when it works normally according to an embodiment of the present application;

[0044] FIG. 5 is a circuit flow schematic diagram of a power factor correction unit in a negative half cycle when it works normally according to an embodiment of the present application;

[0045] FIG. 6 is a detection current / voltage and V of a power factor correction unit when it works normally according to an embodiment of the present application;L a waveform diagram of the voltage detection signal Detection;

[0046] Fig. 7 is a waveform diagram of the detection current / voltage and V L a waveform diagram of the voltage detection signal Detection;

[0047] Fig. 8 is a block diagram of a protection method for coping with a lightning strike event according to an embodiment of the present application. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0049] To solve at least one problem proposed in the background section, one embodiment of the present application provides a protection circuit for coping with a lightning strike event, as shown in Fig. 2, which includes a detection unit 1, a power factor correction unit 2, a comparison unit 3, an execution unit 4 and a bus capacitor C bus , wherein:

[0050] One end of the detection unit 1 is connected with a firewire, and the other end of the detection unit 1 is connected with a ground wire of the bus capacitor C bus , for outputting a voltage detection signal Detection to the comparison unit 3, wherein the voltage detection signal Detection is used to represent a voltage change rate between the firewire and the ground wire;

[0051] The comparison unit 3 is connected with an output end of the detection unit 1, for determining whether a lightning strike event occurs to the power factor correction unit 2 according to the voltage detection signal Detection and a preset voltage threshold V ref ;

[0052] An input end of the execution unit 4 is connected with an output end of the comparison unit 3, and an output end of the execution unit 4 is connected with the power factor correction unit 2, for performing a protection operation on the power factor correction unit 2 when the lightning strike event occurs, until the lightning strike event is eliminated.

[0053] In the embodiment, as shown in Fig. 2, the power factor correction unit 2 includes a first diode D1, a second diode D2, an inductor l, a first power tube Q1, a second power tube Q2, a third power tube Q3 and a fourth power tube Q4, wherein:

[0054] The positive electrode of the first diode D1 is connected with the first end of the inductor l and the negative electrode of the second diode D2; the negative electrode of the first diode D1 is connected with the drain of the first power tube Q1, the drain of the third power tube Q3 and the first end of the bus capacitor Cbus; the negative electrode of the second diode D2, the source of the second power tube Q2, the source of the fourth power tube Q4 and the second end of the bus capacitor Cbus are grounded; the source of the first power tube Q1 and the drain of the second power tube Q2 are connected with the second end of the inductor l; the gate of the third power tube Q3 and the gate of the fourth power tube Q4 are connected with the output end of the execution unit 4; wherein the positive electrode of the first diode D1 and the first end of the inductor l are connected with the live wire L; the source of the third power tube Q3 and the drain of the fourth power tube are connected with the neutral wire N.

[0055] In some optional modes of the embodiment, the transistor types of the first power tube Q1, the second power Q2, the third power tube Q3 and the fourth power tube Q4 are NMOS.

[0056] In the embodiment, during the normal working of the positive half cycle of the power frequency, the third power tube Q3 of the slow bridge arm is turned on, and during the working of the negative half cycle of the power frequency, the fourth power tube Q4 of the slow bridge arm is turned on. If a reverse lightning surge event occurs during the normal working process, a double-tube common event will be triggered, causing the device to be damaged.

[0057] The reverse lightning surge event refers to that, as shown in FIG. 3, during the working of the positive half cycle of the power frequency, a negative lightning surge occurs, causing the input voltage to suddenly reverse; during the working of the negative half cycle of the power frequency, a positive lightning surge occurs, causing the input voltage to suddenly reverse.

[0058] The double-tube common event refers to that, as shown in FIG. 4, during the working of the positive half cycle of the power frequency, the second diode D2 and the third power tube Q3 are common due to the occurrence of the negative lightning surge; as shown in FIG. 5, during the working of the negative half cycle of the power frequency, the first diode D1 and the fourth power tube Q4 are common due to the occurrence of the positive lightning surge.

[0059] Based on this, as shown in FIG. 2, a detection unit 1 is introduced to detect the lightning surge event occurring on the neutral wire N and the live wire L, wherein the detection unit 1 comprises a detection capacitor C sense and a detection resistor R sense , and the end of the detection resistor R sense away from the detection capacitor C sense is grounded. It should be noted that the detection capacitor C sense and the detection resistor R sense constitute a resistance-capacitance network, and the number of the detection capacitor C sense and the detection resistor R sense is exemplary, which can also be multiple detection resistors Rsense and a plurality of detection capacitances C sense The resistance-capacitance network is formed in series and parallel, which is not limited in the application.

[0060] In some optional modes of the embodiment, as shown in FIG. 2, the detection unit 1 comprises a detection capacitance C sense and a detection resistance R sense The voltage detection signal Detection is used to represent the detection voltage across the detection resistance, wherein:

[0061] The first end of the detection capacitance C sense is connected to the live wire, and the second end of the detection capacitance C sense is connected to the first end of the detection resistance R sense .

[0062] The second end of the detection resistance R sense is grounded, and the output end of the detection unit is arranged between the second end of the detection capacitance and the first end of the detection resistance.

[0063] Specifically, in the application, the parameters of the resistance-capacitance network are reasonably selected to ensure that the impedance of the detection capacitance C sense is much larger than that of the detection resistance R sense (for example, between 10 times and 1000 times), so that the current flowing through the resistance-capacitance network is determined by the capacitance and can be expressed as:

[0064] Wherein, V L is the voltage of the L line to ground.

[0065] I detect flows through R sense The expression of the voltage detection signal Detection generated thereby is as follows:

[0066] Wherein, the voltage detection signal Detection is used to represent the detection voltage across the detection resistance.

[0067] As can be seen from formula (2), the size of the detection signal Detection is determined by the slope of the voltage V L . In normal operation, the waveform of V L is shown in FIG. 6, in which there are two voltage slopes: one is the power frequency sine slope K1 caused by the sine voltage itself; and the other is the slope K2 caused by the switching of the slow bridge arm near the zero point of the power frequency voltage. Obviously, the power frequency sine slope K1 is a relatively small slope, and the slow bridge arm switching slope K2 will be larger than K1, but the size of K2 can be set through control. FIG. 6 can also be regarded as the waveform of I detect corresponding to the slopes K1 and K2.

[0068] Specifically, at the K2 zero-crossing point, the duty cycle of the left bridge arm Q1 and Q2 can be controlled to achieve the above-mentioned purpose. Generally, in order to reduce the input current peak caused by the switching of the slow bridge arm and for the purpose of reducing common-mode noise, the switching process of the slow bridge arm is set in the range of >100uS, and thus the upper limit of the slope K2 can also be determined.

[0069] When a lightning surge event occurs, as shown in FIG. 7, the voltage change slope K3 caused thereby will be much greater than K2 and K1. Thus, by reasonably setting the threshold size of the detection signal Detection (i.e., the threshold V ref of the resistance voltage Detection detected during normal operation), the lightning surge event can be effectively and quickly detected, so that protective measures can be taken, that is, after detecting the lightning surge event, the right bridge arm Q3 and Q4 (i.e., Q3 and Q4) are simultaneously turned off to be disconnected.

[0070] Specifically, in some optional manners of the embodiment, as shown in FIG. 2, the positive input end of the comparison unit 3 is connected with the output end of the detection unit 1, for receiving the voltage detection signal Detection; and the negative input end of the comparison unit 3 is used for inputting the preset voltage threshold V ref .

[0071] When the detection voltage is greater than the preset voltage threshold V ref , the comparison unit is specifically configured to determine that the power factor correction unit has a lightning surge event, and output a high-level signal to the execution unit;

[0072] When the detection voltage is less than or equal to the preset voltage threshold V ref , the comparison unit is specifically configured to determine that the power factor correction unit does not have a lightning surge event, and output a low-level signal to the execution unit.

[0073] In some optional manners of the embodiment, as shown in FIG. 2, the execution unit is a NOT gate circuit, wherein:

[0074] The input end of the NOT gate circuit is connected with the output end of the comparison unit, for receiving the high-level signal or the low-level signal; and the output end of the NOT gate circuit is connected with the gate of the third power tube Q3 and the gate of the fourth power tube Q4, for outputting a gate control signal to the third power tube Q3 and the fourth power tube Q4.

[0075] In some alternative manners of the embodiment, the execution unit is specifically configured to: generate the gate control signal according to the high-level signal; and turn off the third power tube and the fourth power tube for a preset time according to the gate control signal until the lightning stroke event is eliminated.

[0076] It should be noted that in the present application, after the lightning stroke event occurs, whether it is a reverse lightning stroke event or a forward lightning stroke event, the size of the detection signal Detection will exceed the safe range, and the measure of closing the slow bridge arm power tube is taken, which can play a protective role. Here, no measures are taken to distinguish between reverse lightning and forward lightning, because doing so will increase the complexity of the circuit. Although forward lightning can not necessarily close the power tube of the slow bridge arm, in order to simplify the circuit, the measure of closing the power tube of the slow bridge arm when all lightning stroke events occur can play a protective role without any side effects.

[0077] Based on the same inventive concept, the embodiments of the present application also provide a protection method for a protection circuit based on the foregoing embodiments to cope with a lightning stroke event, as described in the following embodiments. Since the principle of the protection method for a protection circuit based on the foregoing embodiments to cope with a lightning stroke event is similar to that of the protection circuit for coping with a lightning stroke event, the implementation of the protection method for a protection circuit based on the foregoing embodiments to cope with a lightning stroke event can be referred to the implementation of the protection circuit for coping with a lightning stroke event, and the repeated parts will not be described again.

[0078] Specifically, as shown in FIG. 8, the protection method for a protection circuit based on the foregoing embodiments to cope with a lightning stroke event includes:

[0079] Step 10, the detection unit outputs a voltage detection signal to the comparison unit, wherein the voltage detection signal is used to represent the voltage change rate between the fire line and the ground line;

[0080] Step 20, the comparison unit determines whether the power factor correction unit has a lightning stroke event according to the voltage detection signal and a preset voltage threshold value;

[0081] Step 30, when the lightning stroke event occurs, the execution unit performs a protection operation on the power factor correction unit until the lightning stroke event is eliminated.

[0082] In some alternative manners of the embodiment, the comparison unit determines whether the power factor correction unit has a lightning stroke event according to the voltage detection signal and a preset voltage threshold value, including:

[0083] When the detection voltage corresponding to the voltage detection signal is greater than the preset voltage threshold value, the comparison unit determines that the power factor correction unit has a lightning stroke event, and outputs a high-level signal to the execution unit.

[0084] When the detection voltage corresponding to the voltage detection signal is less than or equal to the preset voltage threshold, the comparison unit determines that the power factor correction unit does not have a lightning strike event, and outputs a low-level signal to the execution unit.

[0085] In some optional manners of the embodiment, the execution unit performs the protection operation on the power factor correction unit until the lightning strike event is eliminated, and the protection operation includes:

[0086] The execution unit generates a gate control signal according to the high-level signal.

[0087] The execution unit turns off the third power tube and the fourth power tube according to the gate control signal within a preset time until the lightning strike event is eliminated.

[0088] It can be understood that the above examples are only examples for better understanding the technical solutions of the embodiments of the present application, and are not the only limitation of the embodiments of the present application.

[0089] It should be noted that, in the description of the present application, the positions or location relationships indicated by the terms "upper", "lower", etc. are based on the positions or location relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular position, be constructed and operated in a particular position, and therefore cannot be understood as a limitation of the present application. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0090] It should also be noted that, in the description of the present application, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed or inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "including a…" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0091] In the embodiments of the present application, the singular form "a", "an", and "the" include the plural form, should be broadly understood as "one" or "a kind of" and not limited to the meaning of "one"; in addition, the term "said" should be understood to include both the singular form and the plural form, unless the context clearly indicates otherwise. In addition, the term "according to" should be understood as "at least partially according to", and the term "based on" should be understood as "at least partially based on", unless the context clearly indicates otherwise.

[0092] It should be understood that the steps shown above can be reordered, added, or deleted using various forms of flow. For example, the steps described in the present disclosure can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions of the present disclosure can be achieved, which are not limited herein.

[0093] The above specific embodiments do not constitute a limitation on the protection scope of the present disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A protection circuit for responding to lightning strikes, characterized in that, It includes a detection unit, a power factor correction unit, a comparison unit, an execution unit, and a bus capacitor, wherein: One end of the detection unit is connected to the live wire, and the other end of the detection unit is connected to the ground wire of the bus capacitor, for outputting a voltage detection signal to the comparison unit, wherein the voltage detection signal is used to characterize the rate of voltage change between the live wire and the ground wire; The comparison unit is connected to the output terminal of the detection unit and is used to determine whether the power factor correction unit has experienced a lightning strike event based on the voltage detection signal and a preset voltage threshold. The input terminal of the execution unit is connected to the output terminal of the comparison unit, and the output terminal of the execution unit is connected to the power factor correction unit. When the lightning strike event occurs, the execution unit performs a protection operation on the power factor correction unit until the lightning strike event is eliminated.

2. The protection circuit according to claim 1, characterized in that, The detection unit includes a detection capacitor and a detection resistor, and the voltage detection signal is used to characterize the detection voltage across the detection resistor, wherein: The first end of the detection capacitor is connected to the live wire, and the second end of the detection capacitor is connected to the first end of the detection resistor; The second end of the detection resistor is grounded, and the output end of the detection unit is located between the second end of the detection capacitor and the first end of the detection resistor.

3. The protection circuit according to claim 2, characterized in that, The positive input terminal of the comparison unit is connected to the output terminal of the detection unit to receive the voltage detection signal; the negative input terminal of the comparison unit is used to input the preset voltage threshold. When the detected voltage is greater than the preset voltage threshold, the comparison unit is specifically used to determine that a lightning strike event has occurred in the power factor correction unit, and outputs a high-level signal to the execution unit; When the detected voltage is less than or equal to the preset voltage threshold, the comparison unit is specifically used to determine that no lightning strike event has occurred in the power factor correction unit, and outputs a low-level signal to the execution unit.

4. The protection circuit according to claim 3, characterized in that, The power factor correction unit includes a first diode, a second diode, an inductor, a first power transistor, a second power transistor, a third power transistor, and a fourth power transistor, wherein: The positive terminal of the first diode is connected to the first terminal of the inductor and the negative terminal of the second diode; The cathode of the first diode is connected to the drain of the first power transistor, the drain of the third power transistor, and the first terminal of the bus capacitor. The cathode of the second diode, the source of the second power transistor, the source of the fourth power transistor, and the second terminal of the bus capacitor are grounded. The source of the first power transistor and the drain of the second power transistor are connected to the second terminal of the inductor; The gates of the third power transistor and the fourth power transistor are connected to the output terminal of the execution unit. The positive terminal of the first diode and the first end of the inductor are connected to the live wire; the source of the third power transistor and the drain of the fourth power transistor are connected to the neutral wire.

5. The protection circuit according to claim 4, characterized in that, The execution unit is a NOT gate circuit, wherein: The input terminal of the NOT gate is connected to the output terminal of the comparator unit to receive the high-level signal or the low-level signal; the output terminal of the NOT gate is connected to the gate of the third power transistor and the gate of the fourth power transistor to output gate signals to the third power transistor and the fourth power transistor.

6. The protection circuit according to claim 5, characterized in that, The execution unit is specifically used for: The gate control signal is generated based on the high-level signal; According to the gate control signal, the third power transistor and the fourth power transistor are turned off within a preset time until the lightning strike event is eliminated.

7. The protection circuit according to any one of claims 4-6, characterized in that, The first power transistor, the second power transistor, the third power transistor, and the fourth power transistor are all NMOS transistors.

8. A protection method for lightning strike events based on the protection circuit according to any one of claims 1-7, characterized in that, include: The detection unit outputs a voltage detection signal to the comparison unit, wherein the voltage detection signal is used to characterize the rate of voltage change between the live wire and the ground wire; The comparison unit determines whether a lightning strike event has occurred in the power factor correction unit based on the voltage detection signal and a preset voltage threshold. When the lightning strike event occurs, the execution unit performs a protection operation on the power factor correction unit until the lightning strike event is eliminated.

9. The protection method according to claim 8, characterized in that, The comparison unit determines whether a lightning strike event has occurred in the power factor correction unit based on the voltage detection signal and a preset voltage threshold, including: When the detected voltage corresponding to the voltage detection signal is greater than the preset voltage threshold, the comparison unit determines that the power factor correction unit has been struck by lightning and outputs a high-level signal to the execution unit. When the detected voltage corresponding to the voltage detection signal is less than or equal to the preset voltage threshold, the comparison unit determines that no lightning strike event has occurred in the power factor correction unit and outputs a low-level signal to the execution unit.

10. The protection method according to claim 9, characterized in that, The execution unit performs a protection operation on the power factor correction unit until the lightning strike event is eliminated, including: The execution unit generates a gate control signal based on the high-level signal; The execution unit turns off the third power transistor and the fourth power transistor within a preset time according to the gate control signal until the lightning strike event is eliminated.

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