WO2024066988A1

WO2024066988A1 - Lightning strike protection circuit and protection method for power supply

Info

Publication number: WO2024066988A1
Application number: PCT/CN2023/117281
Authority: WO
Inventors: 李文杰; 涂大锐; 曾琦一; 李哲旭; 徐先锋; 崔迎春
Original assignee: 中兴通讯股份有限公司
Priority date: 2022-09-30
Filing date: 2023-09-06
Publication date: 2024-04-04
Also published as: CN117856157A

Abstract

Provided are a lightning strike protection circuit and protection method for a power supply. The circuit comprises: a first current detection circuit (303), a control circuit (304), a first element (301), and a second element (302); a cathode of the first element (301) is coupled to a positive output end (F) of a totem bridgeless PFC circuit; an anode of the first element (301) is coupled to a cathode of the second element (302); and an anode of the second element (302) is coupled to a negative output end (A) of the totem bridgeless PFC circuit. The first current detection circuit (303) is used for detecting a current flowing through the first element (301) and the second element (302) to obtain a first current detection signal, and sending the first current detection signal to the control circuit (304). The control circuit (304) is used for controlling, according to the first current detection signal, a switch tube in the totem bridgeless PFC circuit to be turned off.

Description

Lightning protection circuit and protection method for power supply

This disclosure claims priority to Chinese patent application No. 202211213550.2, filed on September 30, 2022, the entire contents of which are incorporated by reference into this application.

Technical Field

The present disclosure relates to the field of circuit technology, and in particular to a lightning protection circuit and a protection method for a power supply.

Background technique

Totem bridgeless power factor correction (PFC) circuit is widely used in high-power power supplies such as communication power supplies and server power supplies. In order to improve the efficiency of power supply, existing Totem bridgeless PFC circuits usually use insulated gate bipolar transistors (IGBT) or metal-oxide-semiconductor field-effect transistors (MOSFET) with low loss as low-frequency synchronous rectifiers. However, when subjected to reverse lightning strikes, a large lightning current will pass through the Totem bridgeless PFC circuit. If the low-frequency synchronous rectifier cannot be turned off in time, it is easy to cause damage to the low-frequency synchronous rectifier. Therefore, Totem bridgeless PFC input lightning protection technology is becoming more and more important.

Summary of the invention

On the one hand, an embodiment of the present disclosure provides a lightning protection circuit for a power supply. The circuit includes: a first current detection circuit, a control circuit, a first element, and a second element, wherein the cathode of the first element is coupled to the positive output end of the totem bridgeless PFC circuit, the anode of the first element is coupled to the cathode of the second element, the anode of the second element is coupled to the negative output end of the totem bridgeless PFC circuit, the first output end of the first current detection circuit is coupled between the anode of the first element and the cathode of the second element, the input end of the first current detection circuit is coupled to the first power input end of the totem bridgeless PFC circuit, the second output end of the first current detection circuit is coupled to the first input end of the control circuit, the first current detection circuit is used to detect the current flowing through the first element and the second element, obtain a first current detection signal, and send the first current detection signal to the control circuit; the control circuit is used to control the switch tube in the totem bridgeless PFC circuit to turn off according to the first current detection signal.

On the other hand, an embodiment of the present disclosure provides a lightning protection method for a power supply, which is applied to a lightning protection circuit, wherein the lightning protection circuit includes a first current detection circuit, a control circuit, a first element and a second element, wherein a cathode of the first element is coupled to a positive output end of a totem bridgeless PFC circuit, an anode of the first element is coupled to a cathode of the second element, and an anode of the second element is coupled to a negative output end of the totem bridgeless PFC circuit, and the method includes: detecting a current flowing through the first element and the second element to obtain a first current detection signal; and controlling a switch tube in the totem bridgeless PFC circuit to be turned off according to the first current detection signal.

In another aspect, an embodiment of the present disclosure provides a power supply device, which includes: a memory and a processor; the memory and the processor are coupled; the memory is used to store a computer program; and when the processor executes the computer program, the lightning protection method for a power supply described in any of the above embodiments is implemented.

In another aspect, an embodiment of the present disclosure provides a computer-readable storage medium having computer program instructions stored thereon, and when the computer program instructions are executed by a processor, the method for lightning protection of a power supply described in any of the above embodiments is implemented.

In another aspect, an embodiment of the present disclosure provides a computer program product, which includes computer program instructions, and when the computer program instructions are executed by a processor, the method for lightning protection of a power supply described in any of the above embodiments is implemented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a totem bridgeless PFC circuit diagram according to some embodiments;

FIG2 is a system structure block diagram of a lightning protection circuit according to some embodiments;

FIG3 is a schematic diagram of a lightning protection circuit according to some embodiments;

FIG4 is a schematic diagram of another lightning protection circuit according to some embodiments;

FIG5 is a schematic diagram of another lightning protection circuit according to some embodiments;

FIG6 is a schematic diagram of another lightning protection circuit according to some embodiments;

FIG7 is a schematic diagram of a hardware implementation of a lightning protection circuit according to some embodiments;

FIG8 is a schematic diagram of a software implementation of a lightning protection circuit according to some embodiments;

FIG9 is a schematic diagram of a lightning protection circuit of a three-phase input totem bridgeless PFC circuit according to some embodiments;

FIG10 is a schematic diagram of a lightning protection circuit of another three-phase input totem bridgeless PFC circuit according to some embodiments;

FIG. 11 is a schematic flow chart of a lightning protection method according to some embodiments.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, the technical solutions of the present disclosure will be clearly and completely described below in conjunction with the drawings in the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

It should be noted that, in the present disclosure, words such as "exemplarily" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplarily" or "for example" in the present disclosure should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a detailed manner.

In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

In the description of the present disclosure, unless otherwise specified, "/" means "or", for example, A/B can mean A or B. "And/or" in this article is only a way to describe the association relationship of associated objects, indicating that there can be three relationships, for example, A and/or B can mean: only A, only B, and A and B. In addition, "at least one" means one or more, and "plurality" means two or more.

At present, the input voltage between the live wire and the neutral wire at the input end of the totem bridgeless circuit can be detected by using a large resistor voltage divider. When the totem bridgeless PFC circuit is struck by lightning, the voltage of the live wire will increase. When the voltage of the live wire increases, the low-frequency synchronous rectifier can be turned off. However, the sampling delay of the large resistor voltage divider is long, and the low-frequency synchronous rectifier may not be turned off in time. In this case, the low-frequency synchronous rectifier is damaged. Alternatively, the low-frequency synchronous rectifier is turned off by detecting the current flowing through the boost inductor in the totem bridgeless PFC circuit. The current detection value during a lightning strike will be much larger than that during normal operation. However, the boost inductor is in a high impedance state to the current generated by the lightning strike, and the lightning current flowing through the boost inductor will be relatively small. When a lightning strike occurs, the problem of low detection sensitivity will occur.

As the scale of 5G technology usage increases, indoor site power supplies can no longer meet current commercial needs, and high-power outdoor distributed integrated power supplies have emerged. Distributed integrated power supplies are installed on outdoor poles, and the outdoor working environment temperature is particularly high, and it is more susceptible to the risk of large lightning strikes, so the protection level requirements for power supplies are getting higher and higher. As the requirements for power efficiency become higher and higher, the totem bridgeless PFC circuit used in high-power power supplies usually uses IGBT or MOS tubes with low loss as the low-frequency synchronous rectifier tube of the totem bridgeless PFC circuit to improve the efficiency of power use.

Figure 1 shows a totem bridgeless PFC circuit. As shown in Figure 1, the totem bridgeless PFC circuit includes a live line terminal L, a neutral line terminal N, lightning protection diodes D1, D2, D3 and D4, high-frequency switching tubes VT1 and VT2, low-frequency synchronous rectifier tubes VT3 and VT4, an inductor L0 and a capacitor C.

The low-frequency synchronous rectifiers VT3 and VT4 can be diodes or fully controlled switch tubes, which are used to control the on and off of the current in the totem bridgeless PFC circuit, and the capacitor C is used to absorb the energy in the switch circuit. However, when the power supply is struck by reverse lightning, if the low-frequency synchronous rectifiers VT3 and VT4 cannot be turned off in time, they may form a low-impedance path with the lightning protection diodes D1 and D2, causing a large lightning current to pass through the totem bridgeless PFC circuit, thereby damaging the low-frequency synchronous rectifiers VT3 and VT4.

At present, the following three solutions are mainly used to protect the totem bridgeless PFC circuit from lightning strikes.

Solution 1: For indoor site power supply, when the indoor site power supply is subject to the risk of reverse lightning strike, the lightning current flowing through the Totem Bridgeless PFC circuit will be relatively small, and the low-frequency synchronous rectifier of the Totem Bridgeless PFC circuit can withstand the lightning current for a short period of time without being damaged. However, for high-power outdoor distributed integrated power supply, if no treatment is done, the low-frequency synchronous rectifier of the Totem Bridgeless PFC circuit is likely to be damaged.

Solution 2: In response to Solution 1, Solution 2 makes the following improvements: When a reverse lightning strike occurs, the voltage at the input terminal L of the totem bridgeless PFC circuit will increase significantly. By detecting the change in the input voltage between the live terminal L and the neutral terminal N, it is possible to determine whether a lightning strike has occurred, thereby controlling the low-frequency synchronous rectifier to shut down and avoid damage to the totem bridgeless PFC circuit. However, in this solution, the input voltage is usually sampled by resistor voltage division, and the sampling resistor value is usually relatively large, which will cause a long sampling delay problem, and there is a risk that the low-frequency synchronous rectifier may not be able to shut down in time.

Solution 3: When a reverse lightning strike occurs, a small portion of the lightning current will also flow through the boost inductor in the Totem Bridgeless PFC circuit. By detecting whether there is current flowing through the boost inductor, it is possible to determine whether a lightning strike has occurred, thereby controlling the shutdown of the low-frequency synchronous rectifier. However, when a lightning strike occurs, the detected current value is usually much larger than the current during normal operation of the Totem Bridgeless PFC circuit, and the boost inductor L0 is a high impedance, which will cause the lightning current passing through the boost inductor L0 to be relatively small, and it is impossible to accurately determine whether a reverse lightning strike has occurred at this time, that is, the detection sensitivity is not high enough.

Therefore, it is necessary to add a new protection technology to the totem bridgeless PFC circuit to improve the lightning protection effect of the totem bridgeless PFC circuit, thereby bringing better user experience to users.

Based on this, in the embodiment of the present disclosure, a current detection circuit is connected in series in the loop formed by the lightning protection diodes D1, D2, D3 and D4 in the totem bridgeless PFC circuit in FIG1, and the current detection circuit determines whether there is a lightning strike by detecting the current flowing through the lightning protection diode. When a lightning strike occurs, the low-frequency synchronous rectifier tube is quickly turned off by hardware or software to avoid damage to the low-frequency synchronous rectifier tube, thereby effectively improving the lightning protection effect of the totem bridgeless PFC circuit.

2 is a system structure block diagram of a lightning protection circuit 20 according to some embodiments. The lightning protection circuit 20 includes: a single-phase/three-phase AC input module 201, an input filter protection circuit module 202, a totem bridgeless PFC circuit 203, a DC load module 204 and an input lightning protection circuit module 205.

The single-phase/three-phase AC input module 201 is used to provide power input to the totem bridgeless PFC circuit 203 , and the power input can be either a single-phase input L1 or a three-phase input L1 , L2 and L3 .

The input filter protection circuit module 202 is composed of safety capacitors, common mode inductors, differential mode inductors, varistors, gas discharge tubes or graphite gap lightning arresters. Under normal circumstances, when the totem bridgeless PFC circuit 203 is at risk of lightning strike, because the decoupling ability of the boost inductor L0 and the capacitor C in FIG1 is relatively strong, the lightning current flowing into the totem bridgeless PFC circuit 203 will be relatively small, and most of the lightning current is absorbed by the input filter protection circuit module 202, thereby preventing the totem bridgeless PFC circuit 203 from being damaged.

The totem bridgeless PFC circuit 203 is used to convert the AC power input provided by the single-phase/three-phase AC input module 201 into DC through an AC/DC (Alternating Current/Direct Current, AC/DC) converter, which is used to power the DC load module 204.

The input lightning protection circuit 205 is connected between the input and output terminals of the totem bridgeless PFC circuit 203. When a reverse lightning strike occurs, the input lightning protection circuit 205 can be used to share the lightning current and control the low-frequency synchronous rectifier of the totem bridgeless PFC circuit 203 to turn off.

The lightning protection circuits 30, 40, 50, and 60 provided in the embodiments of the present disclosure are equivalent to some explanations of the implementation methods of the lightning protection circuit 20. The single-phase/three-phase AC input module 201, the input filter protection circuit module 202, and the DC load module 204 are omitted in the lightning protection circuits 30, 40, 50, and 60, but some implementation methods of the input lightning protection circuit module 205 are shown.

The lightning protection circuit disclosed in the present invention is introduced below.

FIG3 is a schematic diagram of a lightning protection circuit according to some embodiments. The lightning protection circuit 30 includes:

The first power input terminal L1, the totem bridgeless PFC circuit, the first element 301, the second element 302, the first current detection circuit 303 and the control circuit 304, the totem bridgeless PFC circuit includes a positive output terminal F and a negative output terminal A. The cathode of the first element 301 is coupled to the positive output terminal F of the totem bridgeless PFC circuit, the anode of the first element 301 is coupled to the cathode of the second element 302, the anode of the second element 302 is coupled to the negative output terminal A of the totem bridgeless PFC circuit, the first output terminal C1 of the first current detection circuit 303 is coupled between the anode of the first element 301 and the cathode of the second element 302, the input terminal B1 of the first current detection circuit 303 is coupled to the first power input terminal L1 of the totem bridgeless PFC circuit, and the second output terminal C2 of the first current detection circuit 303 is coupled to the first input terminal M1 of the control circuit 304.

The first current detection circuit 303 is used to detect the current flowing through the first element 301 and the second element 302 , obtain a first current detection signal, and send the first current detection signal to the control circuit 304 .

The control circuit 304 is used to control the switch tube in the totem bridgeless PFC circuit to turn off according to the first current detection signal.

The totem bridgeless PFC circuit in the embodiment of the present disclosure may have the same structure as the totem bridgeless PFC circuit shown in FIG. 1 .

FIG3 also shows a neutral terminal N and a ground terminal GND. The lightning protection circuit 30 further includes a third element 305 and a fourth element 306. The third element 305 is connected in series between the neutral terminal N and the positive output terminal F of the totem bridgeless PFC circuit, and the fourth element 306 is connected in series between the neutral terminal N and the negative output terminal A of the totem bridgeless PFC circuit. The third element 305 and the fourth element 306 are used to form a current loop between the first power input terminal L1 and the neutral terminal N.

In some embodiments, when there is no reverse lightning strike, the output voltage of the positive output terminal F of the totem bridgeless PFC circuit is higher than the input voltage of the first power input terminal L1, and the first element 301, the second element 302, the third element 305 and the fourth element 306 are all turned off. Therefore, when the totem bridgeless PFC circuit is not subject to the risk of lightning strike, no current flows through the first current detection circuit 303.

When a reverse lightning strike occurs, the output voltage of the positive output terminal F of the totem bridgeless PFC circuit is lower than the absolute value of the voltage difference between the first power input terminal L1 and the zero line segment N. At this time, the first element 301 and the fourth element 306 will be turned on at the same time or the second element 302 and the third element 305 will be turned on at the same time. Most of the lightning current will pass through the first element 301, the second element 302, the third element 305 and the fourth element 306. In this way, the first current detection circuit 303 can detect the first current detection signal and send the first current detection signal to the control circuit 304. The control circuit 304 controls the switch tube in the totem bridgeless PFC circuit to turn off according to the first current detection signal. The switch tube here can be understood as the low-frequency synchronous rectifier tubes VT3 and VT4 in Figure 1.

For example, when the power frequency of the mains is in the positive half cycle, the current at the live terminal L is greater than the current at the neutral terminal N. At this time, VT4 in the totem bridgeless PFC circuit in FIG1 is turned on. If a reverse lightning strike occurs at this time, in which the lightning current flows from the neutral terminal N to the live terminal L, the path of the lightning current is: the neutral terminal N→the anode of the third element 305→the positive output terminal F of the totem bridgeless PFC circuit→the capacitor C→the negative output terminal A of the totem bridgeless PFC circuit→the anode of the second element 302→the first power input terminal L1. In some embodiments, the live terminal L is the first power input terminal L1.

When the power frequency of the mains is in the negative half cycle, the current at the live terminal L is less than the current at the neutral terminal N. At this time, VT3 in the totem bridgeless PFC circuit is turned on. If a reverse lightning strike occurs at this time, in which the lightning current flows from the live terminal L to the neutral terminal N, the path of the lightning current is: the first power input terminal L1→the anode of the first element 301→the positive output terminal F of the totem bridgeless PFC circuit→the capacitor C→the negative output terminal A of the totem bridgeless PFC circuit→the anode of the fourth element 306→the neutral terminal N. In some embodiments, the live terminal L is the first power input terminal L1.

Therefore, it can be understood that there are two types of reverse lightning strikes. One is when the totem bridgeless PFC circuit is in the positive half cycle of the mains power frequency, a reverse lightning strike occurs in which the lightning current flows from the neutral terminal N to the live terminal L. The other is when the totem bridgeless PFC circuit is in the negative half cycle of the mains power frequency, a reverse lightning strike occurs in which the lightning current flows from the live terminal L to the neutral terminal N.

The embodiment of the present disclosure controls the switch tube in the totem bridgeless PFC circuit to turn off by detecting the lightning current passing through the first element 301 and the second element 302. In the embodiment of the present disclosure, when the first element 301 and the second element 302 are coupled between the first power input terminal L1 and the output terminal (positive output terminal F and negative output terminal A), the control circuit 304 can timely turn off the low-frequency synchronous rectifier tube in the totem bridgeless PFC circuit through the first current detection signal detected by the first current detection circuit 303. The lightning protection circuit of the present disclosure has a fast response speed and high sensitivity, and can quickly and effectively realize the lightning protection of the totem bridgeless PFC circuit.

It should be understood that the totem bridgeless PFC circuit shown in FIG3 is a single-phase input totem bridgeless PFC circuit, and of course, it can also be a three-phase input totem bridgeless PFC circuit. In other words, the totem bridgeless PFC circuit can be either a single-channel totem bridgeless PFC circuit or a multi-channel staggered parallel totem bridgeless PFC circuit. The description of the three-phase input totem bridgeless PFC circuit will be introduced later.

In some embodiments, the first element 301 and the second element 302 may be diodes. Similarly, the third element 305 and the fourth element 306 may also be diodes.

In some embodiments, the first element 301 and the second element 302 are rectifier bridges. Similarly, the third element 305 and the fourth element 306 are also rectifier bridges.

The functions of the rectifier bridge and the diode are similar. When a reverse lightning strike occurs, most of the lightning current will flow through the rectifier bridge or the diode, and the lightning current will be detected by the first current detection circuit 303.

Exemplarily, when the first element 301 , the second element 302 , the third element 305 and the fourth element 306 are all diodes, the lightning protection circuit 30 shown in FIG. 3 may also be the lightning protection circuit 40 shown in FIG. 4 .

In the lightning protection circuit 40 shown in FIG. 4 , the first element 301 is a diode D1 , the second element 302 is a diode D2 , the third element 305 is a diode D3 , and the fourth element 306 is a diode D4 .

The anode b of the diode D1 is coupled to the first output terminal C1 of the first current detection circuit 303 and the cathode c of the diode D2, the cathode a of the diode D1 is coupled to the positive output terminal F of the totem bridgeless PFC circuit, and the anode d of the diode D2 is coupled to the negative output terminal A of the totem bridgeless PFC circuit.

The cathode e of the diode D3 is coupled to the positive output terminal F of the totem bridgeless PFC circuit, the anode f of the diode D3 is coupled to the neutral terminal N and the cathode g of the diode D4, and the anode h of the diode D4 is coupled to the negative output terminal A of the totem bridgeless PFC circuit.

In some embodiments, the control circuit 304 is configured to:

Compare the first current detection signal detected by the first current detection circuit with the first preset range, and if the first current detection signal exceeds the first preset range, control the first switch tube corresponding to the positive half cycle of the power frequency in the totem bridgeless PFC circuit to be turned off;

The first current detection signal detected by the first current detection circuit is compared with the second preset range. If the first current detection signal exceeds the second preset range, the second switch tube corresponding to the negative half cycle of the power frequency in the totem bridgeless PFC circuit is controlled to be turned off.

Exemplarily, assuming that the first element 301 and the second element 302 are diodes, referring to FIG4 , taking a single-phase input totem bridgeless PFC circuit as an example, when the totem bridgeless PFC circuit is in the positive half cycle of the power frequency, a reverse lightning strike occurs at this time, and the control circuit 304 compares the first current detection signal detected by the first current detection circuit with the first preset range. If the first current detection signal exceeds the first preset range, the control circuit 304 can control the first switch tube in the totem bridgeless PFC circuit to turn off.

Comparing the first current detection signal with the first preset range is equivalent to comparing the value of the first current detection signal with the first preset range. The first current detection signal may be a voltage signal.

When the totem bridgeless PFC circuit is in the negative half cycle of the power frequency, a reverse lightning strike occurs at this time, and the control circuit 304 compares the first current detection signal detected by the first current detection circuit with the second preset range. If the first current detection signal exceeds the second preset range, the control circuit 304 can control the second switch tube in the totem bridgeless PFC circuit to turn off.

The first switch tube here may be VT3 in Figure 1, and the second switch tube may be VT4 in Figure 1. Alternatively, the first switch tube may be VT4 in Figure 1, and the second switch tube may be VT3 in Figure 1.

In practical applications, the first preset range and the second preset range may be the same or different.

In some embodiments, the control circuit 304 is further configured to control the first switch tube to be turned on after the duration of controlling the first switch tube to be turned off reaches a preset time period, or to control the first switch tube to be turned on when the current corresponding to the first current detection signal is detected to be within a third preset range.

In some embodiments, the control circuit 304 is further configured to control the second switch tube to be turned on after the duration of controlling the second switch tube to be turned off reaches a preset time period, or to control the second switch tube to be turned on when the current corresponding to the first current detection signal is detected to be within a fourth preset range.

It is understandable that the control circuit 304 can control the first switch tube and the second switch tube to be turned off or turned on. For example, the duration of a general lightning strike is 8 to 20 μs. If the control circuit 304 controls the first switch tube and the second switch tube to be turned off for 100 μs, then when a reverse lightning strike occurs, the control circuit 304 controls the first switch tube and the second switch tube to be turned off. When the off time reaches 100 μs, the control circuit 304 controls the first switch tube and the second switch tube to be turned on.

In some embodiments, when the lightning current is detected to be relatively small, the control circuit 304 will also control the first switch tube and the second switch tube to be turned on. For example, when the current corresponding to the first current detection signal is within the preset range of -10A to 10A, it is considered that the lightning risk is about to end, and the control circuit 304 can control the first switch tube and the second switch tube to be turned on.

In some embodiments, as shown in Fig. 5, the lightning protection circuit 50 further includes a first current limiting circuit 501, which is connected in series between the first power input terminal L1 and the input terminal B1 of the first current detection circuit 303. The first current limiting circuit 501 is used to shunt the current of the first power input terminal L1.

That is to say, the first current limiting circuit 501 can improve the decoupling capability of the totem bridgeless PFC circuit, that is, prevent the current shock formed in the totem bridgeless PFC circuit when the current of the totem bridgeless PFC circuit changes from affecting the normal operation of the totem bridgeless PFC circuit, and avoid the current of the totem bridgeless PFC circuit being too high when a lightning strike occurs.

Exemplarily, the first current limiting circuit 501 generally uses a current limiting device such as a constant resistor, a thermistor, a varistor, an inductor, etc.

In some embodiments, as shown in FIG6 , the first current detection circuit 303 of the lightning protection circuit 60 includes a first current sampling device 601 and a first amplifier circuit 602 , the input terminal B1 of the first current sampling device 601 is coupled to the first power input terminal L1 , the first output terminal C1 of the first current sampling device 601 is coupled between the anode b of the first element 301 and the cathode c of the second element 302 , and the second output terminal N1 of the first current sampling device 601 is coupled to the input terminal N2 of the first amplifier circuit 602 .

The first current sampling device 601 is used to convert the current flowing through the first element 301 or the second element 302 into a first voltage signal, and output the first voltage signal to the first amplifier circuit.

The first amplifier circuit 602 is used to amplify the first voltage signal to obtain a first current detection signal.

Exemplarily, the first current sampling device 601 is generally composed of current detection devices such as a resistor, a shunt, a current transformer, and a Hall sensor. The following takes the first current sampling device 601 as a Hall sensor as an example for explanation. The first current sampling device 601 can convert the current flowing through the diode D1 and the diode D2 shown in FIG5 into a first voltage signal. The first voltage signal U=0.02×(the current I flowing through the diode D1 and the diode D2 shown in FIG5)+1.65.

The first amplifier circuit 602 is used to amplify the obtained first voltage signal to obtain a first current detection signal.

In some embodiments, the control circuit 304 can control the driving of the low-frequency synchronous rectifier tube in the single-phase input totem bridgeless PFC circuit by hardware or software, thereby turning off or turning on the low-frequency synchronous rectifier tube in the single-phase input totem bridgeless PFC circuit.

If implemented in hardware, as shown in FIG7 , the control circuit 304 includes a digital signal controller (DSC), comparators U1 and U3, and AND gate circuits U2 and U4. The first input terminal i of the comparator U1 and the first input terminal k of the comparator U3 are coupled to the second output terminal C2 of the first current detection circuit 303, the output terminal P1 of the comparator U1 is coupled to the first input terminal Q1 of the AND gate circuit U2, the output terminal P2 of the comparator U3 is coupled to the first input terminal Q3 of the AND gate circuit U4, the second input terminal Q2 of the AND gate circuit U2 is coupled to the DSC, the second input terminal Q4 of the AND gate circuit U4 is coupled to the DSC, the output terminal of the AND gate circuit U2 is coupled to the driving circuit of the first switch tube of the totem bridgeless PFC circuit, and the output terminal of the AND gate circuit U4 is coupled to the driving circuit of the second switch tube of the totem bridgeless PFC circuit. It can be understood that the comparator U1 and the first input terminal k of the comparator U3 are coupled to the second input terminal C2 of the first current detection circuit 303, the output terminal P1 of the comparator U1 and the first input terminal Q1 of the AND gate circuit U2, the output terminal P2 of the comparator U3 and the first input terminal Q3 of the AND gate circuit U4, the second input terminal Q2 of the AND gate circuit U2 and the DSC, the second input terminal Q4 of the AND gate circuit U4 and the DSC, the output terminal of the AND gate circuit U2 and the driving circuit of the first switch tube of the totem bridgeless PFC circuit, and the output terminal of the AND gate circuit U4 and the driving circuit of the second switch tube of the totem bridgeless PFC circuit. The first input terminal i of the comparator U1 is a non-inverting input terminal, and the first input terminal k of the comparator U3 is an inverting input terminal.

The first preset range and the second preset range mentioned above can be realized by the reference voltage VREF1 and the reference voltage VREF2.

The comparator U1 is used to compare the first current detection signal with the reference voltage VREF1, obtain a first comparison result, and output the first comparison result to the first input terminal Q1 of the AND gate circuit U2. The comparator U3 is used to compare the first current detection signal with the reference voltage VREF2, also obtain a first comparison result, and output the first comparison result to the first input terminal Q3 of the AND gate circuit U4.

DSC is used to input the driving signal PWM4_DSC to the second input terminal Q2 of the AND gate circuit U2. DSC is also used to input the driving signal PWM3_DSC to the second input terminal Q4 of the AND gate circuit U4.

The AND gate circuit U2 is used to output a first control signal PWM4 according to the drive signal PWM4_DSC and the first comparison result. The first control signal PWM4 is used to control the switch tube of the totem bridgeless PFC circuit to turn off. In this embodiment, this switch tube can be understood as the first switch tube VT4.

The AND gate circuit U4 is used to output the first control signal PWM3 according to the drive signal PWM3_DSC and the first comparison result. The first control signal PWM3 is used to control the switch tube of the totem bridgeless PFC circuit to turn off. In this embodiment, this switch tube can be understood as the second switch tube VT3.

In some embodiments, when the totem bridgeless PFC circuit is in the positive half cycle of the power frequency, the reference voltage VREF1 is input to the inverting input terminal of the comparator U1, and the first current detection signal output by the first current detection circuit 303 is input to the non-inverting input terminal i of the comparator U1. When the totem bridgeless PFC circuit is in the negative half cycle of the power frequency, the reference voltage VREF2 is input to the non-inverting input terminal of the comparator U3, and the first current detection signal output by the first current detection circuit is input to the inverting input terminal k of the comparator U3.

The reference voltage VREF1 is obtained by dividing the voltage of VCC through the voltage divider circuit composed of resistors R1 and R2, and the reference voltage VREF2 is obtained by dividing the voltage of VCC through the voltage divider circuit composed of resistors R3 and R4. PWM4_DSC and PWM3_DSC are PWM drive signals of low-frequency synchronous rectifier tubes sent by the main control chip DSC when the totem bridgeless PFC circuit is not subject to the risk of lightning strike. The drive signal here can be understood as a high-level or low-level drive signal.

When the totem bridgeless PFC circuit is not subject to the risk of lightning strike, the current on the first current detection circuit is 0, and the first current detection signal output by the first current detection circuit 303 is lower than the reference voltage VREF1 or the reference voltage VREF2, and the comparators U1 and U3 output a high level. At this time, PWM4_DSC is the same as the PWM4 signal, PWM3_DSC is the same as the PWM3 signal, and the totem bridgeless PFC circuit works normally.

For example, assuming that the action threshold of the current I flowing through the diode D1 and the diode D2 shown in FIG5 is 49.5 A, if the totem bridgeless PFC circuit is in the positive half cycle of the power frequency, the first current detection signal U=0.02×(-49.5A)+1.65=0.66V, if the totem bridgeless PFC circuit is in the negative half cycle of the power frequency, the first current detection signal U=0.02×49.5A+1.65=2.64V. It can be understood that the first preset range and the second preset range are 0.66V to 2.64V at this time.

Generally, VREF1 and VREF2 are different, and VREF1 is smaller than VREF2. For example, the value of VREF1 is 0.66V, and the value of VREF2 is 2.64V.

When the totem bridgeless PFC circuit is in the positive half cycle of the power frequency, a reverse lightning strike occurs. At this time, the current on the first current detection circuit will increase, that is, the current I flowing through the diode D1 and the diode D2 shown in Figure 5 is less than -49.5A. At this time, the first current detection signal will be lower than the reference voltage VREF1, and the comparator U1 outputs a low-level signal. The low-level signal output by the comparator U1 is ANDed with the drive signal PWM4_DSC issued by the main control chip DSC, and PWM4 outputs a low-level signal. The control circuit 304 controls As the lightning strike disappears, when the first current detection signal is higher than the reference voltage VREF1, the control circuit 304 controls the low-frequency synchronous rectifier VT4 to turn on.

If a reverse lightning strike occurs when the totem bridgeless PFC circuit is in the negative half cycle of the power frequency, the current on the first current detection circuit will increase, that is, the current I flowing through the diode D1 and the diode D2 shown in Figure 5 is greater than 49.5A. At this time, the first current detection signal will be higher than the reference voltage VREF2, and the comparator U3 will output a low-level signal. The low-level signal output by the comparator U3 is ANDed with the drive signal PWM3_DSC issued by the main control chip DSC, PWM3 outputs a low-level signal, and the control circuit 304 controls the low-frequency synchronous rectifier VT3 to turn off. As the lightning strike disappears, when the first current detection signal is lower than the reference voltage VREF2, the control circuit 304 will control the low-frequency synchronous rectifier VT3 to turn on.

In practical applications, there are many ways to implement current sampling of the first current sampling device 601 in the first current detection circuit 303. Different current sampling methods have various connection relationships with lightning current. Therefore, the second output terminal C2 of the first current detection circuit 303 may also be coupled to the non-inverting input terminal of the comparator U1 or the comparator U3, and may also be coupled to the inverting input terminal of the comparator U1 or U3.

FIG. 8 is a schematic diagram showing a control circuit 304 implemented in software.

The first current detection circuit 303 continuously detects the current flowing through the diode D1 and the diode D2 shown in FIG. 5 , and sends the detected lightning current detection value to the corresponding port of the main control chip DSC.

The main control chip DSC judges the current operating state of the totem bridgeless PFC circuit, that is, whether the low-frequency synchronous rectifier in the totem bridgeless PFC circuit is in the off state. If the low-frequency synchronous rectifier is in the on state at this time, it is judged whether the current current detection value reaches the shutdown threshold set by the software. If the current detection value reaches the shutdown threshold set by the software, the main control chip DSC sends a first control signal to drive the low-frequency synchronous rectifier of the totem bridgeless PFC circuit to shut down. The first control signal here can be understood as the corresponding port of the main control chip DSC setting low PWM. That is, the corresponding port of the main control chip DSC outputs a low-level PWM signal. If the current detection value does not reach the shutdown threshold set by the software, no processing is performed, that is, the current totem bridgeless PFC circuit is kept working normally.

If the low-frequency synchronous rectifier of the totem bridgeless PFC circuit is in the off state at this time, it is determined whether the recovery condition is met, that is, the condition for the low-frequency synchronous rectifier to be turned on. The judgment condition here can be understood as whether the duration of the main control chip DSC turning off the drive when the lightning strike occurs has reached the set time, or it can be determined whether the current in the first current detection circuit 303 is 0 at this time. If the judgment condition is met, the low-frequency synchronous rectifier of the totem bridgeless PFC circuit is re-driven to turn on. If not, the low-frequency synchronous rectifier of the totem bridgeless PFC circuit continues to be turned off until the condition is met. Exemplarily, the duration of a general lightning strike is 8 to 20 μs, assuming that the setting time for the main control chip DSC to turn off the drive is 100 μs. Then when the lightning strike occurs, the low-frequency synchronous rectifier of the totem bridgeless PFC circuit is in the off state. If the time for turning off the drive is greater than or equal to 100 μs at this time, the low-frequency synchronous rectifier of the totem bridgeless PFC circuit is turned on again. Or when the current of the first current detection circuit is within the preset current range, the low-frequency synchronous rectifier of the totem bridgeless PFC circuit is turned on again. If the time of driving off is less than 100 μs and the current of the first current detection circuit is not 0, the low-frequency synchronous rectifier continues to remain in the off state until the condition is met.

It should be understood that when the totem bridgeless PFC circuit in the lightning protection circuit provided by the present disclosure is a totem bridgeless PFC circuit with unidirectional input, the totem bridgeless PFC circuit can be a circuit structure as shown in FIG1, or can be other circuit structures, which is not limited in the embodiments of the present disclosure. In some embodiments, it has been described above that the totem bridgeless PFC circuit can be a totem bridgeless PFC circuit with three-phase input. As shown in FIG9 , FIG9 shows a lightning protection circuit 90 based on a totem bridgeless PFC circuit with three-phase input.

On the basis of including the lightning protection circuit 30 shown in FIG. 3 , the lightning protection circuit 90 further includes a second power input terminal L2 , a third power input terminal L3 , a fifth element 901 , a sixth element 902 , a seventh element 903 and an eighth element 904 .

The cathode of the fifth element 901 is coupled to the positive output terminal F of the totem bridgeless PFC circuit, the anode of the fifth element 901 is coupled to the cathode of the sixth element 902, and the anode of the sixth element 902 is coupled to the negative output terminal A of the totem bridgeless PFC circuit.

The cathode of the seventh element 903 is coupled to the positive output terminal F of the totem bridgeless PFC circuit, the anode of the seventh element 903 is coupled to the cathode of the eighth element 904, and the anode of the eighth element 904 is coupled to the negative output terminal A of the totem bridgeless PFC circuit.

Similar to the first current detection circuit 303, considering that reverse lightning strikes may also occur in the current loop between the second power input terminal L2 and the neutral terminal N, and in the current loop between the third power input terminal L3 and the neutral terminal N, as shown in FIG. 9, the lightning protection circuit 90 also includes a second current detection circuit 905 and a third current detection circuit 906.

The first output terminal C3 of the second current detection circuit 905 is coupled between the anode of the fifth element 901 and the cathode of the sixth element 902, the input terminal B2 of the second current detection circuit 905 is coupled to the second power supply input terminal L2 of the totem bridgeless PFC circuit, and the second output terminal C4 of the second current detection circuit 905 is coupled to the second input terminal M2 of the control circuit 304.

The first output terminal C5 of the third current detection circuit 906 is coupled between the anode of the seventh element 903 and the cathode of the eighth element 904, the input terminal B3 of the third current detection circuit 906 is coupled to the third power input terminal L3 of the totem bridgeless PFC circuit, and the second output terminal C6 of the third current detection circuit 906 is coupled to the third input terminal M3 of the control circuit 304.

Based on the example of the lightning protection circuit 90 in Figure 9, the second current detection circuit 905 is used to convert the current flowing through the fifth and sixth elements into a voltage signal, which is then amplified through a peripheral circuit to obtain a second current detection signal, and the second current detection signal is sent to the control circuit 304.

The control circuit 304 is also used to control the turning off and on of the low-frequency synchronous rectifier tube in the totem bridgeless PFC circuit according to the second current detection signal.

The control circuit 304 is used to control the switching tube in the totem bridgeless PFC circuit to turn off and on according to the second current detection signal. The implementation method can refer to the control circuit 304 used to control the switching tube in the totem bridgeless PFC circuit to turn off and on according to the first current detection signal in the above text.

Similarly, based on the example of the lightning protection circuit 90 in Figure 9, the third current detection circuit 905 is used to convert the current flowing through the seventh and eighth elements into a voltage signal, which is then amplified through a peripheral circuit to obtain a third current detection signal, and the third current detection signal is sent to the control circuit 304.

The control circuit 304 is also used to control the turning off and on of the low-frequency synchronous rectifier tube in the totem bridgeless PFC circuit according to the third current detection signal.

The control circuit 304 is used to control the switching tube in the totem bridgeless PFC circuit to turn off and on according to the third current detection signal. The implementation method can refer to the control circuit 304 used to control the switching tube in the totem bridgeless PFC circuit to turn off and on according to the first current detection signal.

Based on the lightning protection circuit 90 illustrated in FIG9 , similar to the first current limiting circuit 501, FIG10 shows a lightning protection circuit 100, which includes a second current limiting circuit 101 and a third current limiting circuit 102. The fifth element 901, the sixth element 902, the seventh element 903 and the eighth element 904 in FIG9 are all shown as diodes in FIG10. The fifth element 901 is shown as a diode D5, the sixth element 902 is shown as a diode D6, the seventh element 903 is shown as a diode D7, and the eighth element 904 is shown as a diode D8.

The second current limiting circuit 101 is connected in series between the second power input terminal L2 and the input terminal B2 of the second current detection circuit 905 .

The second current limiting circuit 101 is used to shunt the current of the second power input terminal L2.

That is, in the embodiment of the present disclosure, the second current limiting circuit 101 can improve the decoupling capability of the totem bridgeless PFC circuit, thereby preventing the output voltage of the totem bridgeless PFC circuit from being too high when a lightning strike occurs.

Similarly, the third current limiting circuit 102 is connected in series between the third power input terminal L3 and the input terminal B3 of the third current detection circuit 906 .

The third current limiting circuit 102 is used to shunt the current of the third power input terminal L3.

That is, in the present disclosure, the third current limiting circuit 102 can improve the decoupling capability of the totem bridgeless PFC circuit, and prevent the output voltage of the totem bridgeless PFC circuit from being too high when a lightning strike occurs.

Similar to the first current limiting circuit 501 , the second current limiting circuit 101 and the third current limiting circuit 102 usually use current limiting devices such as constant resistors, thermistors, varistors, inductors, etc.

Therefore, the technical solution provided by the embodiment of the present disclosure is not only applicable to the lightning protection of the totem bridgeless PFC circuit with single-phase input, but also applicable to the lightning protection of the totem bridgeless PFC circuit with three-phase input.

In combination with any one of the lightning protection circuits corresponding to Figures 3 to 7, the embodiment of the present disclosure further provides a lightning protection circuit method. The method is applied to any one of the lightning protection circuits corresponding to Figures 3 to 7. Figure 11 is a flow chart of a lightning protection method provided by an embodiment of the present disclosure, including the following steps.

Step 111: The electronic device detects the current flowing through the first element and the second element to obtain a first current detection signal.

Step 112: The electronic device controls the switch tube in the totem bridgeless PFC circuit to turn off according to the first current detection signal.

The electronic device may include any one of the lightning protection circuits corresponding to Figures 3 to 7. For example, the electronic device may be a communication device.

The implementation of step 111 can be performed by the first current detection circuit 303. The detailed implementation can refer to the description of the first current detection circuit 303 above.

The implementation of step 112 can be performed by the control circuit 304. The detailed implementation can refer to the description of the control circuit 304 above.

In combination with any one of the lightning protection circuits corresponding to FIG. 7 and FIG. 8 , on the basis of the method embodiment corresponding to FIG. 11 , the lightning protection method of the embodiment of the present disclosure may further include the following steps.

Step 1) The electronic device detects the current flowing through the fifth element and the sixth element to obtain a second current detection signal.

The implementation of step 1) can be performed by the second current detection circuit 905. The detailed implementation can refer to the description of the second current detection circuit 905 above.

Step 2) The electronic device controls the switch tube in the totem bridgeless PFC circuit to turn off according to the second current detection signal.

The implementation of step 2) can be performed by the control circuit 304. The detailed implementation can refer to the description of the control circuit 304 above.

And, step 3) the electronic device controls the switch tube in the totem bridgeless PFC circuit to turn off according to the third current detection signal.

The implementation of step 3) can be performed by the third current detection circuit 906. The detailed implementation can refer to the description of the third current detection circuit 906 above.

Step 4) The electronic device controls the switch tube in the totem bridgeless PFC circuit to turn off according to the third current detection signal.

The implementation of step 4) can be performed by the control circuit 304. The detailed implementation can refer to the description of the control circuit 304 above.

Therefore, the electronic device turns off the switch tube through the control circuit according to the current detection signal between one or more power input terminals and the second output terminal A of the totem bridgeless PFC circuit, thereby improving the problems of insufficient protection capability and untimely protection action of the existing lightning protection circuit.

It is understandable that in order to realize the above functions, the lightning protection circuit of the power supply includes hardware structures and/or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the algorithm steps of each example described in the embodiments of the present disclosure, the present disclosure can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present disclosure.

The embodiments of the present disclosure can divide the lightning protection circuit of the power supply into functional modules according to the above method embodiments. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one functional module. The above integrated modules can be implemented in the form of hardware or software. It should be noted that the division of modules in the embodiments of the present disclosure is schematic and is only a logical function division. There may be other division methods in actual implementation. The following is an example of dividing each functional module corresponding to each function.

Some embodiments of the present disclosure provide a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium), in which computer program instructions are stored. When the computer program instructions are executed on a computer, the computer executes the lightning protection method for a power supply as described in any of the above embodiments.

Exemplarily, the above-mentioned computer-readable storage media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks or magnetic tapes, etc.), optical disks (e.g., Compact Disks (CDs), Digital Versatile Disks (DVDs), etc.), smart cards and flash memory devices (e.g., Erasable Programmable Read-Only Memory (EPROMs), cards, sticks or key drives, etc.). The various computer-readable storage media described in the present disclosure may represent one or more devices and/or other machine-readable storage media for storing information. The term "machine-readable storage medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing and/or carrying instructions and/or data.

An embodiment of the present disclosure provides a computer program product including instructions. When the computer program product is run on a computer, the computer is enabled to execute the method for lightning protection of a power supply described in any one of the above embodiments.

The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

A lightning protection circuit for a power supply, comprising:

a first element, wherein a cathode of the first element is coupled to a positive output terminal of the totem bridgeless PFC circuit, and an anode of the first element is coupled to a cathode of a second element;

the second element, an anode of the second element being coupled to a negative output terminal of the totem bridgeless PFC circuit;

a first current detection circuit, wherein a first output terminal of the first current detection circuit is coupled between an anode of the first element and a cathode of the second element, an input terminal of the first current detection circuit is coupled to a first power input terminal of the totem bridgeless PFC circuit, and a second output terminal of the first current detection circuit is coupled to a first input terminal of a control circuit, wherein the first current detection circuit is used to detect currents flowing through the first element and the second element, obtain a first current detection signal, and send the first current detection signal to the control circuit; and

The control circuit is used to control the switch tube in the totem bridgeless PFC circuit to turn off according to the first current detection signal.
The lightning protection circuit according to claim 1, wherein:

The first element and the second element are diodes; or,

The first element and the second element are rectifier bridges.
The lightning protection circuit according to claim 1, wherein the control circuit is used for:

Corresponding to the first current detection signal exceeding a first preset range, controlling the first switch tube corresponding to the positive half cycle of the power frequency in the totem bridgeless PFC circuit to be turned off;

Corresponding to the first current detection signal exceeding the second preset range, the second switch tube corresponding to the negative half cycle of the power frequency in the totem bridgeless PFC circuit is controlled to be turned off.
The lightning protection circuit according to claim 3, wherein the control circuit is further used for:

After the duration of controlling the first switch tube to be turned off reaches a preset time period, controlling the first switch tube to be turned on; or,

When it is detected that the current corresponding to the first current detection signal is within a third preset range, the first switch tube is controlled to be turned on.
The lightning protection circuit according to claim 3, wherein the control circuit is further used for:

After the duration of controlling the second switch tube to be turned off reaches a preset time period, controlling the second switch tube to be turned on; or,

When it is detected that the current corresponding to the first current detection signal is within a fourth preset range, the second switch tube is controlled to be turned on.
The lightning protection circuit according to claim 1, further comprising a first current limiting circuit, a first end of the first current limiting circuit being coupled to an input end of the first current detection circuit, and a second end of the first current limiting circuit being coupled to the first power supply input end;

The first current limiting circuit is used to shunt the current at the first power input terminal.
The lightning protection circuit according to claim 1, wherein the first current detection circuit comprises a first current sampling device and a first amplification circuit, wherein:

The input terminal of the first current sampling device is coupled to the first power supply input terminal, the first output terminal of the first current sampling device is coupled between the anode of the first element and the cathode of the second element, and the second output terminal of the first current sampling device is coupled to the input terminal of the first amplifier circuit;

The first current sampling device is used to convert the current flowing through the first element or the second element into a first voltage signal, and output the first voltage signal to the first amplifying circuit;

The first amplifier circuit is used to amplify the first voltage signal to obtain the first current detection signal.
The lightning protection circuit according to claim 1, wherein the control circuit comprises a digital signal controller DSC, Comparator and AND gate circuit, where

The first input terminal of the comparator is coupled to the second output terminal of the first current detection circuit, the second input terminal of the comparator is used to input a reference voltage, and the output terminal of the comparator is coupled to the first input terminal of the AND gate circuit;

The second input end of the AND gate circuit is coupled to the DSC, and the output end of the AND gate circuit is coupled to the driving circuit of the switch tube of the totem bridgeless PFC circuit; wherein,

The comparator is used to compare the first current detection signal with the reference voltage to obtain a first comparison result, and output the first comparison result to the first input terminal of the AND gate circuit;

The DSC is used to input a driving signal to the second input terminal of the AND gate circuit;

The AND gate circuit is used to output a first control signal according to the drive signal and the first comparison result, and the first control signal is used to control the switch tube of the totem bridgeless PFC circuit to turn off.
The lightning protection circuit according to claim 1, wherein the control circuit comprises a digital signal controller DSC, an input end of the DSC is coupled to the second output end of the first current detection device, and an output end of the DSC is coupled to the switch tube of the totem bridgeless PFC circuit;

The DSC is used to compare the first current detection signal with a shutdown threshold set by software, and when it is determined that the first current detection signal reaches the shutdown threshold, output a first control signal, wherein the first control signal is used to control the switch tube of the totem bridgeless PFC circuit to shut down.
The lightning protection circuit according to claim 1, wherein the totem bridgeless PFC circuit is a three-phase totem bridgeless PFC circuit;

The lightning protection circuit further includes a second current detection circuit, a fifth element, a sixth element, a third current detection circuit, a seventh element and an eighth element;

The cathode of the fifth element is coupled to the positive output terminal of the totem bridgeless PFC circuit, the anode of the fifth element is coupled to the cathode of the sixth element, the anode of the sixth element is coupled to the negative output terminal of the totem bridgeless PFC circuit, the first output terminal of the second current detection circuit is coupled between the anode of the fifth element and the cathode of the sixth element, the input terminal of the second current detection circuit is coupled to the second power supply input terminal of the totem bridgeless PFC circuit, and the second output terminal of the second current detection circuit is coupled to the second input terminal of the control circuit;

The cathode of the seventh element is coupled to the positive output terminal of the totem bridgeless PFC circuit, the anode of the seventh element is coupled to the cathode of the eighth element, the anode of the eighth element is coupled to the negative output terminal of the totem bridgeless PFC circuit, the first output terminal of the third current detection circuit is coupled between the anode of the seventh element and the cathode of the eighth element, the input terminal of the third current detection circuit is coupled to the third power supply input terminal of the totem bridgeless PFC circuit, and the second output terminal of the third current detection circuit is coupled to the third input terminal of the control circuit.
A lightning protection method for a power supply, wherein the method is applied to a lightning protection circuit, the lightning protection circuit comprises a first current detection circuit, a control circuit, a first element and a second element, the cathode of the first element is coupled to the positive output end of the totem bridgeless PFC circuit, the anode of the first element is coupled to the cathode of the second element, the anode of the second element is coupled to the negative output end of the totem bridgeless PFC circuit, the method comprises:

detecting the current flowing through the first element and the second element to obtain a first current detection signal;

The switch tube in the totem bridgeless PFC circuit is controlled to be turned off according to the first current detection signal.
The method according to claim 11, wherein

The first element and the second element are diodes; or,

The first element and the second element are rectifier bridges.
The method according to claim 11, wherein the control of the image according to the first current detection signal The switch shutdown in the bridgeless PFC circuit includes:

Corresponding to the first current detection signal exceeding a first preset range, controlling the first switch tube corresponding to the positive half cycle of the power frequency in the totem bridgeless PFC circuit to be turned off;

Corresponding to the first current detection signal exceeding the second preset range, the second switch tube corresponding to the half cycle of the power frequency cycle in the totem bridgeless PFC circuit is controlled to be turned off.
The method according to claim 13, further comprising:

After the time for controlling the first switch tube to be turned off reaches a preset time period, controlling the first switch tube to be turned on; or,

When it is detected that the current corresponding to the first current detection signal is within a preset range, the first switch tube is controlled to be turned on.
The method according to claim 13, further comprising:

After the time for controlling the second switch tube to be turned off reaches a preset time period, controlling the second switch tube to be turned on; or,

When it is detected that the current corresponding to the first current detection signal is within a preset range, the second switch tube is controlled to be turned on.
The method according to claim 11, wherein controlling the switch tube in the totem bridgeless PFC circuit to turn off according to the first current detection signal comprises:

converting the current flowing through the first element or the second element into a first voltage signal;

The first voltage signal is amplified to obtain the first current detection signal.
The method according to claim 11, wherein controlling the switch tube in the totem bridgeless PFC circuit to turn off according to the first current detection signal comprises:

The first current detection signal and a shutdown threshold set by software are compared, and when it is determined that the first current detection signal reaches the shutdown threshold, the switch tube of the totem bridgeless PFC circuit is controlled to be turned off.
A computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium. When the instructions in the computer-readable storage medium are executed by a processor of an electronic device, the electronic device executes the lightning protection method according to any one of claims 11 to 17.