WO2017181806A1

WO2017181806A1 - Switching-mode power supply lightning protection apparatus and switching-mode power supply

Info

Publication number: WO2017181806A1
Application number: PCT/CN2017/077544
Authority: WO
Inventors: 林锦武
Original assignee: 中兴通讯股份有限公司
Priority date: 2016-04-18
Filing date: 2017-03-21
Publication date: 2017-10-26
Also published as: CN107306027A; CN107306027B

Abstract

A switching-mode power supply lightning protection apparatus and a switching-mode power supply. The lightning protection apparatus comprises a lightning protection circuit (1), a current limiting circuit (2), a rectifier circuit (3) and a power factor correction (PFC) circuit (4), wherein two input terminals of the current limiting circuit (2) are respectively connected to an L-line output terminal and an N-line output terminal of the lightning protection circuit (1), two input terminals of the rectifier circuit (3) are respectively connected to two output terminals of the current limiting circuit (2), the L-line output terminal of the rectifier circuit (3) is connected to a first input terminal of the PFC circuit (4) and a positive electrode of an electrolytic capacitor (C1), a negative electrode of the electrolytic capacitor (C1) is connected to a second input terminal of the PFC circuit (4) and the N-line output terminal of the rectifier circuit (3), and the N-line output terminal of the rectifier circuit (3) is also connected to ground; and a third input terminal of the PFC circuit (4) is connected to the L-line output terminal of the lightning protection circuit (1), and a fourth input terminal of the PFC circuit (4) is connected to the N-line output terminal of the lightning protection circuit (1). The lightning protection apparatus and the switching-mode power supply can improve lightning protection performance of a lightning protection circuit, thereby improving safety of lightning protection circuits.

Description

Lightning protection device and switching power supply for switching power supply

Technical field

This article relates to, but is not limited to, the field of switching power supplies, and more particularly to a lightning protection device and a switching power supply for a switching power supply.

Background technique

In the field of switching power supplies, power supplies are generally required to have certain lightning protection performance. Specifically, different lightning protection performances are required according to actual use environment conditions, such as nominal discharge currents of 1 kA, 2KA, 5KA. , 10KA, etc., to protect the power supply in the case of lightning strikes, voltage surges can work properly.

The lightning protection performance of the lightning protection circuit in the related art is insufficient, and the power supply may be unstable, power failure, bombing, fire, etc. in the event of a lightning strike or a surge, which may cause a safety accident.

Summary of invention

The following is an overview of the topics detailed in this document. This Summary is not intended to limit the scope of the claims.

The embodiment of the invention provides a lightning protection device and a switching power supply for a switching power supply, which can improve the lightning protection performance of the lightning protection circuit and improve the safety of the lightning protection circuit.

The embodiment of the invention provides a lightning protection device for a switching power supply, comprising: a lightning protection circuit, a current limiting circuit, a rectifier circuit and a power factor correction PFC circuit; wherein the two input terminals of the current limiting circuit respectively The L line output end of the lightning circuit is connected to the N line output end, and the two input ends of the rectifier circuit are respectively connected to the two output ends of the current limiting circuit, and the L line output end of the rectifier circuit and the PFC a first input end of the circuit is connected to an anode of an electrolytic capacitor, a cathode of the electrolytic capacitor is connected to a second input end of the PFC circuit and an N line output end of the rectifier circuit, and an N line output of the rectifier circuit The terminal is also grounded; the third input end of the PFC circuit is connected to the L line output end of the lightning protection circuit, and the fourth input end of the PFC circuit is connected to the N line output end of the lightning protection circuit.

Optionally, the current limiting circuit includes: one or more resistors.

Optionally, the number of the resistors is an even number, wherein the L line of the current limiting circuit and the line corresponding to the N line of the current limiting circuit are respectively provided with an equal number of resistors.

Optionally, the resistor is a negative temperature coefficient NTC thermistor.

Optionally, the rectifier circuit is composed of an even number of diodes, wherein an L-line of the rectifier circuit and a line corresponding to the N-line of the rectifier circuit are respectively provided with an equal number of diodes.

Optionally, when the number of the diodes is four, the rectifier circuit is a rectifier bridge composed of four of the diodes.

Optionally, the lightning protection circuit comprises: a common mode inductor, two decoupling inductors, five varistors and a gas discharge tube; wherein the lightning protection circuit has an L line input end and a first pressure sensitive The inductor, the second varistor and the first decoupling inductor are connected, and the other end of the second varistor is connected to the other end of the first varistor through a third varistor, the first varistor The other end of the inductor is connected to the gas discharge tube; the other end of the first decoupling inductor is connected to one end of the fourth pressure sensitive inductor, and the other end of the first decoupling inductor is also connected to the common mode inductor The input end of the common mode inductor is an L line output end of the lightning protection circuit; one end of the second decoupling inductor is opposite to the second pressure sensitive inductor and the third pressure sensitive Inductive connection, the other end of the second decoupling inductor is connected to the other end of the fourth piezo-sensitive inductor, and the other end of the second decoupling inductor is also connected to the input end of the other side of the common mode inductor, The output end of the other side of the common mode inductor is an N line output of the lightning protection circuit .

In another aspect, the embodiment of the present invention further provides a switching power supply, comprising: the lightning protection device of the switching power supply according to any one of the above items.

Compared with the related art, the technical solution provided by the embodiment of the present invention includes: a lightning protection circuit, a current limiting circuit, a rectifier circuit, and a power factor correction (PFC) circuit; wherein the two input terminals of the current limiting circuit are respectively protected from lightning The L line output end of the circuit is connected to the N line output end, and the two input ends of the rectifier circuit are respectively connected with the two output ends of the current limiting circuit, the L line output end of the rectifier circuit and the first input end of the PFC circuit and an electrolysis The positive pole of the capacitor is connected, the cathode of the electrolytic capacitor is connected with the second input end of the PFC circuit and the N line output end of the rectifier circuit, and the N line output end of the rectifier circuit is also grounded; the third input end of the PFC circuit and the lightning protection circuit L The line output terminal is connected, and the fourth input end of the PFC circuit is connected to the N line output end of the lightning protection circuit.

In the embodiment of the invention, a current limiting circuit and a rectifier circuit are disposed between the lightning protection circuit and the PFC circuit, The current limiting circuit and the rectifying circuit are connected through a specific connection manner, and the lightning protection device obtained by the connection method realizes current limiting by the current limiting circuit when encountering a lightning strike or a surge. The circuit is rectified by the rectifier circuit to shield the impact caused by lightning or surge, and the lightning protection performance of the lightning protection circuit of the related technology is solved, and the power supply is unstable and broken in the event of lightning strike or surge. Electricity, bombers, fires, etc. may cause safety accidents.

Other aspects will be apparent upon reading and understanding the drawings and detailed description.

BRIEF abstract

1 is a schematic structural view of a lightning protection device for a switching power supply according to an embodiment of the present invention;

2 is a schematic circuit diagram of a lightning protection device of a switching power supply according to an alternative embodiment of the present invention;

3 is a schematic diagram of energy release of a lightning protection device when a lightning strike device is subjected to a lightning surge on the L line of the lightning protection device in an alternative embodiment of the present invention;

4 is a schematic diagram of energy release of a lightning protection device when a lightning strike device is subjected to a lightning surge on the N-line of the lightning protection device in an alternative embodiment of the present invention;

5 is a schematic diagram of a connection manner of a first PFC circuit in a lightning protection device according to an embodiment of the present invention;

6 is a schematic diagram of a connection manner of a second PFC circuit in a lightning protection device according to an embodiment of the present invention;

7 is a schematic structural view of still another lightning protection device according to an embodiment of the present invention;

FIG. 8 is a schematic structural view showing a modification of a lightning protection device of a lightning protection device according to an embodiment of the present invention; FIG.

FIG. 9 is still another structural diagram of a lightning protection device rectifier circuit according to an embodiment of the present invention.

Detailed

Embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

The embodiments of the present invention provide a lightning protection device and a switching power supply for a switching power supply. The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment of the invention provides a lightning protection device for a switching power supply, and the structure thereof is shown in FIG. 1 and includes:

Lightning protection circuit 1, current limiting circuit 2, rectifier circuit 3 and PFC circuit 4; wherein the two input terminals of the current limiting circuit are respectively connected with the L line output end and the N line output end of the lightning protection circuit, and the two paths of the rectifier circuit The input ends are respectively connected to the two output ends of the current limiting circuit, and the L line output end of the rectifier circuit is connected with the first input end of the PFC circuit and the positive electrode of an electrolytic capacitor, and the negative electrode of the electrolytic capacitor and the second input end of the PFC circuit and The N line output end of the rectifier circuit is connected, and the N line output end of the rectifier circuit is also grounded; the third input end of the PFC circuit is connected to the L line output end of the lightning protection circuit, and the fourth input end of the PFC circuit and the lightning protection circuit N The line outputs are connected.

In the embodiment of the present invention, a current limiting circuit and a rectifying circuit are disposed between the lightning protection circuit and the PFC circuit, and the current limiting circuit and the rectifying circuit are connected through a specific connection manner, and the lightning protection device obtained by the connection method is In the case of lightning strikes or surges, the circuit can be limited by the current limiting circuit, and the circuit can be rectified by the rectifier circuit to shield the impact caused by lightning or surge, and the protection of the lightning protection circuit of the related technology is solved. The lightning performance is insufficient. In the event of lightning strikes or surges, it may cause unstable power supply, power failure, bombing, fire, etc., causing safety accidents.

In implementation, the current limiting circuit is composed of at least one resistor. If there is only one resistor, a resistor can be placed on any branch (the branch corresponding to the L line or the N line). Of course, only one resistor is provided. The effect of setting the resistors on the branch is good; therefore, it is also possible to provide resistors on both branches. When set, the resistances of the two branches should have equal impedance. Therefore, the resistors in the embodiments of the present invention can also be used. The number of the circuit is set to an even number; wherein the L line of the current limiting circuit and the line corresponding to the N line of the current limiting circuit are respectively provided with an equal number of resistors. Of course, the basis is that the resistance value of each resistor is the same. If the resistance of each resistor is different, set the resistor with the same resistance. Optionally, when the above resistor is set as an NTC thermistor, it has better impact resistance.

For the rectifier circuit, it may be composed of an even number of diodes, wherein the L line of the rectifier circuit and the line corresponding to the N line of the rectifier circuit are respectively provided with an equal number of diodes. When setting, if the number of diodes is four, the rectifier circuit is set as a rectifier bridge composed of four diodes.

The lightning protection circuit of the embodiment of the invention may adopt the lightning protection circuit of the same concept as the related art. Optionally, the lightning protection circuit of the embodiment of the invention may include: a common mode inductor, two decoupling inductors, and five a varistor and a gas discharge tube; wherein the L line input end of the lightning protection circuit is connected to the first pressure sensitive inductor, the second pressure sensitive inductor and the first decoupling inductor, and the other end of the second pressure sensitive inductor passes The third varistor is connected to the other end of the first varistor, and the other end of the first varistor is connected to the gas discharge tube; the other end of the first decoupling inductor is connected to one end of the fourth varistor, the first retreat The other end of the coupled inductor is also connected to the input end of the common mode inductor side, and the output end of the common mode inductor side is an L line output end; one end of the second decoupling inductor is connected with the second pressure sensitive inductor and the third pressure sensitive inductor, The other end of the second decoupling inductor is connected to the other end of the fourth varistor, and the other end of the second decoupling inductor is also connected to the input of the other side of the common mode inductor, and the output of the other side of the common mode inductor is a lightning protection circuit. N line output.

The embodiment of the invention further provides a switching power supply, which comprises the lightning protection device of the above switching power supply. According to the above description, those skilled in the art know how to set the lightning protection device of the above switching power supply in the switching power supply, and details are not described herein again.

Alternative embodiment

The embodiment of the present invention solves the problem that the residual voltage of the lightning protection device still exists in the related art. Therefore, the embodiment of the present invention provides a lightning protection device capable of obtaining a low residual voltage, and the structure of the device is as follows. 2, including: lightning protection circuit, current limiting circuit, rectifier circuit and PFC circuit. The lightning protection circuit includes a common mode inductor, two decoupling inductors and five varistor (MOV), one gas discharge tube; the current limiting circuit includes two NTC thermistors (or resistors); the rectifier circuit includes rectification Bridge (or even number of diodes).

In the circuit setting, the lightning protection circuit is in front, and then the current limiting circuit is connected, and then the rectifier circuit. The lightning surge surges in and goes through the lightning protection circuit, current limiting circuit, and rectifier circuit. When the lightning surge voltage enters the L/N line, its peak voltage enters the lightning protection circuit, which consumes most of the lightning surge. Energy, through the current limiting circuit, rectifier circuit, the final output residual voltage is lower than the ordinary lightning protection circuit, to complete the absorption and limitation of lightning surge energy, the power circuit device stress will be smaller for the main circuit topology, use It is safer, and the whole machine is less prone to failures, ensuring safe and reliable operation of electrical equipment.

In the lightning protection device, a current limiting circuit and a rectifier circuit are used. The circuit can share most of the lightning energy for the PFC circuit, effectively reducing the current stress and voltage stress of the PFC power circuit, thereby protecting the PFC component and its subsequent topological components. The current limiting circuit used here can suppress the lightning energy discharged to the capacitor, and the current limiting circuit can effectively control the peak voltage on the large capacitor, thereby ensuring It proves the reliable operation of the entire switching power supply in the latter stage.

The above process will be optionally described with reference to the accompanying drawings.

As shown in FIG. 3, the energy release diagram of the lightning protection device when the L-line is subjected to a lightning surge, as shown in FIG. 4, is a schematic diagram of energy release of the lightning protection device when the N-line is subjected to a lightning surge. In the above two cases, Its peak voltage is first clamped through the varistor RV2, where most of the lightning surge energy is consumed. Then the energy passes through the decoupling inductor, the rate of current change is slowed down, and the energy release rate is also slowed, so that its energy is more consumed in the front RV2 and the varistor RV4 after the decoupling inductance. The remaining lightning surge energy is again slowed down by the leakage inductance of the common mode inductor and is again consumed and clamped by the last varistor RV5. Finally, a small amount of energy is left to charge the large capacitor C1 through the NTC thermistor (or resistor) and the surge bleeder diode, and is absorbed by the capacitor.

Finally, the peak voltage of the large capacitor C1 after being clamped by the lightning protection circuit is very low, and has little effect on the main circuit topology components. Especially for PFC, lightning surge energy is more to run lightning protection circuit, PFC's power consumption component stress will be smaller, the whole machine is safer and more reliable. When there is no lightning surge, the working current does not directly enter the PFC through the bleeder circuit, so that no excess loss is generated and the high efficiency characteristics of the topology are not affected.

When a lightning strike is applied to the ground, most of its energy is consumed by the varistor RV1, RV3 and the discharge tube G1, which has little effect on the components of the main topology.

For the PFC circuit, this embodiment illustrates two common PFC connection modes by using FIG. 5 and FIG.

As shown in Figure 5, the dotted line frame is the connection mode of the first PFC circuit in the lightning protection device. The L line is connected to the PFC inductor L4, the other end of the L4 is connected to the PFC MOS VT1 tube drain and the VT2 source, and the VT1 source is connected. Large capacitor C1 negative, VT2 drain connected to large capacitor positive. The N line is connected to the VD1 negative electrode and the VD2 positive electrode, the VD1 positive electrode is connected to the large capacitor C1 negative electrode, and the VD2 negative electrode is connected to the large capacitor positive electrode.

As shown in Figure 6, the dotted line frame is the connection mode of the second PFC circuit, the L line is connected to the PFC inductor L4, the other end of the L4 is connected to the PFC MOS VT1 tube drain and the VD1 positive pole, and the VT1 tube source is connected to the large capacitor C1 cathode. The negative electrode of VD1 is connected to the positive electrode of C1. The N line is connected to the PFC inductor L5, the other end of the L5 is connected to the V T2 tube drain and the VD2 anode, the VT2 tube source is connected to the large capacitor C1 cathode, and the VD2 cathode is connected to the C1 anode.

As shown in FIG. 7, another structure of the lightning protection device according to the embodiment of the present invention, in which the defense Both the lightning circuit and the current limiting circuit have been changed. The L/N connection is connected to the single-side decoupling inductor L1. In practice, L and N are interchangeable, and then RV4, common mode inductor, RV5, and single-sided NTC (negative temperature) are connected. Coefficient) Thermistor RT1 (or resistor), etc.

FIG. 8 is a schematic view showing a structure of the above-mentioned lightning protection device rectifying circuit, in which the rectifier circuit is provided with only one diode for the L line and the N line. Of course, the polarity of the two diodes can also be adjusted when implementing the setup, such as the lightning protection device shown in FIG.

By using the lightning protection device provided by the above embodiments, the residual voltage is reduced, the effect of effectively protecting the power device is realized, the research and development cost is saved, and the reliability of the product is improved.

Although alternative embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are also possible, and thus the scope of the invention should not be limited to the embodiments described above.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be performed by a program to instruct related hardware, such as a processor, which may be stored in a computer readable storage medium, such as a read only memory, disk or optical disk. Wait. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware, for example, by implementing an integrated circuit to implement its corresponding function, or may be implemented in the form of a software function module, for example, being executed by a processor and stored in a memory. Programs/instructions to implement their respective functions. The invention is not limited to any specific form of combination of hardware and software.

The embodiments disclosed in the present application are as described above, but the descriptions are only for the purpose of understanding the present application, and are not intended to limit the present application, such as the specific implementation method in the embodiments of the present invention. Any modifications and changes in the form and details of the embodiments may be made by those skilled in the art without departing from the spirit and scope of the disclosure. The scope defined by the appended claims shall prevail.

Industrial applicability

The above technical solution realizes the lightning protection performance of the lightning protection circuit and improves the safety of the lightning protection circuit.

Claims

A lightning protection device for a switching power supply, comprising:

Lightning protection circuit, current limiting circuit, rectifier circuit and power factor correction PFC circuit;

The two input ends of the current limiting circuit are respectively connected to the L line output end and the N line output end of the lightning protection circuit, and the two input ends of the rectifier circuit and the two output ends of the current limiting circuit respectively Connected, an L line output end of the rectifier circuit is connected to a first input end of the PFC circuit and an anode of an electrolytic capacitor, a negative electrode of the electrolytic capacitor and a second input end of the PFC circuit and the rectifier circuit The N line output end is connected, and the N line output end of the rectifier circuit is also grounded;

The third input end of the PFC circuit is connected to the L line output end of the lightning protection circuit, and the fourth input end of the PFC circuit is connected to the N line output end of the lightning protection circuit.
A lightning protection device for a switching power supply according to claim 1, wherein said current limiting circuit comprises: one or more resistors.
The lightning protection device of the switching power supply according to claim 2, wherein the number of the resistors is an even number, wherein the L line of the current limiting circuit and the line corresponding to the N line of the current limiting circuit are respectively set equal The number of resistors.
A lightning protection device for a switching power supply according to claim 2, wherein said resistor is a negative temperature coefficient NTC thermistor.
A lightning protection device for a switching power supply according to claim 1, wherein

The rectifier circuit is composed of an even number of diodes, wherein the L line of the rectifier circuit and the line corresponding to the N line of the rectifier circuit are respectively provided with an equal number of diodes.
A lightning protection device for a switching power supply according to claim 5, wherein said rectifier circuit is a rectifier bridge composed of four said diodes when said number of diodes is four.
The lightning protection device for a switching power supply according to any one of claims 1 to 6, wherein the lightning protection circuit comprises:

a common mode inductor, two decoupling inductors, five varistor and one gas discharge tube;

The L line input end of the lightning protection circuit is connected to the first pressure sensitive inductor, the second pressure sensitive inductor and the first decoupling inductor, and the other end of the second pressure sensitive inductor passes through the third pressure sensitive inductor and the first a varistor The other end of the sense is connected, the other end of the first pressure sensitive inductor is connected to the gas discharge tube;

The other end of the first decoupling inductor is connected to one end of the fourth varistor inductor, and the other end of the first decoupling inductor is further connected to an input end of the common mode inductor side, the common mode inductor side The output end is an L line output end of the lightning protection circuit;

One end of the second decoupling inductor is connected to the second varistor and the third varistor, and the other end of the second decoupling inductor is connected to the other end of the fourth varistor. The other end of the second decoupling inductor is further connected to an input end of the other side of the common mode inductor, and an output end of the other side of the common mode inductor is an N line output end of the lightning protection circuit.
A switching power supply comprising: the lightning protection device of the switching power supply according to any one of claims 1 to 7.