WO2019024416A1

WO2019024416A1 - Lightning protection circuit of led street lamp driving power supply

Info

Publication number: WO2019024416A1
Application number: PCT/CN2017/119899
Authority: WO
Inventors: 彭国允; 贺林波
Original assignee: 深圳市暗能量电源有限公司
Priority date: 2017-08-01
Filing date: 2017-12-29
Publication date: 2019-02-07
Also published as: CN109327018A

Abstract

A lightning protection circuit of an LED street lamp driving power supply, comprising a I-stage lightning protection circuit (001), a II-stage lightning protection circuit (002), an EMI circuit (003) circuit, a rectification filter circuit (004), a III-stage lightning protection circuit (005), a transformer (T1), a secondary circuit (006), a switching circuit (007), a control circuit (008), a IV-stage lightning protection circuit (009), and a V-stage lightning protection circuit (100). A first input end, a second input end, and a third input end of the I-stage lightning protection circuit are respectively connected to a live wire end (L), a neutral line end (N), and a ground end (FG) of an power input end (L); the first input end, the second input end, and the third input end of the I-stage lightning protection circuit are respectively connected to the first input end, the second input end, and the third input end of the II-stage lightning protection circuit; the first input end and the second input end of the II-stage lightning protection circuit are respectively connected to the first input end and the second input end of the EMI circuit. The lightning protection circuit of the LED street lamp driving power supply can solve the problem in the existing LED street lamp of poor lightning protection performance, and can improve the lightning protection reliability of the street lamp driving power supply.

Description

LED street light driving power supply lightning protection circuit

Technical field

The invention relates to the field of LED street lamps, in particular to a lightning protection circuit for an LED street lamp driving power source.

Background technique

With the advocacy of national energy conservation and environmental protection policies, lighting LEDs have become more and more popular, LED lighting era has arrived, LED street lights are being used more and more widely. Because the LED street light is placed at an outdoor high, it is easy to be struck by lightning. In the case of lightning, the lightning will be introduced into the driving power and signal lines of the LED, and the peak voltage or peak current amplitude due to lightning induction or electromagnetic induction. Will be very high, the spike voltage or spike current will destroy the LED street light equipment. In order to achieve the purpose of lightning protection, lightning protection circuits are generally placed at the input end of the driving power supply circuit of the LED street lamp. The lightning protection device uses a metal zinc oxide varistor, but the lightning protection circuit can withstand a limited amplitude and energy. The varistor will gradually age and gradually fail after many lightning strikes or surges, and therefore, the existing LED street lamp has poor lightning protection performance. In addition, the lightning protection device in the existing lightning protection circuit itself has the defects of less impact resistance and short life, and therefore the reliability of the lightning protection of the existing street lamp power supply is not high.

Summary of the invention

The technical problem to be solved by the present invention is that, in view of the above-mentioned defects of the prior art, an LED street lamp driving power source lightning protection capable of solving the problem that the existing LED street lamp has poor lightning protection performance and improving the reliability of the street lamp power supply lightning protection is provided. Circuit.

The technical solution adopted by the invention to solve the technical problem is: constructing a lightning protection circuit for the LED street lamp driving power source, including a class I lightning protection circuit, a class II lightning protection circuit, an EMI circuit, a rectification and filtering circuit, a class III lightning protection circuit, a transformer, a secondary circuit, a switching circuit, a control circuit, a Class IV lightning protection circuit, and a V-level lightning protection circuit, wherein the first input terminal, the second input terminal, and the third input terminal of the Class I lightning protection circuit are respectively a first end, a second end, and a third end of the I-level lightning protection circuit are respectively connected to the first input end of the level II lightning protection circuit The second input end and the third input end are connected, and the first output end and the second output end of the II level lightning protection circuit are respectively connected to the first input end and the second input end of the EMI circuit, wherein the EMI The first output end and the second output end of the circuit are respectively connected to the first input end and the second input end of the rectifying and filtering circuit, and the first output end and the second output end of the rectifying and filtering circuit are respectively associated with the III First input of the lightning protection circuit The first output end of the III-level lightning protection circuit is connected to one end of the primary coil of the transformer, and the second output end of the III-level lightning protection circuit is grounded;

The first end of the switch circuit is connected to the other end of the primary coil of the transformer, the second end of the switch circuit is connected to the ground end of the switch, and the control end of the switch circuit is connected to the drive pin of the control circuit a first input of the secondary circuit is coupled to one end of the secondary winding of the transformer, and a second input of the secondary circuit is coupled to the other end of the secondary winding of the transformer, the IV stage a lightning protection circuit is disposed between the first end and the second end of the switch circuit, a power pin of the control circuit is connected to one end of the auxiliary coil of the transformer, and the other end of the auxiliary coil of the transformer is connected At the ground end of the board, a first input end of the V-level lightning protection circuit is connected to a driving pin of the control circuit, and a second input end of the V-level lightning protection circuit and a power pin of the control circuit connection.

In the LED street lamp driving power source lightning protection circuit of the present invention, the class I lightning protection circuit includes a first suppression common mode lightning strike interference module and a first suppression differential mode lightning strike interference module, and the first suppression common mode lightning strike interference The first input end, the second input end and the third input end of the module are respectively connected to the live end, the neutral end and the ground end of the power input end, and the first output of the first suppression common mode lightning strike interference module, The second output end and the third output end are respectively connected to the first input end, the second input end and the ground end of the first differential mode lightning strike interference module, and the first output end of the first suppression differential mode lightning strike interference module And the second output end is respectively connected to the first input end and the second input end of the level II lightning protection circuit.

In the LED street lamp driving power source lightning protection circuit of the present invention, the class II lightning protection circuit comprises a second suppression common mode lightning strike interference module and a second suppression differential mode lightning strike interference module, and the second suppression common mode lightning strike interference The first input end, the second input end and the third input end of the module are respectively connected to the first output end, the second output end and the ground end of the I-level lightning protection circuit, and the second suppression common mode lightning strike interference module The first output end and the second output end are respectively connected to the first input end and the second input end of the EMI circuit, and the first output end and the second output end of the second suppression differential mode lightning strike interference module respectively The first input of the EMI circuit is coupled to the second input.

In the LED street lamp driving power supply lightning protection circuit of the present invention, the III-level lightning protection circuit includes a third suppression differential mode lightning strike interference module, and the first input and the second suppression of the third suppression differential mode lightning strike interference module The input ends are respectively connected to the first output end and the second output end of the rectifying and filtering circuit, and the first output end and the second output end of the third suppressing differential mode lightning striking interference module are respectively associated with the primary coil of the transformer One end is connected to the ground end of the board.

In the LED street lamp driving power supply lightning protection circuit of the present invention, the first suppression common mode lightning strike interference module comprises a first varistor, a second varistor, a first gas discharge tube and a second gas discharge tube, One end of the first varistor is connected to a live end of the power input end, the other end of the first varistor is connected to one end of the first gas discharge tube, and the other of the first gas discharge tube One end is connected to the ground end, one end of the second varistor is connected to a neutral end of the power input end, and the other end of the second varistor is connected to one end of the second gas discharge tube. The other end of the second gas discharge tube is connected to the ground end, and the first suppression differential mode lightning strike interference module comprises a third varistor and a third gas discharge tube, one end of the third varistor The other end of the third varistor is connected to one end of the third gas discharge tube, and the other end of the third gas discharge tube is connected to the neutral end of the power input end.

In the LED street lamp driving power source lightning protection circuit of the present invention, the second suppression common mode lightning strike interference module comprises a first thermistor, a second thermistor, a first safety capacitor and a second safety capacitor. One end of the first thermistor is connected to the first output end of the first suppression differential mode lightning strike interference module, and the other end of the first thermistor is connected to one end of the first safety capacitor. The other end of the first safety capacitor is connected to the ground terminal, and one end of the second thermistor is connected to the second output end of the first suppression differential mode lightning strike interference module, the second thermistor The other end of the second safety capacitor is connected to the ground end of the second safety capacitor, and the second suppression differential mode lightning strike interference module comprises a fourth varistor. One end of the fourth varistor is connected to the first output end of the second suppression common mode lightning strike interference module, and the other end of the fourth varistor is opposite to the second suppression common mode lightning strike interference module The output is connected.

In the LED street lamp driving power source lightning protection circuit of the present invention, the third suppression differential mode lightning strike interference module includes a fifth varistor connected in parallel between the first output end of the rectifying and filtering circuit and the ground, and a first current limiting inductor, one end of the first current limiting inductor is connected to the first output end of the rectifying and filtering circuit, and the other end of the first current limiting inductor is connected to one end of the fifth varistor The other end of the fifth varistor is connected to the second output end of the rectifying and filtering circuit.

In the LED street lamp driving power source lightning protection circuit of the present invention, the class IV lightning protection circuit comprises a first bidirectional transient voltage suppression diode and a first absorption capacitor, and a cathode of the first bidirectional transient voltage suppression diode a first end of the switching circuit is connected, an anode of the first bidirectional transient voltage suppression diode is connected to a second end of the switching circuit, and one end of the first absorption capacitor and the first bidirectional transient voltage The cathode connection of the diode is suppressed, and the other end of the first absorption capacitor is connected to the anode of the first bidirectional transient voltage suppression diode.

In the LED street lamp driving power supply lightning protection circuit of the present invention, the V-level lightning protection circuit includes a second bidirectional transient voltage suppression diode, a third bidirectional transient voltage suppression diode, and a second peak absorption capacitor, a cathode of the bidirectional transient voltage suppression diode is connected to a control end of the switching circuit, an anode of the second bidirectional transient voltage suppression diode is connected to the ground terminal, and the third bidirectional transient voltage suppression diode a cathode is connected to a power supply pin of the control circuit, an anode of the third bidirectional transient voltage suppression diode is connected to the ground end of the board, and one end of the second peak absorbing capacitor and the third bidirectional transient voltage The cathode connection of the diode is suppressed, and the other end of the second peak absorption capacitor is connected to the anode of the third bidirectional transient voltage suppression diode.

In the LED street lamp driving power supply lightning protection circuit of the present invention, the switching circuit includes a first MOS transistor, and a drain of the first MOS transistor is a first end of the switching circuit, and the first MOS transistor The source is extremely second end of the switching circuit, and the gate of the first MOS transistor is a control end of the switching circuit.

The LED street lamp driving power source lightning protection circuit embodying the invention has the following beneficial effects: a level I lightning protection circuit, a class II lightning protection circuit, an EMI circuit, a rectification and filtering circuit, a class III lightning protection circuit, a transformer, and a secondary circuit. , switch circuit, control circuit, class IV lightning protection circuit and V-level lightning protection circuit, the LED street lamp driving power supply lightning protection circuit is a 5-level lightning protection driving power circuit, which can solve the lightning protection device itself has less impact resistance and short life The defects, thereby significantly improving the lightning protection reliability of the street lamp power supply, can solve the problem that the existing LED street lamp has poor lightning protection performance, and can improve the reliability of the lightning protection of the street lamp power supply.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

1 is a schematic structural view of an embodiment of a lightning protection circuit for an LED street lamp driving power supply according to the present invention;

2 is a circuit schematic diagram of a Class I lightning protection circuit in the embodiment;

3 is a circuit schematic diagram of a class II lightning protection circuit in the embodiment;

4 is a circuit schematic diagram of a class III lightning protection circuit in the embodiment;

Fig. 5 is a circuit schematic diagram of a class V lightning protection circuit in the embodiment.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

In the embodiment of the LED street lamp driving power source lightning protection circuit of the present invention, a schematic structural diagram of the LED street lamp driving power source lightning protection circuit is shown in FIG. 1 . In FIG. 1, the LED street lamp driving power supply lightning protection circuit comprises a class I lightning protection circuit 001, a class II lightning protection circuit 002, an EMI circuit 003, a rectification and filtering circuit 004, a class III lightning protection circuit 005, a transformer T1, and a secondary circuit 006. The switch circuit 007, the control circuit 008, the IV-level lightning protection circuit 009 and the V-level lightning protection circuit 100, wherein the first input end, the second input end and the third input end of the I-level lightning protection circuit 001 are respectively connected with the power input The first end, the second end and the third end of the I-level lightning protection circuit 001 are respectively connected with the first input end of the second-level lightning protection circuit 002, The second input end and the third input end are connected, and the first output end and the second output end of the II level lightning protection circuit 002 are respectively connected to the first input end and the second input end of the EMI circuit 003, and the first of the EMI circuit 003 The output end and the second output end are respectively connected to the first input end and the second input end of the rectifying and filtering circuit 004, and the first output end and the second output end of the rectifying and filtering circuit 004 are respectively the first of the III-level lightning protection circuit 005 The input terminal is connected to the second input terminal, and the level III lightning protection circuit 005 The first output terminal is connected to one end of the primary coil of the transformer T1, and the second output terminal of the III-level lightning protection circuit 005 is grounded.

The first end of the switch circuit 007 is connected to the other end of the primary coil of the transformer T1, the second end of the switch circuit 007 is connected to the ground end of the board, and the control end of the switch circuit 007 is connected to the drive pin of the control circuit 008, and the secondary circuit 006 The first input terminal is connected to one end of the secondary coil of the transformer T1, the second input terminal of the secondary circuit 006 is connected to the other end of the secondary coil of the transformer T, and the IV-level lightning protection circuit 009 is disposed at the switch circuit 007. Between one end and the second end, the power pin of the control circuit 008 is connected to one end of the auxiliary coil of the transformer T, and the other end of the auxiliary coil of the transformer T is connected to the ground end of the board, and the first input of the V-level lightning protection circuit 100 The terminal is connected to the driving pin of the control circuit 008, and the second input terminal of the V-level lightning protection circuit 100 is connected to the power pin of the control circuit 008.

The invention has a level I lightning protection circuit 001, a class II lightning protection circuit 002, an EMI circuit 003, a rectification and filtering circuit 004, a class III lightning protection circuit 005, a transformer T1, a secondary circuit 006, a switching circuit 007, and a control circuit 008. The fourth-level lightning protection circuit 009 and the V-level lightning protection circuit 100, the LED street lamp driving power lightning protection circuit is a 5-level lightning protection driving power circuit, which can solve the defect that the lightning protection device itself has less impact resistance and short life, thereby Significantly improve the lightning protection reliability of the street lamp power supply, so it can solve the problem that the existing LED street lamp has poor lightning protection performance and can improve the reliability of the lightning protection of the street lamp power supply.

2 is a circuit schematic diagram of a class I lightning protection circuit in the embodiment. In FIG. 2, the class I lightning protection circuit 001 includes a first suppression common mode lightning strike interference module 101 and a first suppression differential mode lightning strike interference module 102, wherein The first input end, the second input end, and the third input end of the first suppression common mode lightning strike interference module 101 are respectively connected to the live end L, the neutral end N and the ground end FG of the power input end, and the first suppressing common mode lightning strike The first output end, the second output end, and the third output end of the interference module 101 are respectively connected to the first input end, the second input end, and the ground end FG of the first differential mode lightning strike interference module 102, and the first suppression differential mode lightning strike The first output end and the second output end of the interference module 102 are respectively connected to the first input end and the second input end of the level II lightning protection circuit 002.

The first suppression common mode lightning strike interference module 101 includes a first varistor MOV1, a second varistor MOV2, a first gas discharge tube GD1 and a second gas discharge tube GD2, wherein one end of the first varistor MOV1 and the power source The live end L of the input end is connected, the other end of the first varistor MOV1 is connected to one end of the first gas discharge tube GD1, the other end of the first gas discharge tube GD1 is connected to the ground end FG, and one end of the second varistor MOV2 Connected to the neutral terminal N of the power input terminal, the other end of the second varistor MOV2 is connected to one end of the second gas discharge tube GD2, and the other end of the second gas discharge tube GD2 is connected to the ground terminal FG, the first suppression differential mode The lightning strike interference module 102 includes a third varistor MOV3 and a third gas discharge tube GD3. One end of the third varistor MOV3 is connected to the live end L of the power input end, and the other end of the third varistor MOV3 is discharged with the third gas. One end of the tube GD3 is connected, and the other end of the third gas discharge tube GD3 is connected to the neutral end N of the power input end.

By designing the different parameters of the class I lightning protection circuit 001, the class II lightning protection circuit 002, the class III lightning protection circuit 003, the class IV lightning protection circuit 009 and the class V lightning protection circuit 100, the lightning strike absorbed by the class I lightning protection circuit 001 The energy of the lightning protection circuit 002 is higher than that of the lightning protection circuit 002. The lightning energy of the lightning protection circuit 002 is higher than that of the lightning protection circuit 005. The lightning protection circuit 009 absorbs the residual energy of the two ends of the switching circuit 007. The level lightning protection circuit 100 absorbs residual voltage to the energy of the chip level.

When the lightning strike voltage is applied between the live terminal L and the neutral terminal N of the power input terminal, the first suppression differential mode lightning strike interference module 102 clamps the lightning strike voltage under a safe voltage, thereby protecting the back end circuit when the lightning strike voltage is loaded. When the power line input end is between the live line end L, the neutral line end N and the ground end FG, the first suppression common mode lightning strike interference module 101 absorbs the lightning strike voltage and discharges, thereby protecting the back end circuit, and the pressure sensitive in the level I lightning protection circuit 001 The resistor and gas discharge tube device adopts a large-volume, high-threshold device, absorbs a part of a high-amplitude lightning surge signal, and outputs a high-voltage lightning surge signal. The device of the I-level lightning protection circuit 001 itself suffers a large heat loss. The potting epoxy resin can reduce the thermal effect of the device, and the encapsulating epoxy resin can block the air and moisture, and significantly improve the bearing capacity and anti-interference ability of the device itself.

3 is a circuit schematic diagram of a level II lightning protection circuit in the embodiment. In FIG. 3, the level II lightning protection circuit 002 includes a second suppression common mode lightning strike interference module 201 and a second suppression differential mode lightning strike interference module 202, wherein The first input end, the second input end, and the third input end of the second suppression common mode lightning strike interference module 201 are respectively connected to the first output end, the second output end, and the ground end FG of the I-level lightning protection circuit 001, The first output end and the second output end of the second suppression common mode lightning strike interference module 201 are respectively connected to the first input end and the second input end of the EMI circuit 003, and the second output of the second suppression differential mode lightning strike interference module 202 is The second output is coupled to the first input and the second input of the EMI circuit 003, respectively.

In this embodiment, the second suppression common mode lightning strike interference module 201 includes a first thermistor NTC1, a second thermistor NTC2, a first safety capacitor CY1, and a second safety capacitor CY2, wherein the first thermistor One end of the NTC1 is connected to the first output end of the first suppression differential mode lightning strike interference module 102, and the other end of the first thermistor TC1 is connected to one end of the first safety capacitor CY1, and the other end of the first safety capacitor CY1 is The ground terminal is connected, one end of the second thermistor NTC2 is connected to the second output end of the first suppression differential mode lightning strike interference module 102, and the other end of the second thermistor NTC2 is connected to one end of the second safety capacitor CY2, The other end of the second safety capacitor CY2 is connected to the ground terminal FG, and the second suppression differential mode lightning strike interference module 202 includes a fourth varistor MOV4, one end of the fourth varistor MOV4 and the second suppression common mode lightning strike interference module 201. The first output terminal is connected, and the other end of the fourth varistor MOV4 is connected to the second output end of the second suppression common mode lightning strike interference module 201.

In this embodiment, the higher residual voltage output end of the level I lightning protection circuit 001 is connected to the level II lightning protection circuit 002, and the residual voltage is loaded in the level II lightning protection circuit 002 after being absorbed by the level I lightning protection circuit 001. The second suppression differential mode lightning strike interference module 202 clamps the lightning strike voltage to a lower residual voltage. When absorbed by the I-level lightning protection circuit 001, the residual voltage is loaded on the two input terminals of the second-level lightning protection circuit 002. When between the ground and the ground FG, the second suppression common mode lightning strike interference module 201 absorbs the residual voltage after the absorption of the level I lightning protection circuit 001 and discharges, thereby protecting the back end device.

4 is a circuit schematic diagram of a class III lightning protection circuit in the embodiment. In FIG. 4, the class III lightning protection circuit 005 includes a third suppression differential mode lightning strike interference module, and a third suppression differential mode lightning strike interference module first input. The first output end and the second input end are respectively connected to the first output end and the second output end of the rectifying and filtering circuit 004, and the first output end and the second output end of the third suppression differential mode lightning striking interference module are respectively connected with the primary coil of the transformer T1 One end is connected to the ground end of the board. The third suppression differential mode lightning strike interference module comprises a fifth varistor MOV5 and a first current limiting inductor L1, and the fifth varistor MOV5 and the first current limiting inductor L1 are connected in parallel at the first output end of the rectifying and filtering circuit and the ground One end of the first current limiting inductor L1 is connected to the first output end of the rectifying and filtering circuit 004, the other end of the first current limiting inductor L1 is connected to one end of the fifth varistor MOV5, and the other end of the fifth varistor MOV5 One end is connected to the second output of the rectifying and filtering circuit 004.

In this embodiment, the lower residual voltage output end of the level II lightning protection circuit 002 is connected to the input end of the level III lightning protection circuit 005, and the lower residual voltage is loaded in the class III protection after being absorbed by the level II lightning protection circuit 002. When the lightning circuit 005 is between the two input terminals, the third suppression differential mode lightning strike interference module clamps the lightning strike voltage to a lower residual voltage, so that the residual voltage across the switch circuit 007 is further reduced.

In this embodiment, the level IV lightning protection circuit 009 includes a first bidirectional transient voltage suppression diode TVS1 and a first absorption capacitor C1. The cathode of the first bidirectional transient voltage suppression diode TVS1 is connected to the first end of the switch circuit 008. The anode of a bidirectional transient voltage suppression diode TVS1 is connected to the second end of the switching circuit 008. One end of the first absorption capacitor C1 is connected to the cathode of the first bidirectional transient voltage suppression diode TVS1, and the other end of the first absorption capacitor C1 is The anode of the first bidirectional transient voltage suppression diode TVS1 is connected. The first bidirectional transient voltage suppression diode TVS1 and the first absorption capacitor C1 constitute a fourth suppression differential mode lightning strike interference module.

The lower residual voltage output of the III-level lightning protection circuit 005 is connected to the input end of the IV-level lightning protection circuit 009, and the IV-level lightning protection circuit 009 is mainly composed of the TVS tube, and the fourth suppression differential mode lightning strike interference module is set. The absorption of low residual voltage is faster, thereby better protecting the switching circuit 007.

5 is a circuit schematic diagram of a V-level lightning protection circuit in the embodiment. In FIG. 5, an output port of the control circuit 008 includes a power supply pin VCC, a driving pin DRV, and a reference ground end (not shown). The ground terminal is connected to the ground terminal, and the V-level lightning protection circuit 100 includes a second bidirectional transient voltage suppression diode TVS2, a third bidirectional transient voltage suppression diode TVS3 and a second peak absorption capacitor C2, and a second bidirectional transient voltage. The suppression diode TVS2, the third bidirectional transient voltage suppression diode TVS3 and the second peak absorption capacitor C2 constitute a fifth suppression differential mode lightning strike interference module, wherein the cathode of the second bidirectional transient voltage suppression diode TVS2 and the control terminal of the switch circuit 007 Connected, the second bidirectional transient voltage suppression diode TVS2 is connected to the ground terminal of the anode, the cathode of the third bidirectional transient voltage suppression diode TVS3 is connected with the power supply pin of the control circuit 007, and the third bidirectional transient voltage suppression diode TVS3 At the ground end of the anode connection plate, one end of the second peak absorption capacitor C2 is connected to the cathode of the third bidirectional transient voltage suppression diode TVS3, and the other end of the second peak absorption capacitor C2 Connected to the anode of the third bidirectional transient voltage suppression diode TVS3.

The V-level lightning protection circuit 100 is a chip-level protection circuit, and the V-level lightning protection circuit 100 is mainly composed of a small capacitor and a TVS tube, and the speed and peak absorption capability are more remarkable, and the protection control circuit 008 pins are protected from lightning strikes caused by abnormal interference. The peak destroys the chip; it can also protect the ESD and other abnormal excitation spikes caused by electromagnetic induction from being introduced into the pins of the control circuit 008, thereby better protecting the control circuit 008; thus, the 5-level lightning protection circuit is matched with different parameters step by step. Lightning protection circuit for derating absorption, high energy absorption in the front stage, large-volume high-threshold device, epoxy resin potting method; energy absorption in the middle lightning protection circuit, medium-sized device; small energy absorption in the latter stage, The use of a small-volume, relatively low threshold device; not only can greatly improve the lightning protection capability of the street lamp power supply, but also better improve the impact resistance and withstand capability of the device itself, thereby greatly improving the lightning protection performance of the LED street lamp. Lightning safety, reliability, continuity and flexibility.

In this embodiment, the switch circuit 007 includes a first MOS transistor Q1, the drain of the first MOS transistor Q1 is the first end of the switch circuit 007, and the source of the first MOS transistor Q1 is the second end of the switch circuit 007, the first MOS The gate of the tube Q1 is the control terminal of the switching circuit 007.

When the lightning surge signal is loaded between the live end L and the neutral end N of the power input end, the lightning surge amplitude exceeds the sum of the working threshold voltages of the third varistor MOV3 and the third gas discharge tube GD3, The magnitude of the three varistor MOV3 exceeding the clamp voltage is converted into leakage current discharge, and the third gas discharge tube GD3 exceeds the valve voltage and is instantaneously short-circuited, and a part of the lightning surge between the live end L of the power input end and the zero line end N The circuit is vented to the ground terminal FG by the first suppression differential mode lightning strike interference module 102.

The residual voltage is output to the level II lightning protection circuit 002. When the lightning surge signal is loaded between the live line end L, the neutral line end N and the ground end FG of the power input end, the instantaneous short circuit clamps the lightning strike voltage to a safe voltage, thereby Protecting the back-end circuit, when the lightning strike voltage is applied between the live line end L, the neutral line end N and the ground end G of the power input end, the first suppression common mode lightning strike interference module 101 acts, and the live line end L of the power input end is connected to the ground end The amplitude of the lightning surge of the FG exceeds the sum of the working threshold voltages of the first varistor MOV1 and the first bulk discharge tube GD1, and the amplitude of the first varistor MOV1 exceeding the clamp voltage is converted into a leakage current discharge, A gas discharge tube GD1 exceeds the valve voltage and is instantaneously short-circuited. The energy of the neutral terminal end of the power supply terminal N to the ground terminal FG is discharged through the first varistor MOV1 and the first gas discharge tube GD1; the neutral line N of the power input end The lightning surge amplitude of the ground terminal FG exceeds the sum of the working threshold voltages of the second varistor MOV2 and the second gas discharge tube GD2, and the amplitude of the second varistor MOV2 exceeding the clamp voltage is converted into leakage current discharge. , the second gas discharge tube GD2 Momentary short voltage through the valve, the power input terminal N of the neutral ground terminal FG GD2 discharge energy bleed through the second gas and a second varistor MOV2.

When the differential mode residual voltage absorbed by the level I lightning protection circuit 001 is input to the second suppression differential mode lightning strike interference module 201, the valve voltage of the fourth varistor MOV4 is triggered, and the fourth varistor MOV4 is instantaneously clamped to form The leakage spike absorbs the surge voltage and outputs a lower residual voltage to the III-level lightning protection circuit 005. The first thermistor NTC1 and the second thermistor NTC2 mainly respond to the differential mode current-limit output during cold start, and control the differential mode current wave. The surge peak; the common mode spike output after absorption by the level I lightning protection circuit 001 is output to the second suppression differential mode lightning strike interference module 201, and the absorption can be adjusted according to the adjusted parameters of the first safety capacitor CY1 and the second safety capacitor CY2. The energy of the common mode peak is discharged to the ground terminal FG, thereby adjusting and suppressing the common mode residual voltage output.

The first current limiting inductor L1 prevents the sudden change of the surge current, and provides the decoupling time for the bleeder current of the latter stage, ensuring that the energy can be discharged in time without damage to the lightning surge absorbing device, after the level II lightning protection circuit 002 After absorption, the differential mode has low residual voltage, triggering the valve voltage of the fifth varistor MOV5, the fifth varistor MOV5 clamp output, the differential mode high amplitude peak voltage is converted into leakage current discharge, and the differential mode voltage is absorbed again. The output voltage of the III-level lightning protection circuit 005 is applied to both ends of the transformer T1 and the switch circuit 007. A sharply changing current flows in the primary coil of the transformer T1, and a part of the energy is passed through the auxiliary coil coupled to the transformer T1 to form a large peak voltage. This large spike voltage can damage the power supply pin VCC of the control circuit 008.

The V-level lightning protection circuit 100 is a chip-level lightning protection circuit, and absorbs the third bidirectional transient voltage suppression diode TVS3 (bidirectional bidirectional transient voltage suppression diode) and the second peak absorption capacitor C2 with faster response speed, bidirectional bidirectional transient The voltage suppression diode TVS works on the principle of bidirectional clamping, which can absorb the voltage abrupt signal caused by the coupling, thus better protecting the power supply pin of the control circuit. The residual voltage outputted by the III-level lightning protection circuit 005 is loaded to the two ends of the MOS transistor Q1 of the switch circuit 007 through the primary coil of the transformer T1, and the IV-level lightning protection circuit 009 is the MOS tube lightning protection circuit. When the residual voltage is applied to the MOS tube Q1 is also equivalent to the first bidirectional transient voltage suppression diode TVS1 and the first absorption capacitor C1 loaded on both ends of the MOS transistor Q1, and the response speed is superior to the pressure sensitive first bidirectional transient voltage suppression diode TVS1 and the first absorption. The capacitor C1 instantaneously absorbs the voltage across the MOS transistor Q1, thereby better protecting the MOS transistor Q1 from damage.

The first current limiting inductor L1 and the primary winding of the transformer T1 provide sufficient decoupling discharge time for the TVS tube to better protect the damage of the device itself; the gate of the MOS transistor Q1 is connected to the second bidirectional of the V-level lightning protection circuit 100. The bidirectional transient voltage suppression diode TVS2 tube, when the lightning surge signal passes through the input coupling capacitor of the MOS transistor Q1, when the drain is injected from the drain to the gate, the second bidirectional bidirectional transient voltage suppression diode TVS2 instantaneously clamps the breakdown, The gate voltage of the MOS transistor Q1 is clamped, and the driving pin DRV of the protection control circuit 008 is protected from high voltage filling, thereby preventing the lightning strike signal from being connected to the protection control circuit 008 through induction and coupling for protection purposes.

In summary, the present invention adopts a step-by-step derating absorption method by adjusting the parameters of the 5-level lightning protection absorption, which can greatly improve the lightning protection performance of the LED street lamp, and can also significantly increase the life and reliability of the lightning protection device itself.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., which are included in the spirit and scope of the present invention, should be included in the present invention. Within the scope of protection.

Claims

LED street lamp driving power source lightning protection circuit, comprising: class I lightning protection circuit, class II lightning protection circuit, EMI circuit, rectifier filter circuit, class III lightning protection circuit, transformer, secondary circuit, switching circuit, control a circuit, a class IV lightning protection circuit and a V-level lightning protection circuit, wherein the first input end, the second input end and the third input end of the I-level lightning protection circuit are respectively connected to a live line end and a zero line end of the power input end Connecting the ground terminal, the first output end, the second output end, and the third output end of the I-level lightning protection circuit are respectively connected to the first input end, the second input end, and the third input end of the II-level lightning protection circuit Connecting, the first output end and the second output end of the level II lightning protection circuit are respectively connected to the first input end and the second input end of the EMI circuit, the first output end and the second output of the EMI circuit The terminals are respectively connected to the first input end and the second input end of the rectifying and filtering circuit, and the first output end and the second output end of the rectifying and filtering circuit are respectively associated with the first input end of the III-level lightning protection circuit The second input is connected, and the third-level lightning protection End of the primary winding of the first path output terminal connected to the transformer, the lightning protection circuit stage Ⅲ second output connected to ground;

The first end of the switch circuit is connected to the other end of the primary coil of the transformer, the second end of the switch circuit is connected to the ground end of the switch, and the control end of the switch circuit is connected to the drive pin of the control circuit a first input of the secondary circuit is coupled to one end of the secondary winding of the transformer, and a second input of the secondary circuit is coupled to the other end of the secondary winding of the transformer, the IV stage a lightning protection circuit is disposed between the first end and the second end of the switch circuit, a power pin of the control circuit is connected to one end of the auxiliary coil of the transformer, and the other end of the auxiliary coil of the transformer is connected At the ground end of the board, a first input end of the V-level lightning protection circuit is connected to a driving pin of the control circuit, and a second input end of the V-level lightning protection circuit and a power pin of the control circuit connection.
The LED street lamp driving power source lightning protection circuit according to claim 1, wherein the class I lightning protection circuit comprises a first suppression common mode lightning strike interference module and a first suppression differential mode lightning strike interference module, wherein the first suppression The first input end, the second input end, and the third input end of the common mode lightning strike interference module are respectively connected to the live end, the neutral end and the ground end of the power input end, and the first suppression common mode lightning strike interference module An output terminal, a second output terminal, and a third output terminal are respectively connected to the first input end, the second input end, and the ground end of the first differential mode lightning strike interference module, wherein the first suppression differential mode lightning strike interference module The first output end and the second output end are respectively connected to the first input end and the second input end of the level II lightning protection circuit.
The LED street lamp driving power source lightning protection circuit according to claim 2, wherein the class II lightning protection circuit comprises a second suppression common mode lightning strike interference module and a second suppression differential mode lightning strike interference module, the second suppression The first input end, the second input end, and the third input end of the common mode lightning strike interference module are respectively connected to the first output end, the second output end, and the ground end of the I-level lightning protection circuit, and the second suppression is common to The first output end and the second output end of the mode lightning strike interference module are respectively connected to the first input end and the second input end of the EMI circuit, and the first output end and the second output of the second suppression differential mode lightning strike interference module The output ends are respectively connected to the first input end and the second input end of the EMI circuit.
The LED street lamp driving power source lightning protection circuit according to claim 3, wherein the III-level lightning protection circuit comprises a third suppression differential mode lightning strike interference module, and the third suppression differential mode lightning strike interference module first input The first output end and the second output end are respectively connected to the first output end and the second output end of the rectifying and filtering circuit, and the first output end and the second output end of the third suppressing differential mode lightning striking interference module are respectively connected to the transformer One end of the primary coil is connected to the ground end of the board.
The LED street lamp driving power source lightning protection circuit according to claim 2, wherein the first suppression common mode lightning strike interference module comprises a first varistor, a second varistor, a first gas discharge tube and a second a gas discharge tube, one end of the first varistor is connected to a live end of the power input end, and the other end of the first varistor is connected to one end of the first gas discharge tube, the first gas The other end of the discharge tube is connected to the ground end, one end of the second varistor is connected to the neutral end of the power input end, and the other end of the second varistor is connected to the second gas discharge tube One end of the second gas discharge tube is connected to the ground end, and the first suppression differential mode lightning strike interference module comprises a third varistor and a third gas discharge tube, the third pressure sensitive One end of the resistor is connected to the live end of the power input end, the other end of the third varistor is connected to one end of the third gas discharge tube, and the other end of the third gas discharge tube is zero with the power input end Line end connection.
The LED street lamp driving power source lightning protection circuit according to claim 3, wherein the second suppression common mode lightning strike interference module comprises a first thermistor, a second thermistor, a first safety capacitor and a second a safety capacitor, one end of the first thermistor is connected to the first output end of the first suppression differential mode lightning strike interference module, and the other end of the first thermistor is opposite to the first safety capacitor Connected to one end, the other end of the first safety capacitor is connected to the ground end, and one end of the second thermistor is connected to the second output end of the first suppression differential mode lightning strike interference module, The other end of the second thermistor is connected to one end of the second safety capacitor, the other end of the second safety capacitor is connected to the ground end, and the second suppression differential mode lightning strike interference module includes a fourth pressure a varistor, one end of the fourth varistor is connected to the first output end of the second suppression common mode lightning strike interference module, and the other end of the fourth varistor is interfered with the second suppression common mode lightning strike The second output of the module is connected.
The LED street lamp driving power source lightning protection circuit according to claim 4, wherein said third suppression differential mode lightning strike interference module comprises a fifth connected in parallel between said first output end of said rectifying and filtering circuit and ground a varistor and a first current limiting inductor, one end of the first current limiting inductor is connected to the first output end of the rectifying and filtering circuit, and the other end of the first current limiting inductor and the fifth varistor One end of the fifth varistor is connected to the second output end of the rectifying and filtering circuit.
The LED street lamp driving power supply lightning protection circuit according to any one of claims 1 to 7, wherein the IV-level lightning protection circuit comprises a first bidirectional transient voltage suppression diode and a first absorption capacitor, the first a cathode of the bidirectional transient voltage suppression diode is connected to the first end of the switch circuit, an anode of the first bidirectional transient voltage suppression diode is connected to a second end of the switch circuit, and one end of the first absorption capacitor Connected to the cathode of the first bidirectional transient voltage suppression diode, the other end of the first absorption capacitor is connected to the anode of the first bidirectional transient voltage suppression diode.
The LED street lamp driving power source lightning protection circuit according to any one of claims 1 to 7, wherein the V-level lightning protection circuit comprises a second bidirectional transient voltage suppression diode, a third bidirectional transient voltage suppression diode, and a second peak absorbing capacitor, a cathode of the second bidirectional transient voltage suppression diode is coupled to a control terminal of the switching circuit, and an anode of the second bidirectional transient voltage suppression diode is coupled to the ground terminal of the board a cathode of the third bidirectional transient voltage suppression diode is connected to a power supply pin of the control circuit, an anode of the third bidirectional transient voltage suppression diode is connected to the ground end of the board, and one end of the second peak absorption capacitor Connected to the cathode of the third bidirectional transient voltage suppression diode, the other end of the second peak absorption capacitor is connected to the anode of the third bidirectional transient voltage suppression diode.
The lightning protection circuit for an LED street lamp driving power supply according to any one of claims 1 to 7, wherein the switching circuit comprises a first MOS transistor, and a drain of the first MOS transistor is a first one of the switching circuit The source of the first MOS transistor is the second end of the switch circuit, and the gate of the first MOS transistor is the control end of the switch circuit.