WO2018214189A1

WO2018214189A1 - Power supply system, and multi-stage protection device for same

Info

Publication number: WO2018214189A1
Application number: PCT/CN2017/088961
Authority: WO
Inventors: 马健; 马骥
Original assignee: 中领世能（天津）科技有限公司
Priority date: 2017-05-26
Filing date: 2017-06-19
Publication date: 2018-11-29
Also published as: CN107086554A

Abstract

The present invention relates to the technical field of safe power supply, and particularly relates to a power supply system, and multi-stage protection device for the same. The multi-stage protection device comprises a cut-out relay and multiple protection relays. The protection relays have an output end connected to a control coil of the cut-out relay in series, and one of the protection relays have a control coil connected to a protection mechanism (1) in series. The protection mechanism (1) is configured to detect operation of a powered network, and control, upon a failure of the powered network and by means of the protection relays, an output end of the cut-out relay to cut power supply to a bus of the powered network. The present invention solves the technical problem in which detection of a potential danger of a powered network and a corresponding measure are not performed in a timely manner, and provides the technical effect of improving safety of a powered network.

Description

Power supply system and multi-level protection device

Cross-reference to related applications

This application claims priority to Chinese Patent Application No. CN201710387440.0, entitled "Power Supply System and Multi-Level Protection Device", issued on May 26, 2017, the entire contents of which are hereby incorporated by reference. In this application.

Technical field

The invention relates to the technical field of safe power supply, in particular to a power supply system and a multi-level protection device thereof.

Background technique

With the development of power technology, power frequency AC (ie, city power) has spread throughout every home and unit, and the safety of electricity has become more and more important.

Current power networks are typically powered by two output lines, one of which is a live line and the other is a zero line. The mains voltage between the two output lines is output by a high voltage power from the grid via a transformer. When electrical equipment fails, or when the line is aging, damaged, or other factors, there are various potential hazards in using the electrical network. Moreover, when the danger occurs, the existing electrical protection device cannot be effectively The line is protected.

Summary of the invention

In view of this, the object of the present invention is to provide a power supply system and a multi-level protection device thereof to solve the technical problem that the prior art cannot find the danger of the power network in time and take corresponding measures.

In a first aspect, an embodiment of the present invention provides a multi-level protection device, including a power-off relay and a plurality of protection relays, wherein an output end of the protection relay is connected in series with a control coil of the power-off relay;

The control coil of any of the protection relays has a protection mechanism connected in series;

The protection mechanism is configured to detect operation of the power network and to control the output of the power-off relay to cut off power to the power network bus when the power network fails.

With reference to the first aspect, an embodiment of the present invention provides a first possible implementation manner of the first aspect, further including an alarm mechanism, an input end of the alarm mechanism, and an output end of the power-off relay are connected to the transformer of the power network bus. The primary coils are connected in series.

With reference to the first aspect, an embodiment of the present invention provides a second possible implementation manner of the first aspect, wherein the alarm mechanism includes a first induction coil, an alarm chip, and an alarm, and two ends of the first induction coil are respectively connected to the alarm chip. Two The input chip, the alarm chip is configured to receive the sensing signal generated by the sensing chip through the first induction coil, and the first induction coil is connected in series with the primary coil of the transformer of the electric network bus, and the alarm chip is connected with the alarm, and the alarm chip It is configured to receive the sensing signal. When the sensing signal exceeds the preset value, the alarm chip outputs an alarm starting signal, and the alarm is configured to issue an alarm according to the alarm starting signal.

In conjunction with the first aspect, an embodiment of the present invention provides a third possible implementation of the first aspect, wherein each protection relay is connected in series with a protection mechanism.

In conjunction with the first aspect, an embodiment of the present invention provides a fourth possible implementation manner of the first aspect, wherein the protection relay includes a first protection relay disposed at a load end of the power network, and the control coil of the first protection relay is connected to the arc extinguishing The output of the protection mechanism.

With reference to the first aspect, the embodiment of the present invention provides a fifth possible implementation manner of the first aspect, wherein the arc extinguishing protection mechanism comprises a coupling circuit and an arc extinguishing chip, and the arc extinguishing chip is provided with an arc extinguishing material;

The coupling circuit is configured to be connected to the first AC output end of the load end of the power network, and the input end of the arc extinguishing chip is configured to be connected to the second AC output end of the load end of the power network;

An arc generated between the first alternating current output and the second alternating current output is coupled to the arc extinguishing chip via a coupling circuit and absorbs the arc by the arc extinguishing material.

With reference to the first aspect, the embodiment of the present invention provides a sixth possible implementation manner of the first aspect, the arc extinguishing chip further includes an arc detecting unit, a counting unit, and a second triggering unit;

One end of the arc detecting unit is connected to the first alternating current output end, and the other end of the arc detecting unit is connected to the second alternating current output end, and the arc detecting unit is configured to determine the occurrence of an arc between the first alternating current output end and the second alternating current output end, and Detecting the current of the arc;

The counting unit is coupled to the arc detecting unit and configured to record the current accumulated arc number when the arc detecting unit detects the arc;

The second trigger unit is connected to the arc detecting unit and the counting unit, the output end of the arc extinguishing chip is configured to be connected to the first protection relay, and the second trigger unit is configured to be based on the current of the arc detected by the arc detecting unit and the number recorded by the counting unit , generating a power-off signal, and outputting a power-off signal to the first protection relay from the output end of the arc extinguishing chip.

With reference to the first aspect, the embodiment of the present invention provides a seventh possible implementation manner of the first aspect, the protection relay includes a second protection relay disposed at a load end of the power network, and the control coil of the second protection relay is connected to the electric shock protection mechanism. Output.

With reference to the first aspect, an embodiment of the present invention provides an eighth possible implementation manner of the first aspect, wherein the electric shock protection mechanism includes a first sensing circuit and a first protection chip;

The first sensing circuit senses a current signal applied to the load end of the electrical network, generates an induced signal, and transmits the sensing signal to the first protection chip;

The first protection chip generates a safety carrier signal according to the sensing signal, and outputs the safety carrier signal to the load end of the power network, and outputs the reactive power to the ground using the load end of the electrical network.

With reference to the first aspect, the embodiment of the present invention provides a ninth possible implementation manner of the first aspect, wherein the electric shock protection mechanism further includes a first rectifying circuit, wherein the two input ends of the first rectifying circuit are respectively connected to the first alternating current The output end and the second AC output end, the output end of the first rectifier circuit is connected to the power end of the first protection chip.

With reference to the first aspect, an embodiment of the present invention provides a tenth possible implementation manner of the first aspect, wherein the protection relay comprises a third protection relay disposed at a load end of the power network, and the control coil connection isolation protection of the third protection relay The output of the mechanism.

With reference to the first aspect, an embodiment of the present invention provides an eleventh possible implementation manner of the first aspect, wherein the isolation protection mechanism comprises a second sensing circuit and an isolation chip;

The second sensing circuit senses a current signal applied to the load end of the electrical network, generates an induced signal, and transmits the sensing signal to the isolation chip;

The isolation chip generates an isolated carrier signal according to the sensing signal, and outputs the isolated carrier signal to the load end of the power network.

With reference to the first aspect, the embodiment of the present invention provides the twelfth possible implementation manner of the first aspect, wherein the isolation protection mechanism further includes a second rectifying circuit, and the two input ends of the second rectifying circuit are respectively connected to the first The AC output end and the second AC output end, and the output end of the second rectifying circuit is connected to the power end of the isolation chip.

In conjunction with the first aspect, an embodiment of the present invention provides a thirteenth possible implementation manner of the first aspect, wherein the protection relay includes a fourth protection relay disposed at a load end of the power network, and the control coil of the fourth protection relay is connected The output of the pressure protection mechanism.

With reference to the first aspect, the embodiment of the present invention provides the fourteenth possible implementation manner of the first aspect, wherein the overvoltage protection mechanism comprises a second induction coil, a third rectifier circuit, and a second protection chip;

The second induction coil is configured to be wound around the secondary core of the transformer in the electrical network and generate an alternating current sensing signal;

The third rectifier circuit is connected between the second induction coil and the second protection chip, and the third rectifier circuit rectifies the AC induction signal into a DC induction signal;

The second protection chip receives the DC induction signal, and when the DC induction signal exceeds a preset value, the second protection chip outputs a power-off signal.

With reference to the first aspect, the embodiment of the present invention provides the fifteenth possible implementation manner of the first aspect, wherein the overvoltage protection mechanism further includes a first filter circuit and a first amplification circuit, where the first filter circuit is connected Between the three rectifier circuit and the second protection chip, the first amplification circuit is connected between the first filter circuit and the second protection chip.

In conjunction with the first aspect, an embodiment of the present invention provides a sixteenth possible implementation manner of the first aspect, wherein the protection relay comprises a fifth protection relay disposed on the power network bus, and a control coil connection circuit of the fifth protection relay The output of the security protection mechanism.

With reference to the first aspect, the embodiment of the present invention provides the seventeenth possible implementation manner of the first aspect, wherein the circuit security protection mechanism comprises a third induction coil, a fourth rectifier circuit, and an induction chip;

The third induction coil is configured to be inductively coupled to the primary coil of the transformer in the electrical network bus and generate an alternating current sensing signal;

The fourth rectifying circuit is connected between the third inductive coil and the sensing chip, and the fourth rectifying circuit rectifies the alternating current sensing signal into a direct current sensing signal;

The sensing chip receives the DC sensing signal, and when the DC sensing signal exceeds a preset value, the sensing chip outputs a power-off signal.

With reference to the first aspect, an embodiment of the present invention provides the eighteenth possible implementation manner of the first aspect, wherein the circuit security protection mechanism further includes a second filter circuit and a second amplification circuit, where the second filter circuit is connected to Between the four rectifier circuit and the sensing chip, the second amplification circuit is connected between the second filter circuit and the sensing chip.

In a second aspect, the embodiment of the present invention further provides a power supply system, including a power network, and a multi-level protection device according to the first aspect, which is disposed in the power network;

The protection mechanism in the multi-level protection device is configured to detect the operation of the power network, and to cut off the power supply of the power network bus through the protection relay controlling the output of the power-off relay when the power network fails.

The embodiments of the present invention bring the following beneficial effects:

The multi-level protection device provided by the embodiment of the invention comprises a power-off relay and a plurality of protection relays, wherein the output end of the protection relay is connected in series with the control coil of the power-off relay, and the control coil of any protection relay is connected in series with a protection mechanism; Detecting the operation of the power network, and cutting off the power supply of the power network bus through the protection relay control output terminal of the power-off relay when the power network is faulty; matching the corresponding number of protection relays according to the use environment of the power network and the detection target The corresponding protection mechanism, when the power network fails, the protection mechanism triggers, and the power-off relay is cut off by the protection relay connected in series to cut off the power supply of the power network bus.

Other features and advantages of the invention will be set forth in the description which follows, and The objectives and other advantages of the invention are realized and attained by the invention particularly pointed in

The above described objects, features and advantages of the present invention will become more apparent from the aspects of the appended claims.

DRAWINGS

In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings to be used in the specific embodiments or the description of the prior art will be briefly described below, and obviously, the attached in the following description The drawings are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

1 is a schematic diagram of a multi-level protection device according to Embodiment 1 of the present invention;

2 is another schematic diagram of a multi-level protection device according to Embodiment 1 of the present invention;

3 is a schematic circuit diagram of an alarm mechanism according to Embodiment 1 of the present invention;

4 is a schematic circuit diagram of an arc extinguishing protection mechanism according to Embodiment 1 of the present invention;

FIG. 5 is another schematic circuit diagram of an arc extinguishing protection mechanism according to Embodiment 1 of the present invention; FIG.

6 is a schematic diagram of an arc extinguishing chip of an arc extinguishing protection mechanism according to Embodiment 1 of the present invention;

7 is a schematic circuit diagram of an electric shock protection mechanism according to Embodiment 1 of the present invention;

8 is another schematic circuit diagram of an electric shock protection mechanism according to Embodiment 1 of the present invention;

9 is a schematic diagram of a protection chip of an electric shock protection mechanism according to Embodiment 1 of the present invention;

10 is a schematic circuit diagram of an isolation protection mechanism according to Embodiment 1 of the present invention;

11 is another schematic circuit diagram of an isolation protection mechanism according to Embodiment 1 of the present invention;

12 is a schematic diagram of an isolation chip of an isolation protection mechanism according to Embodiment 1 of the present invention;

13 is a schematic circuit diagram of an overvoltage protection mechanism according to Embodiment 1 of the present invention;

14 is another schematic circuit diagram of an overvoltage protection mechanism according to Embodiment 1 of the present invention;

15 is a schematic circuit diagram of a circuit safety protection mechanism according to Embodiment 1 of the present invention;

FIG. 16 is a schematic diagram of a power supply system according to Embodiment 2 of the present invention.

Icons: 1-protection mechanism; 11-arc protection mechanism; 12-electric shock protection mechanism; 13-isolation protection mechanism; 14-overvoltage protection mechanism; 15-circuit safety protection mechanism; 2-alarm mechanism.

detailed description

The embodiments of the present invention will be clearly and completely described in detail with reference to the accompanying drawings. An embodiment. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The present invention provides a power supply system and a multi-level protection device thereof, which can improve the security of the power network, because the current power grid protection device can not discover the danger of the power network in time and take corresponding technical measures. .

In order to facilitate the understanding of the embodiment, a multi-level protection device disclosed in the embodiment of the present invention is first introduced in detail.

Example 1:

This embodiment provides a multi-level protection device, which can be applied to a power supply scenario such as a home, an office, or a factory. Figure 1 As shown, the multi-stage protection device comprises a power-off relay and a plurality of protection relays, the output end of the protection relay is connected in series with the control coil of the power-off relay; the control coil of any protection relay is connected in series with a protection mechanism 1; the protection mechanism 1 is used for The operation of the load end of the power network is detected, and when the load end of the power network is faulty, the output of the power-off network relay is cut off by the protective relay to control the power supply of the power-off network bus.

According to the use environment of the load end of the power network, the corresponding number of protection relays and corresponding protection mechanisms are matched, and when the load of the power network load fails, the protection mechanism triggers, and the protection relay in series with the control relay is used to control the cut-off electric relay to cut off. Power supply to the electrical network bus. Optionally, the multi-level protection device provided in this embodiment may have a voltage of 2V-1250V and a power of 0-50KW or more.

As shown in FIG. 2, the embodiment may optionally further include an alarm mechanism 2, and the input end of the alarm mechanism 2 and the output end of the power-off relay are all connected in series with the primary coil of the transformer of the power network bus.

As shown in FIG. 3, the alarm mechanism may include a first induction coil L0, an alarm chip, and an alarm. The first induction coil L0 is used in series with the primary coil of the transformer, so the current of the first induction coil L0 is synchronized with the magnitude of the current of the primary coil of the transformer, and the current of the first induction coil L0 is used as an induction signal.

The alarm chip receives the sensing signal, and when the sensing signal exceeds the preset value, the alarm chip outputs an alarm starting signal. The alarm receives the alarm start signal from the alarm chip and issues an alarm according to the alarm start signal.

The alarm mechanism provided by the embodiment of the present invention generates a sensing signal synchronized with the current level of the primary coil of the transformer by using the first induction coil L0, and the current magnitude of the first induction coil L0 (ie, the current of the primary coil of the transformer) As an alarm condition for faults such as overvoltage of the power network bus, the sensitivity of the circuit protection can be improved, and the transmission line can be more effectively protected, thereby improving the safety of the transmission line.

In this embodiment, the two ends of the first induction coil L0 are respectively connected to the two input ends of the alarm chip, so that the alarm chip receives the sensing signal generated by the sensing chip. Moreover, a filter capacitor C0 is connected between one end of the first induction coil L0 and the alarm chip to prevent damage to the alarm chip when the amplitude of the induced signal is excessive.

Optionally, the alarm mechanism in the embodiment of the present invention may include a buzzer alarm or a light alarm. When the alarm mechanism receives the alarm start signal from the alarm chip, the buzzer alarm or the light alarm will issue an alarm prompt to prompt the user to take precautionary measures.

The first comparison unit and the first trigger unit may be included in the alarm chip of this embodiment. The first comparison unit receives the sensing signal and compares the sensing signal with a preset value. When the sensing signal exceeds the preset value, the first trigger unit outputs an alarm activation signal.

Optionally, a multi-stable trigger is disposed in the first trigger unit, and the multi-stable flip-flop is also referred to as an n-state flip-flop. If there is DC coupling between the input of each of the n amplification stages and the output of the remaining stages, then n steady states are obtained under a certain strip, and only one level of conduction is achieved at each steady state, and The rest are closed. In non-binary counting lines, multi-state flip-flops can achieve fast response in many different states, which is faster than the response of a flip-flop.

In the embodiment of the present invention, by using the first comparison unit and the first trigger unit with high sensitivity, and setting the multi-stable trigger in the first trigger unit, the alarm chip can respond within 0.1 seconds, thereby being extremely short. The alarm start signal is issued within the time to effectively protect the power grid and the transformer.

The alarm mechanism provided by the embodiment of the present invention generates a sensing signal synchronized with the current level of the primary coil of the transformer by using the first induction coil L0, and the current of the first induction coil L0, that is, the current of the primary coil of the transformer. The size is used as an alarm condition for faults such as overvoltage of the power network bus, so the sensitivity and safety of the circuit protection can be improved.

Further, each of the protection relays in this embodiment has a protection mechanism in series.

It should be noted that the specific use can be set according to the actual situation. If the power network bus is used to power the multiple load terminals, it is necessary to avoid the same danger on all load terminals. In this case, it can be used for each load end. The protection relays are configured with the same protection mechanism.

The protection relay in this embodiment may include a first protection relay, a second protection relay, a third protection relay, and a fourth protection relay disposed at the load end of the power network, and a fifth protection relay disposed on the power network bus.

The control coil of the first protection relay is connected to the output of the arc extinguishing protection mechanism. As shown in FIG. 4, the arc extinguishing protection mechanism includes a coupling circuit and an arc extinguishing chip, and the arc extinguishing material T is disposed in the arc extinguishing chip. The coupling circuit is used to connect the first AC output terminal d, and the input terminal of the arc extinguishing chip is used to connect the second AC output terminal b. The arc generated between the AC output terminal b and the AC output terminal d is coupled to the arc extinguishing chip via the coupling circuit, and the arc is absorbed by the arc extinguishing material T.

In this embodiment, the coupling circuit may include a coupling resistor R1 and a coupling capacitor C1 connected in parallel. The coupling resistor R1 and the coupling capacitor C1 connected in parallel with each other can couple the current of the arc to the input end of the arc extinguishing chip when an arc occurs between the alternating current output terminal b and the alternating current output terminal d, so that the arc extinguishing chip can sense the Arc.

In the arc extinguishing protection mechanism provided by the embodiment, the coupling circuit is used for connecting the AC output terminal d, and the input end of the arc extinguishing chip is used for connecting the AC output terminal b, that is, the coupling circuit and the arc extinguishing chip are respectively connected to the two outputs of the power supply line. line. The arc generated between the AC output terminal d and the AC output terminal b can be coupled by the coupling circuit, and the current signal of the arc is transmitted to the arc extinguishing chip, and the arc is absorbed by the arc extinguishing material T. Since the response time of the arc extinguishing material T is very short, the arc can be absorbed at the initial stage of forming an arc between the two output lines, so that the current and voltage of the arc can be effectively reduced, or the arc can be completely prevented, and the transmission is improved. The safety of the line.

As shown in FIG. 5, the arc extinguishing protection mechanism may further include a variable resistor R1 for connecting between the input end of the arc extinguishing chip and the alternating current output terminal b, in addition to the above embodiment. The resistance of the variable resistor R1 can be adjusted between 2kΩ and 5.1kΩ to provide a certain resistance value for the arc extinguishing chip, preventing the current input to the arc extinguishing chip from being excessive, and causing damage to the arc extinguishing chip. The resistance of the variable resistor R1 can be adjusted at the factory according to the voltage and current conditions of the application scenario.

Optionally, the arc extinguishing material T in the embodiment may include a niobium titanium alloy. Niobium titanium alloy is a peritectic alloy, It has the advantages of high hardness, oxidation resistance and corrosion resistance, and the niobium titanium alloy has excellent arc extinguishing performance. It has been verified by experiments that niobium-titanium alloy has excellent ability to absorb arc in the same kind of conductor material, and arc in ordinary current range can be completely absorbed by niobium-titanium alloy.

Further, the arc extinguishing material T in the embodiment may further include silver, that is, the arc extinguishing material T is composed of a niobium titanium alloy and silver. The combination of niobium titanium alloy and galaxy may be layered, or a layer of silver may be plated outside the niobium titanium alloy. By combining with silver, the arc-extinguishing ability of the niobium-titanium alloy can be further improved, which is better than the arc-extinguishing ability of the niobium-titanium alloy alone.

As shown in FIG. 6, in another alternative of the arc extinguishing protection mechanism provided by the embodiment of the present invention, the arc extinguishing chip may further include an arc detecting unit and a counting unit. The arc detecting unit is capable of detecting the current of the arc generated between the alternating current output terminal d and the alternating current output terminal b. Further, the A end of the arc detecting unit is connected to the AC output terminal b through the variable resistor R1, and the B end of the arc detecting unit is connected to the AC output terminal b through the sensing capacitor C1. The standard signal of the AC output terminal b can be obtained as the reference reference signal through the sensing capacitor C1 at the A terminal. When an arc is generated between the AC output terminal d and the AC output terminal b, a comparator (not shown) inside the arc detecting unit compares the signals received at the A end and the B end to determine the occurrence of the arc. And the current of the arc is detected.

The counting unit records the number of arcs generated between the alternating current output d and the alternating current output b. Each time the arc detecting unit detects an arc, the counting unit records the current accumulated arc number.

In this embodiment, the arc extinguishing chip may further include a second trigger unit, and an output end of the arc extinguishing chip is used to connect the first protection relay J1. The second trigger unit generates a power-off signal according to the current detected by the arc detecting unit and the number recorded by the counting unit, and outputs a power-off signal to the first protection relay J1 from the output end of the arc extinguishing chip, and is further controlled by the first protection relay J1. The power-off relay cuts off the power network bus to protect the power supply line.

The generation and regulation of the power-off signal can simultaneously refer to the number of arcs and the magnitude of the current. For example, when a continuous weak current arc occurs, a power-off signal can be generated when a cumulative three-time weak current arc is generated; when a strong current arc occurs, a strong current arc can be set to generate a power-off signal.

In addition, the arc extinguishing chip is further connected with a power module, and the power module outputs a DC power to the arc extinguishing chip for supplying power to the arc detecting unit, the counting unit and the second trigger unit.

In addition, in the embodiment, by setting the arc detecting unit and the counting unit in the arc extinguishing chip, the current of the arc can be detected, and the number of times the arc occurs is recorded, and then the second trigger unit sends a power-off signal to the first protection relay J0. The power supply line is cut off by the first protection relay J1 to protect the power supply line, and the safety of the power supply line is further improved.

The control coil of the second protection relay in this embodiment is connected to the output end of the electric shock protection mechanism. As shown in FIGS. 7 and 8, the electric shock protection mechanism may include a first sensing circuit and a first protection chip. The first sensing circuit senses the current signal at the AC output, generates an induced signal, and transmits the sensing signal to the first protection chip. First sensing circuit connection In one of the two AC output terminals b and d, the first embodiment is connected to the AC output terminal b as an example for description. The first protection chip generates a safety carrier signal according to the sensing signal, and outputs the safety carrier signal to the AC output terminal through the diode D20, so that the AC output terminal b and the AC output terminal d output the reactive power to the ground.

The first sensing circuit in this embodiment may include a sensing resistor R21 connected between the first protection chip and the AC output terminal. Further, the first sensing circuit may further include sensing capacitors C21 and C22 coupled to the sensing resistor R21.

The current signal on the AC output terminal b generates an induced signal through the coupling effect between the sensing resistor R21 and the sensing capacitors C21 and C22, and the reaction circuit transmits the sensing signal to the first protection chip.

In this embodiment, the sensing capacitors C21 and C22 are adjustable capacitors, which are suitable for various environments. The specific sizes of the sensing capacitors C21 and C22 can be adjusted according to the voltage and current conditions of the application scenario at the time of shipment.

Further, the electric shock protection mechanism provided by the embodiment of the present invention may further include a first rectifying circuit. The two input ends of the first rectifier circuit are respectively connected to the AC output terminals b and d, and the output end of the first rectifier circuit is connected to the power supply end of the first protection chip, thereby rectifying the AC output terminals b and d into DC power, and is the first The protection chip provides DC power.

Optionally, the first rectifier circuit in this embodiment is a rectifier bridge. The rectifier bridge is composed of four rectifier diodes D1, D2, D3, D4 connected, the rectifier diode D1 is connected to the anode of the rectifier diode D3, the rectifier diode D2 is connected to the cathode of the rectifier diode D4, and the cathode of the rectifier diode D1 is connected to the rectifier diode D2. The anode, the cathode of the rectifier diode D3 is connected to the anode of the rectifier diode D4. During each duty cycle of the rectifier bridge, only two diodes operate at the same time, and the unidirectional conduction function of the diode is used to convert the alternating current into a unidirectional DC pulse voltage.

As shown in FIG. 9, the first protection chip in this embodiment may include a field effect transistor T, a comparator, and a carrier generator, wherein the field effect transistor T is specifically an N-channel junction field effect transistor. The input end of the comparator is connected to the drain d of the FET T, the output end of the comparator is connected to the input end of the carrier generator, and the output end of the carrier generator is connected to the AC output terminal through a diode.

The gate g of the FET T is connected to the first sensing circuit, the source s is grounded, and the drain d is connected to the input of the comparator. A Junction Field-Effect Transistor (JFET) is a three-terminal active device with amplifying function composed of a gate, a source and a drain of a PN junction, which is common in a unipolar FET. One type of junction field effect transistor can be divided into N-channel and P-channel. In this embodiment, an N-channel junction field effect transistor is used.

In this embodiment, the source s of the FET T is grounded, and the drain d is supplied with a positive voltage by the comparator, so that the voltage of the source s is lower than the voltage of the drain d, and the gate g of the FET T is connected to the first The sensing circuit receives a negative voltage sensing signal. The negative value of the voltage Vgs between the gate g and the source s increases, which increases the resistance of the channel and decreases the drain current Id. This is because the electrons inside the N-type semiconductor are repelled by the electric field formed by the negative potential of the gate, and a thicker depletion layer is formed around the P region, the conduction channel of the N-type semiconductor is narrowed, and the drain to the source are The current is reduced. Due to this characteristic, the drain current Id is controlled by the gate-source voltage Vgs.

As the induced signal output from the first inductive circuit changes, the drain current Id of the field effect transistor T also changes. The drain current Id is input to the comparator, which can be used to detect the current grid current.

After receiving the drain current Id of the FET T, the comparator compares the drain current Id with the reference current inside the comparator and outputs a corresponding comparison signal.

The carrier generator outputs a corresponding carrier signal according to the change of the comparison signal. When the comparison signal output by the comparator is within the normal range, the carrier generator outputs a carrier signal of smooth amplitude, and outputs a smooth alternating current in a carrier manner. When the human body directly or indirectly contacts the AC output line, the comparator outputs a high-intensity (abnormal) comparison signal, and the carrier generator outputs a safe carrier signal of a corresponding amplitude according to the intensity of the comparison signal, so that the alternating current is in the form of a safe carrier. The system stabilizes the output, so that the AC output outputs the reactive power to the ground, which can play a safety isolation function, so that the AC output terminal does not form a loop through the human body and the ground.

Further, the first protection chip in the embodiment of the present invention may further include a trigger. The input of the flip-flop is connected to the output of the comparator. When a short circuit or overload occurs on the load end of the power network, the comparison signal exceeds the preset value inside the trigger, and the trigger outputs a power-off signal accordingly, and triggers the second protection relay, and then the second protection relay controls the power-off. The relay cuts off the power supply to the power network bus.

With the electric shock protection mechanism provided by the embodiment, when the human body directly or indirectly contacts the AC output line, the first sensing circuit can sense the abnormal current on the line, and generate an induction signal to be sent to the comparator, and the comparator is based on the abnormality. The signal generates a (abnormal) comparison signal of high intensity and sends the comparison signal of the abnormality to the first protection chip. The first protection chip generates a safety carrier signal of a corresponding amplitude according to the intensity of the comparison signal, so that the alternating current system systematically stabilizes the output in the form of a safety carrier, so that the AC output terminal outputs the reactive power to the ground, which can play a safety isolation function. The AC output does not form a loop through the human body and the ground. In addition, the AC output terminals b and d are still active power, so it can prevent the electric shock damage while maintaining the normal operation of each power equipment on the power supply line.

The control coil of the third protection relay in this embodiment is connected to the output end of the isolation protection mechanism. As shown in FIGS. 10 and 11, the isolation protection mechanism may include a second sensing circuit and an isolation chip. The second sensing circuit senses the current signal at the AC output, generates an induced signal, and transmits the sensing signal to the isolation chip. The second sensing circuit is connected to one of the two AC output terminals b and d. In this embodiment, the second sensing circuit is connected to the AC output terminal b as an example for description. The isolation chip generates an isolated carrier signal according to the sensing signal, and outputs the isolated carrier signal to the AC output through the diode D0.

The second sensing circuit in this embodiment may include a sensing resistor R connected between the isolation chip and the AC output terminal. Further, the second sensing circuit may further include sensing capacitors C31 and C32 coupled to the sensing resistor R.

The current signal on the AC output terminal b is generated by the coupling effect between the sense resistor R30 and the sense capacitors C31 and C32. The signal is induced, and the reaction circuit transmits the sensing signal to the isolation chip.

In this embodiment, the sensing capacitors C31 and C32 are adjustable capacitors, which are suitable for various environments. The specific sizes of the sensing capacitors C31 and C32 can be adjusted according to the voltage and current conditions of the application scenario at the time of shipment.

Further, the isolation protection mechanism provided in this embodiment may further include a second rectifier circuit. The two input ends of the second rectifier circuit are respectively connected to the AC output terminals b and d, and the output end of the second rectifier circuit is connected to the power supply end of the isolation chip, thereby rectifying the AC output terminals b and d into DC power, and providing DC for the isolation chip power supply.

Optionally, the second rectifier circuit in this embodiment is a rectifier bridge.

As shown in FIG. 12, the isolation chip in this embodiment may include a field effect transistor T, a comparator, and a carrier generator, wherein the field effect transistor T is specifically an N-channel junction field effect transistor. The input end of the comparator is connected to the drain d of the FET T, the output end of the comparator is connected to the input end of the carrier generator, and the output end of the carrier generator is connected to the AC output terminal through a diode.

As the induced signal output from the second inductive circuit changes, the drain current Id of the field effect transistor T also changes. The drain current Id is input to the comparator, which can be used to detect the current grid current. After receiving the drain current Id of the FET T, the comparator compares the drain current Id with the reference current inside the comparator and outputs a corresponding comparison signal.

The carrier generator outputs a corresponding carrier signal according to the change of the comparison signal. When the comparison signal output by the comparator is within the normal range, the carrier generator outputs a smooth isolated carrier signal with a stable amplitude to output a smooth alternating current in a manner of isolating the carrier. When the AC output line is wet or wet, the comparator outputs a high-intensity (abnormal) comparison signal. The carrier generator outputs an isolated carrier signal of a corresponding amplitude according to the strength of the comparison signal, so that the alternating current is in the form of an isolated carrier. The system stabilizes the output and acts as an isolation to avoid short-circuit between the two AC output lines, thus effectively preventing the influence of moisture on the power line.

Further, the isolation chip in this embodiment may further include a trigger. The input of the flip-flop is connected to the output of the comparator. When the comparison signal exceeds the preset value inside the trigger, the trigger outputs a power-off signal to disconnect the power of the transmission line.

With the isolation protection mechanism provided by the embodiment, when the AC output line is wet or wet, the second sensing circuit can sense an abnormal current on the line, and generate an induction signal to be sent to the comparator, and the comparator according to the abnormal sensing signal. A high-intensity (abnormal) comparison signal is generated and the comparison signal of the abnormality is sent to the isolation chip. The isolation chip generates an isolated carrier signal of a corresponding amplitude according to the strength of the comparison signal, so that the alternating current systematically stabilizes the output in the form of an isolated carrier, and acts as an isolation to avoid a short circuit between the two AC output lines, thereby effectively preventing moisture. The impact on the power line.

The control coil of the fourth protection relay in this embodiment is connected to the output end of the overvoltage protection mechanism. As shown in FIGS. 13 and 14, the overvoltage protection mechanism may include a second induction coil L41, a third rectifier circuit, and a second protection chip.

The second induction coil is used to wrap around the secondary core of the transformer, and generates an alternating current sensing signal by sensing a change in the magnetic field of the primary core of the transformer. The third rectifier circuit is connected between the second induction coil L41 and the second protection chip for rectifying the AC induction signal sensed by the second induction coil L41 into a DC induction signal. The second protection chip receives the DC induction signal. When the DC induction signal exceeds the preset value, the second protection chip outputs a power-off signal to disconnect the power of the transmission line.

In the overvoltage protection mechanism provided in this embodiment, the primary induction core of the transformer is electromagnetically induced by the second induction coil L41, and the current of the second induction coil L41 is used as a condition for overvoltage protection, thereby improving the sensitivity of the circuit protection. More effective protection of the safety of transmission lines.

In this embodiment, the third rectifier circuit is implemented in the form of a rectifier bridge. By setting the rectifier bridge, the AC induction signal sensed by the second induction coil L41 can be rectified and rectified into a periodic DC induction signal.

The overvoltage protection mechanism provided in this embodiment may further include a first filter circuit connected between the third rectifier circuit and the second protection chip. The first filter circuit is composed of two filter capacitors C41 and C42 and a filter resistor R41. The DC sense signal is filtered by the filter capacitors C41 and C42 and the filter resistor R41 to limit the voltage of the DC sense signal to a certain range.

In addition, the output end of the first filter circuit further supplies power to the second protection chip by connecting the power terminals V+, V- of the second protection chip.

Further, the overvoltage protection mechanism provided in this embodiment may further include a first amplifying circuit connected between the first filter circuit and the second protection chip. The first amplifying circuit is mainly composed of a first variable resistor W41 and a PNP type transistor T41, and the DC induction signal can generate a large current signal through the amplification of the transistor T41, and the current signal is converted into an induced voltage signal through the resistor R43. And inputting the first input end a1 of the second protection chip. The Zener diode D45 and the resistor R42 connected in series with the first variable resistor W41 function as a voltage regulator and a current limit, respectively.

In addition, the first amplifying circuit may further include a second variable resistor W42 for converting the DC induction signal into a reference voltage signal and inputting the second input end a2 of the second protection chip.

In this embodiment, the resistance values of the variable resistors W41 and W42 can be adjusted between 0 and 5.1 kΩ, and the specific resistance values of the variable resistors W41 and W42 can be adjusted according to the voltage and current conditions of the application scenario at the time of shipment. Settings.

The second protection chip mainly monitors the induced voltage signal received by the first input terminal a1, and outputs a power-off signal according to the change of the induced voltage signal. At the same time, the second protection chip can also monitor the reference voltage signal received by the second input terminal a2, and can also output the power-off signal when the reference voltage signal is abnormal.

The second protection chip and the third trigger unit may be included in the second protection chip in this embodiment. The second comparison unit receives the DC induction signal (ie, the induced voltage signal and the reference voltage signal), and compares the induced voltage signal and the reference voltage signal with corresponding preset values. When the induced voltage signal exceeds the corresponding preset value, or the reference voltage signal exceeds the corresponding preset value, the third trigger unit outputs a power-off signal to disconnect the power of the power transmission line.

Optionally, a multi-state trigger is disposed in the third trigger unit. In this embodiment, by using the second comparison unit and the third trigger unit with high sensitivity, and setting the multi-stable trigger in the third trigger unit, the second protection chip can respond within 0.1 seconds, thereby being extremely short. The power supply of the power network bus is disconnected during the time, effectively protecting the power equipment and the power supply line.

The control coil of the fifth protection relay in this embodiment is connected to the output end of the circuit safety protection mechanism. As shown in FIG. 15, the circuit safety protection mechanism may include a third induction coil L51, a fourth rectifier circuit, and an induction chip.

The third induction coil L51 is for mutual inductance connection with the primary coil of the transformer, and generates an alternating current induction signal through mutual inductance with the circuit of the primary coil of the transformer. The fourth rectifier circuit is connected between the third induction coil L51 and the sensing chip for rectifying the AC induction signal sensed by the third induction coil L51 into a DC induction signal. The sensing chip receives the DC sensing signal. When the DC sensing signal exceeds the preset value, the sensing chip outputs a power-off signal and disconnects the power of the power transmission line.

The circuit safety protection mechanism provided by the embodiment uses the third induction coil L51 to interact with the primary coil of the transformer, and the current of the primary coil is used as a condition for short circuit and overload protection, thereby improving the sensitivity and safety of the additional circuit protection.

In this embodiment, the fourth rectifier circuit is implemented in the form of a rectifier bridge. The AC induction signal sensed by the third induction coil L1 is rectified by the rectifier bridge to form a periodic DC induction signal.

The circuit safety protection mechanism provided in this embodiment may further include a second filter circuit connected between the fourth rectifier circuit and the sensing chip. The second filter circuit is a π-type filter composed of two filter capacitors and a filter resistor, so that the voltage of the DC sense signal is limited to a certain range.

In addition, the second filter circuit provides an operating voltage for the sensing chip.

Further, the circuit safety protection mechanism provided in this embodiment may further include a second amplifying circuit connected between the second filter circuit and the sensing chip. Here, the second amplifying circuit can be the same as the second amplifying circuit in the above-mentioned overvoltage protection mechanism, and details are not described herein.

The sensing chip mainly monitors the induced voltage signal received by the first input terminal a1, and outputs a power-off signal according to the change of the induced voltage signal. The sensing chip can also monitor the reference voltage signal received by the second input terminal a2, and can also output the power-off signal when the reference voltage signal is abnormal.

The third comparison unit and the fourth trigger unit may be included in the sensing chip in this embodiment. The third comparison unit receives the DC induction signal (ie, the induced voltage signal and the reference voltage signal), and combines the induced voltage signal and the reference voltage signal with the phase The corresponding preset values are compared. When the induced voltage signal exceeds the corresponding preset value, or the reference voltage signal exceeds the corresponding preset value, the fourth trigger unit outputs a power-off signal to disconnect the power of the power transmission line.

Optionally, a multi-state trigger is disposed in the fourth trigger unit.

In the embodiment of the present invention, by using the third comparison unit and the fourth trigger unit with high sensitivity, and setting the multi-stable trigger in the fourth trigger unit, the sensing chip can respond within 0.1 seconds, thereby being extremely short. Disconnect the power supply during the time to effectively protect the power equipment and power supply lines.

The circuit safety protection mechanism provided by the embodiment of the invention uses the third induction coil L51 to mutual inductance of the primary coil of the transformer, and the current of the primary coil is used as a condition for short circuit and overload protection, thereby improving the sensitivity and safety of the circuit protection. .

Example 2:

The embodiment further provides a power supply system, including a power network and a multi-level protection device as set forth in the first aspect of the power network; the protection mechanism in the multi-level protection device is used to detect the load end of the power network. It runs and cuts off the power supply of the power network bus through the protection relay to control the output of the power-off relay when the load of the power network is faulty.

In this embodiment, the various protection mechanisms in the multi-level protection device quickly discover the danger in the load end of the power network, and trigger a protection relay in series with the protection mechanism, and the protection relay controls the power-off relay to cut off the power supply of the power network bus. Improve the security of the electricity network.

As shown in FIG. 16, the power supply system provided in this embodiment may include a power network, a transformer, and the arc extinguishing protection mechanism 11 as described in Embodiment 1, the electric shock protection mechanism 12, the isolation protection mechanism 13, and the overvoltage protection mechanism. 14 and circuit safety protection mechanism 15.

The primary coil of the transformer TB is connected to the electric network bus, and the two ends of the secondary coil of the transformer TB are respectively connected to the alternating current output terminal d and the alternating current output terminal b, and output alternating current.

The output ends of the fifth protection relay J5, the fourth protection relay J4, the third protection relay J3, the second protection relay J2, and the first protection relay J1 are sequentially connected in series, and the output end of the first protection relay J1 and the power-off relay J0 The control coils are connected in series.

Optionally, the first protection relay J1, the second protection relay J2, the third protection relay J3, the fourth protection relay J4, and the fifth protection relay J5 are normally closed relays, and the power-off relay J0 is a normally-on relay.

When the fourth trigger unit in the sensing chip of the circuit safety protection mechanism 15 issues a power-off signal, the control coil of the fifth protection relay J5 is powered off, so that the output end of the fifth protection relay J5 is disconnected, because the fifth protection relay J5, the fourth protection relay J4, the third protection relay J3, the second protection relay J2 and the output end of the first protection relay J1 are connected in series, so the control coil of the power-off relay J0 is powered off, and the output end of the power-off relay J0 Disconnect, cut off The power supply of the electric network bus realizes effective protection of the power network.

When the arc extinguishing protection mechanism 11, the electric shock protection mechanism 12, the isolation protection mechanism 13, the overvoltage protection mechanism 14, and the electric safety protection mechanism 15 are triggered by any one of the protection mechanisms, the protection relay in series with the triggered protection mechanism is controlled. The coil is de-energized, and then the output end of the protection relay is disconnected, and then the output end of the protection relay located between the protection relay and the power-off relay is sequentially turned off, and finally the control coil of the power-off relay J0 is powered off. The output of the electric relay J0 is disconnected, and the power supply of the electric network bus is cut off, thereby realizing effective protection for the electric power network.

It should be noted that, in this embodiment, the series order of the plurality of protection relays is not limited.

In addition, each protection relay can be directly connected in series with the control coil of the power-off relay J0. At this time, any one of the arc extinguishing protection mechanism, the electric shock protection mechanism, the isolation protection mechanism, the overvoltage protection mechanism, and the electric safety protection mechanism After the protection mechanism is triggered, the control coil of the protection relay connected in series with the triggered protection mechanism is powered off, and then the output end of the protection relay is disconnected, and finally the control coil of the power-off relay J0 is powered off, and the output of the power-off relay J0 is turned off. The terminal is disconnected, and the power supply of the power network bus is cut off, thereby realizing effective protection of the power network.

The power supply system provided by the second embodiment of the present invention has the same technical features as the overvoltage protection mechanism provided in the first embodiment, so that the same technical problem can be solved and the same technical effect can be achieved.

In the description of the embodiments of the present invention, the terms "installation", "connected", and "connected" are to be understood broadly, and may be, for example, a fixed connection or a detachable connection, or Connected integrally; can be mechanical or electrical; can be directly connected or indirectly connected through an intermediate medium, which can be the internal communication between the two components. The specific meaning of the above terms in the present invention can be understood in a specific case by those skilled in the art.

In the description of the present invention, it is to be noted that the orientation or positional relationship of the terms "upper", "inside" and the like is based on the orientation or positional relationship shown in the drawings, and is merely for convenience of description of the present invention and simplified description. Instead of indicating or implying that the device or component referred to must have a particular orientation, constructed and operated in a particular orientation, it is not to be construed as limiting the invention. Moreover, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Finally, it should be noted that the above-mentioned embodiments are merely specific embodiments of the present invention, and are used to explain the technical solutions of the present invention, and are not limited thereto, and the scope of protection of the present invention is not limited thereto, although reference is made to the foregoing. The present invention has been described in detail, and those skilled in the art should understand that any one skilled in the art can still modify the technical solutions described in the foregoing embodiments within the technical scope disclosed by the present invention. The changes may be easily conceived, or equivalents may be substituted for some of the technical features. The modifications, variations, or substitutions of the present invention are not intended to depart from the spirit and scope of the technical solutions of the embodiments of the present invention. Within the scope of protection. Therefore, the scope of the invention should be determined by the scope of the claims.

Industrial applicability

Claims

A multi-stage protection device, comprising: a power-off relay and a plurality of protection relays, wherein an output end of the plurality of protection relays is connected in series with a control coil of the power-off relay;

The control coil of any of the protection relays has a protection mechanism connected in series;

The protection mechanism is configured to detect operation of the power network and to control the output of the power-off relay to cut off power to the power network bus when the power network fails.
The multi-level protection device according to claim 1, further comprising an alarm mechanism, wherein an input end of the alarm mechanism and an output end of the power-off relay are connected in series with a primary coil of a transformer of the power network bus.
The multi-level protection device according to claim 2, wherein the alarm mechanism comprises a first induction coil, an alarm chip and an alarm, and two ends of the first induction coil are respectively connected to two of the alarm chips At the input end, the alarm chip is configured to receive an induction signal generated by the induction chip through the first induction coil, and the first induction coil is connected in series with a primary coil of a transformer of an electrical network bus, the alarm chip Connected to the alarm, the alarm chip is configured to receive an induction signal, and when the sensing signal exceeds a preset value, the alarm chip outputs an alarm activation signal, and the alarm is configured to be issued according to the alarm activation signal Call the police.
The multi-stage protection device according to claim 1, wherein each of said protection relays has a protection mechanism connected in series.
The multi-level protection device according to claim 4, wherein the protection relay comprises a first protection relay disposed at a load end of the power network, and the control coil of the first protection relay is connected to an output end of the arc extinguishing protection mechanism .
The multi-level protection device according to claim 5, wherein the arc extinguishing protection mechanism comprises a coupling circuit and an arc extinguishing chip, wherein the arc extinguishing chip is provided with an arc extinguishing material;

The coupling circuit is configured to be connected to a first AC output end of the load end of the power network, and the input end of the arc extinguishing chip is configured to be connected to the second AC output end of the load end of the power network;

An arc generated between the first alternating current output terminal and the second alternating current output terminal is coupled to the arc extinguishing chip via the coupling circuit, and the arc is absorbed by the arc extinguishing material.
The multi-level protection device according to claim 6, wherein the arc extinguishing chip further comprises an arc detecting unit, a counting unit and a second triggering unit;

One end of the arc detecting unit is connected to the first alternating current output end, the other end of the arc detecting unit is connected to the second alternating current output end, and the arc detecting unit is configured to determine the first alternating current output end and the An arc occurs between the second alternating current output and detects a current of the arc;

The counting unit is coupled to the arc detecting unit and configured to record a current accumulated arc number when the arc detecting unit detects an arc;

The second trigger unit is connected to the arc detecting unit and the counting unit, the output end of the arc extinguishing chip is configured to be connected to a first protection relay, and the second trigger unit is configured to detect according to the arc The current detected by the unit and the quantity recorded by the counting unit generates a power-off signal, and a power-off signal is output from the output end of the arc-extinguishing chip to the first protection relay.
The multi-level protection device according to claim 4, wherein the protection relay comprises a second protection relay disposed at a load end of the power network, and the control coil of the second protection relay is connected to an output end of the electric shock protection mechanism.
The multi-level protection device according to claim 8, wherein the electric shock protection mechanism comprises a first sensing circuit and a first protection chip;

The first sensing circuit senses a current signal applied to the load end of the electrical network, generates an induced signal, and transmits the sensing signal to the first protection chip;

The first protection chip generates a safety carrier signal according to the sensing signal, and outputs the safety carrier signal to a load end of the power network, and outputs the reactive power to the ground using the load end of the electrical network.
The multi-level protection device according to claim 9, wherein the electric shock protection mechanism further comprises a first rectifying circuit, wherein the two input ends of the first rectifying circuit are respectively connected to the first alternating current output end and the second The output end of the first rectifier circuit is connected to the power end of the first protection chip.
The multi-level protection device according to claim 4, wherein the protection relay comprises a third protection relay disposed at a load end of the power network, and the control coil of the third protection relay is connected to an output end of the isolation protection mechanism.
The multi-level protection device according to claim 11, wherein said isolation protection mechanism comprises a second Induction circuit and isolation chip;

The second sensing circuit senses a current signal applied to the load end of the electrical network, generates an induced signal, and transmits the sensing signal to the isolation chip;

The isolation chip generates an isolated carrier signal according to the sensing signal, and outputs the isolated carrier signal to a load end of the power network.
The multi-level protection device according to claim 12, wherein the isolation protection mechanism further comprises a second rectifier circuit, wherein the two input ends of the second rectifier circuit are respectively connected to the first AC output terminal and the second The output end of the second rectifier circuit is connected to the power terminal of the isolation chip.
The multi-level protection device according to claim 4, wherein the protection relay comprises a fourth protection relay disposed at a load end of the power network, and the control coil of the fourth protection relay is connected to the output end of the overvoltage protection mechanism .
The multi-level protection device according to claim 14, wherein the overvoltage protection mechanism comprises a second induction coil, a third rectifier circuit and a second protection chip;

The second induction coil is configured to be wound around a secondary core of a transformer in a power network and generate an alternating current sensing signal;

The third rectifier circuit is connected between the second induction coil and the second protection chip, and the third rectifier circuit rectifies the AC induction signal into a DC induction signal;

The second protection chip receives the DC induction signal, and when the DC induction signal exceeds a preset value, the second protection chip outputs a power down signal.
The multi-level protection device according to claim 15, wherein the overvoltage protection mechanism further comprises a first filter circuit and a first amplification circuit, wherein the first filter circuit is connected to the third rectifier circuit and The first amplifying circuit is connected between the first protection circuit and the second protection chip.
The multi-level protection device according to claim 4, wherein the protection relay comprises a fifth protection relay provided on the power network bus, and the control coil of the fifth protection relay is connected to the output end of the circuit safety protection mechanism .
The multi-level protection device according to claim 17, wherein said circuit safety protection mechanism comprises a third induction coil, a fourth rectifier circuit and an induction chip;

The third inductive coil is configured to be inductively coupled to a primary coil of a transformer in an electrical network bus and to generate an alternating current sensing signal;

The fourth rectifying circuit is connected between the third inductive coil and the sensing chip, and the fourth rectifying circuit rectifies the alternating current sensing signal into a direct current sensing signal;

The sensing chip receives the DC induction signal, and when the DC sensing signal exceeds a preset value, the sensing chip outputs a power-off signal.
The multi-level protection device according to claim 18, wherein the circuit safety protection mechanism further comprises a second filter circuit and a second amplification circuit, wherein the second filter circuit is connected to the fourth rectifier circuit and The second amplifying circuit is connected between the sensing chip and the second filter circuit and the sensing chip.
A power supply system, comprising: a power network; and the multi-level protection device according to any one of claims 1 to 19;

The protection mechanism in the multi-stage protection device is configured to detect an operation of the power consumption network, and when the power supply network is faulty, control the output end of the power-off relay to be cut off by the protection relay Power supply to the electrical network bus.