WO2018145381A1

WO2018145381A1 - Circuit protection device and power supply system

Info

Publication number: WO2018145381A1
Application number: PCT/CN2017/088118
Authority: WO
Inventors: 马健; 马骥
Original assignee: 中领世能 (天津) 科技有限公司
Priority date: 2017-02-13
Filing date: 2017-06-13
Publication date: 2018-08-16
Also published as: CN106786350A

Abstract

Provided are a circuit protection device and power supply system; said circuit protection device comprises an induction coil (L1), a rectifier circuit, and an induction chip; the induction coil (L1) is used for a mutual-inductance connection with the primary winding of a transformer, generating an AC induction signal; the rectifier circuit is connected between the induction coil (L1) and the induction chip, and the rectifier circuit rectifies the AC induction signal into a DC induction signal; the induction chip receives the DC induction signal, and if the DC induction signal exceeds a preset value, the induction chip outputs a power-off signal. The circuit protection device and power supply system effectively protect an electricity transmission line in case of short circuit or overload, improving the safety of electricity transmission lines.

Description

Circuit protection device and power supply system

The present application claims priority to Chinese Patent Application No. PCT-A No. PCT-PCT-------

Technical field

The present invention relates to the field of secure power supply technologies, and in particular, to a circuit protection device and a power supply system.

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 utility power is usually powered by two output lines, one of which is a live line and the other is a zero line. When the electrical equipment fails, or when the line is aging or damaged, a short circuit occurs between the live line and the neutral line, which is likely to cause fire, major property damage and even casualties, especially human life, and electrical equipment and Bad consequences such as burnt lines.

In addition, when the total power of the connected electrical equipment is large and exceeds the rated load of the power supply line itself, that is, when the overload occurs, the current of the power supply line may be too large, and the power equipment and the line may also be caused. burn.

Therefore, short-circuit and overload are two important reasons that affect safe power supply. At present, the short-circuit and overload prevention measures are usually used to monitor the current of the mains output line by means of fuses or relays. When the current of the output line is too large, the power supply of the output line is cut off by the fuse blown or the relay is disconnected to protect the line and the electrical equipment. However, the existing protection methods are less sensitive and cannot effectively protect the line in the event of a short circuit or overload.

Summary of the invention

In view of the above, an object of the present invention is to provide a circuit protection device and a power supply system capable of effectively protecting a power transmission line in the event of a short circuit or an overload, thereby improving the safety of the power transmission line.

In a first aspect, an embodiment of the present invention provides a circuit protection device including an induction coil, a rectifier circuit, and an induction chip;

The induction coil is used for mutual inductance connection with a primary coil of a transformer, and generates an alternating current sensing signal;

The rectifier circuit is connected between the induction coil and the sensing chip, and the rectifier circuit The AC induction signal is rectified into a DC induction 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.

In conjunction with the first aspect, an embodiment of the present invention provides a first possible implementation manner of the first aspect, wherein the rectifier circuit is a rectifier bridge.

In combination with the first aspect, the rectifier bridge includes: a first diode, a second diode, a third diode, and a fourth diode, and a cathode of the first diode and the second An anode of the pole tube is connected, a second diode cathode is connected to a cathode of the fourth diode, and a cathode of the fourth diode is connected to a cathode of the third diode, The anode of the three diode is connected to the anode of the first diode. One end of the induction coil is connected between the first diode and the second diode, and the other end of the induction coil is connected to the first diode and the second diode Between to form a rectifier bridge.

With reference to the first aspect, an embodiment of the present invention provides a second possible implementation manner of the first aspect, wherein the circuit protection device further includes a filter circuit and an amplifying circuit connected between the rectifier circuit and the sensing chip. .

In combination with the first aspect, the filter circuit includes: a first filter capacitor, a second filter capacitor, and a filter resistor, wherein one end of the first filter capacitor is connected to the second diode and the fourth diode The other end of the first filter capacitor is connected between the first diode and the third diode, and the filter resistor is connected in series with the second filter capacitor and then connected in parallel at the first The two ends of the filter capacitor filter the DC induction signal through the first filter capacitor, the second filter capacitor, and the filter resistor.

In combination with the first aspect, the amplifying circuit includes: a first variable resistor, a PNP type transistor, a first resistor, a second resistor, and a Zener diode, and one end of the first resistor is connected to the second filter capacitor and the Between the filter resistors, the other end of the first resistor is connected between the first diode and the third diode via a Zener diode and a first variable resistor. The base set of the PNP type transistor is connected to the first variable resistor, the emitter of the PNP type transistor is connected between the second filter capacitor and the filter resistor, and the collector of the PNP type transistor is connected via the second resistor Between the second filter capacitor and the filter resistor.

In combination with the first aspect, the amplifying circuit further includes a second variable resistor, the second variable resistor is connected in parallel with the second filter capacitor, and the first input end of the input sensing chip and the set of PNP type transistors An electrode is connected, and a second input end of the input sensing chip is connected between the second variable resistor and the filter resistor.

In combination with the first aspect, the first variable resistor and the second variable resistor have adjustable resistance values ranging from 0 to 5.1KΩ.

In combination with the first aspect, the positive power terminal of the sensing chip is connected between the first diode and the third diode, and the negative power terminal of the sensing chip is connected to the second filter capacitor and the filter resistor between.

With reference to the first aspect, the embodiment of the present invention provides a third possible implementation manner of the first aspect, wherein the sensing chip includes a comparing unit and a triggering unit;

The comparing unit receives the DC sensing signal, and compares the DC sensing signal with the preset value;

When the DC sensing signal exceeds a preset value, the trigger unit outputs a power down signal.

With reference to the first aspect, the embodiment of the present invention provides a fourth possible implementation manner of the first aspect, wherein the trigger unit is provided with a multi-stable trigger;

The multi-stable trigger outputs a power down signal when the DC sense signal exceeds a preset value.

In a second aspect, an embodiment of the present invention further provides a power supply system including a transformer and the circuit protection device described above;

The primary coil of the transformer has an inductive winding connected in series,

The induction coil in the circuit protection device is connected to the induction winding in a mutual inductance.

With reference to the second aspect, the embodiment of the present invention provides a first possible implementation manner of the second aspect, wherein the power supply system further includes a first relay;

An output end of the sensing chip is connected to a control end of the first relay.

With reference to the second aspect, the embodiment of the present invention provides a second possible implementation manner of the second aspect, wherein the first output end of the sensing chip is connected to the control coil of the first relay through a thyristor;

The second output end of the sensing chip is connected to the control end of the thyristor through a bidirectional diode.

With reference to the second aspect, the embodiment of the present invention provides a third possible implementation manner of the second aspect, wherein the power supply system further includes a second relay;

An output of the first relay is connected in series with a control coil of the second relay, and an output of the second relay is connected in series with the primary coil.

In conjunction with the second aspect, an embodiment of the present invention provides a fourth possible implementation manner of the second aspect, wherein the first relay is a normally closed relay, and the second relay is a normally open relay.

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

The circuit protection device provided by the embodiment of the invention includes an induction coil, a rectifier circuit and an induction chip. The induction coil is used 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 rectifier circuit is connected between the induction coil and the sensing chip, and is used for rectifying the AC induction signal 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 protection device provided by the embodiment of the invention uses the induction coil 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 providing sensitivity of circuit protection and more effectively protecting the transmission line. , thereby improving the safety of the transmission line.

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 circuit protection device according to Embodiment 1 of the present invention;

2 is a schematic diagram of a circuit protection device according to Embodiment 1 of the present invention;

3 is a schematic diagram of an inductive chip in a circuit protection device according to Embodiment 1 of the present invention;

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

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.

At present, the short-circuit and overload prevention measures are usually used to monitor the current of the mains output line by means of fuses or relays. When the current of the output line is too large, the power supply of the output line is cut off by the fuse blown or the relay is disconnected to protect the line and the electrical equipment. However, existing The protection mode has low sensitivity and cannot effectively protect the line in the event of a short circuit or overload.

Based on this, an object of the present invention is to provide a circuit protection device and a power supply system capable of effectively protecting a transmission line in the event of a short circuit or an overload, and improving the safety of the transmission line.

Embodiment 1:

Embodiments of the present invention provide a circuit protection device, which can be applied to a power supply scenario such as a home, an office, or a factory. As shown in FIG. 1 and FIG. 2, the circuit protection device comprises an induction coil L1, a rectifier circuit and an induction chip.

The induction coil is used 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 rectifier circuit is connected between the induction coil L1 and the sensing chip, and is used for rectifying the AC induction signal sensed by the induction coil L1 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 protection device provided by the embodiment of the invention uses the induction coil L1 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 providing sensitivity of circuit protection and more effectively protecting the transmission line. , thereby improving the safety of the transmission line.

In this embodiment, the rectifier circuit is implemented in the form of a rectifier bridge, and the rectifier bridge is specifically composed of four diodes, and the four diodes are a first diode D1, a second diode D2, a third diode D3, and a first diode. Four diodes D4, the cathode of the first diode D1 is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the cathode of the fourth diode D4, and the cathode of the fourth diode D4 The positive electrode is connected to the negative electrode of the third diode D3, and the positive electrode of the third diode D3 is connected to the positive electrode of the first diode D1. One end of the induction coil L1 is connected between the first diode D1 and the second diode D2, and the other end of the induction coil L1 is connected between the first diode D3 and the second diode D4 to form a rectification bridge. By setting a rectifier bridge, the AC induction signal sensed by the induction coil L1 can be rectified to form a DC induction signal.

The circuit protection device provided by the embodiment of the invention further includes a filter circuit connected between the rectifier circuit and the sensing chip. The filter circuit is composed of a first filter capacitor C1, a second filter capacitor C2 and a filter resistor R1. One end of the first filter capacitor C1 is connected between the second diode D2 and the fourth diode D4, and the first filter capacitor C1 The other end is connected between the first diode D1 and the third diode D3, and the filter resistor R1 and the second filter capacitor C2 are connected in series and connected in parallel across the first filter capacitor C1, and pass through the first filter capacitor C1. The second filter capacitor C2 and the filter resistor R1 filter the DC induction signal to limit the voltage of the DC induction signal to a certain range.

In addition, the output end of the filter circuit is connected to the power supply terminals V+ and V- of the sensor chip to supply power to the sensor chip. The two ends of the second filter capacitor C2 are the output ends of the filter circuit, and the power terminal V- of the sensor chip Connected between the second filter capacitor C2 and the filter resistor R1, the power terminal V+ of the sensor chip is connected between the first diode D1 and the third diode D3.

Further, the circuit protection device provided by the embodiment of the present invention further includes an amplifying circuit connected between the filter circuit and the sensing chip. The amplifying circuit is mainly composed of a first variable resistor W1 and a PNP type transistor T1. The DC sensing signal can generate a larger current signal through the amplification of the transistor T1, and the current signal is converted into an induced voltage signal after passing through the second resistor R3. And inputting the first input end a1 of the sensing chip. The Zener diode D5 and the first resistor R2 connected in series with the first variable resistor W1 function as a voltage regulator and a current limit, respectively. One end of the first resistor R2 is connected between the second filter capacitor C2 and the filter resistor R1, and the other end of the first resistor R2 is connected to the first diode D1 and the third via the Zener diode D5 and the first variable resistor W1. Between diodes D3. The base set of the PNP type transistor T1 is connected to the first variable resistor W1, the emitter of the PNP type transistor T1 is connected between the second filter capacitor C2 and the filter resistor R1, and the collector of the PNP type transistor T1 is connected via the second resistor R3. Connected between the second filter capacitor C2 and the filter resistor R1. The first input end a1 of the input inductive chip is connected to the collector of the PNP type transistor T1.

In addition, the amplifying circuit further includes a second variable resistor W2 for converting the DC induction signal into a reference voltage signal and inputting the second input end a2 of the sensing chip. The second variable resistor W2 is connected in parallel with the second filter capacitor C2, and the second input terminal a2 of the input sensor chip is connected between the second variable resistor W2 and the filter resistor R1.

In this embodiment, the resistance values of the variable resistors W1 and W2 can be adjusted between 0 and 5.1 kΩ, and the specific resistance values of the variable resistors W1 and W2 can be adjusted according to the voltage and current conditions of the application scenario at the time of shipment. Settings.

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. At the same time, 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.

As shown in FIG. 3, the sensing chip in this embodiment specifically includes a comparing unit 31 and a triggering unit 32. The comparing unit 31 receives the DC induced 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 trigger unit 32 outputs a power-off signal to disconnect the power of the power transmission line.

As a preferred solution, the multi-state trigger is disposed in the trigger unit 32. When the DC induction signal exceeds a preset value, the multi-stable trigger outputs a power-off signal. Multi-stable flip-flops, also known as n-state flip-flops, are a further development of bistable contacts. 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, so the response speed is faster than that of the flip-flop.

In the embodiment of the present invention, by using the comparison unit 31 and the trigger unit 32 with high sensitivity, and setting the multi-stable trigger in the trigger unit 32, the sensing chip can respond within 0.1 seconds, thereby breaking in a very short time. The power supply is turned on to effectively protect the electrical equipment and the power supply line.

Embodiment 2:

As shown in FIG. 4, an embodiment of the present invention provides a power supply system including a transformer TB and the circuit protection device provided in the first embodiment. The primary winding L3 of the transformer TB is connected in series with the induction winding L2, and the induction coil L1 in the circuit protection device is connected to the induction winding L2. Both ends of the secondary coil L4 of the transformer TB serve as an alternating current output terminal, and provide an alternating current power source for the electric equipment.

The power supply system provided by the embodiment of the present invention further includes a first relay J1, and an output end of the sensing chip is connected to the control end of the first relay J1.

Specifically, the sensing chip in this embodiment has two output terminals b1 and b2. The first output end b1 of the sensing chip is connected to the control coil of the first relay J1 through the thyristor BG. The second output b2 of the inductive chip is connected to the control terminal of the thyristor BG via a bidirectional diode VD.

The thyristor BG, also known as the Silicon Controlled Rectifier (SCR), has the characteristics of small size, relatively simple structure, and strong function, and is one of the more commonly used semiconductor devices. The thyristor BG in this embodiment is a unidirectional thyristor, and the unidirectional thyristor is a unidirectional conductive device having a cathode and an anode, and the difference is that one control section is added, which makes it have Diodes have completely different operating characteristics. When a level signal is input to the control terminal of the unidirectional thyristor, the cathode and the anode are turned on.

The level of the output of the second output terminal b2 of the sensing chip is transmitted to the control terminal of the thyristor BG through the bidirectional diode VD, and the anode and the cathode of the thyristor BG are turned on. At the same time, the first output terminal b1 of the sensing chip The output level is output to the control coil of the first relay J1 through the thyristor BG, and the output end of the first relay J1 is disconnected, thereby realizing the protection of the power supply line.

Further, the power supply system provided by the embodiment of the present invention further includes a second relay J2. The output of the first relay J1 is connected in series with the control coil of the second relay J2, and the output of the second relay J2 is connected in series with the primary coil L3 of the transformer TB.

As a preferred solution, the first relay J1 is a normally closed relay, that is, the output end of the first relay J1 is in a closed state when the control coil is not energized. At the same time, the second relay J2 is a normally open type relay, that is, the output end of the first relay J1 is in an off state when the control coil is not energized.

In the case that the power supply system is normally powered, the control coil of the first relay J1 is not energized, and the output end of the first relay J1 is in a closed state, so the control power supply can supply power to the control coil of the second relay J2 through the first relay J1. When the control coil of the second relay J2 is energized, its output terminal is in a closed state to maintain the primary coil L3 of the transformer TB for continuous power supply. At the same time, the first output terminal b1 and the second output terminal b2 of the sensing chip have no level signal output.

When the trigger unit in the sensing chip issues a power-off signal, the control coil of the first relay J1 is energized to disconnect the output of the first relay J1. Since the output end of the first relay J1 is disconnected, the control coil of the second relay J2 is de-energized, and the output end of the second relay J2 is disconnected, thereby disconnecting the grid from the primary coil L3 of the transformer TB to cut off the power supply system. The power supply ensures the protection of the power supply line.

In this embodiment, the first relay J1 adopts a normally closed type relay, and the second relay J2 adopts a normally open type relay, and has the following advantages: in the actual power supply system, the output end of the first relay J1 and the second relay J2 A plurality of relays for different purposes are connected in series between the control coils, such as relays for arc protection, relays for overvoltage protection, and relays for short circuit protection. These relays also use a normally closed relay, and the output of each relay is connected in series with the control coil of the second relay J2, and when any one of the relays is turned off, the control coil of the second relay J2 can be powered off. Thereby cutting off the power supply of the power system.

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

In addition, in the description of the embodiments of the present invention, the terms "installation", "connected", and "connected" are to be understood broadly, and may be a fixed connection or a detachable connection, unless otherwise explicitly defined and defined. , or connected integrally; can be mechanical or electrical; can be directly connected or through The intermediate medium is indirectly connected and can be internal to 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 terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. The orientation or positional relationship of the indications is based on the orientation or positional relationship shown in the drawings, and is merely for the convenience of the description of the invention and the simplified description, rather than indicating or implying that the device or component referred to has a specific orientation, in a specific orientation. The construction and operation are therefore 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

Embodiments of the present invention provide a circuit protection device and a power supply system, wherein the circuit protection device includes an induction coil, a rectifier circuit, and an induction chip. The induction coil is used 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 rectifier circuit is connected between the induction coil and the sensing chip, and is used for rectifying the AC induction signal 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 protection device provided by the embodiment of the invention uses the induction coil 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 providing sensitivity of circuit protection and more effectively protecting the transmission line. , thereby improving the safety of the transmission line.

Claims

A circuit protection device, comprising: an induction coil, a rectifier circuit and an induction chip;

The induction coil is used for mutual inductance connection with a primary coil of a transformer, and generates an alternating current sensing signal;

The rectifier circuit is connected between the induction coil and the induction chip, and the rectifier circuit rectifies the AC induction signal into a DC induction 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 circuit protection device of claim 1 wherein said rectifier circuit is a rectifier bridge.
The circuit protection device according to claim 2, wherein the rectifier bridge comprises: a first diode, a second diode, a third diode, and a fourth diode, the first two a cathode of the pole tube is connected to a cathode of the second diode, a cathode of the second diode is connected to a cathode of the fourth diode, and a cathode of the fourth diode is opposite to the third A cathode of the diode is connected, and a cathode of the third diode is connected to a cathode of the first diode. One end of the induction coil is connected between the first diode and the second diode, and the other end of the induction coil is connected to the first diode and the second diode Between to form a rectifier bridge.
The circuit protection device according to claim 3, further comprising a filter circuit and an amplification circuit connected between said rectifier circuit and said sensor chip.
The circuit protection device according to claim 4, wherein the filter circuit comprises: a first filter capacitor, a second filter capacitor, and a filter resistor, one end of the first filter capacitor is connected to the second diode Between the tube and the fourth diode, the other end of the first filter capacitor is connected between the first diode and the third diode, the filter resistor and the second The filter capacitors are connected in series and then connected in parallel at the two ends of the first filter capacitor, and the DC sense signals are filtered by the first filter capacitor, the second filter capacitor and the filter resistor.
The circuit protection device according to claim 5, wherein the amplifying circuit comprises: a first variable resistor, a PNP type transistor, a first resistor, a second resistor, and a Zener diode, and one end of the first resistor Connected between the second filter capacitor and the filter resistor, the other end of the first resistor is connected to the first diode and the third diode via a Zener diode and a first variable resistor between. The base set of the PNP type transistor is connected to the first variable resistor, and the emitter of the PNP type transistor is connected to the second filter Between the capacitor and the filter resistor, the collector of the PNP transistor is connected between the second filter capacitor and the filter resistor via the second resistor.
The circuit protection device according to claim 6, wherein the amplifying circuit further comprises a second variable resistor, the second variable resistor is connected in parallel with the second filter capacitor, and the input sensing chip The first input end is connected to the collector of the PNP type transistor, and the second input end of the input sensing chip is connected between the second variable resistor and the filter resistor.
The circuit protection device according to claim 7, wherein the first variable resistor and the second variable resistor have adjustable resistance values ranging from 0 to 5.1 K?.
The circuit protection device according to any one of claims 4-8, wherein a positive power terminal of the sensor chip is connected between the first diode and the third diode, and a negative power source of the sensor chip The end is connected between the second filter capacitor and the filter resistor.
The circuit protection device of claim 1 , wherein the sensing chip comprises a comparison unit and a trigger unit;

The comparing unit receives the DC sensing signal, and compares the DC sensing signal with the preset value;

When the DC sensing signal exceeds a preset value, the trigger unit outputs a power down signal.
The circuit protection device according to claim 10, wherein a multi-stable trigger is disposed in the trigger unit;

The multi-stable trigger outputs a power down signal when the DC sense signal exceeds a preset value.
A power supply system, comprising: a transformer and the circuit protection device according to any one of claims 1 to 10;

The primary coil of the transformer has an inductive winding connected in series,

The induction coil in the circuit protection device is connected to the induction winding in a mutual inductance.
The power supply system of claim 12, further comprising a first relay;

An output end of the sensing chip is connected to a control end of the first relay.
The power supply system according to claim 13, wherein the first output end of the sensing chip is connected to the control coil of the first relay through a thyristor;

The second output end of the sensing chip is connected to the control end of the thyristor through a bidirectional diode.
The power supply system of claim 14 further comprising a second relay;

An output of the first relay is connected in series with a control coil of the second relay, and an output of the second relay is connected in series with the primary coil.
The power supply system according to claim 15, wherein said first relay is a normally closed relay, and said second relay is a normally open relay.