Protection circuit and relay protection system

Abstract

The utility model provides a protection circuit and a relay protection system, and relates to the technical field of switching power supplies. The protection circuit is connected in parallel to a conduction loop of a relay module to be protected. The protection circuit comprises a driving module, an isolation module, a switch module and a current limiting module. Wherein one end of the switch module is connected with one port of the conduction loop, the other end of the switch module is connected with one end of the current limiting module, and the other end of the current limiting module is connected with the other port of the conduction loop; the input end of the isolation module is used for being connected with the control module and further connected with the input end of the driving module, the output end of the driving module is connected with the driving end of the isolation module, the first output end of the isolation module is connected with one end of the switch module, and the second output end of the isolation module is connected with the control end of the switch module. Therefore, the anti-interference performance and the reliability of the relay protection system can be improved, and the suppression of the protection circuit on the impact current of the relay module is improved.

Description

Technical Field

[0001] The present application relates to the technical field of switching power supplies, and more particularly, to a protection circuit and a relay protection system. Background Art

[0002] With the development and innovation of power electronics technology, the switching power supply technology is also constantly evolving. When a switching power supply supplies power to a preset load, a large inrush current is often generated when the power is just turned on. This inrush current can cause power quality problems and may damage the load or other functional circuits.

[0003] In the prior art, in a relay protection system where multiple relay modules or current limiting units are connected in series in a switching power supply, the inrush current to the relay modules after power-on is suppressed.

[0004] However, even after power-on, there is still an inrush current in the existing solutions, which reduces the anti-interference ability and reliability of the relay protection system in the switching power supply. Summary of the Utility Model

[0005] The purpose of the present application is to provide a protection circuit and a relay protection system, which can improve the anti-interference ability and reliability of the relay protection system and improve the suppression of the inrush current of the protection circuit to the relay module.

[0006] To achieve the above object, the technical solutions adopted in the embodiments of the present application are as follows:

[0007] In a first aspect, an embodiment of the present application provides a protection circuit. The protection circuit is connected in parallel to the conduction loop of the relay module to be protected. The protection circuit includes: a driving module, an isolation module, a switching module, and a current limiting module;

[0008] One end of the switching module is connected to a port of the conduction loop, the other end of the switching module is connected to one end of the current limiting module, and the other end of the current limiting module is connected to another port of the conduction loop;

[0009] The input end of the isolation module is used to connect to a control module. The input end of the isolation module is also connected to the input end of the driving module. The output end of the driving module is connected to the driving end of the isolation module. The first output end of the isolation module is connected to one end of the switching module, and the second output end of the isolation module is connected to the control end of the switching module.

[0010] Optionally, the switching module includes: a semiconductor switching device;

[0011] If the semiconductor switch device is a thyristor switch device, one end of the switch module is the second pin of the thyristor switch device, the other end of the switch module is the first pin of the thyristor switch device, and the control end of the switch module is the third pin of the thyristor switch device.

[0012] Optionally, the isolation module includes: an optocoupler or a magnetic coupler;

[0013] If the isolation module includes: an optocoupler, the input end of the isolation module is the anode of the optocoupler, and the driving end of the isolation module is the cathode of the optocoupler;

[0014] The first output end and the second output end of the isolation module are respectively the first output terminal and the second output terminal of the optocoupler.

[0015] Optionally, the isolation module further includes: a first resistor, and the second output end of the optocoupler is connected to the control end of the switch module through the first resistor.

[0016] Optionally, the driving module is a driving module composed of switching tubes, or a driving chip;

[0017] If the driving module is a driving module composed of switching tubes, the driving module includes: a first switching tube, a second switching tube, a second resistor, and a third resistor; wherein, the control end of the first switching tube is connected to the input end of the isolation module through the second resistor, the first end of the first switching tube is connected to the driving end of the isolation module, the control end of the first switching tube is further connected to the first end of the second switching tube, the second end of the second switching tube is grounded, the control end of the second switching tube is connected to the second end of the first switching tube, and the control end of the second switching tube is further grounded through the third resistor.

[0018] Optionally, the current limiting module includes: at least one current limiting element such as a thermistor, a resistor, and an inductor.

[0019] Optionally, the switch module further includes: a semiconductor protection circuit, and the semiconductor protection circuit is connected to the semiconductor switch device.

[0020] Optionally, the semiconductor protection circuit includes: a clock circuit or a capacitor absorption circuit.

[0021] In a second aspect, an embodiment of the present application provides a relay protection system, and the relay protection system includes: a control module, a relay module, a power supply module, and the protection circuit according to any one of the first aspects above;

[0022] The power supply module is respectively connected to the control module and the relay module; the control module is connected to the input end of the protection circuit, the protection circuit is connected in parallel on the conduction loop of the circuit breaker module, and the control module is connected to the relay module.

[0023] Optionally, the relay protection system further includes: a key module, the key module is connected to the control module; the key module is also connected to the power supply module.

[0024] The beneficial effects of a protection circuit and a relay protection system provided by this application are:

[0025] This application provides a protection circuit and a relay protection system. The protection circuit is connected in parallel on the conduction loop of the relay module to be protected. The protection circuit may include: a driving module, an isolation module, a switching module, and a current limiting module; wherein, one end of the switching module is connected to a port of the conduction loop, the other end of the switching module is connected to one end of the current limiting module, and the other end of the current limiting module is connected to another port of the conduction loop; the input end of the isolation module is used to connect to the control module, the input end of the isolation module is also connected to the input end of the driving module, the output end of the driving module is connected to the driving end of the isolation module, the first output end of the isolation module is connected to one end of the switching module, and the second output end of the isolation module is connected to the control end of the switching module. Thus, in this application, by connecting the relay module to be protected in parallel in the protection circuit, and the switching module and the current limiting module are connected in series, the current limiting module can preferentially suppress the inrush current in the circuit through the conduction of the switching module when the relay protection system is powered on. After the current limiting module suppresses the inrush current, the switching module is disconnected, so that the relay module can operate safely, thereby improving the anti-interference ability and reliability of the relay protection system. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of this application, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of this application, so they should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0027] Figure 1 Structural schematic of a relay protection system provided by an embodiment of this application Figure 1 ;

[0028] Figure 2 Structural schematic of a relay protection system provided by an embodiment of this application Figure 2 ;

[0029] Figure 3 Structural schematic of a protection circuit provided by an embodiment of this applicationFigure 1 ;

[0030] Figure 4 Structural schematic of a protection circuit provided by an embodiment of the present application Figure 2 ;

[0031] Figure 5 Structural schematic of a protection circuit provided by an embodiment of the present application Figure 3 ;

[0032] Figure 6 Structural schematic of a protection circuit provided by an embodiment of the present application Figure 4 ;

[0033] Figure 7 Structural schematic of a protection circuit provided by an embodiment of the present application Figure 5 ;

[0034] Figure 8 Structural schematic of a protection circuit provided by an embodiment of the present application Figure 6 ;

[0035] Figure 9 Structural schematic of a protection circuit provided by an embodiment of the present application Figure 7 ;

[0036] Figure 10 Structural schematic of a protection circuit provided by an embodiment of the present application Figure 8 ;

[0037] Figure 11 Structural schematic of a relay protection system provided by an embodiment of the present application Figure 3 . Detailed implementation manners

[0038] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. The components of the embodiments of the present application described and illustrated herein usually can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0040] It should be noted that like reference numerals and letters refer to like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the utility model product is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application.

[0042] In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0043] In the description of the present application, it should also be noted that unless otherwise clearly defined and limited, the terms "set", "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0044] To better understand the various solutions provided by the embodiments of the present application, the following will separately describe in detail a protection circuit and a relay protection system provided by the embodiments of the present application in sequence with reference to the figures.

[0045] The following will first give an exemplary description of the relay protection system provided by the embodiments of the present application with reference to the figures. Figure 1 The structural schematic of a relay protection system provided by an embodiment of the present application Figure 1 . As Figure 1 shown, the relay protection system 500 may include: a power supply module 400, a control module 300, a relay module 200, and a protection circuit 100.

[0046] Among them, the power supply module 400 is respectively connected to the control module 300 and the relay module 200, and is used to provide workable power supplies for the control module 300 and the relay module 200 respectively when the relay protection system 500 starts to be powered on. For example, it can provide a working voltage power supply of 3.3V for the control module 300 and a working voltage power supply of 5V for the control module 300. The control module 300 is connected to the input end of the protection circuit 100 and is used to provide a control instruction for the protection circuit 100. The protection circuit 100 can be connected in parallel on the conduction loop of the relay module 200 to be protected. The control module 300 is connected to the relay module 200 and is used to control the closing and opening of the relay module 200.

[0047] Among them, the power supply module 400 is used for the power supply of the entire relay protection system 500 to ensure the normal operation of the entire relay protection system 500. The control module 300 can be used to first send a control instruction to the protection circuit 100. After the protection circuit 100 receives this control instruction and withstands the inrush current, then the control module 300 sends a control command to the relay module 200 to make the relay module 200 close and conduct. The protection circuit 100 is used to provide protection for the relay module 200 in the relay protection system 500 to prevent damage to the relay module 200 caused by the inrush current after power-on.

[0048] It should be noted that this relay protection system can be applied in a preset intelligent switch product, and the preset intelligent switch product can be selected according to the actual situation. For example, the preset intelligent switch product can be selected as a switching power supply.

[0049] This application provides a relay protection system, which may include: a control module, a relay module, a power supply module, and a protection circuit. Among them, the power supply module is respectively connected to the control module and the relay module. The control module is connected to the input end of the protection circuit, and the protection circuit is connected in parallel on the conduction loop of the circuit breaker module. The control module is connected to the relay module. Thus, when the power supply module in this application is used to provide working power supplies for the control module and the relay module respectively, the control module controls the protection circuit and the relay module to close successively, improving the anti-interference performance and reliability of the relay protection system, and improving the suppression of the inrush current of the protection circuit to the relay module.

[0050] For the convenience of understanding the above relay protection system, the embodiment of this application also provides another relay protection system 500. Figure 2 The structural schematic diagram of a relay protection system provided by the embodiment of this application Figure 2 . As Figure 2 shown, this relay protection system 500 may further include: a key module 510.

[0051] Among them, the button module 510 is connected to the control module 300 and is used to provide an input of a control signal to the control module 300. The button module 510 is also connected to the power supply module 400 and is used to provide a working power supply for the button module 510. For example, a 3.3V working voltage power supply is provided for the button module 510.

[0052] The relay protection system provided by this application may further include: a button module, and the button module is connected to the control module. Thus, the button module of this application can provide an input of a control signal for the control module, so that the control module can successively control the protection circuit and the relay module through the control signal, which can not only improve the anti-interference performance and reliability of the relay protection system, but also improve the suppression of the impact current of the protection circuit on the relay module.

[0053] To facilitate the understanding of the above relay protection system 500, an embodiment of this application also provides a protection circuit 100. Figure 3 The structural schematic diagram of a protection circuit provided by an embodiment of this application Figure 1 As Figure 3 shown, the protection circuit 100 can be connected in parallel to the conduction loop of the relay module 200 to be protected.

[0054] The protection circuit 100 may include: a driving module 110, an isolation module 120, a switching module 130, and a current limiting module 140.

[0055] Among them, one end of the switching module 130 is connected to a port of the conduction loop, the other end of the switching module 130 is connected to one end of the current limiting module 140, and the other end of the current limiting module 140 is connected to another port of the conduction loop, which is used to realize the parallel connection of the protection circuit 100 and the relay module 200 to be protected. The input end of the isolation module 120 is used to be connected to the control module 300 and is used to receive the control instruction of the control module 300; the input end of the isolation module 120 is also connected to the input end of the driving module 110, and the output end of the driving module 110 is connected to the driving end of the isolation module 120, which is used to drive the output of the isolation module 120 to ensure the stability of the output signal of the isolation module 120; the first output end of the isolation module 120 is connected to one end of the switching module 130, and the second output end of the isolation module 120 is connected to the control end of the switching module 130, which is used to control the on-off of the switching module 130.

[0056] The present application provides a protection circuit, which is connected in parallel to the conduction loop of the relay module to be protected. The protection circuit may include: a driving module, an isolation module, a switching module, and a current limiting module. One end of the switching module is connected to a port of the conduction loop, the other end of the switching module is connected to one end of the current limiting module, and the other end of the current limiting module is connected to another port of the conduction loop. The input end of the isolation module is used to connect to the control module, and the input end of the isolation module is also connected to the input end of the driving module. The output end of the driving module is connected to the driving end of the isolation module. The first output end of the isolation module is connected to one end of the switching module, and the second output end of the isolation module is connected to the control end of the switching module. Thus, in the present application, by connecting the relay module to be protected in parallel to the protection circuit and connecting the switching module and the current limiting module in series, when the relay protection system is powered on, the current limiting module can preferentially suppress the inrush current in the circuit through the conduction of the switching module. After the current limiting module suppresses the inrush current, the switching module is disconnected, so that the relay module can operate safely, thereby improving the anti-interference performance and reliability of the relay protection system.

[0057] Optionally, in a possible implementation embodiment, the switching module 130 in the protection circuit 100 may include: a semiconductor switching device.

[0058] Wherein, if the semiconductor switching device is a silicon controlled switch device SCI, then Figure 3 Based on this, the protection circuit 100 will be further described by way of examples as follows. Figure 4 The structural schematic diagram of a protection circuit provided by an embodiment of the present application Figure 2 . As Figure 4 shown, one end of the switching module 130 is the second pin of the silicon controlled switch device SCI, the other end of the switching module 130 is the first pin of the silicon controlled switch device SCI, and the control end of the switching module 130 is the third pin of the silicon controlled switch device SCI. The third pin of the silicon controlled switch device SCI is used to activate the silicon controlled switch device SCI.

[0059] The protection circuit provided by this application, wherein the switch module includes: a semiconductor switch device; if the semiconductor switch device is a thyristor switch device, one end of the switch module is the second pin of the thyristor switch device, the other end of the switch module is the first pin of the thyristor switch device, and the control end of the switch module is the third pin of the thyristor switch device. Thus, this application can activate the thyristor switch device through the third pin of the thyristor switch device, control the operation of the current limiting module by activating the thyristor switch device, and then, when the relay protection system is powered on, by activating the thyristor switch device, the inrush current in the circuit can be preferentially suppressed. After the current limiting module suppresses the inrush current, the thyristor switch device is disconnected for the safe operation of the relay module, thereby improving the anti-interference ability and reliability of the relay protection system.

[0060] Optionally, in a possible implementation embodiment, the isolation module 120 may include: an optocoupler or a magnetic coupler.

[0061] Wherein, if the isolation module 120 may include: an optocoupler U1. Then on the Figure 4 basis, the protection circuit 100 will be further illustrated by examples as follows. Figure 5 The structural schematic of a protection circuit provided by an embodiment of this application Figure 3 . As Figure 5 shown, the input end of the isolation module 120 is the anode of the optocoupler U1, and the anode of the optocoupler U1 is used to connect to the control module; the anode of the optocoupler U1 is also used to connect to the input end of the drive module; the drive end of the isolation module 120 is the cathode of the optocoupler U1, and the cathode of the optocoupler U1 is connected to the output end of the drive module; the first output end and the second output end of the isolation module 120 are respectively the first output terminal and the second output terminal of the optocoupler U1, that is, the first output terminal of the optocoupler U1 is connected to the switch module 130 (such as the second pin of the thyristor switch device SCI); the second output terminal of the optocoupler U1 is connected to the switch module 130 (such as the third pin of the thyristor switch device SCI), that is, the second output terminal of the optocoupler U1 is connected to the control end of the switch module 130.

[0062] The optocoupler U1 can be used to isolate AC electrical signals to avoid damage to the protection circuit 100. The model of the optocoupler U1 can be selected according to the actual situation. For example, the model of the optocoupler U1 can be selected as EL3063.

[0063] The protection circuit provided by the present application, wherein the isolation module includes: an optocoupler or a magnetic coupler; if the isolation module includes: an optocoupler, the input end of the isolation module is the anode of the optocoupler, and the driving end of the isolation module is the cathode of the optocoupler; the first output end and the second output end of the isolation module are respectively the first output terminal and the second output terminal of the optocoupler. Thus, the control instruction issued by the control module can reach the switching module through the isolation module in the present application, which is used to ensure the stable output of the control instruction and avoid the impact of the AC signal, resulting in the damage of the protection circuit, thereby improving the anti-interference ability and reliability of the relay protection system.

[0064] Based on Figure 5 , the protection circuit 100 will be further illustrated by examples as follows. Figure 6 The structural schematic diagram of a protection circuit provided by an embodiment of the present application Figure 4 . As Figure 6 shown, the isolation module 120 may further include: a first resistor R1.

[0065] Among them, the second output end of the optocoupler U1 is connected to the control end of the switching module 130 through the first resistor R1, which is used to avoid the output electrical signal of the second output end of the optocoupler U1 from being too large, causing damage to the switching module 130, for protecting the switching module 130, and the second output end of the optocoupler U1 is connected to the control end of the switching module 130 through the first resistor R1, which can make the control signal of the switching module 130 more stable.

[0066] The protection circuit provided by the present application, wherein the isolation module further includes: a first resistor, and the second output end of the optocoupler is connected to the control end of the switching module through the first resistor. Thus, the present application stabilizes the output signal of the second output end of the optocoupler through the first resistor, makes the control signal of the switching module more stable, and further improves the anti-interference ability and reliability of the relay protection system.

[0067] Optionally, in a possible implementation embodiment, the driving module 110 is a driving module composed of switching tubes, or a driving chip.

[0068] If the driving module 110 is a driving module composed of switching tubes, then based on Figure 6 , the protection circuit 100 will be further illustrated by examples as follows. Figure 7 The structural schematic diagram of a protection circuit provided by an embodiment of the present application Figure 5 . As Figure 7 shown, the driving module 110 may include: a first switching tube Q1, a second switching tube Q2, a second resistor R2, and a third resistor R3.

[0069] Among them, the control terminal of the first switching transistor Q1 is connected to the input terminal of the isolation module 120 through the second resistor R2, that is, the control terminal of the first switching transistor Q1 is connected to the anode of the optocoupler U1 through the second resistor R2; the first terminal of the first switching transistor Q1 is connected to the driving terminal of the isolation module 120, that is, the first terminal of the first switching transistor Q1 is connected to the cathode of the optocoupler U1; the control terminal of the first switching transistor Q1 is further connected to the first terminal of the second switching transistor Q2, the second terminal of the second switching transistor Q2 is grounded, the control terminal of the second switching transistor Q2 is connected to the second terminal of the first switching transistor Q1, and the control terminal of the second switching transistor Q2 is further grounded through the third resistor R3 for providing a stable driving signal to the isolation module 120.

[0070] The protection circuit provided by the present application, wherein the driving module is a driving module composed of switching transistors or a driving chip; if the driving module is a driving module composed of switching transistors, the driving module includes: a first switching transistor, a second switching transistor, a second resistor, and a third resistor; wherein, the control terminal of the first switching transistor is connected to the input terminal of the isolation module through the second resistor, the first terminal of the first switching transistor is connected to the driving terminal of the isolation module, the control terminal of the first switching transistor is further connected to the first terminal of the second switching transistor, the second terminal of the second switching transistor is grounded, the control terminal of the second switching transistor is connected to the second terminal of the first switching transistor, and the control terminal of the second switching transistor is further grounded through the third resistor. Thus, the present application can provide a stable and reliable driving signal to the isolation module through the driving module composed of the first switching transistor, the second switching transistor, the second resistor, and the third resistor, improving the anti-interference performance and reliability of the relay protection system.

[0071] Optionally, in a possible implementation embodiment, the current limiting module 140 may include at least one current limiting element such as a thermistor NTC, a resistor R, and an inductor C. That is, the current limiting module 140 can be a preset load of the above at least one current limiting element for suppressing the inrush current when the relay protection system is powered on.

[0072] If the current limiting module 140 is a thermistor NTC, then Figure 7 On this basis, the protection circuit 100 will be further described by way of examples as follows. Figure 8 is a schematic structural diagram of a protection circuit provided by an embodiment of the present application Figure 6 . One end of the thermistor NTC is connected to the first pin of the thyristor switch device SCI, and the other end of the thermistor NTC is used to connect to the circuit breaker module.

[0073] The protection circuit provided by the present application, wherein the current limiting module includes at least one current limiting element such as a thermistor, a resistor, and an inductor. Thus, the present application can suppress the inrush current when the relay protection system is powered on through the current limiting module, improving the anti-interference performance and reliability of the relay protection system.

[0074] Optionally, inFigure 4 Based on the above, the protection circuit 100 will be further illustrated with examples as follows. Figure 9 The structural schematic diagram of a protection circuit provided by an embodiment of the present application Figure 7 As Figure 9 shown, the switch module 130 may further include: a semiconductor protection circuit.

[0075] Among them, the semiconductor protection circuit is connected to a semiconductor switching device (such as a thyristor switching device SCI). This semiconductor protection circuit can be used to prevent leakage current protection.

[0076] For the protection circuit provided by the present application, the switch module further includes: a semiconductor protection circuit, and the semiconductor protection circuit is connected to a semiconductor switching device. Thus, the present application can better control the suppression of the inrush current when the current limiting module powers on the relay protection system by connecting the semiconductor protection circuit to the semiconductor switching device.

[0077] Optionally, based on Figure 9 the above, the protection circuit 100 will be further illustrated with examples as follows. Figure 10 The structural schematic diagram of a protection circuit provided by an embodiment of the present application Figure 8 As Figure 10 shown, the semiconductor protection circuit may include: a clock circuit RV1 or a capacitor absorption circuit.

[0078] Among them, the clock circuit RV1 can be used for surge protection; the capacitor absorption circuit is composed of a resistor R4 and a capacitor C1, and the clock circuit RV1 can be connected in parallel with the capacitor absorption circuit.

[0079] For the protection circuit provided by the present application, the semiconductor protection circuit includes: a clock circuit or a capacitor absorption circuit. Thus, the present application can better control the suppression of the inrush current when the current limiting module powers on the relay protection system by including: a clock circuit or a capacitor absorption circuit in the semiconductor protection circuit.

[0080] Optionally, based on Figure 8 the above, the relay module 200 provided by the embodiment of the present application will be first illustrated with reference to the accompanying drawings as follows. Figure 11 The structural schematic diagram of a relay protection system provided by an embodiment of the present application Figure 3 As Figure 11 shown, the relay module 200 in the above relay protection system 500 may include: a diode D1 and a relay unit K1.

[0081] Among them, the anode of diode D1 is connected to the output terminal of the power supply module, providing a working voltage of 5V for diode D1; the cathode of diode D1 is connected to the output terminal of the control module, used to control the closing and opening of the relay unit K1 in the relay module 200. The cathode of diode D1 is connected to the first port of the relay unit K1; the anode of diode D1 is connected to the second port (i.e., the DC port) of the relay unit K1; the third port (i.e., the AC port) of the relay unit K1 is connected to a preset AC power supply (such as an AC voltage source of 220V); the fourth port of the relay unit K1 is used to connect the current limiting module 140 (such as a thermistor NTC) in the protection circuit.

[0082] Among them, this diode D1 is used to provide protection for the relay unit K1 to prevent excessive electrical signals from damaging the relay unit K1.

[0083] The relay protection system provided by this application, among which, the relay module includes: a diode and a relay unit. The anode of the diode is connected to the output terminal of the power supply module; the cathode of the diode is connected to the output terminal of the control module, and the cathode of the diode is connected to the first port of the relay unit; the anode of the diode is connected to the second port of the relay unit; the third port of the relay unit is connected to a preset AC power supply; the fourth port of the relay unit is used to connect the current limiting module in the protection circuit. Thus, the control module in this application controls the protection circuit and the relay module to close successively, improving the anti-interference ability and reliability of the relay protection system, and improving the suppression of the impact current of the protection circuit on the relay module.

[0084] The above are only the preferred embodiments of this application and are not used to limit this application. For those skilled in the art, this application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. A protection circuit, characterized in that: The protection circuit is connected in parallel to the conduction loop of the relay module to be protected, and the protection circuit includes: a driving module, an isolation module, a switch module and a current limiting module; Wherein, one end of the switch module is connected to one port of the conduction loop, the other end of the switch module is connected to one end of the current limiting module, and the other end of the current limiting module is connected to another port of the conduction loop; The input end of the isolation module is used to connect to the control module, the input end of the isolation module is also connected to the input end of the driving module, the output end of the driving module is connected to the driving end of the isolation module, the first output end of the isolation module is connected to one end of the switch module, and the second output end of the isolation module is connected to the control end of the switch module.

2. The protection circuit according to claim 1, characterized in that: The switch module comprises: a semiconductor switch device; If the semiconductor switch device is a thyristor switch device, one end of the switch module is the second pin of the thyristor switch device, the other end of the switch module is the first pin of the thyristor switch device, and the control end of the switch module is the third pin of the thyristor switch device.

3. The protection circuit according to claim 1, characterized in that: The isolation module includes: an optical coupler or a magnetic coupler; If the isolation module includes: an optical coupler, the input end of the isolation module is the anode of the optical coupler, and the driving end of the isolation module is the cathode of the optical coupler; The first output end and the second output end of the isolation module are respectively the first output terminal and the second output terminal of the optical coupler.

4. The protection circuit according to claim 3, characterized in that: The isolation module further includes: a first resistor, and the second output end of the optical coupler is connected to the control end of the switch module through the first resistor.

5. The protection circuit according to claim 1, characterized in that: The driving module is a driving module composed of a switch tube, or a driving chip; If the driving module is a driving module composed of a switch tube, the driving module includes: a first switch tube, a second switch tube, a second resistor and a third resistor; wherein the control end of the first switch tube is connected to the input end of the isolation module through the second resistor, the first end of the first switch tube is connected to the driving end of the isolation module, the control end of the first switch tube is also connected to the first end of the second switch tube, the second end of the second switch tube is grounded, the control end of the second switch tube is connected to the second end of the first switch tube, and the control end of the second switch tube is also grounded through the third resistor.

6. The protection circuit according to claim 1, characterized in that: The current limiting module includes: at least one type of current limiting element among the thermistor, resistor, and inductor.

7. The protection circuit according to claim 2, characterized in that: The switch module further includes: a semiconductor protection circuit, wherein the semiconductor protection circuit is connected to the semiconductor switch device.

8. The protection circuit according to claim 7, characterized in that: The semiconductor protection circuit includes: a clock circuit or a capacitor absorption circuit.

9. A relay protection system, characterized in that: The relay protection system comprises: a control module, a relay module, a power module and a protection circuit according to any one of claims 1 to 8; The power supply module is connected to the control module and the relay module respectively; the control module is connected to the input end of the protection circuit, the protection circuit is connected in parallel to the conduction loop of the relay module to be protected, and the control module is connected to the relay module.

10. The relay protection system according to claim 9, characterized in that: The relay protection system further comprises: a key module, wherein the key module is connected to the control module; the key module is also connected to the power module.

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