Current protection device and power supply system

Abstract

The invention provides a current protection device and a power supply system. The current protection device comprises a main control switch, a current detection unit, a control unit and a first switch unit, and the main control switch comprises a main control contact and a driving coil which are in magnetic fit; the main control contact is used for being connected in series in a to-be-protected main loop, and the driving coil and the first switch unit are connected in series in a driving loop; the current detection unit is electrically connected with the input end of the control unit and is used for detecting the current of the main loop and feeding back a detection signal to the control unit; the output end of the control unit is electrically connected with the first switch unit, and the control unit is used for controlling the on-off state of the first switch unit according to the detection signal so as to control the on-off state of the main loop through the driving loop. According to the invention, through an active protection mode, consumption parts are not needed, continuous work can be carried out in an electrical scene in which current protection needs to be triggered for multiple times, the protection efficiency is improved, and the protection cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical protection, and particularly to a current protection device and a power supply system. Background Art

[0002] In many electrical scenarios, electrical protection needs to be performed on relevant circuits, such as current protection. Specifically, in some existing technologies, consumables such as fuses are usually connected in series to the circuit to be protected. When the current in the circuit is abnormal and the current becomes too large, the consumables such as fuses will be disconnected passively, so as to achieve the protection purpose of disconnecting the circuit.

[0003] However, after the existing technology realizes the primary current protection, the corresponding consumables usually need to be replaced to ensure that the next current protection can be realized. It can be seen that when dealing with long-term electrical work, due to the need to trigger the current protection multiple times, the protection efficiency of the existing technology is low and the protection cost is high. Summary of the Invention

[0004] Aiming at the deficiencies in the existing technology, the present invention provides a current protection device and a power supply system.

[0005] In a first aspect, in one embodiment, the present invention provides a current protection device, which includes a main control switch, a current detection unit, a control unit, and a first switch unit. The main control switch includes a main control contact and a drive coil that are magnetically coupled;

[0006] The main control contact is used to be connected in series to the main circuit to be protected, and the drive coil and the first switch unit are connected in series to the drive circuit;

[0007] The current detection unit is electrically connected to the input end of the control unit, and is used to detect the current of the main circuit and feed back a detection signal to the control unit;

[0008] The output end of the control unit is electrically connected to the first switch unit, and is used to control the switch state of the first switch unit according to the detection signal, so as to control the on-off state of the main circuit through the drive circuit.

[0009] In one embodiment, the drive circuit is used to access an AC power supply, and the first switch unit includes a bidirectional switch sub-unit.

[0010] In one embodiment, the bidirectional switch sub-unit includes a triac;

[0011] The first anode and the second anode of the triac are connected in series to the drive coil, and the gate of the triac is electrically connected to the output end of the control unit.

[0012] In one embodiment, the bidirectional switch sub-unit includes a relay, and the relay includes a relay coil and a relay contact that are magnetically coupled;

[0013] The relay contact is connected in series with the driving coil, and the relay coil is electrically connected to the output end of the control unit.

[0014] In one embodiment, the current detection unit includes a current transformer;

[0015] The current transformer is used to sleeved on the power line of the main circuit, and the first end and the second end of the current transformer are respectively electrically connected to the first input end and the second input end of the control unit.

[0016] In one embodiment, the current protection device further includes a short-circuit release and a second switch unit;

[0017] The short-circuit release is used to be connected in series in the main circuit;

[0018] The second switch unit is mechanically connected to the short-circuit release and is used to be connected in series in the driving circuit, and is used to be in an open state based on the tripping action of the short-circuit release when a short circuit occurs in the main circuit, so as to control the on-off state of the main circuit through the driving circuit.

[0019] In one embodiment, the second switch unit includes a micro switch;

[0020] The micro switch is used to be connected in series in the driving circuit, and is used to trigger a conversion action based on the tripping action of the short-circuit release, so as to convert itself from a closed state to an open state.

[0021] In one embodiment, the second switch unit further includes an operating mechanism;

[0022] The operating mechanism is respectively mechanically connected to the short-circuit release and the micro switch, and is used to transmit an operating action with an action degree less than the tripping action to the micro switch based on the tripping action of the short-circuit release, so as to trigger the conversion action of the micro switch.

[0023] In one embodiment, the second switch unit further includes a handle;

[0024] The handle is mechanically connected to the operating mechanism and is used to control the operating mechanism to reset.

[0025] Second, in one embodiment, the present invention provides a power supply system, and the power supply system includes a main power supply, a driving power supply, and the current protection device in any one of the above embodiments;

[0026] The main power supply is connected in series with the main circuit and is used to provide a main power supply signal to the main circuit;

[0027] The driving power supply is connected in series with the driving circuit and is used to provide a driving power supply signal to the driving circuit.

[0028] Through the above-mentioned current protection device and power supply system, the main switch is used to control the on / off of the main circuit; since the main switch includes a main contact and a drive coil with magnetic cooperation, the current detection unit, the control unit and the first switch unit are further used to control the on / off of the drive circuit where the drive coil is located, and the on / off of the drive circuit depends on the switch state of the first switch unit. Finally, the on / off control of the main circuit is converted into the switch state of the first switch unit; in an active protection manner, no consumables are required, and it can continuously work in electrical scenarios where current protection needs to be triggered multiple times, improving the protection efficiency and reducing the protection cost. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0030] Figure 1 Structural schematic diagram of the current protection device in an embodiment of the present invention;

[0031] Figure 2 Structural schematic diagram of the first switch unit including a triac in an embodiment of the present invention;

[0032] Figure 3 Structural schematic diagram of the first switch unit including a relay in an embodiment of the present invention;

[0033] Figure 4 Structural schematic diagram of the current detection unit including a current transformer in an embodiment of the present invention;

[0034] Figure 5 Structural schematic diagram of the current protection device further including a short-circuit release and a second switch unit in an embodiment of the present invention;

[0035] Figure 6 Structural schematic diagram of the second switch unit including a micro switch in an embodiment of the present invention;

[0036] Figure 7 Structural schematic diagram of the second switch unit further including an operating mechanism in an embodiment of the present invention;

[0037] Figure 8 Structural schematic diagram of the second switch unit further including a handle in an embodiment of the present invention;

[0038] Figure 9 Mechanical assembly schematic diagram of the current protection device in an embodiment of the present invention. Detailed Embodiments

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention 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 to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined. In the present invention, the term "exemplary" is used to mean "serving as an example, illustration, or description". Any embodiment described as "exemplary" in the present invention is not necessarily to be construed as more preferred or advantageous than other embodiments. In order for any person skilled in the art to implement and use the present invention, the following description is given. In the following description, details are set forth for the purpose of explanation. It should be understood that those of ordinary skill in the art can recognize that the present invention can be implemented without these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid unnecessary details from obscuring the description of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

[0041] In a first aspect, as Figure 1 shown, in one embodiment, the present invention provides a current protection device, which includes a main control switch K1, a current detection unit, a control unit, and a first switch unit. The main control switch K1 includes a main control contact K11 and a drive coil K12 that are magnetically coupled.

[0042] The main control contact K11 is used to be connected in series in the main circuit to be protected, and the drive coil K12 and the first switch unit are connected in series in the drive circuit.

[0043] Among them, the main circuit accesses the corresponding main power supply through terminals L1 / L2 / L3 and outputs to the corresponding electrical load through terminals T1 / T2 / T3.

[0044] Among them, the drive circuit accesses the corresponding drive power supply through terminals A1 and A2.

[0045] The current detection unit is electrically connected to the input end of the control unit, and is used to detect the current of the main circuit and feedback a detection signal to the control unit.

[0046] The output end of the control unit is electrically connected to the first switch unit, and is used to control the switch state of the first switch unit according to the detection signal, so as to control the on-off state of the main circuit through the drive circuit.

[0047] Among them, it should be added that in Figure 1 the control unit is also connected in series with the drive circuit to draw power from the drive circuit to ensure its own power supply. However, it should be noted that since the first switch unit is also connected in series with the drive circuit and is used to control the power-on and power-off of the drive coil K12, when the first switch unit is disconnected, the first drive branch where the drive coil K12 and the first switch unit are located in the drive circuit is disconnected. In order to ensure that the control unit can continue to draw power from the drive circuit, the control unit needs to form a second drive branch in front of the aforementioned first drive branch with the drive circuit. That is to say, the switch state of the first switch unit cannot affect the power-on of the control unit.

[0048] Among them, the current detection unit is specifically used to detect the current value of the main circuit and feedback it to the control unit in the form of voltage to achieve current protection in aspects such as overload and leakage of the main circuit. Specifically, when the main circuit has an overload or leakage, the current detected by the current detection unit of the main circuit is relatively large, which causes the detection signal fed back to the control unit to indicate a relatively large current. The control unit controls the first switch unit to disconnect according to its own processing logic, so that the first drive branch where the drive coil K12 and the first switch unit are located in the drive circuit is disconnected. The drive coil K12 loses magnetism when powered off, and the corresponding main control contact K11 disconnects, finally disconnecting the main circuit to achieve current protection.

[0049] Through the above current protection device, the main control switch is used to control the on-off of the main circuit; since the main control switch includes a main control contact and a drive coil with magnetic cooperation, the current detection unit, the control unit and the first switch unit are further used to control the on-off of the drive circuit where the drive coil is located. The on-off of the drive circuit depends on the switch state of the first switch unit. Finally, the on-off control of the main circuit is converted into the switch state of the first switch unit; through the active protection method, no consumables are required, and it can work continuously in electrical scenarios where current protection needs to be triggered multiple times, improving the protection efficiency and reducing the protection cost.

[0050] In one embodiment, the drive circuit is used to connect to an AC power supply, and the first switch unit includes a bidirectional switch subunit.

[0051] Among them, when the drive circuit is used to connect to an AC power supply, it means that the first switch unit connected in series with the drive circuit needs to work in an AC environment and is used to control the on / off of the AC circuit. Taking semiconductor switches as an example, some semiconductor switches have polarities, and most single switch devices are usually used to work in a DC environment and are used to control the on / off of the DC circuit, such as MOS transistors, bipolar transistors, etc.

[0052] Therefore, in this embodiment, a bidirectional switch subunit with bidirectional switch capabilities needs to be adopted to ensure reliable on / off control of the drive circuit for connecting to an AC power supply.

[0053] As Figure 2 shown, in one embodiment, the bidirectional switch subunit includes a triac D1.

[0054] Among them, the first anode S1 and the second anode S2 of the triac D1 are connected in series with the drive coil K12, and the gate G of the triac D1 is electrically connected to the output terminal of the control unit.

[0055] Among them, the triac forms an automatically regulated loop through internal transistors and MOS transistors, and can switch states in different loops to achieve bidirectional control.

[0056] As Figure 3 shown, in one embodiment, the bidirectional switch subunit includes a relay K2, and the relay K2 includes a relay coil K22 and a relay contact K21 with magnetic cooperation.

[0057] Among them, the relay contact K21 is connected in series with the drive coil K12, and the relay coil K22 is electrically connected to the output terminal of the control unit.

[0058] Among them, since the relay contact K21 has no polarity, it can be used to control the on / off of the AC circuit. When the relay contact K21 is disconnected, neither the positive current nor the negative current can pass through. On the contrary, when the relay contact K21 is conducting, both the positive current and the negative current can pass through.

[0059] Among them, when the relay coil K22 has current, it can generate a magnetic force to disconnect the relay contact K21. Both ends of the relay coil K22 are electrically connected to the control unit. At this time, the control unit needs to provide a corresponding current loop for the relay coil K22 and provide a voltage difference at both ends of the relay coil K22 to form a current.

[0060] Among them, the relay K2 can specifically adopt an intermediate relay. The intermediate relay is mainly used in scenarios with higher voltage or larger current, can achieve larger conduction current and higher operating frequency, and can be more adapted to the AC power supply connected to the drive circuit.

[0061] As a supplement, the control unit can be an integrated control board including cores such as MCU, or a collection of discrete devices including cores such as MCU.

[0062] It should be noted that in the above embodiments, the drive circuit is used to connect to the AC power supply, while cores such as MCU need to work in a low-voltage DC environment. Therefore, the control unit includes a corresponding power processing circuit, and the power processing circuit can process the connected AC power supply to output the corresponding DC power supply to cores such as MCU.

[0063] Refer to Figures 1 to 3 , regardless of what specific device the first switch unit adopts, its purpose is to control the on / off of the first drive branch where the drive coil K12 in the drive circuit is located, and the first drive branch needs to form a loop through terminals A1 and A2. Therefore, in other embodiments, the drive coil K12 can also be connected in series between terminal A2 and the first switch unit; however, it should be noted that since the power-on and power-off of the drive coil K12 cannot affect the power-on of the control unit, when the drive coil K12 is connected in series between terminal A2 and the first switch unit, the second drive branch where the control unit is located still needs to be located in the front stage of the drive coil K12.

[0064] Such as Figure 4 shown, in one embodiment, the current detection unit includes a current transformer L1.

[0065] Among them, the current transformer L1 is used to be sleeved on the power line of the main circuit, and the first end and the second end of the current transformer L1 are respectively electrically connected to the first input end and the second input end of the control unit.

[0066] Among them, the current transformer (CT) L1 is a device used to measure AC current, and its working principle is based on electromagnetic induction. The main function of the current transformer L1 is to convert the high current in the main circuit into a smaller and easily measurable current for the use of the control unit.

[0067] Among them, what the current transformer L1 outputs is usually the analog quantity of the current. Therefore, the control unit needs to include a corresponding signal conditioning circuit (such as a sampling resistor and an operational amplifier, etc.) to convert the analog quantity of the current output by the current transformer L1 into a digital quantity of voltage so that cores such as MCU can process it.

[0068] Such as Figure 5As shown, in one embodiment, the current protection device further includes a short-circuit release K3 and a second switch unit.

[0069] The short-circuit release K3 is used to be connected in series in the main circuit.

[0070] Wherein, the short-circuit release K3 can perform a tripping action when a short circuit occurs in the main circuit.

[0071] The second switch unit is mechanically connected to the short-circuit release K3 and is used to be connected in series in the drive circuit, and is used to be in an off state based on the tripping action of the short-circuit release K3 when a short circuit occurs in the main circuit, so as to control the on-off state of the main circuit through the drive circuit.

[0072] As mentioned in the above embodiment, the over-current protection of the main circuit can be realized through the current detection unit, the first switch unit and the control unit. Since the whole process involves multiple operations such as detection, feedback, judgment, and execution, the time required is relatively long, and it mainly realizes long-delay over-current protection in aspects such as overload and leakage. However, short-circuit protection usually needs to be completed in a relatively short time, which belongs to instantaneous protection. When a short circuit occurs in the main circuit, the processing time required by the current detection unit, the first switch unit and the control unit is difficult to meet the requirements. If it is still realized through these units, the reliability of short-circuit protection will be relatively low.

[0073] Specifically, a short-circuit fault usually causes a sharp rise in current, so it is necessary to respond quickly. The short-circuit protection can act within milliseconds and quickly cut off the power supply. Overload is usually caused by the current exceeding the rated value but not immediately causing damage. The long-delay protection allows short-term overload (such as starting current), but will act during continuous overload. For leakage protection, it will act when current imbalance is detected. The long-delay setting allows short-term current imbalance (such as the transient state during equipment startup), but will cut off the power supply during continuous leakage.

[0074] Therefore, in this embodiment, a short-circuit release K3 and a second switch unit are added. When a short circuit occurs in the main circuit, the short-circuit release K3 immediately performs a tripping action, thereby triggering the second switch unit to be in an off state, and then quickly disconnecting the main circuit by disconnecting the drive circuit, ensuring the reliability of short-circuit protection.

[0075] Such as Figure 6 As shown, in one embodiment, the second switch unit includes a micro switch.

[0076] It should be noted that since the drive power supply connected to the drive circuit is usually obtained by processing the main power supply connected to the main circuit, and short-circuit faults are more harmful to the circuit, when a short circuit occurs in the main circuit, the power supply of the control unit can be cut off simultaneously. Therefore, in this embodiment, the second switch unit can be connected in series in the drive circuit and located in front of the control unit. After the second switch unit is disconnected, the first drive branch where the drive coil K12 is located and the second drive branch where the control unit is located are disconnected simultaneously, improving the effect of short-circuit protection.

[0077] Among them, the micro switch is used to be connected in series in the drive circuit and is used to trigger a conversion action based on the tripping action of the short-circuit release K3 to convert itself from the closed state to the open state.

[0078] Among them, when there is no short circuit in the main circuit, the micro switch is in the closed state, and the short-circuit release K3 will not perform the corresponding tripping action, which makes the micro switch not trigger the corresponding conversion action, thus remaining in the closed state. On the contrary, when a short circuit occurs in the main circuit, the short-circuit release K3 will perform the corresponding tripping action, which makes the micro switch also trigger the corresponding conversion action, thus converting the closed state to the open state.

[0079] Among them, the micro switch is a mechanical switch, named for its small contact spacing and rapid action. It is usually used in application scenarios that require rapid switching. Since the short-circuit protection itself requires a relatively high speed, using a micro switch as the actuator to disconnect the drive circuit can further improve the reliability of short-circuit protection.

[0080] As Figure 7 shown, in one embodiment, the second switch unit further includes an operating mechanism.

[0081] Among them, the operating mechanism is mechanically connected to the short-circuit release K3 and the micro switch respectively, and is used to transmit an operating action with an action degree less than the tripping action to the micro switch based on the tripping action of the short-circuit release K3 to trigger the conversion action of the micro switch.

[0082] Among them, as mentioned in the above embodiment, the core of the rapid action of the micro switch lies in its small action degree, while the tripping action of the short-circuit release K3 has a relatively large action degree. If the tripping action is directly transmitted to the micro switch, it is easy to damage the micro switch. Therefore, in this embodiment, an operating mechanism is added. The operating mechanism is used to realize the action transmission between the short-circuit release K3 and the micro switch, which can not only achieve short-circuit protection but also protect the micro switch and avoid damage to the micro switch.

[0083] As Figure 8 shown, in one embodiment, the second switch unit further includes a handle.

[0084] Wherein, the handle is mechanically connected to the operating mechanism and is used to control the operating mechanism to reset.

[0085] Wherein, the operating mechanism is used to achieve action transmission, and it can have the ability to reset itself. For example, when the short-circuit release K3 recloses, the operating mechanism can automatically reset to facilitate the action transmission of the next tripping action. If it does not have the ability to reset itself, it can be manually reset through the handle, or when its automatic reset ability fails, it can be manually reset.

[0086] Such as Figure 9 As shown, in one embodiment, the main control switch K1 further includes a static iron core K13 and a moving iron core K14 of the driving coil K12, and a push rod K15 for driving the main control contact K11 to act; in addition to being mechanically connected to the microswitch 101 through the operating mechanism 102, the short-circuit release K3 is also directly mechanically connected to the main control contact K11 through a cross bar 201 and an elastic member 202.

[0087] Wherein, when a short circuit occurs in the main circuit, regardless of whether the short-circuit current is large or small, the short-circuit release K3 will perform a tripping action to transmit the action to the operating mechanism 102 through the shaft rod inside itself, so that the operating mechanism 102 transmits the action to the microswitch 101, causing the microswitch 101 to trigger a conversion action, converting itself from a closed state to an open state, and then powering off the driving coil K12, and disconnecting the main control contact K11 through the action of the push rod K15 to achieve short-circuit protection in the first aspect. In addition, when a short circuit occurs in the main circuit and the short-circuit current is large, the kinetic energy obtained by the shaft rod inside the short-circuit release K3 is large, and the elastic energy stored in the spring surrounding the shaft rod is large. Eventually, the displacement limit of the shaft rod is broken through, causing the spring to drive the shaft rod to fall back, so that the cross bar 201 rotates, and then the elastic member 202 is compressed, and finally the main control contact K11 is disconnected to achieve short-circuit protection in the second aspect.

[0088] In summary, the current protection device provided by the present invention can, when non-short-circuit faults such as overload and leakage occur, control the bidirectional thyristor or relay to disconnect the driving circuit, thereby disconnecting the main control switch; it can also, when a short-circuit fault occurs, disconnect the driving circuit through the short-circuit release, the operating mechanism, and the microswitch, thereby disconnecting the main control switch; and it can also directly disconnect the main control switch through the short-circuit release, the cross bar, and the elastic member when a short-circuit fault occurs and the short-circuit current is large.

[0089] In a second aspect, in one embodiment, the present invention provides a power supply system, which includes a main power supply, a driving power supply, and the current protection device in any one of the above embodiments.

[0090] The main power supply is connected in series with the main circuit and is used to provide a main power supply signal to the main circuit; the drive power supply is connected in series with the drive circuit and is used to provide a drive power supply signal to the drive circuit.

[0091] Through the current protection device included in the above power supply system, the main switch is used to control the on / off of the main circuit; since the main switch includes a main contact and a drive coil with magnetic cooperation, further, a current detection unit, a control unit, and a first switch unit are used to control the on / off of the drive circuit where the drive coil is located, and the on / off of the drive circuit depends on the switch state of the first switch unit. Finally, the on / off control of the main circuit is converted into the switch state of the first switch unit. By means of active protection, no consumables are required, and it can continuously work in electrical scenarios where current protection needs to be triggered multiple times, improving the protection efficiency and reducing the protection cost.

[0092] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the detailed descriptions of other embodiments above, and they will not be elaborated here.

[0093] The above has introduced in detail a current protection device and a power supply system provided by the present invention. Specific examples are used herein to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

[0094] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered as the scope recorded in this specification.

Claims

1. A current protection device, characterized in that: The current protection device comprises a main control switch, a current detection unit, a control unit, and a first switch unit, wherein the main control switch comprises a main control contact and a drive coil that cooperate with magnetic force; The main control contact is used to be connected in series in the main circuit to be protected, and the drive coil and the first switch unit are connected in series in the drive circuit; The current detection unit is electrically connected to the input end of the control unit, and is used to detect the current of the main circuit and feed back a detection signal to the control unit; The output end of the control unit is electrically connected to the first switch unit, and is used to control the switch state of the first switch unit according to the detection signal, so as to control the on-off state of the main circuit through the drive circuit.

2. The current protection device according to claim 1, characterized in that: The driving circuit is used to access an AC power supply, and the first switch unit includes a bidirectional switch subunit.

3. The current protection device according to claim 2, characterized in that: The bidirectional switch subunit includes a bidirectional thyristor; The first anode and the second anode of the bidirectional thyristor are connected in series with the driving coil, and the gate of the bidirectional thyristor is electrically connected to the output end of the control unit.

4. The current protection device according to claim 2, characterized in that: The bidirectional switch subunit includes a relay, and the relay includes a magnetically matched relay coil and a relay contact; The relay contact is connected in series with the drive coil, and the relay coil is electrically connected to the output end of the control unit.

5. The current protection device according to claim 1, characterized in that: The current detection unit includes a current transformer; The current transformer is used to be mounted on the power line of the main circuit, and the first end and the second end of the current transformer are electrically connected to the first input end and the second input end of the control unit respectively.

6. The current protection device according to any one of claims 1 to 5, characterized in that: The current protection device also includes a short-circuit release and a second switch unit; The short-circuit release is used to be connected in series in the main circuit; The second switch unit is mechanically connected to the short-circuit release and is used to be connected in series in the drive circuit. It is used to be in an open state based on the tripping action of the short-circuit release when a short circuit occurs in the main circuit, so as to control the on-off state of the main circuit through the drive circuit.

7. The current protection device according to claim 6, characterized in that: The second switch unit includes a micro switch; The micro switch is used to be connected in series in the driving circuit, and is used to trigger a conversion action based on the tripping action of the short-circuit release, so as to convert itself from a closed state to an open state.

8. The current protection device according to claim 7, characterized in that: The second switch unit also includes an operating mechanism; The operating mechanism is mechanically connected to the short-circuit releaser and the micro switch respectively, and is used to transmit an operating action with an action degree less than the tripping action to the micro switch based on the tripping action of the short-circuit releaser, so as to trigger a switching action of the micro switch.

9. The current protection device according to claim 8, characterized in that: The second switch unit also includes a handle; The handle is mechanically connected to the operating mechanism and is used to control the operating mechanism to reset.

10. A power supply system, characterized in that: The power supply system comprises a main power supply, a driving power supply and a current protection device according to any one of claims 1 to 9; The main power supply is connected in series with the main circuit to provide a main power supply signal to the main circuit; The driving power supply is connected in series with the driving circuit and is used to provide a driving power supply signal to the driving circuit.

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