Switching device and power supply system
By designing a pre-charge circuit that pre-charges the capacitor before the main switch is closed, and by utilizing the cooperation of limit components and pre-charge switch units, the problem of insufficient high-specification breaking capacity of traditional disconnect switches is solved, thereby improving safety and convenience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI LIANGXIN ELECTRICAL CO LTD
- Filing Date
- 2025-06-20
- Publication Date
- 2026-07-21
AI Technical Summary
Traditional disconnect switches lack sufficient high-specification breaking capacity, leading to safety accidents such as arc burning, contact welding, and insulation breakdown. Furthermore, their complex wiring methods increase the difficulty of operation and the risk of errors for users, making it difficult to meet the safety and convenience requirements of modern power systems.
Before closing the main switch, the pre-charge circuit is closed to pre-charge the capacitor. Through the cooperation of the limit device and the pre-charge switch unit, the correct operation sequence is ensured, the wiring difficulty for users is reduced, and the inrush current and arc energy are reduced through the pre-charge process.
It effectively reduces the difficulty of wiring for users, improves the safety and reliability of the power supply system, protects the insulation life of equipment, and avoids high current surges and arc damage.
Smart Images
Figure CN224536905U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of switchgear technology, and more specifically, to a switchgear device and a power supply system. Background Technology
[0002] In the field of switchgear technology, the insufficient breaking capacity of traditional disconnecting switches is a key challenge restricting equipment reliability. In existing technologies, traditional rotary disconnecting switches often fail to meet international standard certifications such as PV2 and UL due to design flaws in their arc-extinguishing structure, leading to continuous arcing during contact breaking. This not only shortens contact life but also makes it difficult to meet high-specification breaking capacity requirements. When abnormal conditions such as overload or short circuit occur, traditional disconnecting switches cannot quickly disconnect the circuit, potentially causing safety accidents such as contact welding and insulation breakdown. This problem is particularly prominent in scenarios requiring frequent switching of large currents, such as photovoltaic inverters and energy storage systems. Furthermore, the complex wiring of traditional disconnecting switches increases the difficulty of user operation and the risk of errors. Incorrect wiring can easily lead to circuit faults, significantly reducing the safety of the power supply system and failing to meet the demands of modern power systems for both convenience and safety.
[0003] In the field of switchgear technology, there is a high voltage difference between the input and output terminals before closing the circuit, and there is also a relatively large capacitance in the system. If the circuit is closed directly, there will be a large inrush current, which will cause damage to the switch and system safety accidents. Utility Model Content
[0004] To address this challenge, a pre-charge circuit is first closed to pre-charge the capacitor before the main switch is closed, reducing the voltage difference between the two sides and minimizing damage from inrush current and system safety incidents. The purpose of this application is to provide a switching device and power supply system that reduces user wiring and improves the safety of the power supply system.
[0005] The embodiments of this application are implemented as follows:
[0006] A first aspect of this application provides a switching device including a main switch unit, a precharge switch unit, and a limiting member. In a free state, the limiting member is located in a first position, preventing the main switch unit from closing, at which time the precharge switch unit is in an open state. When the limiting member is driven to move towards the side closer to the precharge switch unit, the precharge switch unit can switch from an open state to a closed state. When the precharge switch unit is in a closed state, the limiting member is located in a second position, no longer preventing the main switch unit from closing. This switching device can reduce user wiring and improve the safety of the power supply system.
[0007] As one possible implementation, a locking member is also included. When the limiting member is driven to move toward the side closer to the precharge switch unit to the second position, the locking member is used to lock the limiting member so that the limiting member remains in the second position.
[0008] As one possible implementation, when the main switch unit switches from the open state to the closed state, the main switch unit is used to drive the locking member to release the locking of the limiting member, so that the limiting member moves in the opposite direction.
[0009] As one possible implementation, it also includes an elastic element, which is used to provide a restoring force for the limiting element. The two ends of the elastic element are connected to the housing of the limiting element and the switching device. When the limiting element is driven to move towards the side closer to the pre-charge switching unit, the elastic element compresses and stores energy. When the locking member releases the locking of the limiting element, the elastic element releases energy and drives the limiting element to move in the opposite direction.
[0010] As one possible implementation, the limiting member is provided with a locking part, and the locking member and the locking part cooperate with each other to lock the limiting member.
[0011] As one possible implementation, a limiting shell is also included. The limiting member is provided with a limiting part. When the limiting member moves in the opposite direction to the first position, the limiting shell is used to limit the limiting part so that the limiting member is kept in the first position.
[0012] As one possible implementation, the limiting member includes a guide section and a stop section arranged opposite to each other. The angle between the guide section and the opening direction of the main switch unit is an acute angle, and the angle between the stop section and the closing direction of the main switch unit is a right angle or an obtuse angle.
[0013] As one possible implementation, the guide section is an inclined surface. When the main switch unit switches from the closed state to the open state, the main switch unit cooperates with the inclined surface to drive the limiting member to move towards the side closer to the precharge switch unit. At this time, the precharge switch unit is in the open state, and the limiting member is in the third position, no longer obstructing the opening of the main switch unit.
[0014] As one possible implementation, when the main switch unit is in the open state, the limiting member moves in the opposite direction to the first position, thereby preventing the main switch unit from closing again.
[0015] A second aspect of this application provides a power supply system including an input module, an output module, and the aforementioned switching device connected between the input module and the output module. When the main switching unit and the precharge switching unit are disconnected, the input module is disconnected from the output module. This switching device reduces user wiring, thereby improving the safety of the power supply system.
[0016] The beneficial effects of the embodiments of this application include:
[0017] This switching device includes a main switch unit, a precharge switch unit, and a limiting member. In its free state, the limiting member is in a first position, preventing the main switch unit from closing, at which point the precharge switch unit is in an open state. When the limiting member is driven to move towards the side closest to the precharge switch unit, the precharge switch unit can switch from an open state to a closed state. When the precharge switch unit is in a closed state, the limiting member is in a second position, no longer preventing the main switch unit from closing. This switching device, through the limiting member's obstruction, ensures that the main switch unit cannot close before the precharge switch unit is closed, thus preventing large current surges caused by accidental contact with the main switch unit. Furthermore, since the precharge process can gradually build up the system voltage, it can also reduce the operational overvoltage caused by inductive-capacitive oscillations when the main switch unit closes directly, thereby protecting the insulation life of transformers, cables, and other equipment. When the precharge switch unit closes, if a main circuit fault is detected, the limiting member can be held in its initial state, preventing the main switch unit from closing and avoiding damage caused by the main switch unit being switched on. This barrier mechanism replaces the traditional wiring requirement of "controlling the sequence of two switches via independent electrical lines," thereby reducing the number of control lines and simplifying wiring and operation for users. In summary, this switching device reduces user wiring and improves the safety of the power supply system. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is one of the state diagrams of the switching device provided in the embodiments of this application;
[0020] Figure 2 for Figure 1 Corresponding structural diagram;
[0021] Figure 3This is a second schematic diagram of the state of the switching device provided in the embodiments of this application;
[0022] Figure 4 for Figure 3 Corresponding structural diagram;
[0023] Figure 5 This is the third schematic diagram of the state of the switching device provided in the embodiments of this application;
[0024] Figure 6 for Figure 5 Corresponding structural diagram;
[0025] Figure 7 This is the fourth schematic diagram of the state of the switching device provided in the embodiments of this application;
[0026] Figure 8 Fifth schematic diagram of the state of the switching device provided in the embodiments of this application;
[0027] Figure 9 This is a schematic diagram of the structure of the limiting member provided in the embodiment of this application.
[0028] Icons: 100-Switch device; 10-Main switch unit; 11-Open position; 13-Closed position; 14-Pulley; 20-Pre-charge switch unit; 30-Limiting element; 31-Locking part; 33-Guide section; 34-Stop section; 35-Limiting part; 40-Locking element; 60-Elastic element; 70-Limiting shell. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0030] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These terms are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "horizontal," "vertical," etc., do not indicate that the component must be absolutely horizontal or suspended, but can be slightly tilted. The terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0031] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0032] Please refer to the reference. Figures 1 to 9 This application provides a switching device 100, including a main switching unit 10, a pre-charge switching unit 20, and a limiting member 30. In a free state, the limiting member 30 is located in a first position, preventing the main switching unit 10 from closing, at which time the pre-charge switching unit 20 is in an open state. When the limiting member 30 is driven to move towards the side closer to the pre-charge switching unit 20, the pre-charge switching unit 20 can switch from an open state to a closed state. When the pre-charge switching unit 20 is in a closed state, the limiting member 30 is located in a second position, no longer preventing the main switching unit 10 from closing. This switching device 100 can reduce user wiring and improve the safety of the power supply system.
[0033] It should be noted that, as Figures 1 to 6As shown, the switching device 100 includes a main switching unit 10, a pre-charge switching unit 20, and a limiting member 30. The main switching unit 10, as the core switching component, can be composed of moving and stationary contacts, an arc-extinguishing chamber, etc., and is used to carry and disconnect the rated current of the main circuit. In the initial state, the limiting member 30 is in the first position, which can hinder the closing movement of the main switching unit 10, preventing the main switching unit 10 from directly closing. The pre-charge switching unit 20 is connected in series in the main circuit. The rated current of the pre-charge switching unit 20 is usually less than the rated current of the main switching unit 10, and can be composed of low-power contacts and a simple arc-extinguishing structure. When the limiting member 30 is driven by an external force... When the device moves toward the side closer to the precharge switch unit 20 (e.g., manually pressed, driven by the main switch unit 10 or the precharge switch unit 20), the precharge switch unit 20 can switch from the open state to the closed state, so that the precharge switch unit 20 can connect the main circuit before the main switch unit 10, thereby limiting the surge current of the main switch unit 10 at the moment of closing. When the precharge switch unit 20 is in the closed state, the limit member 30 is in the second position. At this time, the limit member 30 no longer obstructs the closing of the main switch unit 10, so that the main switch unit 10 can close after the precharge switch unit 20 closes.
[0034] In actual operation, the pre-charge switch unit 20 closes first. The main circuit can be connected by current limiting through the pre-charge resistor or the pre-charge switch unit 20 itself. After the current in the main circuit stabilizes, the limiter 30 is in the second position and no longer obstructs the closing of the main switch unit 10. At this time, the main switch unit 10 can be closed, thus realizing the sequential control of "pre-charge switch unit 20 is connected first, and main switch unit 10 is connected later". In this way, the surge current (such as capacitor charging current and transformer excitation inrush current) at the moment the main switch unit 10 closes can be limited to 2 to 3 times the rated value (the surge current of the traditional main switch unit 10 directly closing can reach 10 to 20 times the rated value). In addition, since the current in the main circuit has already stabilized when the main switch unit 10 closes, the arc energy when the moving and stationary contacts of the main switch unit 10 close can also be reduced, optimizing the arc extinguishing conditions.
[0035] For example, the limiting member 30 can be movably disposed on the housing of the switching device 100. When the limiting member 30 is in the first position, the limiting member 30 moves to the closing path of the main switching unit 10, obstructing the closing of the main switching unit 10. When the limiting member 30 is in the second position, the limiting member 30 moves away from the closing path of the main switching unit 10 and no longer obstructs the closing of the main switching unit 10.
[0036] Compared to existing technologies, the switching device 100 provided in this application, through the obstruction effect of the limiting member 30, ensures that the main switching unit 10 cannot close before the pre-charge switching unit 20 is closed, thereby avoiding the large current surge caused by accidental contact with the main switching unit 10 by the operator. Furthermore, since the pre-charge process can gradually build up the system voltage, it can also reduce the operating overvoltage caused by inductor-capacitor oscillation when the main switching unit 10 is directly closed (the overvoltage when the main switching unit 10 is directly closed in the traditional manner can reach 2.5 times the rated voltage), thus protecting the insulation life of transformers, cables, and other equipment. When the pre-charge switching unit 20 is closed, if a main circuit fault (such as a short circuit) is detected, the limiting member 30 can be held in its initial state (i.e., the first position). At this time, the main switching unit 10 cannot perform the closing action, preventing damage caused by the main switching unit 10 being connected. This obstruction mechanism replaces the traditional wiring requirement of "controlling the sequence of two switches through independent electrical lines," thereby reducing the number of control lines and thus reducing the difficulty of wiring and operation for users.
[0037] As one possible implementation method, such as Figure 7 As shown, the switching device 100 also includes a locking member 40. When the limiting member 30 is driven to move toward the side close to the precharge switching unit 20 to the second position, the locking member 40 is used to lock the limiting member 30 so that the limiting member 30 is kept in the second position.
[0038] It should be noted that the switching device 100 also includes a locking member 40, which together with the limiting member 30 forms an interlocking mechanism. For example, the locking member 40 can be fixedly installed inside the housing of the switching device 100, with the locking end (such as a latch) of the locking member 40 aligned with the movement trajectory of the limiting member 30. When an external force drives the limiting member 30 to move towards the side closer to the precharge switching unit 20 to the second position, the locking end of the locking member 40 inserts into the limiting member 30, forming a mechanical lock. In this way, the switching device 100 can ensure that the limiting member 30 remains in a fixed position (i.e., the second position) after the precharge switching unit 20 is closed, preventing the limiting member 30 from resetting (i.e., returning to the first position) due to vibration, external force, or other factors, thereby affecting the closing operation of the main switching unit 10.
[0039] For example, the locking member 40 can be spring-driven or electromagnetically driven. For instance, in a spring-driven locking member 40, when the limiting member 30 reaches the second position, the locking tongue engages in the groove of the limiting member 30 under the action of the return spring; or, in an electromagnetically driven locking member 40, when the limiting member 30 reaches the second position, the locking tongue generates magnetic force through the energization of the coil, attracting the armature on the limiting member 30 to achieve locking, and releasing when the power is off.
[0040] As one possible implementation method, such as Figure 7As shown, when the main switch unit 10 switches from the open state to the closed state (or the main switch unit 10 moves from the open position 11 to the closed position 13), the main switch unit 10 drives the locking member 40 to release the lock on the limit member 30, so that the limit member 30 moves in the opposite direction.
[0041] It should be noted that during the switching process from the open state to the closed state of the main switch unit 10, its internal operating mechanism (such as a cam or connecting rod) moves synchronously, reaching the unlocking end of the locking member 40 through transmission components (such as a push rod or lever). For example, when the lever 14 of the main switch unit 10 moves, it pushes the locking tongue of the locking member 40 to retract through the push rod, releasing the lock on the limit member 30. After the lock on the locking member 40 is released, the limit member 30 moves in the opposite direction (such as returning from the second position to the first position) towards the closing path of the main switch unit 10 under the action of a return spring or other return mechanism. In this way, it can be ensured that when closing again, the limit member 30 must be removed first, so that the precharge switch unit 20 closes first, and then the main switch unit 10 can close, ensuring the correctness of the operation sequence.
[0042] As one possible implementation method, such as Figure 7 and Figure 8 As shown, the switching device 100 also includes an elastic element 60, which provides a reset force for the limiting element 30. When the limiting element 30 is driven to move toward the side closer to the precharge switching unit 20, the elastic element 60 compresses and stores energy. When the locking member 40 releases the lock on the limiting element 30, the elastic element 60 releases energy and drives the limiting element 30 to move in the opposite direction.
[0043] It should be noted that the switching device 100 also includes an elastic element 60 (such as a compression spring or a disc spring). For example, both ends of the elastic element 60 are connected to the limiting element 30 and the housing of the switching device 100 to form a reset mechanism. Preferably, one end of the elastic element 60 can be fixed to the housing, and the other end is connected to the bottom end of the limiting element 30 (i.e., the end away from the main switching unit 10). When an external force drives the limiting element 30 to move towards the pre-charge switching unit 20, the elastic element 60 is compressed and stores elastic potential energy. At this time, the locking element 40 can lock the limiting element 30 to maintain the compressed state of the elastic element 60. When the main switching unit 10 switches from the open state to the closed state, the locking element 40 can be driven to release the locking of the limiting element 30. The elastic element 60 immediately releases the stored elastic potential energy, and the elastic potential energy pushes the limiting element 30 to move in the opposite direction towards the closing path of the main switching unit 10 until the limiting element 30 returns to the first position. In this way, the restoring force of the elastic element 60 can ensure that the limiting element 30 returns to its position quickly and accurately, preparing for the next operation cycle.
[0044] As one possible implementation method, such as Figure 9As shown, the switching device 100 also includes a limiting shell 70. The limiting member 30 is provided with a limiting part 35. When the limiting member 30 moves in the opposite direction to the first position, the limiting shell 70 is used to limit the limiting part 35 so that the limiting member 30 is kept in the first position.
[0045] It should be noted that the switching device 100 also includes a limiting shell 70. The limiting member 30 is provided with a limiting part 35. When the limiting member 30 moves in the opposite direction to the first position under the drive of the elastic member 60, the limiting shell 70 is used to limit the limiting part 35 so that the limiting member 30 is kept in the first position, preparing for the next operation cycle, and also preventing the limiting member 30 from disengaging from the switching device 100.
[0046] As one possible implementation method, such as Figure 7 and Figure 8 As shown, the limiting member 30 is provided with a locking part 31, and the locking member 40 and the locking part 31 cooperate with each other to lock the limiting member 30.
[0047] It should be noted that the limiting member 30 is provided with a locking part 31, which forms a precise mechanical engagement with the locking member 40. Specifically, the locking part 31 can be a groove or slot formed on the side of the limiting member 30, and its position corresponds to the second position of the limiting member 30. When the limiting member 30 moves to the second position under the drive of external force, the locking end of the locking member 40 (such as a locking tongue or a locking block) is inserted into the locking part 31, and locking is achieved through mechanical engagement.
[0048] As one possible implementation method, such as Figures 7 to 9 As shown, the limiting member 30 includes a guide section 33 and a stop section 34 arranged opposite to each other. The angle between the guide section 33 and the opening direction of the main switch unit 10 is an acute angle, and the angle between the stop section 34 and the closing direction of the main switch unit 10 is a right angle or an obtuse angle.
[0049] It should be noted that the angle between the guide section 33 and the opening direction of the main switch unit 10 is an acute angle (e.g., 30° to 60°). When the main switch unit 10 opens, the lever 14 of the main switch unit 10, its internal operating mechanism or transmission component (e.g., push rod, lever) moves along the opening direction and contacts the guide section 33. The guide section 33 decomposes the opening force into a component force that pushes the limit member 30 to move, thereby realizing the movement of the limit member 30 and preventing the limit member 30 from obstructing the opening of the main switch unit 10.
[0050] The angle between the stop section 34 and the closing direction of the main switch unit 10 is a right angle (i.e., the angle is 90°) or an obtuse angle (such as 120° to 150°). When the limit member 30 is in the first position, the surface of the stop section 34 can be directly facing the closing movement trajectory of the main switch unit 10 (such as the forward direction of the toggle 14 or the moving contact), forming a rigid mechanical stop, thereby preventing the main switch unit 10 from closing.
[0051] As one possible implementation, the guide section 33 is an inclined plane. When the main switch unit 10 switches from the closed state to the open state (or the main switch unit 10 moves from the closed position 13 to the open position 11), the main switch unit 10 cooperates with the inclined plane to drive the limiting member 30 to move towards the side closer to the precharge switch unit 20. At this time, the precharge switch unit 20 is in the open state, and the limiting member 30 is in the third position, no longer obstructing the opening of the main switch unit 10.
[0052] It should be noted that the guide section 33 can be an inclined plane, and its surface can be hardened to ensure low-friction transmission. The lever 14 of the main switch unit 10, its internal operating mechanism or transmission component (such as push rod, lever) can be a wedge-shaped structure that matches the inclined plane, forming a sliding fit. When the main switch unit 10 moves from the closed position 13 to the open position 11, the wedge-shaped structure contacts the inclined plane, and the opening force is decomposed through the inclined plane into a normal force perpendicular to the inclined plane and a component force parallel to the inclined plane. The component force pushes the limiting member 30 to move in the direction close to the precharge switch unit 20, so that the limiting member 30 moves from the first position to the third position. At this time, the precharge switch unit 20 remains in the open state, and after the limiting member 30 moves, it no longer obstructs the opening of the main switch unit 10, ensuring that the opening of the main switch unit 10 is completed smoothly.
[0053] As one possible implementation, when the main switch unit 10 is in the open state, the limit member 30 moves in the opposite direction to the first position, thus preventing the main switch unit 10 from closing again.
[0054] It should be noted that when the main switch unit 10 is in the open state, the precharge switch unit 20 is also in the open state. When the limit member 30 moves in the reverse direction to the first position, it will again prevent the main switch unit 10 from closing. The limit member 30 needs to be driven by external force to move towards the side closer to the precharge switch unit 20 before the main switch unit 10 can be allowed to close again, thus improving the safety of the switch device 100.
[0055] This application also provides a power supply system, including an input module, an output module, and the aforementioned switching device 100 connected between the input module and the output module. When the main switching unit 10 and the precharge switching unit 20 are disconnected, the input module is disconnected from the output module. Since the structure and beneficial effects of the switching device 100 have been described in detail in the foregoing embodiments, they will not be repeated here.
[0056] The above description is merely an optional embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
[0057] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not describe the various possible combinations separately.
Claims
1. A switching device, characterized in that, The device includes a main switch unit (10), a precharge switch unit (20), and a limiting member (30). In a free state, the limiting member (30) is located in a first position, which prevents the main switch unit (10) from closing. At this time, the precharge switch unit (20) is in an open state. When the limiting member (30) is driven to move towards the side closer to the precharge switch unit (20), the precharge switch unit (20) can switch from an open state to a closed state. When the precharge switch unit (20) is in a closed state, the limiting member (30) is located in a second position and no longer prevents the main switch unit (10) from closing.
2. The switching device according to claim 1, characterized in that, It also includes a locking member (40), which locks the limiting member (30) to the second position when the limiting member (30) is driven to move toward the side closer to the precharge switch unit (20). The locking member (40) is used to lock the limiting member (30) so that the limiting member (30) is held in the second position.
3. The switching device according to claim 2, characterized in that, When the main switch unit (10) switches from the open state to the closed state, the main switch unit (10) drives the locking member (40) to release its lock on the limiting member (30), so that the limiting member (30) moves in the opposite direction.
4. The switching device according to claim 2, characterized in that, It also includes an elastic element (60) for providing a restoring force to the limiting element (30). When the limiting element (30) is driven to move toward the side closer to the precharge switch unit (20), the elastic element (60) compresses and stores energy. When the locking element (40) releases the lock on the limiting element (30), the elastic element (60) releases energy and drives the limiting element (30) to move in the opposite direction.
5. The switching device according to claim 2, characterized in that, The limiting member (30) is provided with a locking part (31), and the locking member (40) and the locking part (31) cooperate with each other to lock the limiting member (30).
6. The switching device according to claim 1, characterized in that, It also includes a limiting shell (70), on which a limiting part (35) is provided. When the limiting part (30) moves in the opposite direction to the first position, the limiting shell (70) is used to limit the limiting part (35) so that the limiting part (30) is kept in the first position.
7. The switching device according to claim 1, characterized in that, The limiting member (30) includes a guide section (33) and a stop section (34) arranged opposite to each other. The angle between the guide section (33) and the opening direction of the main switch unit (10) is an acute angle, and the angle between the stop section (34) and the closing direction of the main switch unit (10) is a right angle or an obtuse angle.
8. The switching device according to claim 7, characterized in that, The guide section (33) is an inclined surface. When the main switch unit (10) switches from the closed state to the open state, the main switch unit (10) cooperates with the inclined surface to drive the limiting member (30) to move toward the side closer to the precharge switch unit (20). At this time, the precharge switch unit (20) is in the open state, and the limiting member (30) is in the third position, no longer obstructing the opening of the main switch unit (10).
9. The switching device according to claim 8, characterized in that, When the main switch unit (10) is in the open state, the limiting member (30) moves in the opposite direction to the first position, which again prevents the main switch unit (10) from closing.
10. A power supply system, characterized in that, The device includes an input module, an output module, and a switching device (100) according to any one of claims 1 to 9 connected between the input module and the output module. When the main switching unit (10) and the precharge switching unit (20) are disconnected, the input module is disconnected from the output module.