Quick switch for micro-grid

Abstract

The invention relates to the technical field of low-voltage electrical switches, and discloses a quick switch for a micro-grid, which comprises a shell, and a contact mechanism, an arc extinguishing mechanism, an operating mechanism and a control system which are arranged in the shell, the contact mechanism comprises a moving contact and a static contact, and the operating mechanism comprises an electromagnetic assembly and an amplification assembly. The electromagnetic assembly comprises an opening coil, a closing coil, a movable iron core arranged in the opening coil and a driving rod connected to the movable iron core, and the amplification assembly is used for converting input motion of the driving rod into higher-speed output motion of the movable contact. The moving iron core is directly driven to act through electromagnetic force generated when the opening coil is powered on, so that the moving contact quickly acts, small displacement of the moving iron core is converted into large displacement of the moving contact through the amplification assembly, and the effects of improving the breaking speed of the moving contact and reducing the influence of faults on a main loop of a micro-grid are achieved.

Description

Technical Field

[0001] This application relates to the technical field of low-voltage electrical switches, and in particular to a fast switch for microgrids. Background Technology

[0002] Microgrid systems typically contain multiple distributed power sources and load sub-circuits. When a fault such as a short circuit occurs in a sub-circuit, the protection device is required to act quickly to limit the fault to a minimum, reduce the impact of the fault on the main circuit, and prevent the entire microgrid from affecting stable operation.

[0003] In related technologies, microgrid sub-circuit typically uses molded case circuit breakers as protective switches. Traditional molded case circuit breakers rely on thermal-magnetic trip units to trigger and release pre-stored mechanical springs to achieve tripping.

[0004] However, the "spring energy storage-mechanical tripping" mechanism of the aforementioned molded case circuit breaker has inherent operational inertia, resulting in a longer breaking time. Consequently, the short-circuit current and the resulting voltage drop will persist for some time, and the impact of the fault may even spread to the microgrid main circuit, causing serious consequences such as main circuit voltage fluctuations and tripping of sensitive loads. Therefore, improvements are needed. Summary of the Invention

[0005] To improve the breaking speed of protective switches, this application provides a fast switch for microgrids.

[0006] The fast switching method for microgrids provided in this application adopts the following technical solution: A fast switch for a microgrid includes a housing, a contact mechanism, an arc-extinguishing mechanism, an operating mechanism, and a control system disposed within the housing. The contact mechanism includes a moving contact and a stationary contact. The operating mechanism includes an electromagnetic component and an amplification component. The electromagnetic component includes a tripping coil, a closing coil, a moving iron core disposed within the tripping coil, and a drive rod connected to the moving iron core. When energized, the tripping coil generates an electromagnetic force to drive the moving contact to trip. The closing coil drives the moving contact to close. The power input terminal of the amplification component is connected to the drive rod, and the power output terminal of the amplification component is connected to the moving contact. The amplification component converts the input motion of the drive rod into a higher-speed output motion of the moving contact.

[0007] By adopting the above technical solution, when the fast switch detects a sub-circuit fault, it energizes the trip coil. The trip coil then generates electromagnetic force, causing the moving iron core to move in the direction of tripping. This, in turn, drives the drive rod in the direction of tripping. The amplification component then enables the drive rod to drive the moving contact to break at a higher speed, making the breaking speed of the moving contact higher than the displacement speed of the drive rod, thus improving the breaking speed of the protection switch. Compared to the slow operating mode of traditional molded case circuit breakers using "spring energy storage-mechanical tripping," the trip coil generates a huge electromagnetic force instantly after energizing, directly driving the moving iron core. This eliminates the mechanical delay of tripping and unlocking in traditional mechanisms, achieving a fundamental speed increase from the power source. The extremely fast breaking speed ensures that short-circuit faults in the microgrid sub-circuit are completely isolated in the early stages of development, effectively preventing the spread of fault current and voltage drops to the microgrid main circuit, and ensuring the stable operation of the main circuit and core loads.

[0008] Optionally, the amplification assembly includes an acceleration gear, a fixed rack, and a movable rack. The acceleration gear is rotatably mounted on a drive rod. The fixed rack is fixedly mounted in the housing and meshes with one side of the acceleration gear. The movable rack is slidably mounted on the housing and meshes with the other side of the acceleration gear. A connecting rod is rotatably mounted on the movable rack, and the connecting rod is connected to the moving contact in a transmission manner.

[0009] By adopting the above technical solution, a specific and efficient gear-rack speed amplification scheme is provided. This mechanism utilizes the principle that when a gear rolls purely on a fixed rack, the combined speed at the meshing point with the moving rack is twice the speed of the center of rotation, achieving stable and reliable amplification of twice the theoretical speed with high transmission efficiency. It cleverly converts the linear motion of the drive rod into the reverse linear motion of the moving rack through the gear, and finally transmits it to the moving contact via a connecting rod, thus optimizing the power transmission path and resulting in a compact structure.

[0010] Optionally, the accelerating gear includes an amplifying part and a driving part, the amplifying part meshing with a moving rack, and the driving part meshing with a fixed rack. The tooth size and gear radius of the amplifying part are both larger than the tooth size and gear radius of the driving part.

[0011] By adopting the above technical solution and designing the acceleration gear as an asymmetrical double gear, the limitation of a fixed speed amplification ratio of 2 when using a single gear can be overcome. By adjusting the radius ratio of the amplification section to the drive section, customized speed amplification ratios greater than 2 can be flexibly designed and achieved to meet the extreme requirements for breaking speed in different application scenarios. Larger teeth and radii in the amplification section mean higher tooth strength, better able to withstand the impact loads from the output end of the moving rack, thus improving the mechanical reliability and service life of the amplification component under frequent and rapid operation.

[0012] Optionally, the amplification assembly further includes a transmission rod rotatably mounted on the housing and a sliding rod slidably mounted on the housing. One end of the connecting rod is rotatably mounted on a movable rack, and the other end is mounted on the transmission rod. The movable contact is mounted on the sliding rod, and the sliding direction of the sliding rod is the same as the opening and closing direction of the movable contact. A linkage plate is provided between the transmission rod and the sliding rod, and an oblong hole is provided on the linkage plate. A connecting rod is radially inserted through the sliding rod, and the connecting rod is slidably mounted in the oblong hole. The connecting rod is rotatably mounted on the sliding rod. A rotary bearing is provided between the transmission rod and the housing, and a sliding bearing is provided between the sliding rod and the housing.

[0013] By adopting the above technical solution, the linear motion of the moving rack is converted into the linear motion of the sliding rod through the transmission rod and the linkage plate, thus decoupling the motion path of the moving contact from the drive source and allowing for a more flexible layout. By specially designing rotating and sliding bearings, the frictional forces during the rotation of the transmission rod and the sliding of the sliding rod are reduced, significantly minimizing mechanical energy loss and ensuring that the electromagnetic driving force is converted into the kinetic energy of the moving contact to the maximum extent, thus guaranteeing the ultimate realization of high-speed disconnection.

[0014] Optionally, the distance between the connecting rod hinge point and the transmission rod is greater than the distance between the linkage plate hinge point and the transmission rod.

[0015] By adopting the above technical solution, a force-saving lever is constructed. With a constant breaking force required by the moving contact, the longer the distance between the connecting rod hinge point and the transmission rod, the longer the lever arm of the electromagnetic force generated by the tripping coil. This reduces the force required to drive the connecting rod in the tripping direction, meaning only a smaller electromagnetic force is needed to drive the connecting rod and the moving contact in the tripping direction. This eliminates the need for an excessively large tripping coil and a large current flowing through it during tripping, saving material and electricity costs. Furthermore, the force-saving lever allows the electromagnetic force generated by a tripping coil of the same size to drive the drive rod, connecting rod, linkage plate, and sliding rod at a faster speed, further improving the tripping speed of the moving contact.

[0016] Optionally, a tripping spring is provided at the end of the connecting rod away from the transmission rod. The tripping spring has a tendency to drive the connecting rod to rotate in the tripping direction. A limit cam is coaxially provided on the acceleration gear. A fixed plate is provided on the side of the connecting rod near the moving rack. A sliding groove is provided on the fixed plate. An abutment block is slidably disposed in the sliding groove. An arc-shaped block is provided on the side of the abutment block near the connecting rod. The side wall of the arc-shaped block near the connecting rod is horizontal and abuts against the connecting rod. A closing spring is provided on the side of the arc-shaped block away from the limit cam. The closing spring can drive the arc-shaped block to move in the direction closer to the limit cam. The limit cam abuts against the abutment block. When tripping, the limit cam pushes the abutment block to slide away from the connecting rod.

[0017] By adopting the above technical solution, the cooperation of the limit cam, the abutment block, the arc-shaped block, and the connecting rod can accurately lock the mechanism in the closed position, reducing the possibility of accidental opening due to vibration or electrodynamics and ensuring the stability of the closed state. During opening, the electromagnetic force generated by the opening coil drives the drive rod to move, which in turn drives the acceleration gear to rotate, thereby driving the limit cam to rotate. This causes the limit cam to push the abutment block to slide away from the connecting rod, causing the horizontal surface of the arc-shaped block to no longer abut against the connecting rod, but rather the arc-shaped surface of the arc-shaped block to abut against the connecting rod. At this time, the arc-shaped block no longer limits the connecting rod, and the connecting rod can rotate in the opening direction under the combined action of the drive rod and the opening spring. Simultaneously, the connecting rod pushes the arc-shaped block towards the closing spring, compressing the closing spring, which facilitates the closing spring pushing the arc-shaped block to lock the connecting rod during the next closing. The electromagnetic force of the opening coil and the elastic force of the opening spring work together to achieve rapid unlocking of the connecting rod and rapid opening of the moving contact, further improving the opening speed of the moving contact. The trip spring applies a constant preload in the tripping direction to the linkage, forming a mechanical redundancy protection. Even in extreme cases where the electromagnetic drive fails, the trip spring can still drive the switch to trip, greatly improving the reliability of the protection function.

[0018] Optionally, the arc-extinguishing mechanism includes a vacuum arc-extinguishing chamber disposed within the housing, wherein both the moving contact and the stationary contact are disposed within the vacuum arc-extinguishing chamber.

[0019] By adopting the above technical solution, firstly, the vacuum interrupter can reliably extinguish the powerful electric arc generated by high-speed breaking. Secondly, the vacuum environment has almost no air resistance, which significantly reduces the friction and damping experienced by the moving contact during movement, further ensuring that the speed amplification effect is truly reflected in the separation speed of the moving contact.

[0020] Optionally, the control system includes a fault detection circuit and a pulse power supply, wherein the fault detection circuit is used to control the pulse power supply to discharge to the trip coil when a fault current is detected.

[0021] By adopting the above technical solution, when a sub-circuit fault occurs, the pulse power supply can instantly provide a huge pulse current to the trip coil, thereby generating a strong electromagnetic force and driving the entire mechanism to move at high speed, achieving rapid tripping. This realizes a fully electronic process from "current detection" to "energy release," which, compared to the mechanical sensing mechanism of traditional molded case circuit breakers, offers a faster response speed and facilitates rapid operation of the subsequent moving contact.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. When a fault occurs in a sub-circuit of the microgrid, the pulse power supply discharges to the trip coil. The electromagnetic force generated by the trip coil drives the drive rod to move, thereby driving the moving rack, connecting rod and moving contact to move. The displacement of the drive rod is amplified by the cooperation of the acceleration gear and the fixed rack and moving rack, thereby improving the tripping speed of the moving contact. 2. The acceleration gear has a special structure, which includes a large amplification part and a small driving part, so that the displacement of the driving rod is further amplified by the acceleration gear, thereby further improving the breaking speed of the moving contact. 3. The rotating bearing on the transmission rod and the sliding bearing on the sliding rod reduce the transmission friction of the amplification component, which effectively ensures that the movement of the drive rod can drive the movement of the moving contact more smoothly while improving the breaking speed of the moving contact. Attached Figure Description

[0023] Figure 1 This is an overall structural diagram of Embodiment 1 of this application.

[0024] Figure 2 This is a partial structural diagram of the operating mechanism shown after the shell portion is hidden in Embodiment 1 of this application.

[0025] Figure 3 This is a partial structural diagram of the limiting cam shown behind the hidden portion of the housing in Embodiment 2 of this application.

[0026] Figure 4 This is a partial structural diagram of the enlarged section shown behind the hidden portion of the housing in Embodiment 2 of this application.

[0027] Explanation of reference numerals in the attached figures: 1. Housing; 2. Arc extinguishing mechanism; 21. Vacuum arc extinguishing chamber; 3. Operating mechanism; 31. Electromagnetic assembly; 311. Opening coil; 312. Moving iron core; 313. Drive rod; 32. Amplification assembly; 321. Accelerating gear; 322. Fixed rack; 323. Moving rack; 324. Connecting rod; 325. Transmission rod; 326. Sliding rod; 327. Linkage plate; 328. Amplification section; 329. Drive section; 4. Opening spring; 5. Limiting cam; 51. Fixing plate; 511. Sliding groove; 512. Abutment block; 513. Arc-shaped block; 514. Closing spring; 6. Rotary bearing; 7. Sliding bearing; 8. Connecting rod; 9. Waist-shaped hole. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0029] This application discloses a fast switch for microgrids.

[0030] Example 1 Reference Figure 1 and Figure 2 A fast switch for a microgrid includes a housing 1, a contact mechanism (not shown in the figure) disposed within the housing 1, an arc extinguishing mechanism 2, an operating mechanism 3, and a control system (not shown in the figure). The contact mechanism, the arc extinguishing mechanism 2, the operating mechanism 3, and the control system are all installed within the housing 1. The contact mechanism includes a moving contact and a stationary contact, which cooperate with each other to achieve the function of fast switching.

[0031] Reference Figure 2 The operating mechanism 3 includes an electromagnetic component 31 and an amplification component 32. The electromagnetic component 31 includes a tripping coil 311, a closing coil (not shown), a moving iron core 312 disposed within the tripping coil 311, and a drive rod 313 connected to the moving iron core 312. The tripping coil 311 can be made of enameled wire, and its number of turns and wire diameter are determined according to the required electromagnetic force. The tripping coil 311 is designed to receive large current pulses, generating a strong electromagnetic force sufficient to directly drive the tripping operation.

[0032] Reference Figure 2 When the trip coil 311 is energized, it generates a magnetic field, causing the moving iron core 312 to move under the influence of the magnetic force. This, in turn, drives the drive rod 313 to actuate, thereby generating an electromagnetic force to open the moving contact. The structure and working principle of the closing coil are similar to those of the trip coil 311, and it is used to drive the moving contact to close.

[0033] Reference Figure 2 The moving iron core 312 is typically cylindrical and made of a material with good magnetic permeability. It can slide freely within the trip coil 311. One end of the drive rod 313 is fixedly connected to the moving iron core 312, and the other end is connected to the power input terminal of the amplification assembly 32. It is used to transmit the movement of the moving iron core 312.

[0034] Reference Figure 2 The power input end of the amplification component 32 is connected to the drive rod 313, and the power output end is connected to the moving contact, which is used to convert the input motion of the drive rod 313 into a higher speed output motion of the moving contact.

[0035] Reference Figure 2 The amplification component 32 includes an acceleration gear 321, a fixed rack 322, and a movable rack 323. The acceleration gear 321 is rotatably mounted on the drive rod 313 and can be made of a metal material, such as carbon steel, which has high strength and wear resistance. The fixed rack 322 is fixedly mounted in the housing 1 by bolts or other means, and meshes with one side of the acceleration gear 321.

[0036] Reference Figure 2The movable rack 323 is slidably mounted on the housing 1, and its tooth profile matches that of the acceleration gear 321. It can slide on the guide rail inside the housing 1, and the movable rack 323 meshes with the other side of the acceleration gear 321. A connecting rod 324 is rotatably mounted on the movable rack 323. One end of the connecting rod 324 is rotatably connected to the movable rack 323 via a pin, and the other end is connected to the movable contact for transmission.

[0037] Reference Figure 2 The amplification assembly 32 also includes a transmission rod 325 rotatably mounted on the housing 1 and a sliding rod 326 slidably mounted on the housing 1. The transmission rod 325 is provided with a rotary bearing 6. The sliding rod 326 is provided with a sliding bearing 7. The sliding rod 326 can slide in the sliding hole of the housing 1, and its sliding direction is the same as the opening and closing direction of the moving contact.

[0038] Reference Figure 2 One end of the connecting rod 324 is rotatably mounted on the movable rack 323, and the other end is fixedly mounted on the transmission rod 325. The movable contact is mounted on the sliding rod 326. A linkage plate 327 is provided between the transmission rod 325 and the sliding rod 326. A connecting rod 8 is radially mounted on the sliding rod 326. The connecting rod 8 is rotatably mounted on the sliding rod 326. The linkage plate 327 has an oblong hole 9 for the connecting rod 8 to slide. One end of the linkage plate 327 is rotatably mounted on the sliding rod 326, and the other end is fixedly mounted on the transmission rod 325. The rotational motion of the transmission rod 325 is converted into the linear motion of the sliding rod 326 through the linkage plate 327.

[0039] Reference Figure 2 The distance between the hinge point of the connecting rod 324 and the transmission rod 325 is greater than the distance between the hinge point of the linkage plate 327 and the transmission rod 325, thus forming a force-saving lever. The arc-extinguishing mechanism 2 includes a vacuum arc-extinguishing chamber 21 disposed within the housing 1, with both the moving contact and the stationary contact disposed within the vacuum arc-extinguishing chamber 21.

[0040] Reference Figure 2 The vacuum interrupter chamber 21 is a high-vacuum environment. When the moving and stationary contacts open, the generated arc is quickly extinguished in the vacuum, which can effectively prevent the arc from damaging the contacts, improve the service life and reliability of the switch, and reduce the friction when the moving and stationary contacts break.

[0041] Reference Figure 2The control system includes a fault detection circuit and a pulse power supply. The fault detection circuit controls the pulse power supply to discharge to the trip coil 311 when a fault current is detected. The fault detection circuit can use components such as current transformers to detect the current in the circuit. When a fault current is detected, it controls the pulse power supply to discharge to the trip coil 311, causing the trip coil 311 to generate electromagnetic force and drive the moving contact to trip. The pulse power supply can use energy storage components such as capacitors to quickly provide a large current to the trip coil 311 when needed to generate sufficient electromagnetic force.

[0042] The implementation principle of a fast switch for a microgrid according to an embodiment of this application is as follows: Through the cooperation of the electromagnetic component 31 and the amplification component 32, rapid opening and closing of the moving contact can be achieved. When the fault detection circuit detects a fault current, it controls the pulse power supply to discharge to the opening coil 311. The opening coil 311 generates electromagnetic force to drive the moving iron core 312 and the drive rod 313 to move. The drive rod 313 drives the acceleration gear 321 to rotate. The acceleration gear 321, through meshing with the fixed rack 322 and the moving rack 323, converts the input motion of the drive rod 313 into a higher-speed output motion of the moving rack 323. The moving rack 323, through the connecting rod 324, the transmission rod 325, and the linkage plate 327, drives the sliding rod 326 and the moving contact to quickly open the circuit. At the same time, the vacuum interrupter 21 quickly extinguishes the arc, effectively shortening the switching time, reducing the impact of faults on the microgrid, and improving the stability and reliability of the microgrid. Compared with traditional molded case circuit breakers, it overcomes the shortcomings of the "spring energy storage - mechanical tripping" mechanism, such as large operating inertia and long breaking time.

[0043] Example 2 Reference Figure 3 and Figure 4 The difference between this embodiment and embodiment 1 is that: the end of the connecting rod 324 away from the transmission rod 325 is provided with a brake spring 4, the brake spring 4 has the tendency to drive the connecting rod 324 and the moving contact to rotate in the brake opening direction, a limit cam 5 is coaxially provided on the acceleration gear 321, a fixing plate 51 is provided on the side of the connecting rod 324 near the moving rack 323, a sliding groove 511 is provided on the fixing plate 51, and an abutment block 512 is slidably provided in the sliding groove 511.

[0044] Reference Figure 3 and Figure 4 An arc-shaped block 513 is fixed on the side of the abutment block 512 near the connecting rod 324. The side wall of the arc-shaped block 513 near the connecting rod 324 is horizontal and abuts against the connecting rod 324. A closing spring 514 is provided on the side of the arc-shaped block 513 away from the limit cam 5. The closing spring 514 can drive the arc-shaped block 513 to move towards the limit cam 5. The limit cam 5 abuts against the abutment block 512. When the circuit is opened, the limit cam 5 pushes the abutment block 512 to slide away from the connecting rod 324, thereby releasing the opening spring 4, so that the switch breaks off faster.

[0045] Reference Figure 4 The acceleration gear 321 includes an amplification part 328 and a drive part 329. The size of the teeth and the radius of the gear in the amplification part 328 are both larger than the size of the teeth and the radius of the gear in the drive part 329. The amplification part 328 meshes with the moving rack 323, and the drive part 329 meshes with the fixed rack 322.

[0046] Reference Figure 3 and Figure 4 When the drive rod 313 moves, the smaller input speed can be converted into a larger output speed of the moving rack 323 through the transmission of the acceleration gear 321. This is because when the acceleration gear 321 rotates at a certain angle, the distance that the amplification part 328 drives the moving rack 323 to slide is greater than the distance that the drive part 329 moves on the fixed rack 322.

[0047] The implementation principle of a fast switch for a microgrid in this application embodiment is as follows: Through a specially designed acceleration gear 321 structure, the input motion of the drive rod 313 can be converted into a high-speed output motion of the moving contact more efficiently, further improving the opening speed. The setting of the opening spring 4 and the limiting cam 5 allows the fast switch to stably maintain the closed state when closed, and to open more quickly under the action of the opening spring 4, thus more effectively shortening the switching time and improving the protection performance of the microgrid.

[0048] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A fast switch for a microgrid, comprising a housing (1), a contact mechanism arranged in the housing (1), an arc extinguishing mechanism (2), an operating mechanism (3) and a control system, the contact mechanism comprising a moving contact and a stationary contact, characterized in that: The operating mechanism (3) comprises an electromagnetic assembly (31) and an amplification assembly (32), the electromagnetic assembly (31) comprises a split coil (311), a closing coil, a moving iron core (312) arranged in the split coil (311) and a driving rod (313) connected to the moving iron core (312), the split coil (311) can generate an electromagnetic force for driving the moving contact to split after being electrified, the closing coil is used for driving the moving contact to close, the power input end of the amplification assembly (32) is connected with the driving rod (313), the power output end of the amplification assembly (32) is connected with the moving contact, and the amplification assembly (32) is used for converting the input motion of the driving rod (313) into the higher speed output motion of the moving contact.

2. The fast switch for microgrid of claim 1, wherein: The amplification assembly (32) comprises an acceleration gear (321), a fixed rack (322) and a movable rack (323), the acceleration gear (321) is rotationally arranged on the driving rod (313), the fixed rack (322) is fixedly arranged in the shell (1) and meshes with one side of the acceleration gear (321), and the movable rack (323) is slidingly arranged on the shell (1) and meshes with the other side of the acceleration gear (321), a connecting rod (324) is rotationally arranged on the movable rack (323), and the connecting rod (324) is in transmission connection with the moving contact.

3. A fast switch for a microgrid according to claim 2, characterized in that: The acceleration gear (321) comprises an amplification part (328) and a driving part (329), the amplification part (328) meshes with the movable rack (323), and the driving part (329) meshes with the fixed rack (322), the tooth size and gear radius of the amplification part (328) are greater than those of the driving part (329).

4. The fast switch for a microgrid of claim 2, wherein: The amplification assembly (32) further comprises a transmission rod (325) rotationally arranged on the shell (1) and a sliding rod (326) slidingly arranged on the shell (1), one end of the connecting rod (324) is rotationally arranged on the movable rack (323), the other end is arranged on the transmission rod (325), the moving contact is arranged on the sliding rod (326), the sliding direction of the sliding rod (326) is the same as the split and closing directions of the moving contact, a linkage piece (327) is arranged between the transmission rod (325) and the sliding rod (326), a waist-shaped hole (9) is formed in the linkage piece (327), a connecting rod (8) is radially arranged on the sliding rod (326), the connecting rod (8) is slidingly arranged in the waist-shaped hole (9), the connecting rod (8) is rotationally arranged on the sliding rod (326), a rotating bearing (6) is arranged between the transmission rod (325) and the shell (1), and a sliding bearing (7) is arranged between the sliding rod (326) and the shell (1).

5. A fast switch for a microgrid according to claim 4, characterized in that: The distance between the hinge point of the connecting rod (324) and the transmission rod (325) is greater than the distance between the hinge point of the linkage piece (327) and the transmission rod (325).

6. A fast switch for a microgrid according to claim 5, characterized in that: The connecting rod (324) is provided with a disconnecting spring (4) at one end away from the transmission rod (325), the disconnecting spring (4) has a tendency to drive the connecting rod (324) to rotate in the disconnecting direction, a limiting cam (5) is coaxially arranged on the accelerating gear (321), one side of the connecting rod (324) close to the movable rack (323) is provided with a fixed plate (51), the fixed plate (51) is provided with a sliding groove (511), the sliding groove (511) is slidably provided with an abutting block (512), one side of the abutting block (512) close to the connecting rod (324) is provided with an arc-shaped block (513), one side wall of the arc-shaped block (513) close to the connecting rod (324) is a horizontal plane and abuts against the connecting rod (324), one side of the arc-shaped block (513) away from the limiting cam (5) is provided with a closing spring (514), the closing spring (514) can drive the arc-shaped block (513) to move in the direction close to the limiting cam (5), the limiting cam (5) abuts against the abutting block (512), when disconnecting, the limiting cam (5) pushes the abutting block (512) to slide in the direction away from the connecting rod (324).

7. The fast switch for a microgrid of claim 1, wherein: The arc extinguishing mechanism (2) comprises a vacuum arc extinguishing chamber (21) arranged in the shell (1), and the movable contact and the fixed contact are arranged in the vacuum arc extinguishing chamber (21).

8. The fast switch for a microgrid of claim 1, wherein: The control system comprises a fault detection circuit and a pulse power supply, and the fault detection circuit is used for controlling the pulse power supply to discharge to the disconnecting coil (311) when a fault current is detected.

Images