Conductive structure, intelligent fuse and opening and closing control method

Abstract

The present invention discloses a conductive structure, an intelligent fuse, and a method for controlling the on-off switching of a circuit breaker, and relates to the technical field of on-off control equipment for power systems. The intelligent fuse includes the conductive structure, and the control method is implemented based on the fuse. The conductive structure includes a vacuum tube, a lead wire, and a drive mechanism. The vacuum tube is provided with a second conductive rod connected to its movable contact, and the second conductive rod is connected to the drive mechanism via an insulating pull rod. The conductive structure also includes a flexible conductive structure and a metal shielding cover. The second conductive rod and the lead wire are connected in series via the flexible conductive structure. The flexible conductive structure is located within a cavity structure surrounded by the shielding cover. The cavity structure has a boundary located directly below the flexible conductive structure. A connection structure is provided between the shielding cover and the second conductive rod to achieve electrical connection between the two. This solution can effectively ensure the overall insulation performance and withstand voltage level of the line power control equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of on-off control equipment for power systems, and in particular to a conductive structure, an intelligent fuse, and an opening and closing control method. Background Art

[0002] In the existing technology, taking a 10kV transmission line as an example, the line on-off control device thereon includes a fuse that melts due to overcurrent heating of the fuse. The fuse cuts off the line and is not affected by mechanical or electronic control system failures. However, due to its working characteristics, the fuse needs to reach the melting temperature after a period of overcurrent before it will operate. The operating current accuracy is relatively low, and the time required for melting is greatly affected by the external environment. Since there is no fuse protection system, when a fuse blows, the fault must be eliminated and the fuse must be replaced before power can be restored. At the same time, for fuses without intelligent functions, it is impossible to determine the location of the line melting and the specific time of melting. Other line on-off control devices also include circuit breakers. Circuit breakers are the most commonly used and powerful switching devices. They can not only identify load current and fault current, but also cooperate with protection devices, and have the characteristics of realizing efficient line protection.

[0003] Regarding circuit safety, the prior art patent application with the number CN200910152955.8 (name: A vacuum-isolated phase-changing switch circuit) provides a line safety protection structure including a manual isolating switch, a vacuum tube, and a fuse. The applicant has also previously proposed a primary-secondary integrated pole-mounted circuit breaker and its conductive column structure (patent application number: CN202520618121.6). In this patent document, a flexible cable is used to establish an electrical connection between the third conductive column and the second conductive column. The flexible cable is specifically used to adapt to the position change of the third conductive column relative to the second conductive column by deforming.

[0004] Line on-off control equipment is an indispensable control and safety component in the power system. Further optimizing its performance is of great significance to the development of smart grids. Summary of the Invention

[0005] In response to the above-mentioned technical problem of further optimizing the line power control equipment, the present invention provides a conductive structure, an intelligent fuse and a switching control method. This solution can effectively ensure the overall insulation performance and voltage resistance level of the line power control equipment.

[0006] In response to the above problems, the conductive structure, intelligent fuse and opening and closing control method provided by the present invention solve the problems through the following technical points: the conductive structure includes a vacuum tube, a lead wire and a driving mechanism, the vacuum tube is equipped with a second conductive rod connected to its moving contact, the second conductive rod is connected to the driving mechanism through an insulating pull rod, and also includes a flexible conductive structure and a shielding cover made of metal, the second conductive rod and the lead wire are connected in series through the flexible conductive structure, the flexible conductive structure is located in a cavity structure surrounded by the shielding cover, the cavity structure has a boundary located directly below the flexible conductive structure, and a connecting structure is provided between the shielding cover and the second conductive rod to realize electrical connection between the two.

[0007] In this solution, the vacuum tube serves as a switching element on the conductive structure. Specifically, the vacuum tube includes a vacuum chamber and a moving contact and a static contact arranged in the vacuum chamber. Under the action of a driving mechanism, when the moving contact and the static contact are in contact with each other, the vacuum tube is in a conducting state, for example, the first conductive rod connected to the static contact and the second conductive rod connected to the moving contact are in a conducting state. Conversely, under the action of the driving mechanism, when the moving contact and the static contact are separated from each other, the vacuum tube is in a disconnected state, for example, the first conductive rod connected to the static contact and the second conductive rod connected to the moving contact are in a disconnected state. The driving mechanism acts on the moving contact through the insulating pull rod and the second conductive rod to Adjust the position of the moving contact in the vacuum chamber to achieve the corresponding state adjustment. The lead wire serves as a conductive structure that connects the vacuum tube in series on the line. According to the structural characteristics of the existing switchgear / opening and closing equipment, the conductive structure can be a conductive rod, a conductive cable, or a structure formed by a conductive rod and a conductive cable in series. The flexible conductive structure serves as a flexible conductive structure that connects the second conductive rod in series with the lead wire. Specifically, when the second conductive rod moves under the action of the driving mechanism, the flexible conductive structure adapts to the position change of the second conductive rod relative to the lead wire through flexible deformation, so that the second conductive rod can still be adjusted in position according to the opening and closing needs under the action of the driving mechanism while maintaining electrical connection with the lead wire. When this conductive structure is used on the line, it can be specifically used as the static contact of the vacuum tube connected to the power supply side of the line through the first conductive rod, one end of the lead wire is connected to the flexible conductive structure, and the other end is provided with a terminal, which is used to connect the conductive structure to the power consumption side of the line.

[0008] Different from the prior art, this solution is that the flexible conductive structure is configured with a shielding cover, the flexible conductive structure is located in a cavity structure surrounded by the shielding cover, a connection structure is provided between the shielding cover and the second conductive rod to achieve electrical connection between the two, and the cavity structure has a boundary located directly below the flexible conductive structure, aiming to achieve:

[0009] First, the flexible conductive structure will be deformed during the movement of the second conductive rod. This deformation may cause the electrical gap between the flexible conductive structure and the surrounding conductor / insulation structure to become smaller and the creepage distance to be shortened, eventually causing problems such as surface discharge and air breakdown. Especially after the flexible conductive structure has undergone multiple deformations, due to material fatigue, deformation beyond design expectations, friction produces conductive debris scattered in the surrounding environment, and burrs are generated at the bending position, the risk of surface discharge, breakdown, and local discharge will be greatly increased. Therefore, the flexible conductive structure is a weak part of the overall external insulation withstand voltage capability of the conductive structure. This solution is configured to also include a shielding cover and to arrange the flexible conductive structure in a cavity structure surrounded by the shielding cover. The shielding cover can be used as an equipotential surface on the outside of the flexible conductive structure to stabilize the withstand voltage distance between the conductive structure and the surrounding structures in the use scenario, effectively suppress local discharge caused by the flexible conductive structure, and ensure the number of times the vacuum tube can be opened and closed. At the same time, for debris generated by friction and fatigue of the flexible conductive structure, the shielding cover serves as a physical isolation barrier on the side and bottom sides of the flexible conductive structure. By confining these debris within the cavity structure, these debris are prevented from being scattered uncontrollably in the surrounding environment to form conductive pollutants, thereby greatly reducing the problems of breakdown and flashover on the insulating surface.

[0010] Secondly, a connection structure is provided to electrically connect the shielding cover to the second conductive rod, aiming to optimize the installation convenience of the structure and ensure the insulation performance of the structure. When the connection structure is provided, due to the electrical conductivity of the connection structure, even if the flexible conductive structure is used in an AC transmission line, the voltage on the shielding cover strictly changes with the voltage on the flexible conductive structure. For the insulating shell that is generally required to be provided on the periphery of the shielding cover (the insulating shell is generally at a reference potential of 0V), the insulation capability of the insulating shell and the shielding cover is such that the electric field change rate exhibits a steady-state periodic change (sinusoidal variation). This avoids the floating voltage generated on the shielding cover due to capacitive coupling with the flexible conductive structure. Due to the unpredictable voltage and high-frequency voltage fluctuations, the resulting surface electric field stability, high risk of partial discharge, and higher creepage distance requirements are problematic. In this solution, the corresponding insulation gap only needs to be designed according to the voltage level of the transmission line. For example, under a fixed voltage variation pattern, the insulation risk can be effectively controlled by designing a standard creepage distance, thereby avoiding the impact of fluctuation effects on the insulation reliability of the corresponding structure. At the same time, for solutions such as grounding the shielding cover to solve the problem of floating voltage significantly exacerbating partial discharge and arc formation, the application of this solution is not limited by whether there are conditions for reliable grounding in the specific use environment, which makes this solution less dependent on on-site conditions and highly convenient to install.

[0011] In specific applications, in order to protect the vacuum tube, drive mechanism, etc. and provide a relatively stable environment for the shielding cover, the vacuum tube, drive mechanism, and shielding cover should be placed in an insulating shell with a good protection level (such as IP65). By controlling the temperature and humidity of the internal environment and other electrical insulation pollutants through the insulating shell, the service life of the conductive structure can be further guaranteed.

[0012] As a further technical solution of the conductive structure:

[0013] The second conductive rod is coaxial with the insulating pull rod, and the connecting structure is a flexible conductive structure: one end of the flexible conductive structure is fixed to the second conductive rod, and the other end is fixed to the shielding cover;

[0014] The shielding cover is a spherical shell structure with a through hole on the bottom and an opening on the top, and the insulating pull rod and the through hole are fitted with a clearance fit;

[0015] The wiring terminals of the lead wires are connected to the shielding cover.

[0016] In the above scheme, a technical solution is provided that uses a flexible conductive structure as the connecting structure to simplify the structural design of the conductive structure; and the shielding cover is further determined to be a hemispherical / non-complete spherical shell structure with a through hole on the bottom side and an opening on the top side. The through hole serves as a channel for the insulating pull rod to pass through the shielding cover. The inner surface of the bottom side of the shielding cover serves as a boundary for receiving debris generated by the flexible conductive structure during use. The upper opening is used to make the shielding cover have convection heat dissipation performance, so that the heat generated by the flexible conductive structure can be reliably dissipated. This type of shielding cover structure is not only easy to process, but also convenient for processing a shielding cover with a smooth surface and a shielding cover with a spacious inner cavity space. In specific applications, the shielding cover is fixed to the above insulating shell.

[0017] It also includes a connecting ring, which is a silver ring or a copper ring, and is crimped onto the second conductive rod. The connecting ring and the second conductive rod are welded together by silver-based welding;

[0018] The flexible conductive structure, the connecting ring and the shielding cover are all connected by silver-based welding.

[0019] The above provides a specific connection form of a flexible conductive structure. Specifically, the connecting ring, which is a silver ring or a copper ring, has good conductivity and is a soft ring. Under the condition of the same electrical connection performance, it can effectively reduce the load of the driving mechanism when the driving mechanism adjusts the contact matching state in the vacuum tube, so as to optimize the opening response speed of the vacuum tube. After being electrically connected to the second conductive rod by crimping, the contact area between the connecting ring and the second conductive rod can be effectively guaranteed. The above silver-based welding is used to form a reliable connection relationship between the connecting ring and the second conductive rod, the flexible conductive structure and the connecting ring, and the flexible conductive structure and the shielding cover, as well as reliable electrical connection performance.

[0020] It also includes a connecting ring, which is a silver ring or a copper ring, and is sleeved on the second conductive rod;

[0021] The connecting ring is provided with a plurality of slots spaced apart along the circumferential direction of the connecting ring. Each slot has a length along the axial direction of the connecting ring, passes through the side wall of the connecting ring, and is connected to the end of the connecting ring away from the insulating pull rod.

[0022] Each slot is provided with a protrusion located on the second conductive rod and having its length along the axis of the connecting ring. The protrusion is embedded in the slot, and each protrusion is welded to the connecting ring by silver-based welding.

[0023] The flexible conductive structure, the connecting ring and the shielding cover are all connected by silver-based welding.

[0024] The above provides a specific flexible conductive structure connection form, which is a parallel technical solution for the above-mentioned connection ring crimped to the second conductive rod. Specifically, the connection ring and the second conductive rod are crimped and then welded to achieve a quick connection between the connection ring and the second conductive rod. However, in specific applications, such as when the conductive structure has alternating thermal deformation of the second conductive rod and the connection ring due to large fluctuations in current, thermal cycle failure will occur in such an operating mode, which is not conducive to ensuring the quality of the electrical connection between the connection ring and the second conductive rod. This is especially true when the connection ring is set to be thinner to ensure the response speed of the vacuum tube tripping action. Therefore, the above crimping solution is suitable for transmission lines with stable current. For transmission lines with large current fluctuations, the above-mentioned technical solution based on the slot and the protrusion is preferably used. In specific applications, the above-mentioned technical solution based on the slot and the protrusion ensures the conductive cross-sectional area of ​​the connection ring and the second conductive rod through the matching relationship between multiple slots and protrusions and the weld formed, thereby ensuring the electrical connection performance of the second conductive rod and the connection ring under thermal cycling at the expense of structural and assembly simplicity. Specifically, in the structural form of the slot, the connecting ring can be inserted into the second conductive rod from the side where the insulating pull rod is located, and a protrusion can be embedded in each slot. The protrusion is exposed relative to the connecting ring, and then welding is used to fill the gap between the protrusion and the slot, and establish an electrical connection channel between the protrusion and the surface of the connecting ring. In this way, multiple welds serving as the electrical connection channels can be formed on the side of the connecting ring. Compared with the crimping scheme, it is convenient to perform welding at the end of the connecting ring, which can effectively ensure the conductive cross-sectional area between the connecting ring and the second conductive rod and ensure the electrical connection performance between the connecting ring and the second conductive rod. Therefore, the technical solution of combining the slot and the protrusion and further based on the welding connection is suitable for transmission lines with large current fluctuations, such as the crimping scheme is used for the feeder, and the slot and protrusion scheme is used for the branch line on the feeder.

[0025] The flexible conductive structure is a laminated structure formed by stacking multiple layers of copper sheets, and the laminated structure is coaxial with the second conductive rod;

[0026] Each copper sheet has a trumpet-shaped structure. The end with a smaller diameter is sleeved on the connecting ring and welded to the connecting ring, and the end with a larger diameter is welded to the shielding cover.

[0027] The above provides a specific implementation method of a flexible conductive structure. Specifically, the copper sheet is also called copper foil. The trumpet-shaped structure is a cylindrical structure with a diameter at one end larger than the other end and a linear transition of the diameter at each position along the axial direction. In order to reduce the resistance brought by the flexible conductive structure to the movement of the second conductive rod, it is preferably set that the normal of the copper sheet is a curve with curvature, for example, the cross section is parallel to the axis of the copper sheet, and the cross section of the copper sheet on which the axis of the copper sheet is located is in the shape of a bridge arch; the stacked structure is coaxial with the second conductive rod to address the following problems: for a vacuum tube, in order to form a vacuum boundary, a metal bellows needs to be provided between the vacuum tube and the second conductive rod. In order to improve the power-off response speed of the vacuum tube, the drive The moving mechanism preferably adopts a mechanism based on electromagnetic force to drive the movement of the moving contact in the vacuum tube. Under such application, if the lateral force applied by the flexible conductive structure to the second conductive rod is unevenly distributed in the circumferential direction of the second conductive rod, the contact quality between the moving contact and the static contact may be deteriorated. For the metal bellows, it may cause uneven force in the circumferential direction, affecting the life of the metal bellows (mainly due to its role as a vacuum boundary). For the driving mechanism, it may cause uneven wear of its moving iron core and other components, affecting its reliability. The above coaxial solution can effectively optimize the uneven force in the circumferential direction of the second conductive rod, which is beneficial to ensuring the conductive performance of the vacuum tube contact, the life of the metal bellows and the reliability of the driving mechanism.

[0028] The laminated structure formed by the laminated copper foil is a flexible conductive structure, which has the characteristics of low friction during use and is not easy to form conductive debris during repeated deformation. However, in specific applications, it is necessary to consider the actual voltage of the line, the requirements for the current carrying capacity of the flexible conductive structure, and the operating frequency of the vacuum tube. When the voltage level is high, the current carrying capacity requirement is high, and the vacuum tube may need relatively frequent opening and closing operations, in order to avoid corona discharge, premature cracking, etc., it is not appropriate to adopt the technical solution of forming a laminated structure by copper sheets.

[0029] Based on the above, as a way to implement a flexible conductive structure that can avoid corona discharge, the flexible conductive structure includes multiple strands of flexible wires, and the flexible wires are evenly distributed in a ring relative to the axis of the connecting ring;

[0030] Each flexible wire is welded to the connecting ring at one end and to the shielding cover at the other end.

[0031] When the above scheme is used in practice, the multi-strand flexible conductor adopts a copper wire braid. In order to weaken the skin effect, the diameter of the copper wire is less than or equal to 0.3 mm, and the surface of the copper wire braid is smoothed. Compared with the use of copper sheets to form the laminated structure, the flexible conductive structure using multi-strand flexible conductors is suitable for application scenarios with higher voltage levels, such as being used in series on a 10kV cable. The above axial ring is also used to solve the problem of the second conductive rod being subjected to lateral force.

[0032] The present solution also relates to an intelligent fuse, comprising a fuse element, an energy transformer, a sampling transformer and a controller, and further comprising a conductive structure as described in any one of the above items;

[0033] The melt is connected in series to the conductive structure;

[0034] The energy transformer is used to obtain electrical energy from the conductive structure and supply power to the drive mechanism and the controller;

[0035] The sampling transformer is used to collect the current value passing through the conductive structure and transmit the current value collection result to the controller;

[0036] The controller is used to control the action of the drive mechanism to adjust the position of the moving contact in the vacuum tube through the insulating pull rod and the second conductive rod. Specifically, the controller receives a control instruction and the collection result of the current value. When the controller receives a switching-off control instruction or determines that the current value exceeds a first set threshold, the controller controls the drive mechanism to output an action to separate the moving contact from the static contact; when the controller receives a switching-on control instruction, the controller controls the drive mechanism to output an action to bring the moving contact into contact with the static contact.

[0037] As described above, in the structure disclosed by the conductive structure, the on-off control of the conductive structure is achieved by acting on the vacuum tube through the driving mechanism. When assisted by the controller, automatic control of line opening and closing can be achieved, adapting to the further development of smart grid technology, in order to further ensure the reliability of the line and avoid electrical faults affecting the controllability of the line, the above provides an intelligent fuse including the conductive structure. Specifically, the intelligent fuse is connected in series on the line when in use, and the fuse cuts off the conductive structure based on the heat and melting when overcurrent occurs (if the vacuum tube can be normally opened, since the response speed of the driving mechanism to perform the opening action is significantly faster than the melting response speed of the fuse, under normal circumstances, the fuse only realizes line opening control through the vacuum tube), realizing the opening of the line and the power supply side, as a supplement to automatically cutting off the conductive structure when the driving mechanism fails, and the energy transformer (energy CT) is used to obtain electrical energy from the conductive structure to In order to meet the energy consumption demand of the smart fuse and reduce the energy power requirement of the energy transformer, the electric energy collected by the energy transformer can be stored in a battery, and then the functional purpose can be achieved through the battery. The sampling transformer (using CT) is used to monitor the current value on the line. When it is determined to be overcurrent through the first set threshold, the controller controls the action of the driving mechanism to realize the opening of the conductive structure. The control instruction transmission can be realized based on wireless communication, such as using a 4G communication module and a Bluetooth / LoRa module to realize the control instruction transmission. It is easy to understand that the 4G communication module can realize remote communication and complete the control of the opening and closing of the fuse by the control center. The Bluetooth / LoRa module can realize local communication. For example, the operation and maintenance personnel can use handheld devices to realize opening and closing control according to local needs, based on the three-phase microgrid operation control strategy, to realize mutual communication between smart fuses on different phases, and realize multi-phase synchronous opening operation, etc.

[0038] As a further technical solution of the intelligent fuse:

[0039] The fuse is connected in series on the lead wire, the position of the energy transformer for acquiring electric energy is located on the lead wire, and the position of the sampling transformer for collecting current value is located on the lead wire;

[0040] The melt is a fuse, and further comprises a fuse tube, wherein the melt is located inside the fuse tube, and further comprises a temperature sensor for collecting the temperature inside the fuse tube;

[0041] The controller receives the temperature acquisition result of the temperature sensor and determines the temperature rising speed inside the fuse tube. When the temperature rising speed exceeds a second set threshold, the controller controls the driving mechanism to output an action to separate the moving contact and the static contact.

[0042] The above scheme further clarifies the specific placement of the various functional components on the fuse. Specifically, it aims to achieve: a cylindrical insulating housing enclosing the strip structure formed by the vacuum tube, the second conductive rod, the insulating pull rod, and the drive mechanism. The fuse element, the energy transformer, the sampling transformer, and the controller are each positioned on the side of the insulating housing, and their positions relative to the insulating housing are adjustable (achieved by deforming the lead wires, the corresponding power lines, and the signal lines). This structural form effectively reduces the installation space requirements of the smart fuse. This scheme further includes a temperature sensor to collect the internal temperature of the fuse tube. Based on the controller's determination, when the temperature rise rate inside the fuse tube exceeds a second set threshold, the drive mechanism activates to open the contacts in the vacuum tube. This allows: when a fault in the line causes a surge in current, the temperature rise rate is used as a trigger signal for the drive mechanism to activate. This prevents the drive mechanism from triggering the corresponding opening action when a sampling transformer fault occurs, and allows the line to be opened before the fuse blows. At the same time, this solution uses the temperature inside the fuse tube as the pickup signal, and can take advantage of the relatively stable environment inside the fuse tube to ensure the reliability of triggering the tripping action based on the temperature signal.

[0043] The second conductive rod is arranged on the lower side of the vacuum tube, and also includes a first conductive rod arranged on the upper side of the vacuum tube and connected to the static contact in the vacuum tube. An isolating switch is connected in series on the first conductive rod. The isolating switch is equipped with a mechanical break that is manually opened and closed. The mechanical break is: when the mechanical break is disconnected, a visible breakpoint visible to the naked eye is formed on the isolating switch.

[0044] The above solution involves connecting a disconnector with a mechanical break in series with the first conductive rod. This allows, for example, manual operation of the disconnector during line maintenance to create a visible breakpoint, ensuring safe power outages. Furthermore, by integrating the disconnector, vacuum tube, and fuse into the fuse, the solution effectively reduces the number of circuit breaker control components on the line, facilitating their installation and maintenance, and reducing operational costs.

[0045] This solution also relates to a method for controlling the opening and closing of a circuit breaker, which is used to control the on and off of a circuit breaker. The method is implemented based on the above-mentioned intelligent fuse.

[0046] Among them, when closing is required, first, the mechanical break of the disconnector is manually closed to the closed state, and then the controller receives the closing state detection result of the mechanical break. When the detection result is in the closed state and after receiving the main body or remote closing control command, the controller controls the drive mechanism to output the action of making the moving contact and the static contact contact; after the vacuum tube completes closing, the controller performs closing protection based on the collected data: when it is determined based on the data that there is a fault in the subsequent stage of the line, the controller controls the vacuum tube to open through the drive mechanism, and the data includes one or more of the following data: phase current, phase voltage, line voltage, zero-sequence current, zero-sequence voltage, phase angle, frequency, closing transient current, and closing inrush current characteristics;

[0047] When opening is required, first, after receiving the main body or remote opening control command, the controller controls the drive mechanism to output the action to separate the moving contact and the static contact, and then manually opens the mechanical break of the disconnector to the opening state.

[0048] In the above method, when closing is required, the disconnector is first adjusted to the closed state, and then the vacuum tube is adjusted to the closed state through the driving mechanism. When opening is required, the vacuum tube is first adjusted to the open state, and then the disconnector is adjusted to the open state to form a visible break. The specific purpose is to avoid arcing at the mechanical break position, significantly shorten the arcing time on the entire line (the arcing time may only exist for a few milliseconds in the vacuum tube), avoid damage to the disconnector due to arcing, and avoid damage to the transformer on the line due to overvoltage and high-frequency harmonics on the line.

[0049] In the above scheme, when closing the circuit breaker, after the disconnector is closed, the controller needs to collect the mechanical break closing status detection results and corresponding control instructions before executing the drive mechanism action control, aiming to standardize the necessary sequence of closing the disconnector first and closing the vacuum tube later. It is further configured to include a closing protection action based on the controller to realize the opening action of the vacuum tube when it is determined that there is a fault in the downstream stage of the line. Based on existing signal detection methods, closing protection algorithms, and the response speed of the driving mechanism, the downstream fault isolation can be completed within 50ms, avoiding damage to the downstream equipment caused by closing the circuit breaker due to the failure of the downstream equipment not being eliminated. It is easy to understand that the phase current is associated with faults such as line short circuit and overload, the phase voltage / line voltage is associated with faults such as voltage loss and asymmetry, the zero-sequence current / zero-sequence voltage is associated with ground fault, and the phase angle / frequency is associated with synchronous fault. The closing transient current / closing inrush current characteristics are used to distinguish between real faults and normal inrush currents to avoid malfunction of the closing protection.

[0050] The present invention has the following beneficial effects:

[0051] This solution utilizes the shielding cover as the equipotential surface on the outside of the flexible conductive structure to stabilize the withstand voltage distance between the conductive structure and the surrounding structures in the use scenario, effectively suppress the local discharge caused by the flexible conductive structure, and ensure the number of times the vacuum tube can be broken; at the same time, for the debris generated by friction and fatigue of the flexible conductive structure, the shielding cover serves as a physical isolation barrier on the side and bottom sides of the flexible conductive structure. By confining these debris within the cavity structure, these debris are prevented from being scattered uncontrollably in the surrounding environment to form conductive pollutants, greatly reducing the problems of breakdown and flashover on the insulating surface.

[0052] This solution is configured to have a connection structure that realizes electrical connection between the shielding cover and the second conductive rod, aiming to optimize the installation convenience of this structure and ensure the insulation performance of this structure. Even if the flexible conductive structure is used in an AC transmission line, the voltage on the shielding cover strictly changes with the voltage on the flexible conductive structure. For an insulating shell that generally needs to be set on the periphery of the shielding cover, regarding the insulation capacity of the insulating shell and the shielding cover, since the electric field change rate shows a steady-state periodic change, the floating voltage generated on the shielding cover due to capacitive coupling with the flexible conductive structure is avoided. Due to the voltage unpredictability and high-frequency voltage fluctuations, the surface electric field stability is poor, the risk of partial discharge is high, and the requirements for creepage distance are higher, thereby ensuring the voltage withstand level of the line power control equipment including this conductive structure.

[0053] In this solution, the insulation gaps only need to be designed for the voltage level of the transmission line, thus avoiding the impact of fluctuations on the insulation reliability of the corresponding structure. The application of this solution is not limited by the availability of reliable grounding in the specific use environment, making it less dependent on site conditions and highly convenient to install. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a structural diagram of a specific embodiment of the intelligent fuse described in this solution;

[0055] Figure 2 A cross-sectional view of the local structure of the shielding cover in a specific embodiment of the intelligent fuse described in this solution;

[0056] Figure 3 A top view of the local structure of the shielding cover in a specific embodiment of the intelligent fuse described in this solution;

[0057] Figure 4 This is a schematic diagram of the partial structure of the second conductive rod and the connecting ring structure in a specific embodiment of the intelligent fuse described in this solution.

[0058] The reference numerals in the accompanying drawings are: 1. first conductive rod, 2. disconnector, 3. vacuum tube, 4. shielding cover, 5. melt, 6. energy transformer, 7. sampling transformer, 8. driving mechanism, 9. insulating pull rod, 10. second conductive rod, 11. controller, 12. flexible conductive structure, 13. connecting ring, 14. lead wire, 15. slot, 16. protrusion, 17. temperature sensor. DETAILED DESCRIPTION

[0059] The present invention will be further described in detail below with reference to the embodiments, but the present invention is not limited to the following embodiments:

[0060] Example 1:

[0061] like Figures 1 to 4 As shown, the conductive structure includes a vacuum tube 3, a lead wire 14 and a drive mechanism 8. The vacuum tube 3 is equipped with a second conductive rod 10 connected to its moving contact, and the second conductive rod 10 is connected to the drive mechanism 8 through an insulating pull rod 9. It also includes a flexible conductive structure 12 and a shielding cover 4 made of metal. The second conductive rod 10 and the lead wire 14 are connected in series through the flexible conductive structure 12. The flexible conductive structure 12 is located in a cavity structure surrounded by the shielding cover 4. The cavity structure has a boundary located directly below the flexible conductive structure 12. A connection structure is provided between the shielding cover 4 and the second conductive rod 10 to achieve electrical connection between the two.

[0062] In this solution, the vacuum tube 3 serves as a switching element on the conductive structure, specifically: the vacuum tube 3 includes a vacuum chamber and a moving contact and a static contact arranged in the vacuum chamber. Under the action of the driving mechanism 8, when the moving contact and the static contact are in contact with each other, the vacuum tube 3 is in a conducting state, such as the first conductive rod 1 connected to the static contact and the second conductive rod 10 connected to the moving contact are in a phase-conducting state. Conversely, under the action of the driving mechanism 8, when the moving contact and the static contact are separated from each other, the vacuum tube 3 is in a disconnected state, such as the first conductive rod 1 connected to the static contact and the second conductive rod 10 connected to the moving contact are in a phase-disconnected state. The driving mechanism 8 acts on the moving contact through the insulating pull rod 9 and the second conductive rod 10 to adjust the moving contact. The position of the head in the vacuum chamber is adjusted accordingly. The lead wire 14 serves as a conductive structure that connects the vacuum tube 3 in series to the line. According to the structural characteristics of existing switchgear / opening and closing equipment, the conductive structure can be a conductive rod, a conductive cable, or a structure formed by a conductive rod and a conductive cable in series. The flexible conductive structure 12 serves as a flexible conductive structure 12 that connects the second conductive rod 10 in series with the lead wire 14. Specifically, when the second conductive rod 10 moves under the action of the driving mechanism 8, the flexible conductive structure 12 adapts to the position change of the second conductive rod 10 relative to the lead wire 14 through flexible deformation, so that the second conductive rod 10 can still be adjusted according to the opening and closing requirements under the action of the driving mechanism 8 while maintaining electrical connection with the lead wire 14. When this conductive structure is used on the line, it can be specifically used as the static contact of the vacuum tube 3 is connected to the power supply side of the line through the first conductive rod 1, one end of the lead wire 14 is connected to the flexible conductive structure 12, and the other end is provided with a terminal, which is used to connect the conductive structure to the power consumption side of the line.

[0063] Different from the prior art, this solution is that the flexible conductive structure 12 is configured with a shielding cover 4, the flexible conductive structure 12 is located in a cavity structure surrounded by the shielding cover 4, a connection structure is provided between the shielding cover 4 and the second conductive rod 10 to achieve electrical connection between the two, and the cavity structure has a boundary located directly below the flexible conductive structure 12, aiming to achieve:

[0064] First, the flexible conductive structure 12 will be deformed during the movement of the second conductive rod 10. This deformation may cause the electrical gap between the flexible conductive structure 12 and the surrounding conductor / insulation structure to become smaller and the creepage distance to be shortened, eventually causing problems such as surface discharge and air breakdown. Especially after the flexible conductive structure 12 has undergone multiple deformations, due to material fatigue, deformation beyond design expectations, friction produces conductive debris scattered in the surrounding environment, and burrs are generated at the bending position, the risk of surface discharge, breakdown, and local discharge will be greatly increased. Therefore, the flexible conductive structure 12 is a weak part of the overall external insulation withstand voltage capability of the conductive structure. This solution is configured to also include a shielding cover 4 and to arrange the flexible conductive structure 12 in a cavity structure surrounded by the shielding cover 4. The shielding cover 4 can be used as an equipotential surface on the outside of the flexible conductive structure 12 to stabilize the withstand voltage distance between the conductive structure and the surrounding structures in the use scenario, effectively suppress local discharge caused by the flexible conductive structure 12, and ensure the number of times the vacuum tube 3 can be broken. At the same time, for the debris generated by friction and fatigue of the flexible conductive structure 12, the shielding cover 4 serves as a physical isolation barrier on the side and bottom sides of the flexible conductive structure 12. By confining these debris within the cavity structure, these debris are prevented from being scattered uncontrollably in the surrounding environment to form conductive pollutants, thereby greatly reducing the problems of breakdown and flashover on the insulating surface.

[0065] Secondly, a connection structure is provided to electrically connect the shielding cover 4 to the second conductive rod 10, aiming to optimize the ease of installation and ensure the insulation performance of the structure. With this connection structure, due to the electrical conductivity provided by the connection structure, even when the flexible conductive structure 12 is used in an AC transmission line, the voltage on the shielding cover 4 strictly varies with the voltage on the flexible conductive structure 12. For the insulating housing generally required to be provided on the periphery of the shielding cover 4 (the insulating housing is generally at a reference potential of 0V), the insulation capability of the insulating housing and the shielding cover 4 is such that, because the rate of change of the electric field exhibits a steady-state periodic variation (sinusoidal variation), the floating voltage generated on the shielding cover 4 due to capacitive coupling with the flexible conductive structure 12 is avoided. Due to the unpredictable voltage and high-frequency voltage fluctuations, the resulting poor surface electric field stability, high risk of partial discharge, and higher creepage distance requirements are avoided. In this solution, the corresponding insulation gap only needs to be designed for the voltage level of the transmission line. For example, under a fixed voltage variation pattern, a standard creepage distance design can effectively control insulation risks and avoid the impact of fluctuation effects on the insulation reliability of the corresponding structure. At the same time, for solutions such as grounding the shielding cover 4 to solve the problem of floating voltage significantly exacerbating local discharge and arc formation, the application of this solution is not limited to whether there are conditions for reliable grounding in the specific use environment, so that this solution has the characteristics of low dependence on site conditions and high installation convenience.

[0066] In specific applications, in order to protect the vacuum tube 3, the driving mechanism 8, etc. and provide a relatively stable environment for the shielding cover 4, the vacuum tube 3, the driving mechanism 8, and the shielding cover 4 should be placed in an insulating shell with a good protection level (such as IP65). By controlling the temperature and humidity of the internal environment and other electrical insulation pollutants through the insulating shell, the service life of the conductive structure can be further guaranteed.

[0067] Example 2:

[0068] This embodiment is further refined based on the embodiment 1:

[0069] The second conductive rod 10 is coaxial with the insulating pull rod 9, and the connection structure is a flexible conductive structure 12: one end of the flexible conductive structure 12 is fixed to the second conductive rod 10, and the other end is fixed to the shielding cover 4;

[0070] The shielding cover 4 is a spherical shell structure with a through hole on the bottom and an opening on the top. The insulating pull rod 9 and the through hole are fitted with a clearance fit.

[0071] The connection ends of the lead wires 14 are connected to the shielding cover 4 .

[0072] In the above scheme, a technical solution is provided in which a flexible conductive structure 12 is used as the connecting structure to simplify the structural design of the conductive structure; and the shielding cover 4 is further determined to be a hemispherical / non-complete spherical shell structure with a through hole on the bottom side and an opening on the top side. The through hole serves as a channel for the insulating pull rod 9 to pass through the shielding cover 4. The inner surface of the bottom side of the shielding cover 4 serves as a boundary for receiving debris generated by the flexible conductive structure 12 during use. The upper opening is used to enable the shielding cover 4 to have convection heat dissipation performance, so that the heat generated by the flexible conductive structure 12 can be reliably dissipated. This structural form of the shielding cover 4 is not only easy to process, but also convenient for processing a shielding cover 4 with a smooth surface and a shielding cover 4 with a spacious inner cavity space. In specific applications, the shielding cover 4 is fixed to the above insulating shell.

[0073] Example 3:

[0074] This embodiment is further refined based on embodiment 2:

[0075] The second conductive rod 10 is crimped onto the connecting ring 13. The connecting ring 13 is a silver ring or a copper ring. The connecting ring 13 is connected to the second conductive rod 10 by silver-based welding.

[0076] The flexible conductive structure 12 is connected to the connecting ring 13 and the shielding cover 4 by silver-based welding.

[0077] The above provides a specific connection form of the flexible conductive structure 12. Specifically, the connecting ring 13, which is a silver ring or a copper ring, has good electrical conductivity and is a soft ring. Under the condition of the same electrical connection performance, it can effectively reduce the load of the driving mechanism 8 when the driving mechanism 8 adjusts the contact matching state in the vacuum tube 3, so as to optimize the opening response speed of the vacuum tube 3. After being electrically connected to the second conductive rod 10 by crimping, the contact area between the connecting ring 13 and the second conductive rod 10 can be effectively guaranteed. The above silver-based welding is used to form a reliable connection relationship between the connecting ring 13 and the second conductive rod 10, the flexible conductive structure 12 and the connecting ring 13, and the flexible conductive structure 12 and the shielding cover 4, as well as reliable electrical connection performance.

[0078] Example 4:

[0079] This embodiment is further refined based on embodiment 2:

[0080] It also includes a connecting ring 13, which is a silver ring or a copper ring, and is sleeved on the second conductive rod 10;

[0081] The connecting ring 13 is provided with a plurality of slots 15 arranged at intervals along the circumferential direction of the connecting ring 13. Each slot 15 has a length direction along the axial direction of the connecting ring 13, penetrates the side wall of the connecting ring 13, and is connected to the end of the connecting ring 13 away from the insulating pull rod 9.

[0082] Each slot 15 is provided with a protrusion 16 located on the second conductive rod 10 and having its length along the axis of the connecting ring 13. The protrusion 16 is embedded in the slot 15 and each protrusion 16 is welded to the connecting ring 13 by silver-based soldering.

[0083] The flexible conductive structure 12 is connected to the connecting ring 13 and the shielding cover 4 by silver-based welding.

[0084] The above provides a specific connection form of the flexible conductive structure 12, which is a parallel technical solution for the implementation method of crimping the connecting ring 13 to the second conductive rod 10 as above. Specifically, the connecting ring 13 and the second conductive rod 10 are crimped and then welded to achieve a quick connection between the connecting ring 13 and the second conductive rod 10. However, in specific applications of such a structure, if the second conductive rod 10 and the connecting ring 13 have alternating thermal deformation due to large fluctuations in current on the conductive structure, thermal cycle failure will be caused in such an operating mode, which is not conducive to ensuring the quality of the electrical connection between the connecting ring 13 and the second conductive rod 10. This is especially true when the connecting ring 13 is set to be thinner to ensure the response speed of the vacuum tube 3 opening action. Therefore, the above crimping solution is suitable for transmission lines with stable current. For transmission lines with large current fluctuations, the above technical solution based on the slot 15 and the protrusion 16 is preferably adopted. When the above technical solution based on the slots 15 and the protrusions 16 is used in practice, the conductive cross-sectional area of ​​the connecting ring 13 and the second conductive rod 10 is ensured by the matching relationship between the multiple slots 15 and the protrusions 16 and the welds formed, thereby ensuring the electrical connection performance of the second conductive rod 10 and the connecting ring 13 under thermal cycling at the expense of structural and assembly simplicity. Specifically, the structure of the slot 15 enables the connecting ring 13 to be inserted into the second conductive rod 10 from the side where the insulating pull rod 9 is located, and enables the protrusion 16 to be embedded in each slot 15. The protrusion 16 is exposed relative to the connecting ring 13, and then welding is used to fill the gap between the protrusion 16 and the slot 15, and establish an electrical connection channel between the protrusion 16 and the surface of the connecting ring 13. In this way, multiple welds serving as the electrical connection channels can be formed on the side of the connecting ring 13. Compared with the crimping scheme, it is convenient to perform welding at the end of the connecting ring 13, which can effectively ensure the conductive cross-sectional area between the connecting ring 13 and the second conductive rod 10 and ensure the electrical connection performance of the connecting ring 13 and the second conductive rod 10. Therefore, the technical solution of using the slot 15 and the protrusion 16 in combination and further based on the welding connection is suitable for transmission lines with large current fluctuations, such as the crimping scheme is used for the feeder, and the slot 15 and protrusion 16 scheme is used for the branch line on the feeder.

[0085] Example 5:

[0086] This embodiment is further refined based on embodiment 3 or 4:

[0087] The flexible conductive structure 12 is a laminated structure formed by stacking multiple layers of copper sheets, and the laminated structure is coaxial with the second conductive rod 10;

[0088] Each copper sheet has a trumpet-shaped structure. The end with a smaller diameter is sleeved on the connecting ring 13 and welded to the connecting ring 13 , and the end with a larger diameter is welded to the shielding cover 4 .

[0089] The above provides a specific implementation method of the flexible conductive structure 12. Specifically, the copper sheet is also called copper foil. The trumpet-shaped structure is a cylindrical structure with a diameter at one end larger than the other end and a linear transition of the diameter at each position along the axial direction. In order to reduce the resistance of the flexible conductive structure 12 to the movement of the second conductive rod 10, it is preferably set so that the normal of the copper sheet is a curve with curvature, for example, the cross section is parallel to the axis of the copper sheet, and the cross section of the copper sheet on which the axis of the copper sheet is located is in the shape of a bridge arch; the stacked structure is coaxial with the second conductive rod 10 to address the following problems: for the vacuum tube 3, in order to form a vacuum boundary, a metal bellows needs to be provided between the vacuum tube 3 and the second conductive rod 10. In order to improve the power-off response speed of the vacuum tube 3, the drive The moving mechanism 8 preferably adopts a mechanism based on electromagnetic force to drive the movement of the moving contact in the vacuum tube 3. Under such an application, the lateral force applied by the flexible conductive structure 12 to the second conductive rod 10 is unevenly distributed in the circumferential direction of the second conductive rod 10. For the moving contact and the static contact, this may cause the contact quality between the two to deteriorate. For the metal bellows, it may cause uneven force in the circumferential direction, affecting the life of the metal bellows (mainly due to its role as a vacuum boundary). For the driving mechanism 8, it may cause uneven wear of its moving iron core and other components, affecting its reliability. The above coaxial solution can effectively optimize the uneven force in the circumferential direction of the second conductive rod 10, which is beneficial to ensuring the conductive performance of the contacts of the vacuum tube 3, the life of the metal bellows, and the reliability of the driving mechanism 8.

[0090] The laminated structure of the flexible conductive structure 12 is formed by using laminated copper foil, which has the characteristics of low friction during use and is not easy to form conductive debris during repeated deformation. However, in specific applications, it is necessary to consider the actual voltage of the line, the current carrying capacity requirements of the flexible conductive structure 12, and the operating frequency of the vacuum tube 3. When the voltage level is high, the current carrying capacity requirements are high, and the vacuum tube 3 may need to be opened and closed relatively frequently, in order to avoid corona discharge, premature cracking, etc., it is not appropriate to adopt the technical solution of forming a laminated structure using copper sheets.

[0091] Example 6:

[0092] This embodiment is further refined based on Embodiment 3 or 4, and Embodiment 5:

[0093] Based on the above, as an implementation method of the flexible conductive structure 12 that can avoid corona discharge, the flexible conductive structure 12 includes multiple flexible wires, and the flexible wires are evenly distributed in a ring relative to the axis of the connecting ring 13;

[0094] Each flexible wire has one end welded to the connecting ring 13 and the other end welded to the shielding cover 4 .

[0095] When the above scheme is used in practice, the multi-strand flexible conductor adopts a copper wire braid. In order to weaken the skin effect, the diameter of the copper wire is less than or equal to 0.3 mm, and the surface of the copper wire braid is smoothed. Compared with the use of copper sheets to form the laminated structure, the flexible conductive structure 12 using multi-strand flexible conductors is suitable for application scenarios with higher voltage levels, such as being used in series on a 10kV cable. The above axial ring is also used to solve the problem of the second conductive rod 10 being subjected to lateral force.

[0096] Example 7:

[0097] This embodiment relates to an intelligent fuse, comprising a fuse element 5, an energy transformer 6, a sampling transformer 7 and a controller 11, and further comprising a conductive structure as described in any of the above embodiments;

[0098] The melt 5 is connected in series to the conductive structure;

[0099] The energy transformer 6 is used to obtain electrical energy from the conductive structure and supply power to the drive mechanism 8 and the controller 11;

[0100] The sampling transformer 7 is used to collect the current value passing through the conductive structure and transmit the current value collection result to the controller 11;

[0101] The controller 11 is used to control the action of the drive mechanism 8 to adjust the position of the moving contact in the vacuum tube 3 through the insulating pull rod 9 and the second conductive rod 10. Specifically, the controller 11 receives a control instruction and the collection result of the current value. When the controller 11 receives a switching-off control instruction or determines that the current value exceeds a first set threshold, the controller 11 controls the drive mechanism 8 to output an action to separate the moving contact from the static contact; when the controller 11 receives a switching-on control instruction, the controller 11 controls the drive mechanism 8 to output an action to make the moving contact and the static contact contact.

[0102] As described above, in the structure disclosed by the conductive structure, the driving mechanism 8 acts on the vacuum tube 3 to realize the on-off control of the conductive structure. When assisted by the controller 11, the line opening and closing automatic control can be realized, adapting to the further development of smart grid technology. In order to further ensure the reliability of the line and avoid electrical faults affecting the controllability of the line, the above provides an intelligent fuse including the conductive structure. Specifically, the intelligent fuse is connected in series on the line when in use, and the fuse 5 is cut off by heating and melting when overcurrent occurs (if the vacuum tube 3 can be opened normally, since the response speed of the driving mechanism 8 to perform the opening action is significantly faster than the melting response speed of the fuse 5, under normal circumstances, the fuse only realizes the line opening control through the vacuum tube 3), realizing the opening of the line and the power supply side, as a supplement to the automatic cutting off of the conductive structure when the driving mechanism 8 fails. The energy transformer 6 (energy CT) is used to obtain electricity from the conductive structure. It can meet the energy consumption demand of the intelligent fuse. In order to reduce the energy power requirement of the energy transformer 6, the electric energy collected by the energy transformer 6 can be stored in a battery, and then the functional purpose is achieved through the battery. The sampling transformer 7 (using CT) is used to monitor the current value on the line. When it is determined to be overcurrent through the first set threshold, the controller 11 controls the driving mechanism 8 to realize the opening of the conductive structure. The control instruction transmission can be realized based on wireless communication, such as using a 4G communication module and a Bluetooth / LoRa module to realize the control instruction transmission. It is easy to understand that the 4G communication module can realize remote communication and complete the control center's opening and closing control of the fuse. The Bluetooth / LoRa module can realize local communication. For example, the operation and maintenance personnel can use handheld devices to realize opening and closing control according to local needs, based on the three-phase microgrid operation control strategy, to realize mutual communication between intelligent fuses on different phases, and realize multi-phase synchronous opening operation, etc.

[0103] Example 8:

[0104] This embodiment is further refined based on embodiment 7:

[0105] The fuse 5 is connected in series on the lead wire 14, the position where the energy transformer 6 obtains electric energy is located on the lead wire 14, and the position where the sampling transformer 7 collects the current value is located on the lead wire 14;

[0106] The melt 5 is a fuse and also includes a fuse tube. The melt 5 is located inside the fuse tube and also includes a temperature sensor 17 for collecting the temperature inside the fuse tube.

[0107] The controller 11 receives the temperature acquisition result from the temperature sensor 17 and determines the temperature rising speed inside the fuse tube. When the temperature rising speed exceeds a second set threshold, the controller 11 controls the driving mechanism 8 to output an action to separate the moving contact from the static contact.

[0108] The above scheme further clarifies the specific placement of the various functional components on the fuse. Specifically, it aims to achieve: a cylindrical insulating housing enclosing the strip structure formed by the vacuum tube 3, the second conductive rod 10, the insulating pull rod 9, and the drive mechanism 8. The fuse 5, the energy transformer 6, the sampling transformer 7, and the controller 11 are each positioned on the side of the insulating housing, and their respective positions relative to the insulating housing are adjustable (achieved by deforming the lead wires, the corresponding power supply lines, and the signal lines). This structural form effectively reduces the installation space requirements of the smart fuse. This scheme further includes a temperature sensor 17 for collecting the internal temperature of the fuse tube. Based on the controller 11, when the temperature rise rate inside the fuse tube exceeds a second set threshold, the drive mechanism 8 is activated to open the contacts in the vacuum tube 3. This allows: when a fault in the line causes a surge in current, the temperature rise rate is used as a trigger signal for the drive mechanism 8 to operate. This prevents the drive mechanism 8 from triggering the corresponding opening action when a fault in the sampling transformer 7 occurs, and achieves line opening before the fuse blows. At the same time, this solution uses the temperature inside the fuse tube as the pickup signal, and can take advantage of the relatively stable environment inside the fuse tube to ensure the reliability of triggering the tripping action based on the temperature signal.

[0109] Example 9:

[0110] This embodiment is further refined based on embodiment 7 or 8:

[0111] The second conductive rod 10 is arranged on the lower side of the vacuum tube 3, and also includes a first conductive rod 1 arranged on the upper side of the vacuum tube 3 and connected to the static contact in the vacuum tube 3. The first conductive rod 1 is connected in series with an isolating switch 2. The isolating switch 2 is equipped with a mechanical breaker that is manually opened and closed. The mechanical breaker is: when the mechanical breaker is disconnected, a visible breakpoint visible to the naked eye is formed on the isolating switch 2.

[0112] The above solution involves connecting a disconnector 2 with a mechanical break in series with the first conductive rod 1. This allows, for example, manual operation of the disconnector 2 during line maintenance to create a visible breakpoint, ensuring safe power outages. Furthermore, by integrating the disconnector 2, vacuum tube 3, and fuse 5 into the fuse, the above solution effectively reduces the number of circuit breakers 11 on the line, facilitating their installation and maintenance, and reducing their operating costs.

[0113] Example 10:

[0114] This embodiment is an improvement on the embodiment 9, and provides a method for controlling the opening and closing of a circuit breaker. The method is used to control the on-off of a circuit breaker, and is implemented based on the above-mentioned intelligent fuse.

[0115] When closing is required, first, the mechanical break of the disconnector 2 is manually closed to the closed state. Then, the controller 11 receives the closing state detection result of the mechanical break. When the detection result shows that the disconnector is in the closed state and after receiving the main body or remote closing control command, the controller 11 controls the drive mechanism 8 to output the action of making the moving contact and the static contact contact. After the vacuum tube 3 completes closing, the controller 11 performs closing protection based on the collected data. When it is determined based on the data that there is a fault in the subsequent stage of the line, the controller 11 controls the vacuum tube 3 to open through the drive mechanism 8. The data includes one or more of the following data: phase current, phase voltage, line voltage, zero-sequence current, zero-sequence voltage, phase angle, frequency, closing transient current, and closing inrush current characteristics.

[0116] When opening is required, first, after receiving the main body or remote opening control command, the controller 11 controls the drive mechanism 8 to output the action of separating the moving contact and the static contact, and then manually opens the mechanical break of the disconnector 2 to the opening state.

[0117] In the above method, when closing is required, the disconnector 2 is first adjusted to the closed state, and then the vacuum tube 3 is adjusted to the closed state through the driving mechanism 8. When opening is required, the vacuum tube 3 is first adjusted to the open state, and then the disconnector 2 is adjusted to the open state to form a visible break. The specific purpose is to avoid arcing at the mechanical break position, so that the arcing time on the entire line is significantly shortened (the arcing time may only exist for a few milliseconds in the vacuum tube 3), and to avoid damage to the disconnector 2 due to arcing, and damage to the transformer on the line due to overvoltage and high-frequency harmonics.

[0118] In the above scheme, during closing, after the disconnector 2 is closed, the controller 11 needs to collect the mechanical break closing state detection results and corresponding control instructions before executing the drive mechanism 8 action control, aiming to standardize the necessary order of closing the disconnector 2 first and closing the vacuum tube 3 later. It is further configured to include a closing protection action based on the controller 11 to realize the opening action of the vacuum tube 3 when it is determined that there is a fault in the downstream stage of the line. Based on existing signal detection methods, closing protection algorithms, and the response speed of the drive mechanism 8, the downstream fault isolation can be completed within 50ms, avoiding damage to the downstream equipment caused by closing the circuit breaker due to the failure of the downstream equipment not being eliminated. It is easy to understand that the phase current is associated with faults such as line short circuit and overload, the phase voltage / line voltage is associated with faults such as voltage loss and asymmetry, the zero-sequence current / zero-sequence voltage is associated with ground fault, and the phase angle / frequency is associated with synchronous fault. The closing transient current / closing inrush current characteristics are used to distinguish between real faults and normal inrush currents to avoid malfunction of the closing protection.

[0119] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific embodiments of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art to which the present invention belongs, other embodiments derived without departing from the technical solution of the present invention should be included in the scope of protection of the present invention.

Claims

1. A conductive structure comprising a vacuum tube (3), a lead wire (14) and a drive mechanism (8), wherein the vacuum tube (3) is provided with a second conductive rod (10) connected to its movable contact, and the second conductive rod (10) is connected to the drive mechanism (8) via an insulating pull rod (9), characterized in that: It also includes a flexible conductive structure (12) and a shielding cover (4) made of metal, the second conductive rod (10) and the lead wire (14) are connected in series via the flexible conductive structure (12), the flexible conductive structure (12) is located in a cavity structure surrounded by the shielding cover (4), the cavity structure has a boundary located directly below the flexible conductive structure (12), and a connecting structure is provided between the shielding cover (4) and the second conductive rod (10) to achieve electrical connection between the two; The vacuum tube (3), the driving mechanism (8), and the shielding cover (4) are all arranged in an insulating housing; The shielding cover (4) serves as a physical isolation barrier on the side and bottom sides of the flexible conductive structure (12); The second conductive rod (10) is coaxial with the insulating pull rod (9), and the connection structure is a flexible conductive structure (12): one end of the flexible conductive structure (12) is fixed to the second conductive rod (10), and the other end is fixed to the shielding cover (4); The shielding cover (4) is a spherical shell structure with a through hole provided on the bottom side and an opening on the top side, and the fitting relationship between the insulating pull rod (9) and the through hole is a clearance fit; It also includes a connecting ring (13), the connecting ring (13) is a silver ring or a copper ring, and the connecting ring (13) is sleeved on the second conductive rod (10); The connecting ring (13) is provided with a plurality of slots (15) arranged at intervals along the circumferential direction of the connecting ring (13), and each slot (15) is: the length direction of the slot (15) is along the axial direction of the connecting ring (13), the slot (15) passes through the side wall of the connecting ring (13), and the slot (15) is connected to the end of the connecting ring (13) away from the insulating pull rod (9); Each slot (15) is provided with a protrusion (16) located on the second conductive rod (10) and having a length direction along the axial direction of the connecting ring (13); the protrusion (16) is embedded in the slot (15); and each protrusion (16) is welded to the connecting ring (13) by silver-based welding; The flexible conductive structure (12), the connecting ring (13) and the shielding cover (4) are all connected by silver-based welding.

2. The conductive structure according to claim 1, wherein: The flexible conductive structure (12) is a laminated structure formed by stacking multiple layers of copper sheets, and the laminated structure is coaxial with the second conductive rod (10); Each copper sheet has a trumpet-shaped structure, and each copper sheet has: an end with a smaller diameter is sleeved on the connecting ring (13) and welded to the connecting ring (13), and an end with a larger diameter is welded to the shielding cover (4).

3. The conductive structure according to claim 1, wherein: The flexible conductive structure (12) comprises a plurality of flexible wires, and the flexible wires are evenly distributed in a ring relative to the axis of the connecting ring (13); Each flexible wire has one end welded to the connecting ring (13) and the other end welded to the shielding cover (4).

4. An intelligent fuse, comprising a fuse element (5), an energy transformer (6), a sampling transformer (7) and a controller (11), characterized in that: Also comprising the conductive structure according to any one of claims 1 to 3; The melt (5) is connected in series to the conductive structure; The energy-taking transformer (6) is used to obtain electrical energy from the conductive structure and to supply power to the driving mechanism (8) and the controller (11); The sampling transformer (7) is used to collect the current value passing through the conductive structure and transmit the current value collection result to the controller (11); The controller (11) is used to control the action of the drive mechanism (8) to adjust the position of the moving contact in the vacuum tube (3) through the insulating pull rod (9) and the second conductive rod. Specifically, the controller (11) receives a control instruction and a result of collecting the current value. When the controller (11) receives a switch-off control instruction or determines that the current value exceeds a first set threshold, the controller controls the drive mechanism (8) to output an action to separate the moving contact from the static contact; when the controller (11) receives a switch-on control instruction, the controller controls the drive mechanism (8) to output an action to bring the moving contact into contact with the static contact.

5. The intelligent fuse according to claim 4, characterized in that: The fuse (5) is connected in series to the lead wire (14), the position of the energy transformer (6) for acquiring electric energy is located on the lead wire (14), and the position of the sampling transformer (7) for collecting current value is located on the lead wire (14); The melt (5) is a fuse and further includes a fuse tube. The melt (5) is located inside the fuse tube and further includes a temperature sensor (17) for collecting the temperature inside the fuse tube. The controller (11) receives the temperature acquisition result of the temperature sensor (17) and determines the temperature rise rate inside the fuse tube. When the temperature rise rate exceeds a second set threshold, the controller (11) controls the driving mechanism (8) to output an action to separate the moving contact from the static contact.

6. The intelligent fuse according to claim 4 or 5, characterized in that: The second conductive rod (10) is arranged on the lower side of the vacuum tube (3), and further comprises a first conductive rod (1) arranged on the upper side of the vacuum tube (3) and connected to the static contact in the vacuum tube (3); an isolating switch (2) is connected in series to the first conductive rod (1); the isolating switch (2) is provided with a mechanical break for manually opening and closing the switch; the mechanical break is such that when the mechanical break is disconnected, a visible breakpoint visible to the naked eye is formed on the isolating switch (2).

7. A method for controlling the opening and closing of a circuit breaker, wherein: The method is implemented based on the smart fuse described in claim 6; Wherein, when closing is required, first, the mechanical break of the disconnector (2) is manually closed to the closed state, and then the controller (11) receives the closing state detection result of the mechanical break, and when the detection result is in the closed state and after receiving the main body or remote closing control instruction, the control driving mechanism (8) outputs the action of making the moving contact and the static contact contact; after the vacuum tube (3) completes closing, the controller (11) performs closing protection based on the collected data: when it is determined based on the data that there is a fault in the rear stage of the line, the controller (11) controls the vacuum tube (3) through the driving mechanism (8) to open the circuit, and the data includes one or more of the following data: phase current, phase voltage, line voltage, zero sequence current, zero sequence voltage, phase angle, frequency, closing transient current, and closing inrush current characteristics; When opening is required, first, after receiving the main body or remote opening control command, the controller (11) controls the driving mechanism (8) to output the action of separating the moving contact and the static contact, and then manually opens the mechanical break of the disconnector (2) to the opening state.

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