Flexible direct current capacitor with non-metal shell for power grid

Abstract

The invention discloses a non-metal shell flexible direct current capacitor for a power grid, and relates to the technical field of capacitors, the non-metal shell flexible direct current capacitor comprises a shell and a core assembly installed in the shell, the shell comprises a top plate, a bottom plate and a plurality of vertically arranged side plates, every two adjacent side plates are vertically connected, a reinforcing rib in the horizontal direction is arranged between every two adjacent side plates, and the core assembly is installed in the shell. The shell is made of a polyether-ether-ketone carbon fiber composite material; the invention relates to a flexible metal capacitor, and aims to solve the problems that a metal shell is difficult to transport and install during installation due to heavy weight of the metal shell, and the installation service life is short due to the fact that a supporting piece bears large gravity especially during high-position installation of the flexible metal capacitor.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitors, and in particular to a non-metallic shell flexible capacitor for a power grid. Background Art

[0002] Flexible direct current transmission is an important equipment for building smart grids. Compared with traditional methods, flexible direct current transmission has strong technical advantages in island power supply, capacity expansion and transformation of urban distribution networks, AC system interconnection, and large-scale wind farm grid connection. It is a strategic choice to change the development pattern of large power grids.

[0003] The flexible DC capacitors used in existing power grids have large currents and voltages, resulting in a large number of internal cores, which increases the size of the flexible DC capacitors. In order to load and protect these cores, a larger casing is required. Existing casings mostly use metal casings to consider issues such as sealing, heat dissipation and durability. Combined with the large number of cores, the existing flexible DC capacitors are heavy overall, making transportation and installation difficult, especially when installed at high places and hung at high places for a long time, which places high demands on the quality of the supporting parts.

[0004] In addition, existing flexible capacitors generally use metal casings (such as aluminum alloy and stainless steel), which have the following fatal defects: Heavy weight: The metal casing accounts for 20%-30% of the total weight of the capacitor, increasing transportation and installation costs (for example, the difficulty of hoisting an offshore wind power platform); Corrosion-prone: In coastal, humid, or high-salt fog environments, the metal casing is prone to rust, resulting in reduced casing strength and internal components becoming damp (such as deterioration of the core insulation performance); Electromagnetic interference: Metal casings can reflect or shield electromagnetic waves, potentially affecting the normal operation of surrounding communication devices or sensors. High processing cost: Metal housings with complex shapes need to be manufactured through casting, machining and other processes, which takes a long time and is costly; Insulation relies on additional processing: The metal casing itself is conductive, so an insulating layer (such as an epoxy board) needs to be added between the casing and the internal components, which increases the structural complexity. Summary of the Invention

[0005] This invention provides a non-metallic-cased flexible DC capacitor for power grids, addressing the challenges of transporting and securing the heavy metal casing during installation. Flexible DC capacitors for power grids are typically installed at high altitudes, where their supporting components bear significant gravity, which can reduce the overall lifespan of the capacitor.

[0006] To achieve the above object, the present invention provides the following solutions: A non-metallic shell flexible capacitor for power grids includes a shell and a core assembly installed in the shell. The shell includes a top plate, a bottom plate and several vertically arranged side plates. Adjacent side plates are vertically connected, and horizontal reinforcing ribs are provided between adjacent side plates. The shell is made of polyetheretherketone carbon fiber composite material.

[0007] The present invention strengthens the strength of the housing by vertically connecting two adjacent side panels and providing reinforcing ribs. This reduces the thickness of a single side panel, thereby reducing the weight of the entire housing. The housing is made of polyetheretherketone carbon fiber composite material, which is lightweight and high in strength. This solves the problem of heavy metal housings, thereby reducing the overall weight of the capacitor and the difficulty of installation. When installed at a high location, it also reduces the bearing capacity of the support member. The density of polyetheretherketone carbon fiber composite material is only 1 / 4 to 1 / 5 of that of metal shell, which can reduce the overall weight of the capacitor by more than 40%, reduce the load-bearing requirements of the power grid tower, increase the tensile strength by 100% (room temperature) to 300% (150℃), and the heat deformation temperature is greater than 300℃, which meets the high temperature working conditions of the flexible direct current system. The volume resistivity is >10 16 Ω·cm, acid and alkali resistance is better than metal, avoiding shell degradation caused by electrolytic corrosion.

[0008] Furthermore, the core assembly includes a busbar, a plurality of busbars connected to the busbar, and a capacitor core installed on the busbar. A plurality of limiting plates are provided on the outside of the busbar, and the limiting plates are installed on the reinforcing ribs.

[0009] Due to the structural characteristics of the vertical connection between the two adjacent side panels and the provision of reinforcing ribs, by arranging a limit plate on the outside of the busbar and installing the limit plate on the reinforcing ribs, it not only combines the characteristics of the device shell, making the device structure more compact and reasonable, but also enhances the bearing capacity of the busbar and improves the impact resistance of the device.

[0010] Furthermore, the capacitor core includes large cores and small cores for filling gaps between the large cores.

[0011] By filling the gaps between large cores with small cores, the space utilization rate within the shell is improved. The staggered arrangement between the large and small cores makes the gaps between the cores more uniform, forming a honeycomb structure, reducing ineffective space, and reducing the volume by 15% at the same capacity. The staggered arrangement increases the airflow channel between the cores (increasing the longitudinal gap by 50%). Combined with the thermally conductive insulating coating of the non-metallic shell (boron nitride coating, with a thermal conductivity increased by 30 times), the core temperature rise is reduced by 13°C, extending the lifespan by 5 to 8 years. Moreover, at the same capacitor capacity, the improved space utilization rate means that the overall volume of the capacitor will be reduced, and the shell and internal connectors will also be reduced accordingly, thereby reducing the overall weight of the capacitor.

[0012] Furthermore, the busbar includes a connecting section connected to the capacitor core and a vibration-damping section connecting two adjacent connecting sections, and the vibration-damping section is configured as a corrugated structure.

[0013] The corrugated structure of the vibration-damping section can give the busbar a certain degree of elasticity, provide a certain displacement compensation for the capacitor core, and solve the stress concentration problem of traditional rigid copper busbars.

[0014] Furthermore, a honeycomb hollow area is provided on the vibration-damping section.

[0015] By setting the vibration-damping section into a honeycomb hollow structure, not only the weight of the busbar can be reduced, but also the charge along the longitudinal end can be dispersed.

[0016] Furthermore, the limiting plate is arranged on the vibration reduction section.

[0017] The vibration reduction section is divided into two sections, upper and lower, by the limiting plate. The upper vibration reduction section is used to bear the capacitor core installed on the upper connecting section, and the impact force borne by the upper capacitor core is buffered by the upper vibration reduction section, and the remaining impact force is released to the reinforcing ribs and the shell through the limiting plate; the lower vibration reduction section is used to pull the capacitor core installed on the lower connecting section, and the impact force borne by the lower capacitor core is pulled and buffered by the lower vibration reduction section, and the remaining impact force is also released to the reinforcing ribs and the shell through the limiting plate, thereby enhancing the overall impact resistance of the capacitor core.

[0018] Furthermore, the top plate, bottom plate and side plates, as well as the side plates are connected to each other in a detachable manner.

[0019] Through modular settings, the number of side plates can be increased or decreased according to actual needs, thereby achieving flexible adjustment of the capacitor capacity and improving the applicability of the capacitor.

[0020] Furthermore, a sealing structure is provided at the connection of the detachable connection, and a riveting seal is adopted. A riveting unit and a sealing element are provided at the module connection. The riveting unit is responsible for fixing two or more components together, while the sealing element is used to prevent leakage at the connection. During the riveting process, the rivet is deformed by applying pressure, thereby firmly fixing the connected parts together. At the same time, the sealing element is compressed or extruded to fill the gap at the connection to achieve a sealing effect. Through the design of sealing fluid or elastic sealing ring, the riveting sealing structure can provide a reliable sealing effect while connecting. The riveting process can provide higher connection strength than traditional bolt connections. Since the riveting sealing structure can complete connection and sealing in one operation, the module splicing and assembly process is greatly simplified, and the installation efficiency is improved.

[0021] Furthermore, a transverse groove is provided on the inner side wall of the side plate, and the reinforcing rib is embedded in the groove for installation.

[0022] By embedding the reinforcing ribs transversely into the grooves, the bearing capacity of the reinforcing ribs is enhanced, and the installed reinforcing ribs can also better connect the two adjacent side panels, thereby enhancing the connection strength of the side panels.

[0023] Furthermore, an insulating elastic member is provided on the upper surface of the reinforcing rib.

[0024] The insulating elastic member isolates the housing and busbar, and further provides buffering force for the capacitor core, reducing the impact force it bears and increasing the service life of the device; the insulating elastic member used as an insulator should have a volume insulation resistance of 1x10 13 Ω·cm; Under normal circumstances, the larger the volume resistance, the larger the surface resistance. The breakdown voltage per unit thickness of the insulating elastic part is an indispensable technical parameter for measuring the electrical insulation performance of insulating rubber products. When the rubber formula and process design are reasonable and the breakdown voltage test is in compliance with the specifications, the breakdown voltage shall not be less than 15KV / mm (AC) and 25KV / mm (DC), ensuring the safety and reliability of the insulating rubber products during normal use.

[0025] Furthermore, an electric field shielding layer is provided on the inner wall of the shell, and a heat-conducting insulating coating is provided on the outer wall.

[0026] The electric field shielding layer can reduce the mutual influence of the electric field inside and outside the capacitor. It is usually deposited by magnetron sputtering to form a 50-100nm aluminum oxide film with a surface resistivity controlled at 10 6 -10 8 Ω range, suppressing high voltage electric field distortion, the electric field shielding layer has strong insulation performance, can effectively prevent charge leakage and short circuit, ensure the normal operation and safe use of the capacitor, and extend the service life of the capacitor; Thermally conductive insulating coatings reduce the risk of capacitor leakage, while also enhancing internal heat conduction, improving the lateral heat dissipation efficiency of the shell, reducing the temperature inside the capacitor, and preventing the internal temperature of the capacitor from being too high, which affects the operation and service life of the capacitor. It must simultaneously meet key performance requirements such as thermal conductivity, insulation, and high temperature resistance to adapt to the heat dissipation and safety requirements of electronic equipment, industrial machinery, and other scenarios. Thermally conductive insulating coatings can effectively isolate electronic devices from the external environment, avoid electrical short circuits and leakage, and ensure the long-term stable operation of electronic components.

[0027] One or more technical solutions provided by the present invention have at least the following technical effects or advantages: (1) The present invention strengthens the strength of the shell by vertically connecting two adjacent side plates and providing reinforcing ribs, thereby reducing the thickness of a single side plate and thus reducing the weight of the entire shell. The shell is made of polyetheretherketone carbon fiber composite material, which is light in weight and high in strength, solving the problem of heavy metal shells, thereby reducing the overall weight of the capacitor and the difficulty of installation. When installed at a high place, it also reduces the bearing capacity of the support member; (2) By setting a limit plate on the outside of the busbar and placing the limit plate on the reinforcement rib for installation, not only the characteristics of the device shell are combined to make the device structure more compact and reasonable, but also the bearing capacity of the busbar is enhanced and the impact resistance of the device is improved; through modular settings, the number of side plates can be increased or decreased according to actual needs, thereby realizing flexible adjustment of the capacitor capacity and improving the application range of the capacitor; (3) By filling the gaps between large cores with small cores, the space utilization rate inside the shell is improved. The large cores and small cores are staggered to make the gaps between the cores more uniform, forming a honeycomb structure, reducing the ineffective space, and reducing the volume by 15% at the same capacity. The staggered arrangement increases the airflow channel between the cores (the longitudinal gap is increased by 50%). Combined with the thermal conductive insulating coating of the non-metallic shell (boron nitride coating, the thermal conductivity is increased by 30 times), the core temperature rise is reduced by 13°C, and the service life is extended by 5 to 8 years. Moreover, at the same capacitor capacity, the improved space utilization rate means that the overall volume of the capacitor will be reduced, and the shell and internal connectors will also be reduced accordingly, thereby reducing the overall weight of the capacitor. (4) The vibration reduction section is divided into two sections, the upper and lower sections, by the limiting plate. The upper vibration reduction section is used to bear the capacitor core installed on the upper connecting section, and the impact force borne by the upper capacitor core is buffered by the upper vibration reduction section, and the remaining impact force is released to the reinforcing ribs and the shell through the limiting plate; while the lower vibration reduction section is used to pull the capacitor core installed on the lower connecting section, and the impact force borne by the lower capacitor core is pulled and buffered by the lower vibration reduction section, and the remaining impact force is also released to the reinforcing ribs and the shell through the limiting plate, thereby enhancing the overall impact resistance of the capacitor core; (5) The shell and busbar are isolated by insulating elastic parts, which further provide buffering force for the capacitor core, reduce the impact force it bears, and increase the service life of the device; the volume insulation resistance of the insulating elastic parts used as insulators should be 1x10 13Ω·cm; Under normal circumstances, the larger the volume resistance, the larger the surface resistance. The breakdown voltage per unit thickness of the insulating elastic part is an indispensable technical parameter for measuring the electrical insulation performance of insulating rubber products. When the rubber formula and process design are reasonable and the breakdown voltage test is in compliance with the specifications, the breakdown voltage should not be lower than 15KV / mm (AC) and 25KV / mm (DC), ensuring the safety and reliability of the insulating rubber products during normal use. (6) The electric field shielding layer can reduce the mutual influence of the electric field inside and outside the capacitor. It is usually deposited by magnetron sputtering to form a 50-100nm aluminum oxide film with a surface resistivity controlled at 10 6 -10 8 The electric field shielding layer has strong insulation performance, which can effectively prevent charge leakage and short circuit, ensure the normal operation and safe use of the capacitor, and extend the service life of the capacitor; the thermal conductive insulation coating reduces the risk of capacitor leakage, while also enhancing internal heat conduction, improving the lateral heat dissipation efficiency of the shell, reducing the temperature inside the capacitor, and preventing the internal temperature of the capacitor from being too high and affecting the operation and service life of the capacitor. It is necessary to meet key performance requirements such as thermal conductivity, insulation, and high temperature resistance to meet the heat dissipation and safety requirements of electronic equipment, industrial machinery and other scenarios. The thermal conductive insulation coating can effectively isolate electronic devices from the external environment, avoid electrical short circuits and leakage, and ensure the long-term stable operation of electronic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of the present invention, and do not constitute a limitation of the embodiments of the present invention; Figure 1 This is a cross-sectional view of the non-metallic shell flexible capacitor of the present invention; Figure 2 This is a schematic diagram of the arrangement of capacitor cores in the present invention; Figure 3 It is a schematic diagram of the busbar structure in the present invention; Among them, 1-side plate, 2-reinforcement rib, 3-busbar, 301-connecting section, 302-vibration reduction section, 4-capacitor core, 401-large core, 402-small core, 5-limiting plate. DETAILED DESCRIPTION

[0029] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features therein can be combined with each other without conflict.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0031] Example 1

[0032] This embodiment provides a non-metallic shell flexible capacitor for power grid, such as Figure 1-Figure 3 As shown, it includes a shell and a core assembly installed in the shell, the shell includes a top plate, a bottom plate and several vertically arranged side plates 1, the adjacent two side plates 1 are vertically connected, and horizontal reinforcing ribs 2 are provided between the adjacent two side plates 1. The shell is made of polyetheretherketone carbon fiber composite material.

[0033] Among them, a single side panel 1 is a plate with a rectangular structure as a whole, and its height is higher than its length and width. It is placed vertically during installation. During installation, the heights of two adjacent side panels 1 fit together to form a right-angle structure when viewed from above, and reinforcing ribs 2 are provided inside the right angle. This structure greatly enhances the load in the vertical direction, and when the load reaches the requirement, the thickness of the side panel 1 can be greatly reduced, thereby reducing the overall weight of the shell. The number of reinforcing ribs 2 is arbitrary, and two reinforcing ribs 2 are preferably provided inside the right angle formed by each two adjacent side panels 1, respectively located at On the upper and lower sides of the side panel 1, and the number of reinforcing ribs 2 increases with the length of the side panel 1; the polyetheretherketone carbon fiber composite material preferably adopts a 30% carbon fiber reinforced PEEK matrix, which has the comprehensive advantages of high strength, high modulus, high temperature resistance, corrosion resistance, etc., and the density is only 1 / 4~1 / 5 of the metal shell, which can achieve an overall weight reduction of more than 40% of the capacitor, reduce the load-bearing requirements of the power grid tower, increase the tensile strength by 100% (room temperature) to 300% (150℃), and the heat deformation temperature is greater than 300℃, which meets the high temperature working conditions of the flexible direct current system, and the volume resistivity is>10 16 Ω·cm, acid and alkali resistance is better than metal, avoiding shell degradation caused by electrolytic corrosion.

[0034] In a more preferred embodiment, the core assembly includes a busbar, several busbars 3 connected to the busbar and a capacitor core 4 installed on the busbar 3, and several limiting plates 5 are provided on the outside of the busbar 3, and the limiting plates 5 are installed on the reinforcing ribs 2.

[0035] Among them, the busbar 3 is installed vertically and is installed on one side of the reinforcement rib 2 inside the shell, so that the limiting plate 5 corresponds to the reinforcement rib 2. Two busbars are set at the top of the shell, respectively connected to the positive terminal and the negative terminal installed on the top of the shell. The number of limiting plates 5 is set according to actual conditions, preferably one-to-one corresponding to the reinforcement rib 2 located on the inside of the shell, and an insulating coating is provided on the outer surface of the limiting plate 5.

[0036] The capacitor core 4 includes a first electrode and a second electrode stacked together. The first electrode comprises a first electrode layer and a first base layer, and the second electrode comprises a second electrode layer and a second base layer. In the capacitor core 4, the first and second electrode layers serve as the two capacitor plates. The first base layer, to which the first electrode layer is attached, is sandwiched between the first and second electrode layers, serving as a dielectric material between the capacitor plates. The second base layer, to which the second electrode layer is attached, prevents contact between the first and second electrodes during winding, which could cause a short circuit in the capacitor.

[0037] Before winding the capacitor core 4, only the first and second electrodes need to be stacked, eliminating the need for repeated stacking of conductive electrodes and insulating film materials. Tight connections between the first electrode layer and the first base layer, and between the second electrode layer and the second base layer, further ensure that the film electrodes within the capacitor core 4 do not misalign during the winding process, improving the electrical performance and operational stability of the non-metallic-cased flexible capacitor for power grids.

[0038] Among them, the first electrode layer and / or the second electrode layer can be any metal electrode layer that can form an electrode, such as titanium, aluminum, zinc, etc., or any non-metallic electrode layer that can form an electrode, such as carbon nanotubes, conductive polymers, etc. The specific material of the first electrode layer and / or the second electrode layer is determined according to actual needs, and this embodiment does not make specific restrictions here; the first base layer and / or the second base layer can be a polypropylene film, a polyester film or a polyimide film, and the first base layer and / or the second base layer are preferably high-insulation polypropylene films, which have a dielectric strength of 800V / μm, a dielectric loss of approximately 0.02%, and a temperature resistance of 125°C. Preferably, the thickness of the first base layer and / or the second base layer is 3.4 to 10μm, and the length and width of the first base layer and / or the second base layer are determined according to the actual size requirements of the non-metallic shell flexible capacitor, and this embodiment does not make specific restrictions here.

[0039] In a more preferred embodiment, the top and bottom panels and the side panels 1 , and the side panels 1 and the side panels 1 are all connected in a detachable manner.

[0040] Among them, the detachable connection preferably adopts a mortise and tenon structure, that is, two adjacent side panels 1, one of which is provided with a groove, and the other is provided with a protrusion, and the protrusion is embedded in the groove to form a connection, and the top panel and the bottom panel have installation grooves at the edges extending towards the upper and lower ends of the side panel 1, and the upper end of the side panel 1 is embedded in the top panel, and the lower end is embedded in the bottom panel to form a closed box structure. Other detachable connection methods can also be used, and this application will not go into details. During installation, according to the overall size of the internal core assembly, select an appropriate number of side panels 1 for splicing, select the top panel and bottom panel of the corresponding size, install the bottom panel in turn, put the spliced ​​side panels 1 into the core assembly, and then cover the top panel.

[0041] Alternatively, the shell can be set as a modular structure; the side panels 1 are modular, and since the spliced ​​side panels 1 are continuously spliced ​​together with similar structures, the smallest unit can be selected as a module, that is, an L-shaped structure, which is spliced ​​by two side panels 1, and a reinforcing rib 2 is embedded on the inner side of the angle. At this time, the reinforcing rib 2 can be fixedly connected, such as by welding; the top panel is modular, and can be a plurality of cube blocks or rectangular blocks that can be connected with mortise and tenon joints. The top panel module includes a top panel middle block with no groove at the lower end and a top panel with an L-shaped groove The plate edge blocks are selected according to the circumference of the side panels, and the corresponding number of top plate edge blocks and top plate middle blocks are spliced ​​into the top panel, and the top panel is fixed with welding, clamps and other fasteners; the bottom panel is modular, and can be a plurality of cube blocks or rectangular blocks that can be connected with mortise and tenon joints. The bottom panel module includes a bottom panel middle block without a groove at the lower end and a bottom panel edge block with an L-shaped groove. According to the circumference of the side panels, the corresponding number of bottom panel edge blocks and bottom panel middle blocks are selected, and the bottom panel is spliced ​​into the bottom panel, and the bottom panel is fixed with welding, clamps and other fasteners.

[0042] In addition, in order to enhance the sealing of the modular rear housing, a sealing structure needs to be provided. If the capacity of the capacitor will not be changed after it is spliced ​​and installed, it is preferred to seal the splicing gaps by welding after the top plate, bottom plate and side plates are spliced ​​together. This will provide a good sealing effect and make the housing stronger. If the capacity of the capacitor will need to be changed after it is spliced ​​and installed, it is preferred to provide a sealing layer, such as a silicone layer or rubber layer, in the mortise and tenon groove of the module splicing. For example, using riveting sealing, a riveting unit and a sealing element are set at the module connection. The riveting unit is responsible for fixing two or more components together, while the sealing element is used to prevent leakage at the connection. During the riveting process, the rivet is deformed by applying pressure, thereby firmly fixing the connected parts together. At the same time, the sealing element is compressed or extruded to fill the gap at the connection to achieve a sealing effect. Through the design of sealing fluid or elastic sealing ring, the riveting sealing structure can provide a reliable sealing effect while connecting. The riveting process can provide higher connection strength than traditional bolt connections. Since the riveting sealing structure can complete connection and sealing in one operation, it greatly simplifies the module splicing and assembly process and improves installation efficiency.

[0043] In a more preferred embodiment, a transverse groove is provided on the inner side wall of the side panel 1, and the reinforcing rib 2 is embedded in the groove for installation.

[0044] Since the two adjacent side panels 1 are connected in a detachable manner, the reinforcing ribs 2 cannot be cast and manufactured in advance, so they are also installed in a detachable manner. After the two adjacent side panels 1 are installed, the grooves on the two side panels 1 correspond one to one, and the reinforcing ribs 2 are embedded in the grooves. The length of the grooves is equal to the length of the side panels 1, which is convenient for embedding the reinforcing ribs 2. The width of the grooves is equal to the thickness of the reinforcing ribs 2, so that the embedded reinforcing ribs 2 are stuck. Preferably, the reinforcing ribs 2 can be fixed by welding after installation to enhance the sealing and strength of the side panels.

[0045] In a more preferred embodiment, an insulating elastic member is provided on the upper surface of the reinforcing rib 2 .

[0046] Since the reinforcing rib 2 is in contact with the side plate 1 and the limiting plate 5, and the limiting plate 5 is connected to the busbar 3, the capacitor core 4 is directly connected to the shell and needs to be isolated. Since the capacitor core 4 is easily damaged by external vibration, it is necessary to reduce the impact force it receives. Therefore, an insulating and elastic material is required, preferably an insulating rubber pad. The insulating rubber pad used as an insulator should have a volume insulation resistance of 1x10 13 Ω·cm; In the case where the electrical insulation environment requirements are not very high, its volume insulation resistance is not less than 1x10 10 Ω·cm. Under normal circumstances, the larger the volume resistance, the larger the surface resistance. The breakdown voltage per unit thickness of the rubber insulator is an indispensable technical parameter for measuring the electrical insulation performance of insulating rubber products. When the rubber formula and process design are reasonable and the breakdown voltage test is in compliance with the specifications, the breakdown voltage shall not be less than 15KV / mm (AC) and 25KV / mm (DC), ensuring the safety and reliability of insulating rubber products during normal use.

[0047] In a more preferred embodiment, an electric field shielding layer is provided on the inner wall of the shell, and a heat-conducting insulating coating is provided on the outer wall.

[0048] The electric field shielding layer is formed by embedding a nano-aluminum oxide coating on the inner wall of the side plate 1. Generally, a 50-100 nm aluminum oxide film is deposited by magnetron sputtering, and the surface resistivity is controlled at 10 6 -10 8 Ω range, suppressing high-voltage electric field distortion; composite materials can also be used, such as polyphenylene sulfide (PPS), which is a high-performance material and is widely used in capacitor housings. Capacitors are devices that store charge and release energy, and their housings play an important role in protecting the internal components of the capacitor. PPS material has excellent comprehensive properties, making it an ideal material for capacitor housings; PPS material has high reliability and heat resistance. Capacitors, as an important component of electronic devices, need to withstand long-term operation and harsh environmental conditions. PPS material has high heat resistance and chemical stability, and can work stably for a long time under harsh conditions such as high temperature and high humidity. It is not easily corroded and damaged, and can ensure the long-term reliability and stability of capacitors; PPS material has excellent flame retardant properties As a key component in electronic equipment, the safety of capacitors is of vital importance. PPS material has self-extinguishing properties at high temperatures, which can effectively suppress the spread of flames and prevent combustion, thereby improving the safety performance of capacitors; PPS material has good electrical insulation properties. There is usually a high electric field strength inside the capacitor, so its shell needs to have good insulation properties to prevent charge leakage and short circuit phenomena, ensuring the normal operation and safe use of the capacitor; PPS material also has good mechanical properties and corrosion resistance. Modified PPS material has excellent mechanical strength and rigidity, which can effectively resist the effects of external forces and maintain the stability of the capacitor. At the same time, PPS material also has good corrosion resistance, can resist the erosion of chemicals such as acids and alkalis, and extend the service life of the capacitor.

[0049] The thermally conductive insulating coating must simultaneously meet key properties such as thermal conductivity, insulation, and high temperature resistance to meet the heat dissipation and safety requirements of electronic equipment, industrial machinery, and other scenarios. Preferably, a boron nitride thermally conductive insulating coating is sprayed on the outer wall of the side panel 1. Its thermal conductivity is about 30-40W / (m·K), which is more than 3 times that of aluminum and more than 2 times that of copper. This characteristic makes boron nitride thermally conductive insulating sheet have important application value in the heat dissipation design of high-power electronic devices; its high insulation strength and high insulation resistance can effectively isolate electronic devices from the external environment, avoiding problems such as electrical short circuits and leakage. Boron nitride is also a high-temperature stable material with a melting point of over 3000°C, and can work stably for a long time in high-temperature environments. Therefore, boron nitride thermal conductive insulating coating can maintain its thermal conductivity and insulation properties under high-temperature conditions. At the same time, boron nitride thermal conductive insulating coating has good corrosion resistance and can resist the erosion of chemicals such as acids, alkalis, and solvents, ensuring the long-term stable operation of electronic components. It also has a low density of approximately 2.3g / cm³, which is lighter than aluminum. It can reduce the weight of electronic equipment and improve the portability and reliability of the equipment.

[0050] In a more preferred embodiment, the capacitor core 4 includes a large core 401 and a small core 402 for filling the gaps between the large cores 401. The large core 401 is formed by winding a stacked third electrode and a fourth electrode; the small core 402 is formed by winding a stacked fifth electrode and a sixth electrode. The third, fourth, fifth, and sixth electrodes include electrode layers and base layers made of the same material.

[0051] The large core 401 and the small core 402 are arranged in a staggered topology structure. For example, the size of the large core 401 is φ120mm×300mm, and the size of the small core 402 is φ80mm×300mm. The large core 401 is arranged in a 4×4 matrix, and adjacent rows / columns are offset by 60mm (1 / 2 of the radius of the large core) to form a honeycomb hexagonal cavity. The edge gaps are filled with the small core 402, eliminating the traditional neatly arranged rectangular dead corners. The space utilization rate reaches 92%, which is more than 7% higher than the traditional matrix arrangement, thereby reducing the volume of the non-metallic shell flexible capacitor for the power grid after installation.

[0052] Example 2

[0053] On the basis of Example 1, Figure 1-Figure 3 As shown, the busbar 3 includes a connecting section 301 connected to the capacitor core 4 and a vibration-damping section 302 connecting two adjacent connecting sections 301 , and the vibration-damping section 302 is configured as a corrugated structure.

[0054] Among them, the connecting sections 301 correspond to the number and position of the capacitor cores 4 one by one, and the length of the vibration-damping section 302 is determined by the distance between the two adjacent capacitor cores 4 above and below. A vibration-damping section 302 is preferably provided at the lower end of the busbar 3 and connected to the bottom plate of the shell. An insulating gasket is provided at the connection point. The length of the connecting section 301 is slightly larger than the diameter of the installed capacitor core 4, and the remaining parts are all provided with vibration-damping sections 302. Therefore, the busbar 3 with a large core 401 installed has a longer connecting section 301, and correspondingly, the length of the vibration-damping section 302 is shorter, while the busbar 3 with a small core 402 installed has a shorter connecting section 301, and correspondingly, the length of the vibration-damping section 302 is longer.

[0055] In a more preferred embodiment, a honeycomb hollow area is provided on the vibration-damping section 302 .

[0056] The honeycomb hollow area is preferably a plurality of regular hexagonal holes, which can be evenly distributed on the vibration-damping section 302 or only provided on one side or both sides of the vibration-damping section 302. Without affecting the strength of the vibration-damping section 302, it can effectively improve its elasticity and reduce its weight.

[0057] In a more preferred embodiment, the limit plate 5 is disposed on the vibration-damping section 302. Preferably, the limit plate 5 is disposed in the middle of the vibration-damping section 302, i.e., the vibration-damping sections 302 on the upper and lower sides of the limit plate 5 are of equal length, which can provide the same elastic force to the two capacitor cores 4 above and below the limit plate 5, thereby preventing uneven force on the upper and lower sides of the limit plate 5. The limit plate divides the vibration-damping section into two sections, the upper vibration-damping section being used to support the capacitor core installed on the upper connecting section, and cushioning the impact force borne by the upper capacitor core through the upper vibration-damping section, and then releasing the remaining impact force to the reinforcing rib and the housing through the limit plate; while the lower vibration-damping section being used to pull the capacitor core installed on the lower connecting section, and cushioning the impact force borne by the lower capacitor core through the lower vibration-damping section, and similarly releasing the remaining impact force to the reinforcing rib and the housing through the limit plate, thereby enhancing the overall impact resistance of the capacitor core.

[0058] Example 3

[0059] Based on any of the above embodiments, the following installation steps are included: S1. Confirm the overall size of the capacitor and select a base plate of corresponding size; S2. Splice all side panels 1 in pairs to form an L-shaped structure and install reinforcement ribs 2; S3, installing the L-shaped structure on the bottom plate to form an enclosing structure, and installing reinforcing ribs 2 between two adjacent L-shaped structures; S4. Install the core assembly into the shell, select a top plate of corresponding size, cover the top plate, and complete the corresponding electrical connections.

[0060] In a more preferred embodiment, the base plate selected in step S1 can be a whole cast according to the overall size of the capacitor, or it can be a structure spliced ​​together by modules, which is a base plate module, which can be a plurality of cube blocks or rectangular blocks that can be connected by mortise and tenon joints. The base plate module includes a base plate middle block without a groove at the lower end and a base plate edge block with an L-shaped groove. According to the circumference of the side panel, a corresponding number of base plate edge blocks and base plate middle blocks are selected and spliced ​​into a base plate, and the base plate is fixed using welding, clamps and other fasteners.

[0061] In a more preferred embodiment, the core assembly in step S4 is installed as follows: two busbars 3 are selected and placed in a manner such that the connecting section 301 corresponds to the connecting section 301 and the vibration-damping section 302 corresponds to the vibration-damping section 302; the two ends of the large core 401 are respectively welded to the connecting sections 301 corresponding to the two busbars 3 to form a large core module; two other busbars 3 are also selected and the small core 402 is also welded to the connecting sections 301 corresponding to the two busbars 3 to form a small core module; the large core module is then placed into the shell, the limiting plate 5 is placed on the reinforcement rib 2, the small core module is placed next to the large core module, and the limiting plate 5 is also placed on the reinforcement rib 2; the large core module and the small core module are then placed in sequence until the shell is full; and the large core module and the small core module are then connected to the bus.

[0062] In a more preferred embodiment, the top plate selected in step S4 can be a whole cast according to the overall size of the capacitor, or it can be a structure spliced ​​together by modules, which is a top plate module, which can be a plurality of cube blocks or rectangular blocks that can be connected by mortise and tenon joints. The top plate module includes a top plate middle block without a groove at the lower end and a top plate edge block with an L-shaped groove. According to the circumference of the side panel, a corresponding number of top plate edge blocks and top plate middle blocks are selected and spliced ​​into a top plate, and the top plate is fixed using welding, clamps and other fasteners.

[0063] Although preferred embodiments of the present invention have been described in detail herein, those skilled in the art, after understanding the basic inventive concepts of the present invention, may make other changes and modifications to these embodiments without departing from the technical concept and core ideas of the present invention. Therefore, the appended claims should be interpreted as covering not only the preferred embodiments, but also all changes and modifications that fall within the scope of the present invention.

[0064] Obviously, based on the technical principles and innovations of the present invention, those skilled in the art may make various reasonable changes and modifications to the present invention in the process of implementing the present invention, and these changes and modifications do not exceed the spirit and scope of the present invention. In other words, any modifications and variations made within the scope of the claims of the present invention and their equivalents should be considered as an integral part of the present invention. Therefore, the scope of protection of the present invention is not limited to the specifically described embodiments, but should also include all technically feasible changes and adjustments, as long as these changes and adjustments do not deviate from the basic concept and technical solution of the present invention.

Claims

1. A non-metallic shell flexible capacitor for power grid, comprising a shell and a core assembly installed in the shell, characterized in that: The shell comprises a top plate, a bottom plate and a plurality of vertically arranged side plates (1), two adjacent side plates (1) are vertically connected, and horizontal reinforcing ribs (2) are provided between the two adjacent side plates (1). The shell is made of polyetheretherketone carbon fiber composite material.

2. The non-metallic shell flexible capacitor for power grid according to claim 1, characterized in that: The core assembly comprises a busbar, a plurality of busbars (3) connected to the busbar, and a capacitor core (4) mounted on the busbar (3); a plurality of limiting plates (5) are provided on the outside of the busbar (3); and the limiting plates (5) are mounted on the reinforcing ribs (2).

3. The non-metallic shell flexible capacitor for power grid according to claim 2, characterized in that: The capacitor core (4) comprises a large core (401) and a small core (402) for filling in the gap between the large cores (401).

4. The non-metallic shell flexible capacitor for power grid according to claim 2, characterized in that: The busbar (3) comprises a connecting section (301) connected to the capacitor core (4) and a vibration-damping section (302) connecting two adjacent connecting sections (301), wherein the vibration-damping section (302) is configured as a corrugated structure.

5. The non-metallic shell flexible capacitor for power grid according to claim 4, characterized in that: The vibration-damping section (302) is provided with a honeycomb-shaped hollow area.

6. The non-metallic shell flexible capacitor for power grid according to claim 4, characterized in that: The limiting plate (5) is arranged on the vibration reduction section (302).

7. The non-metallic shell flexible capacitor for power grid according to claim 1, characterized in that: The top and bottom plates and the side plates (1), and the side plates (1) and the side plates (1) are all connected in a detachable manner.

8. The non-metallic shell flexible capacitor for power grid according to claim 1, characterized in that: A transverse groove is provided on the inner side wall of the side plate (1), and the reinforcing rib (2) is embedded in the groove for installation.

9. The non-metallic shell flexible capacitor for power grid according to claim 1, characterized in that: An insulating elastic member is provided on the upper surface of the reinforcing rib (2).

10. The non-metallic shell flexible capacitor for power grid according to claim 1, characterized in that: An electric field shielding layer is provided on the inner wall of the shell, and a heat-conducting insulating coating is provided on the outer wall.

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