A flexible DC capacitor with a composite busbar

Abstract

The present invention discloses a flexible direct current capacitor of a composite busbar type, which relates to the field of capacitors. By arranging a shock-absorbing connecting piece between the busbar and the capacitor core, the present invention improves the impact and vibration resistance of the capacitor core, can disperse the impact force to part or a single core, and eliminates the impact force through the shock-absorbing connecting piece, reducing the risk of displacement, breakage or capacitance loss of the core. By changing the conductive plate to a busbar arranged at the edge of the housing, and dividing the capacitor core into multiple groups through an extended connecting plate, the impact force is dispersed and eliminated. An arc-shaped groove is arranged at the connection between the connecting plate and the busbar to reduce the risk of breakage and improve the reliability of the busbar and the connecting plate. The first and second thrust elastic pieces are used to offset the impact force, and then part of the force is conducted to the support plate and further offset by an external shock-absorbing device, enhancing the impact resistance of the capacitor. The adjacent capacitor cores on the connecting plate are connected to other cores through elastic ropes to enhance the impact resistance of the capacitor.

Description

Technical Field

[0001] The present invention relates to the field of capacitors, and more particularly to a flexible DC capacitor with a composite busbar structure. Background Art

[0002] With the rapid progress of domestic ionization electron technology, the converter technology has been widely applied in many fields such as smart grids, flexible DC transmission, high-voltage high-power frequency converters, and rail transit. These applications have gradually increased the technical requirements for converters. In particular, as one of the core components of the converter, the performance requirements for DC support capacitors have also been continuously enhanced. As the converter technology develops towards high power and large capacity, the capacity of DC support capacitors has gradually increased. To meet the requirements of high-power converters, the DC support capacitors in the prior art usually increase their capacity to meet higher power demands, resulting in a further increase in the volume of the capacitors. However, this increase in volume not only affects the external shock and vibration resistance of the capacitors. To address this issue, the prior art generally uses shock-absorbing devices such as springs and foams to be installed outside the capacitors. These shock-absorbing measures can effectively reduce the impact between the capacitors and surrounding equipment, but their effects are limited to reducing external shocks.

[0003] However, as the capacity of the capacitors gradually increases, not only does the external volume of the capacitors increase, but the capacitor cores inside also increase in size and quantity. As a result, the internal shock resistance of the capacitors decreases, and there is a risk of internal damage due to vibration. Such internal damage may lead to a decrease in the performance of the capacitors or even failure, affecting the normal operation of the converters. Therefore, simply relying on external shock-absorbing devices cannot meet the requirements of modern high-power capacitors. It is urgent to innovate in the internal design and materials of the capacitors to improve their overall shock and vibration resistance and ensure that the capacitors can operate stably and reliably in more demanding working environments. Summary of the Invention

[0004] The present invention provides a flexible DC capacitor with a composite busbar structure to solve the problem of low internal shock and vibration resistance of capacitors caused by the increase in the volume of the capacitor cores inside due to the increase in the volume of the capacitors in the prior art.

[0005] To achieve the above object, the present invention provides the following solution:

[0006] A flexible DC capacitor with a composite busbar structure includes a housing, a busbar, and capacitor cores installed in the housing. The busbar and the capacitor cores are connected by a plurality of shock-absorbing connectors.

[0007] By arranging a damping connecting piece between the busbar and the capacitor core, the shock and vibration resistance of the capacitor core is improved. In the prior art, all capacitor cores are usually welded into a whole. Therefore, when the capacitor is impacted, the internal capacitor cores are also subjected to impact force. Due to the increase in volume and length of the capacitor cores, the capacitor cores are likely to be displaced or broken due to the impact force, resulting in hitting adjacent capacitor cores and posing a risk of capacitance loss. By arranging a damping connecting piece between the busbar and the capacitor core, the impact force received by the capacitor can be dispersed to some or even a single capacitor core, and then the impact force is eliminated by the damping connecting piece that fixes the capacitor core, reducing the risk of displacement, breakage or capacitance loss of the capacitor core and improving the reliability of the flexible DC capacitor in operation.

[0008] Further, the damping connecting piece includes a plurality of connecting plates fixedly connected to the busbar, and arc-shaped grooves are provided at both ends of the side of the connecting plate close to the busbar.

[0009] The busbar in the prior art is usually a whole conductive plate, and the capacitor cores are arranged and welded to the conductive plate at one time, so that the capacitor cores are connected in parallel with each other through the conductive plate to form a whole, resulting in a decrease in its shock resistance. In this solution, the conductive plate is changed to a busbar arranged at the edge of the housing, and a plurality of connecting plates extend from the busbar, and then the capacitor cores are welded to the connecting plates, dividing the capacitor cores into multiple groups to disperse the impact force received by the whole, and eliminating the impact force through the elasticity of the suspended connecting plates, and an arc-shaped groove is opened at the part where the connecting plate is connected to the busbar to reduce the risk of breakage of the connecting plate due to excessive impact, improving the reliability of the busbar and the connecting plate.

[0010] Further, a first thrust elastic member is installed between adjacent connecting plates.

[0011] Since it is necessary to ensure the strength of the connecting plate, the elasticity it can provide is limited. Therefore, the present invention arranges a first thrust elastic member between two adjacent connecting plates. By means of the first thrust elastic member, the shock resistance of the connecting plate is improved, and the shock resistance of the whole capacitor is further improved, so that the composite busbar flexible DC capacitor has better working stability.

[0012] Further, the housing includes side plates, and a plurality of support plates are provided on the inner side of the side plates. The support plates are embedded between adjacent connecting plates, and a plurality of second thrust elastic members are provided between the support plates and the connecting plates.

[0013] Under the action of the first thrust elastic member, a linkage is formed between two adjacent connecting plates, and the impact force received can be conducted and shared with each other. However, there is always an upper limit. That is, when the impact force received by one of the connecting plates reaches the critical point of being about to be damaged, and the adjacent connecting plate conducts part of the impact force over, it is very likely to cause this connecting plate to be damaged. Therefore, in order to increase the upper limit of the impact resistance of the connecting plate, it is solved by arranging a support plate between two adjacent connecting plates. When the connecting plate receives an impact force, part of it can be offset by the first thrust elastic member and the second thrust elastic member, and then conducted to the support plate through the second thrust elastic member. And the support plate is also connected to the capacitor housing, so part of the impact force can be directly conducted to the outside of the capacitor and offset by the external shock absorption device in the prior art, further enhancing the impact resistance inside the capacitor.

[0014] Further, the busbar includes a positive busbar and a negative busbar. The connecting plates on the positive busbar and the negative busbar correspond one by one. Both ends of the capacitor core are fixedly connected to the corresponding connecting plates respectively. A number of elastic ropes are sleeved on two capacitor cores installed on adjacent connecting plates.

[0015] By connecting the capacitor cores welded on two adjacent connecting plates through elastic ropes, part of the impact force received by the capacitor cores can also be offset. And it can also provide a certain connecting force for all capacitor cores, reducing the possibility of collision between adjacent capacitor cores.

[0016] Further, the capacitor cores installed on two adjacent connecting plates are staggeredly distributed. Any capacitor core is sleeved with the elastic rope on one and / or two of the closest capacitor cores on the adjacent connecting plate.

[0017] After the capacitor cores are staggeredly distributed, a triangular arrangement is formed between two adjacent capacitor cores on the same connecting plate and the closest capacitor core on the adjacent connecting plate. By connecting two adjacent capacitor cores on the same connecting plate to the closest capacitor core on the adjacent connecting plate through elastic ropes respectively, a triangular stable structure is formed. All capacitor cores are connected together through this connection method, enhancing the impact resistance of all capacitor cores.

[0018] Further, a number of welding holes for welding with the capacitor cores are formed on the connecting plate. The welding holes include a contact part and two bifurcated parts.

[0019] The capacitor core is welded to the connecting plate by injecting solder into the welding hole. The contact part has a large area, which is used to ensure full contact between the capacitor core, the connecting plate and the solder. While increasing the contact area of the solder, the bifurcated parts can also make the solder present an irregular shape, enhancing the impact resistance of the solder and reducing the possibility of solder joint detachment.

[0020] Furthermore, the two forked parts are arranged in parallel, and an arc-shaped protrusion is provided between the forked part and the contact part.

[0021] By providing a protrusion between the forked part and the contact part, after the welding hole is filled with solder, the adjacent parts between the solder in the forked part and the solder in the contact part are not easily broken, improving the impact resistance of the solder.

[0022] Furthermore, the capacitor cores are connected in parallel with each other through a connecting plate and then connected to an external circuit through the bus bar and the lead-out terminal in sequence. In order to reduce the contact resistance of the welding part when the capacitor cores are connected in parallel and improve the welding stability between the capacitor cores and the connecting plate, the capacitor cores correspond to a plurality of the welding holes. By corresponding one capacitor core to a plurality of welding holes, the welding strength between the capacitor core and the connecting plate is improved, and the risk of de-soldering is reduced.

[0023] Furthermore, the forked part is arranged towards the top of the housing. The solder filled in the contact part with a larger area is located below, bearing the weight of the capacitor core, reducing the possibility of de-soldering and avoiding damage to the solder of the relatively fragile forked part, thus improving the working life of the capacitor.

[0024] Furthermore, for a flexible DC capacitor, the capacitor cores installed inside are usually composed of a conductive electrode and an insulating film material, and the conductive electrode and the insulating film material are stacked. When preparing the capacitor core, the above-mentioned stacked film materials are tightly wound into a cylindrical core by a winding machine, and it is ensured that the film materials are neatly and tightly fitted to avoid gaps or misalignments between the film materials, thereby improving the electrical performance and working stability of the flexible DC capacitor. Therefore, in order to ensure that the film electrodes inside the capacitor core do not shift during the winding process, the capacitor core includes a first electrode and a second electrode arranged in a stacked manner. The first electrode includes a first electrode layer and a first base layer, and the second electrode includes a second metal electrode layer and a second base layer. In the first electrode, the electrode material is attached to the surface of the first base layer by evaporation, sputtering or spin coating to obtain the first electrode layer; in the second electrode, the electrode material is also attached to the surface of the second base layer by evaporation, sputtering or spin coating to obtain the second electrode layer. The first electrode layer and the first base layer, and the second electrode layer and the second base layer are tightly connected, effectively avoiding gaps or misalignments between the conductive electrode layer and the insulating film material during the winding process of the capacitor core, and improving the electrical performance and working stability of the composite bus bar flexible DC capacitor.

[0025] Furthermore, during the winding process of the capacitor core, due to mechanical stress, there is a risk of cracking in the first electrode layer and / or the second electrode layer attached to the surface of the insulating substrate. At the same time, temperature changes and mechanical vibrations during the use of the flexible DC capacitor will also increase the risk of cracking in the first electrode layer and / or the second electrode layer. Cracking of the electrode layer in the capacitor core will affect the electrical performance of the flexible DC capacitor, resulting in poor electrical contact, breakdown or failure. Therefore, in order to avoid the risk of cracking in the first electrode layer and / or the second electrode layer, the first electrode layer and / or the second electrode layer are of a multi-layer structure. When cracks appear inside the first electrode layer and / or the second electrode layer, the interlayer interface effect of the multi-layer electrode structure can delay the spread of cracks, improve the mechanical strength and flexibility of the first electrode layer and / or the second electrode layer, and thus improve the electrical performance and working stability of the composite busbar flexible DC capacitor.

[0026] Furthermore, after the capacitor core is wound, the edges of the metal thin film used as the electrode material will be exposed on the two circular end faces of the capacitor core. By spraying gold on the two circular end faces of the capacitor core, a uniform conductive metal layer can be formed on the two end faces of the capacitor core, providing a good electrical connection basis for pin welding and external connection of the capacitor. The capacitor core includes a first gold spraying layer and a second gold spraying layer at both ends. After the capacitor core is wound, the first electrode layer is exposed on one circular end face of the capacitor core, and the first gold spraying layer is electrically connected to the first electrode layer; the second electrode layer is exposed on the other circular end face of the capacitor core, and the second gold spraying layer is electrically connected to the second electrode layer. In order to ensure good electrical connection between the first electrode layer and the first gold spraying layer, and between the second electrode layer and the second gold spraying layer, and improve the performance of the composite busbar flexible DC capacitor, the edges of the first electrode layer and / or the second electrode layer are wavy.

[0027] One or more technical solutions provided by the present invention have at least the following technical effects or advantages:

[0028] (1) By setting a shock-absorbing connecting piece between the busbar and the capacitor core, the present invention improves the anti-impact and vibration resistance of the capacitor core. By setting a shock-absorbing connecting piece between the busbar and the capacitor core, the impact force received by the capacitor can be dispersed to some or even a single capacitor core, and then the shock-absorbing connecting piece fixing the capacitor core eliminates the impact force, reducing the risk of displacement, breakage or loss of capacitance of the capacitor core;

[0029] (2) By changing the conductive plate to a busbar arranged at the edge of the housing, extending multiple connecting plates from the busbar, and then welding the capacitor cores to the connecting plates, the capacitor cores are divided into multiple groups to disperse the impact force received by the whole, and the impact force is eliminated by the elasticity of the suspended connecting plates. An arc-shaped groove is opened at the part where the connecting plate is connected to the busbar to reduce the risk of the connecting plate breaking due to excessive impact, thereby improving the reliability of the busbar and the connecting plate;

[0030] (3) Part of the impact force is offset by the first thrust elastic member and the second thrust elastic member, and then part of the impact force is conducted to the support plate through the second thrust elastic member. Since the support plate is connected to the capacitor housing, part of the impact force can be directly conducted to the outside of the capacitor and offset by the external shock-absorbing device in the prior art, further enhancing the impact resistance inside the capacitor;

[0031] (4) Adjacent two capacitor cores on the same connecting plate are respectively connected to the closest capacitor core on the adjacent connecting plate through an elastic rope to form a triangular stable structure, and all the capacitor cores are connected together through this connection method, enhancing the impact resistance of all the capacitor cores;

[0032] (5) The capacitor core is welded to the connecting plate by injecting solder into the welding hole. The contact area is relatively large to ensure full contact between the capacitor core, the connecting plate and the solder. While increasing the solder contact area, the bifurcated part can also make the solder present an irregular shape, enhancing the impact resistance of the solder and reducing the possibility of solder joint detachment. Description of the Drawings

[0033] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of the present invention, and do not limit the embodiments of the present invention;

[0034] Figure 1 It is a cross-sectional view of the internal structure of the capacitor in the present invention;

[0035] Figure 2 is Figure 1 The enlarged view of part A in

[0036] Figure 3 It is a schematic diagram of the arrangement of capacitor cores in the present invention;

[0037] Figure 4 It is a schematic diagram of the welding hole structure in the present invention;

[0038] Wherein, 1 - housing, 101 - support plate, 2 - busbar, 3 - capacitor core, 401 - connecting plate, 402 - arc-shaped groove, 5 - first thrust elastic member, 6 - second thrust elastic member, 7 - elastic rope, 8 - welding hole, 801 - contact part, 802 - bifurcated part, 803 - arc-shaped protrusion. Detailed implementation manners

[0039] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0040] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0041] Embodiment 1

[0042] This embodiment provides a flexible DC capacitor of a composite busbar type. As Figures 1-4 shown, it includes a housing 1, a busbar 2 and a capacitor core 3 installed in the housing 1. The busbar 2 and the capacitor core 3 are connected by a plurality of vibration damping connectors.

[0043] Among them, 8 M12 internal thread lead-out terminals are provided on the housing 1, 4 of which are for one pole. The busbar 2 has a positive busbar and a negative busbar, which are respectively connected to 4 lead-out terminals. A pressure sensor (threshold set at 40 kPa) and a pressure relief valve (action threshold at 30 kPa) are also installed on the housing 1, which has the function of continuously monitoring the operation state of the capacitor. Under the double protection of the sensor and the pressure relief valve, the product is safer and more reliable. The outside of the housing 1 is made of 304 non-magnetic stainless steel, which has high strength, will not rust, and is not affected by the electric and magnetic fields of the surrounding environment. The housing body, the housing cover and the housing bottom are all welded by argon arc welding, and the welding strength is far greater than the pressure of the product under 40 kPA; the capacitor core 3 is produced by a winding process, and after spraying gold and heat setting, it is welded into a capacitor core group through the busbar 2, and then after insulation encapsulation, it is installed in a stainless steel shell and filled with flame-retardant epoxy resin in a fully sealed dry structure; the busbar 2 is preferably a copper busbar.

[0044] In a more preferred embodiment, the vibration damping connector includes a plurality of connecting plates 401 fixedly connected to the busbar 2. Both ends of the side of the connecting plate 401 close to the busbar 2 are provided with arc-shaped grooves 402.

[0045] Among them, the connecting plate 401 and the busbar 2 are preferably integrally formed by a mold to enhance the structural strength. The arc-shaped groove 402 is opened at the junction of the connecting plate 401 and the busbar 2, and the angle between the connecting plate 401 and the busbar 2 is rounded.

[0046] In a more preferred embodiment, a first thrust elastic member 5 is installed between adjacent connecting plates 401. The first thrust elastic member 5 can be a thrust spring, a rubber pad, etc. Since the first thrust elastic member 5 is connected to the same connecting plate 401, there is no requirement for the electrical conductivity of the first thrust elastic member 5.

[0047] In a more preferred embodiment, the housing 1 includes side plates, and a plurality of support plates 101 are provided on the inner side of the side plates. The support plates 101 are embedded between adjacent connecting plates 401, and a plurality of second thrust elastic members 6 are provided between the support plates 101 and the connecting plates 401.

[0048] Among them, the support plate 101 is preferably arranged on one side of the end of the connecting plate 401. The second thrust elastic member 6 is a thrust spring, a rubber pad, etc. Since the support plate 101 is connected to the housing 1, insulation treatment is required. Therefore, the surface of the support plate 101 is preferably coated with an insulating coating, and the second thrust elastic member 6 is made of rubber or a thrust spring coated with an insulating coating.

[0049] In a more preferred embodiment, the bus bar 2 includes a positive bus bar and a negative bus bar. The connecting plates 401 on the positive bus bar and the negative bus bar correspond one by one. Both ends of the capacitor core 3 are fixedly connected to the corresponding connecting plates 401, and a plurality of elastic ropes 7 are sleeved on two capacitor cores 3 installed on adjacent connecting plates 401.

[0050] Among them, both ends of the capacitor core 3 are preferably welded to the same horizontal height, and the elastic rope 7 is preferably a rubber rope loop.

[0051] In a more preferred embodiment, the capacitor cores 3 installed on adjacent two connecting plates 401 are staggeredly distributed, and the elastic rope 7 is sleeved on any one and / or two of the capacitor cores 3 closest to the capacitor core 3 on the adjacent connecting plate 401.

[0052] Among them, since there are two adjacent connecting plates for one connecting plate 401, and there are capacitor cores 3 adjacent to the capacitor core 3 on each connecting plate, therefore, there can be multiple elastic ropes 7 on the same capacitor core 3, and multiple elastic ropes 7 can also be provided on two adjacent capacitor cores 3. Therefore, the specific number of the elastic ropes 7 can be arbitrary and is determined according to user requirements.

[0053] Embodiment Two

[0054] On the basis of Embodiment One, a plurality of welding holes 8 for welding with the capacitor core 3 are formed in the connecting plate 401. The welding holes 8 include a contact portion 801 and two bifurcated portions 802.

[0055] Among them, in order to improve the structural strength of the solder filled in the welding hole 8, the edges and corners on the side wall of the welding hole 8 are all rounded.

[0056] In a more preferred embodiment, the two branching portions 802 are arranged in parallel, and an arc-shaped protrusion 803 is provided between the branching portion 802 and the contact portion 801. The arc-shaped protrusion 803 is also for making the side walls of the solder filled in the welding hole 8 all rounded, so as to improve the structural strength of the solder filled in the welding hole 8.

[0057] In a more preferred embodiment, the capacitor core 3 corresponds to a plurality of the welding holes 8. One end of the capacitor core 3 preferably corresponds to two welding holes 8.

[0058] In a more preferred embodiment, the branching portion 802 faces the top of the housing 1.

[0059] Furthermore, the capacitor core 3 includes a first electrode and a second electrode which are stacked. The first electrode includes a first electrode layer and a first base layer, and the second electrode includes a second electrode layer and a second base layer. In the capacitor core 3, the first electrode layer and the second electrode layer serve as the two capacitor plates. The first base layer attached to the first electrode layer is sandwiched between the first electrode layer and the second electrode layer and serves as the dielectric material between the capacitor plates. The second base layer attached to the second electrode layer is used to prevent the first electrode from contacting the second electrode during the winding process, resulting in a short circuit of the capacitor.

[0060] Before winding the capacitor core 3, it is only necessary to stack the first electrode and the second electrode, without repeatedly stacking the conductive electrode and the insulating film material. The connection between the first electrode layer and the first base layer and between the second electrode layer and the second base layer is tight, which further ensures that the thin film electrodes inside the capacitor core 3 do not shift during the winding process, improving the electrical performance and working stability of the composite busbar flexible DC capacitor.

[0061] Among them, the first electrode layer and / or the second electrode layer can be a metal electrode layer such as titanium, aluminum, zinc, etc. that can form an electrode, or a non-metal electrode layer such as carbon nanotubes, conductive polymers, etc. that can form an electrode. The specific materials of the first electrode layer and / or the second electrode layer are determined according to actual needs, and are not specifically limited in this embodiment; the first substrate and / or the second substrate can be a polypropylene film, a polyester film or a polyimide film. The first substrate and / or the second substrate are preferably high-insulation polypropylene films, with an electrical breakdown strength of 800 V / μm, a dielectric loss of about 0.02%, and a heat resistance performance of up to 125 °C. Preferably, the thickness of the first substrate and / or the second substrate is 3.4 to 10 μm. The length and width of the first substrate and / or the second substrate are determined according to the actual size requirements of the composite busbar flexible DC capacitor, and are not specifically limited in this embodiment.

[0062] Specifically, when the first electrode layer and / or the second electrode layer is a metal electrode layer, the first electrode layer and / or the second electrode layer is attached to the surface of the corresponding insulating substrate by means of evaporation coating in physical vapor deposition technology. The evaporation coating process is carried out in a vacuum environment. The metal to be evaporated is placed in an evaporation source, and the metal layer is heated to the evaporation temperature by means of resistance heating or electron beam heating, so that metal atoms evaporate from the surface of the solid metal source, diffuse in the form of atoms or small molecules in the vacuum, and finally deposit on the surface of the insulating substrate. The thickness of the first electrode layer and / or the second electrode layer can be controlled by the evaporation coating time and the evaporation coating temperature. The evaporation coating time and the evaporation coating temperature are determined according to actual needs and are not specifically limited in this embodiment. After the evaporation coating is completed, the metal layer is cured on the surface of the insulating substrate to form a uniform and dense metal electrode layer. The first electrode layer and / or the second electrode layer have good adhesion and electrical properties after annealing treatment, so that the composite busbar flexible DC capacitor has good electrical properties and working stability.

[0063] Specifically, when the first electrode layer and / or the second electrode layer is a non-metal electrode layer, that is, when the electrode material is a non-metal material such as conductive ceramics, metal oxides, conductive polymers, etc., the first electrode layer and / or the second electrode layer is attached to the surface of the corresponding insulating substrate by sputtering deposition. Sputtering deposition sputters atoms or molecules of the target material by high-energy particles hitting the target material and deposits them on the surface of the insulating substrate to form a uniform and dense non-metal electrode layer.

[0064] Specifically, when the first electrode layer and / or the second electrode layer is a non-metallic electrode layer, that is, the electrode material is a non-metallic material such as carbon nanotubes, graphene, conductive polymers, etc., the first electrode layer and / or the second electrode layer are attached to the surface of the corresponding insulating base layer by chemical vapor deposition. Chemical vapor deposition decomposes or reacts a gas precursor (usually a compound containing non-metallic elements) at high temperature to generate the required thin film material and deposit it on the insulating base layer to form a uniform and dense non-metallic electrode layer.

[0065] Furthermore, the first electrode layer and / or the second electrode layer is a multilayer structure. When the first electrode layer includes multiple sub-electrode layers, when the first electrode layer is cracked due to the mechanical stress during the winding process of the capacitor core 3 and the temperature and pressure during the operation of the capacitor, when the tiny cracks inside the first electrode layer extend from one sub-electrode layer to the next sub-electrode layer, the interface stress between the sub-electrode layers can change the crack extension direction, slow down the crack extension speed and improve the working stability of the busbar-type flexible capacitor. The internal structure of the second electrode layer is the same as the internal structure of the first electrode layer, and this embodiment will not be repeated here.

[0066] Wherein, the sub-electrode layers inside the first electrode layer and / or the second electrode layer are made of different electrode materials. When the first electrode layer and / or the second electrode layer are metal electrode layers, the sub-electrode layers can be selected as sub-metal layers with different physical and mechanical properties, such as copper, gold and other metal layers have good flexibility and ductility; aluminum and titanium metal layers have strong hardness and crack resistance. Specifically, when preparing the first electrode layer and / or the second electrode layer, a copper metal layer with strong flexibility is first evaporated on the insulating base layer, and then an aluminum metal layer with higher hardness is evaporated on the copper metal layer. The aluminum-copper metal layers obtained by the evaporation method are densely connected and have good mechanical properties. At the same time, the copper metal layer effectively alleviates the stress concentration of the aluminum metal layer and reduces the occurrence and propagation of electrode cracks.

[0067] Among them, the sub-electrode layers inside the first electrode layer and / or the second electrode layer are made of the same electrode material. When the first electrode layer and / or the second electrode layer is a metal electrode layer, the sub-electrode layers can be selected as sub-metal layers of the same material. The physical properties (such as thermal expansion coefficient, hardness, ductility, etc.) between the sub-metal layers of the same material are relatively consistent, avoiding the thermal stress differences between different metal layers and enabling the electrode to have good mechanical properties. Specifically, when preparing the first electrode layer and / or the second electrode layer, first deposit a relatively thin first aluminum metal layer on the insulating base layer, and then deposit a relatively thick second aluminum metal layer on the first aluminum metal layer. The relatively thin second aluminum metal layer has good adhesion to the insulating base layer, and the relatively thick first aluminum metal layer has good crack resistance. Moreover, the interfacial stress between the first aluminum metal layer and the second aluminum metal layer can change the crack propagation direction, delay the crack propagation speed, and improve the working stability of the flexible DC capacitor conforming to the busbar type.

[0068] Among them, the number, sub-electrode material, and sub-electrode thickness of the sub-electrode layers provided inside the first electrode layer and / or the second electrode layer are all determined according to actual needs, and are not specifically limited in this embodiment.

[0069] Further, the capacitor core 3 includes a first sprayed metal layer and a second sprayed metal layer at both ends, and the edges of the first electrode and / or the second electrode are wavy. Specifically, before winding the capacitor core 3, stack the first electrode and the second electrode, and cut the first electrode and the second electrode so that the sizes of the first electrode and the second electrode are the same, and the edges of the first electrode layer and the second electrode layer are wavy. After the capacitor core 3 is wound, the first electrode layer is exposed on one circular end face of the capacitor core 3, and the second electrode layer is exposed on the other circular end face of the capacitor core 3. After spraying metal on both ends of the capacitor core 3, a sprayed metal layer is formed. The first sprayed metal layer at one end of the capacitor core 3 is electrically connected to the first electrode layer, and the second sprayed metal layer at the other end of the capacitor core 3 is electrically connected to the second electrode layer. After electrically connecting the first sprayed metal layer and the second sprayed metal layer to the positive busbar and the negative busbar respectively, the capacitor core 3 is connected to the external circuit by the lead terminals.

[0070] Although the preferred embodiments of the present invention have been described in detail herein, those skilled in the art can, after understanding the basic creative concepts of the present invention, make other changes and modifications to these embodiments without departing from the technical concept and core idea of the present invention. Therefore, the appended claims should be construed to cover not only the preferred embodiments, but also all changes and modifications that fall within the scope of the present invention.

[0071] Obviously, based on the technical principles and innovative points of the present invention, those skilled in the art can make various reasonable modifications and variations during the implementation of the present invention, and these modifications and variations 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 its equivalent technologies shall be regarded as part of the present invention. Therefore, the protection scope 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 composite busbar type flexible capacitor, comprising a housing (1) and a busbar (2) and a capacitor core (3) installed in the housing (1), characterized in that: The busbar (2) and the capacitor core (3) are connected via a plurality of vibration-damping connecting pieces; The vibration-damping connecting member comprises a plurality of connecting plates (401) fixedly connected to the busbar (2), and arc-shaped grooves (402) are provided at both ends of a side of the connecting plate (401) close to the busbar (2); The housing (1) comprises a side plate, a plurality of support plates (101) are provided on the inner side of the side plate, the support plates (101) are embedded between adjacent connecting plates (401), and a plurality of second thrust elastic members (6) are provided between the support plates (101) and the connecting plates (401).

2. A composite busbar type flexible capacitor according to claim 1, characterized in that: A first thrust elastic member (5) is installed between adjacent connecting plates (401).

3. The composite busbar type flexible capacitor according to claim 1, characterized in that: The busbar (2) comprises a positive busbar and a negative busbar, the connection plates (401) on the positive busbar and the negative busbar correspond to each other one by one, the two ends of the capacitor core (3) are respectively fixedly connected to the corresponding connection plates (401), and a plurality of elastic ropes (7) are sleeved on two capacitor cores (3) mounted on adjacent connection plates (401).

4. The composite busbar type flexible capacitor according to claim 3, characterized in that: The capacitor cores (3) installed on two adjacent connection plates (401) are arranged in a staggered manner, and the elastic rope (7) is sleeved on the closest one and / or two capacitor cores (3) on any capacitor core (3) and the adjacent connection plates (401).

5. The composite busbar type flexible capacitor according to claim 1, characterized in that: The connection plate (401) is provided with a plurality of welding holes (8) for welding to the capacitor core (3), and the welding holes (8) include a contact portion (801) and two bifurcated portions (802).

6. The composite busbar type flexible capacitor according to claim 5, characterized in that: The two bifurcated portions (802) are arranged in parallel, and an arc-shaped protrusion (803) is provided between the bifurcated portion (802) and the contact portion (801).

7. The composite busbar type flexible capacitor according to claim 5, characterized in that: The capacitor core (3) corresponds to a plurality of welding holes (8).

8. The composite busbar type flexible capacitor according to claim 5, characterized in that: The forked portion (802) is arranged towards the top of the shell (1).

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