Capacitor plate with Y-shaped grid film

Abstract

The invention discloses a capacitor plate with a Y-shaped grid film, and relates to the technical field of grid metallized films. Comprising at least two groups of polypropylene films which are arranged from top to bottom, metal coatings are arranged on the two groups of polypropylene films, and Y-shaped grid films are arranged on the metal coatings; the Y-shaped grid film is provided with a margin area, a partition area, a fuse area and a Y-shaped grid. A conventional single-layer fuse grid is improved into a multi-layer fuse grid, and the isolation area is added, so that the area capable of being isolated by the fuses is larger, and the required non-plating area is reduced. Compared with a conventional single-layer fuse grid, multiple layers of fuses are considered in the scheme of the utility model, so that the overall sensitivity to overvoltage is improved, and the reliability of the capacitor is improved; a plating-free region is reduced, so that the effective area on the metalized film with the same length is larger, and the size requirement of the capacitor is reduced; therefore, the film capacitor can be researched, developed and manufactured better.

Description

Technical Field

[0001] The invention relates to the technical field of grid metallized films, in particular to a capacitor plate with a Y-shaped grid film. Background Art

[0002] With the continuous development of high-power power electronic equipment, the requirements for the voltage withstand capability of film capacitors in some high-power energy storage and converter equipment are getting higher and higher. Because the electrodes of metallized film capacitors are very thin, under the action of surge voltage, it will bring about a series of problems such as loss of metallized film coating, capacitance attenuation, deterioration of capacitor dielectric performance and even breakdown. In order to increase the voltage withstand capability of film capacitors, the metallized film with a split design can isolate abnormal areas on the film surface and protect other effective areas. This patent provides a new split grid for film capacitors, which has the advantages of small capacitance coefficient, high voltage resistance and good surge resistance. Summary of the Invention

[0003] The purpose of this application is to provide a capacitor plate with a Y-shaped grid film, so as to solve the technical problems raised in the above background.

[0004] To achieve the above objectives, the present application provides the following technical solution: a capacitor plate with a Y-shaped mesh film, characterized in that it includes at least two groups of polypropylene films arranged from top to bottom, and both groups of polypropylene films are provided with a metal coating, and the Y-shaped mesh film is provided on the metal coating; The Y-shaped grid film is provided with a margin area, a partition area, a fuse area and a Y-shaped grid.

[0005] As a preferred implementation in this embodiment, the outer edge shape of the margin area is set to be wavy.

[0006] As a preferred implementation in this embodiment, the height of the wave crest and the depth of the wave trough of the margin area are both 1 / 4 to 1 / 3 of the average width of the margin area.

[0007] As a preferred implementation in this embodiment, the interval between the wave crest and the wave trough is 1 to 2 times the average width of the margin area.

[0008] As a preferred implementation in this embodiment, the ratio of the width of the margin area to the width of the partition area is 5:3.

[0009] As a preferred implementation in this embodiment, the branch angle of the Y-shaped grid membrane is controlled between 45° and 65°.

[0010] As a preferred implementation in this embodiment, the branch angle of the Y-shaped grid membrane is set to 55°.

[0011] As a preferred implementation in this embodiment, the fuse area is made of a low-melting-point metal material, and the layout of the fuse area adopts a non-uniform distribution, so that fuse areas of different densities are set in different areas of the capacitor plate.

[0012] As a preferred implementation in this embodiment, in the non-uniformly distributed fuse areas, the density of the fuse areas in the high current density area is 1.5 to 2 times the density of the fuse areas 5 in the low current density area.

[0013] In summary, the technical effects and advantages of the present invention are as follows: The present invention has a rational structure, improving the conventional single-layer fuse grid into a multi-layer fuse grid. By increasing the isolation area, the area that can be isolated by the fuse is larger, reducing the required uncoated area. Compared with the conventional single-layer fuse grid, this patent solution takes into account the multi-layer fuse, thereby increasing the overall sensitivity to overvoltage and improving the reliability of the capacitor. The reduction of the uncoated area increases the effective area of ​​the metallized film of the same length, reducing the capacitor size requirements, and thus better facilitating the development and production of thin film capacitors. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 Schematic diagram of the plate of the metallized film capacitor of the present invention; Figure 2 This is a schematic diagram of the evaporation of the metal coating at the electrical weak point of the metallized film under the action of overvoltage; Figure 3 It is the specific structure of the Y-type grid metallized film; Figure 4 This is a schematic diagram after the isolation area is formed; Figure 5 Schematic diagram of a conventional grid membrane structure.

[0016] In the figure: 1. Metal coating evaporated on polypropylene film medium; 2. Polypropylene film; 3. Border area; 4. Partition area; 5. Fuse area. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] Embodiment: A capacitor plate with a Y-shaped grid film, characterized in that it includes at least two groups of polypropylene films 1 arranged from top to bottom, and both groups of polypropylene films 1 are provided with a metal coating 2, and a Y-shaped grid film is provided on the metal coating 2, and the Y-shaped grid film is provided with a margin area 3, a partition area 4, a fuse area 5 and a Y-shaped grid.

[0019] According to e.g. Figure 2 As shown in the schematic diagram, the metallized film will break down under the action of overvoltage to generate a large current, causing the coating to evaporate; 2. This coating evaporation principle makes it possible for example Figure 3 In the structure shown, the fuse is disconnected; 3. After the fuse is disconnected, the weak area is isolated, thereby protecting the normal operation of the remaining areas (such as Figure 4 shown); The innovative process implemented in this invention is to improve the conventional single-layer fuse grid (i.e., the Y-shaped grid) into a multi-layer fuse grid. By increasing the isolation area, the area that can be isolated by the fuse is larger, reducing the required uncoated area. Compared with the conventional single-layer fuse grid, this patented solution takes into account the multi-layer fuse, thereby increasing the overall sensitivity to overvoltage and improving the reliability of the capacitor. The reduction of the uncoated area increases the effective area of ​​the metallized film of the same length, reducing the capacitor size requirements, and thus better facilitating the development and production of thin film capacitors.

[0020] As a preferred implementation in this embodiment, the shape of the margin area 3 is set to be wavy.

[0021] Instead of the traditional straight-line design, the wavy margin area 3 can more effectively disperse the electric field strength and avoid excessive concentration of the electric field in the edge area, thereby optimizing the electric field distribution of the capacitor and improving the withstand voltage and reliability.

[0022] As a preferred implementation in this embodiment, the height of the wave crest and the depth of the wave trough of the wavy margin area are both 1 / 4 to 1 / 3 of the average width of the margin area 3.

[0023] The electric field strength can be dispersed more effectively. This design avoids excessive concentration of the electric field in the edge area, thereby reducing the local electric field strength and improving the withstand voltage capability of the capacitor. An appropriate peak height helps maintain the structural stability of the margin area 3. If the peak height is too low, it may not provide sufficient mechanical support, causing the margin area to deform or be damaged during the operation of the capacitor. A peak height within the range of 1 / 4 to 1 / 3 of the average width of the margin area can ensure both the optimization of the electric field distribution and the structural stability of the margin area. The trough height is kept consistent with the peak height to ensure the symmetry of the wave shape, thereby optimizing the electric field distribution.

[0024] When the peak is less than 1 / 4: The peak height is too low, which may cause the electric field to be too concentrated at the edge of the margin area, and the electric field strength cannot be effectively dispersed. This will reduce the capacitor's voltage resistance and increase the risk of breakdown under high voltage. If the peak height is too low, the margin area may not provide sufficient mechanical support, making it easy to deform or damage during the operation of the capacitor. This will affect the overall performance and reliability of the capacitor. When the peak is higher than 1 / 3: Excessively high peak heights can increase manufacturing difficulty and cost. During the manufacturing process, higher precision and more complex processes are required to ensure the accuracy of the peak height. While excessively high peak heights may improve the capacitor's withstand voltage in some cases, they may also lead to uneven electric field distribution or increase unnecessary stress, which will affect the capacitor's overall performance and reliability.

[0025] As a preferred implementation in this embodiment, the interval between the wave crest and the wave trough is 1 to 2 times the average width of the margin area 3 .

[0026] Within this spacing ratio range, the electric field distribution can be further optimized to ensure that the electric field is evenly distributed in the margin area, avoiding excessive concentration of the electric field in local areas; at the same time, the current path on the capacitor plates can be optimized to reduce the risk of current concentration and local overheating.

[0027] As a preferred implementation in this embodiment, the ratio of the width of the margin area 3 to the width of the partition area 4 is 5:3.

[0028] At this width ratio, a better balance can be found between the effective area and voltage resistance of the capacitor. The wider margin area 3 can provide a larger insulation space and improve the voltage resistance; while the wider isolation area 4 can more effectively block the propagation path of abnormal current, improving the capacitor's surge resistance and fault isolation capabilities; at this width ratio, the capacitor's current path can also be optimized, reducing the concentration of current in the edge area, thereby reducing the risk of local overheating and damage; by balancing the effective area, voltage resistance and current carrying capacity, the optimal width ratio of the margin area and the isolation area can significantly improve the overall performance and reliability of the capacitor.

[0029] As a preferred implementation in this embodiment, the branch angle of the Y-shaped grid membrane is controlled between 45° and 65°.

[0030] In the range of 45° to 65°, the Y-shaped mesh film can effectively disperse the electric field strength. This angle range helps to avoid excessive concentration of the electric field in a local area, thereby optimizing the electric field distribution of the capacitor. The optimized electric field distribution can improve the withstand voltage capability of the capacitor, enabling it to withstand higher voltages without breakdown. The Y-shaped mesh film can effectively isolate abnormal areas on the capacitor plates, preventing the spread of faults and thus protecting the capacitor from further damage. This design makes the capacitor more stable under high voltage, improving its reliability and service life. Within this angle range, the Y-shaped mesh film can maintain good mechanical strength and stability. An angle that is too small may cause the mesh to be too dense, increasing the equivalent series resistance (ESR) of the capacitor and possibly reducing mechanical strength. An angle that is too large may cause the mesh to be too sparse, failing to effectively isolate abnormal areas and also affecting mechanical stability. The branch angle range of 45° to 65° finds a balance between mechanical strength and stability, helping to reduce deformation or damage caused by mechanical or thermal stress.

[0031] As a preferred implementation in this embodiment, the branch angle of the Y-shaped grid membrane is set to 55°.

[0032] By precisely controlling the branch angle of the Y-shaped mesh film at 55°, the capacitor's electric field distribution is uniform during operation, significantly improving its withstand voltage capability. This design allows the capacitor to withstand higher voltages without breakdown, increasing its reliability and service life.

[0033] As a preferred implementation in this embodiment, the fuse area 5 is made of a low-melting-point metal material, and the layout of the fuse area 5 adopts a non-uniform distribution, so that fuse areas 5 of different densities are set in different areas of the capacitor plate.

[0034] Using low-melting-point metal materials to create the fuse zone ensures rapid fuse opening in the event of an overcurrent, effectively protecting the capacitor from high current surges. Furthermore, employing a non-uniformly distributed fuse zone layout allows for optimized design based on the current density and temperature distribution in different areas of the capacitor plate, more effectively protecting the capacitor from localized overvoltage or overcurrent, and improving its safety and reliability.

[0035] As a preferred implementation in this embodiment, in the non-uniformly distributed fuse areas 5 , the density of the fuse areas 5 in the high current density area is 1.5 to 2 times the density of the fuse areas 5 in the low current density area.

[0036] By placing a higher density of fuse zones 5 in high-current density areas, these areas can be more effectively protected from overcurrent. When the current density in a certain area of ​​the capacitor plate is too high, the fuse zones 5 in that area will quickly fuse, isolating the faulty area and preventing the fault from spreading. This design significantly improves the capacitor's self-protection capabilities and overall reliability, ensuring stable operation even in complex operating environments. Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A capacitor plate with a Y-shaped mesh film, characterized in that: It comprises at least two groups of polypropylene films (1) arranged from top to bottom, wherein the two groups of polypropylene films (1) are both provided with a metal coating (2), and the metal coating (2) is provided with a Y-shaped grid film; The Y-shaped grid membrane is provided with a margin area (3), a partition area (4), a fuse area (5) and a Y-shaped grid.

2. The capacitor plate with a Y-shaped mesh film according to claim 1, characterized in that: The outer edge shape of the margin area (3) is set to be wavy.

3. The capacitor plate with a Y-shaped mesh film according to claim 2, characterized in that: The height of the wave crest and the depth of the wave trough of the edge-retaining area (3) are both 1 / 4 to 1 / 3 of the average width of the edge-retaining area (3).

4. The capacitor plate with a Y-shaped mesh film according to claim 3, characterized in that: The interval between the wave crest and the wave trough is 1 to 2 times the average width of the edge region (3).

5. The capacitor plate with a Y-shaped mesh film according to claim 1, characterized in that: The ratio of the width of the margin area (3) to the width of the partition area (4) is 5:

3.

6. The capacitor plate with a Y-shaped mesh film according to claim 1, characterized in that: The branch angle of the Y-shaped grid membrane is controlled between 45° and 65°.

7. The capacitor plate with a Y-shaped mesh film according to claim 6, characterized in that: The branch angle of the Y-shaped mesh membrane is set to 55°.

8. The capacitor plate with a Y-shaped mesh film according to claim 1, characterized in that: The fuse area (5) is made of a low melting point metal material, and the layout of the fuse area (5) adopts a non-uniform distribution, so that fuse areas (5) of different densities are arranged in different areas of the capacitor plate.

9. The capacitor plate with a Y-shaped mesh film according to claim 8, characterized in that: In the non-uniformly distributed fuse areas (5), the density of the fuse areas (5) in the high current density area is 1.5 to 2 times the density of the fuse areas (5) in the low current density area.

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