An internally-strung edge-thickened high sheet resistance safety metallized counter film

Abstract

The present invention provides an inner series type edge thickened high sheet resistance safety metallized pair film, which includes a middle-edge-retained safety film and a double-edge-retained safety film disposed on the middle-edge-retained safety film. The double-edge-retained safety film includes a first base film, a retained-edge area is provided on one side of the first base film, a first metal coating is plated on the first base film, and a first low sheet resistance area, a first middle sheet resistance area, and a first high sheet resistance area are symmetrically arranged about the central axis on the first metal coating; the middle-edge-retained safety film includes a second base film, a second metal coating is plated on the second base film, an inner series edge gap for longitudinally separating the second metal coating is arranged in the middle of the second metal coating, and a second high sheet resistance area, a second middle sheet resistance area, and a second low sheet resistance area are symmetrically arranged about the inner series edge gap on the second metal coating. The present invention adopts a safety gate protection design for safety protection, and the performance of the capacitor is more reliable and safe; adopts a high sheet resistance design, and the self-healing performance of the capacitor is better; by setting an inner series type structure, the nominal voltage of the component is higher, and the equivalent series resistance and equivalent series inductance are extremely low; the heat generation of the component is relatively small.

Description

Technical Field

[0001] The present invention relates to a new type of safety film for self-healing metallized film DC support capacitors used in UHV DC projects and new energy converters, and particularly to an in-series edge-thickened high-resistance safety metallized pair film. Background Art

[0002] With the development of the domestic economy, the demand for DC support capacitors in UHV flexible DC and new energy power transmission is increasing, and DC support capacitors are one of the core components of the multi-level converters for flexible DC power transmission. However, so far, the DC support capacitors in the domestic-built flexible DC power transmission projects all use imported capacitor equipment, and foreign products hold a monopoly position in the domestic DC support capacitor market.

[0003] Although traditional ordinary-structure high-resistance films and existing safety film structure capacitor technologies can continue to operate when self-healing is successful, currently, the DC capacitors designed and manufactured with traditional metallized film structures in China cannot meet the relevant technical requirements such as the safety and reliability of DC support capacitors. Reliability and safety problems such as bulging and even explosion during capacitor operation have not been effectively solved, and DC support capacitors are still in a state of being "stuck" by foreign technologies.

[0004] In view of the current domestic DC support capacitor technology situation, the in-series edge-thickened high-resistance safety film of the present invention can, in the case of self-healing failure of the capacitor, effectively isolate the connection between the capacitor plate region corresponding to the self-healing failure and the intact plate regions of the surrounding live-running blocks through the safety door, prevent the further expansion of the fault, and ensure the safer and more reliable operation of the capacitor. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides an in-series edge-thickened high-resistance safety metallized pair film to ensure the safer and more reliable operation of the capacitor. The technical solution adopted by the present invention is as follows:

[0006] An in-series edge-thickened high-resistance safety metallized pair film, wherein: the in-series edge-thickened high-resistance safety metallized pair film includes a middle-edge-retained safety film and a double-edge-retained safety film provided on the middle-edge-retained safety film. The double-edge-retained safety film includes a base film 1, a retained-edge region is provided on one side of the base film 1, a metal coating 1 is plated on the base film 1, and a low-resistance region 1, a medium-resistance region 1, and a high-resistance region 1 are symmetrically provided about the central axis on the metal coating 1;

[0007] The double-edge-retained safety film further includes a plurality of T-shaped insulating gaps 1 that separate the metal coating 1 of the high-resistance region 1. The T-shaped insulating gaps 1 include a plurality of T-shaped insulating gap monomers arranged at intervals, and adjacent two of the insulating gap monomers are connected by a safety door 1;

[0008] The middle-edge-retaining safety film includes a second base film, on which a second metal coating is plated. An inner series edge gap is longitudinally provided in the middle of the second metal coating to divide the second metal coating. The second metal coating is symmetrically provided with a second high-resistance region, a second medium-resistance region, and a second low-resistance region with respect to the inner series edge gap;

[0009] The middle-edge-retaining safety film further includes a plurality of T-shaped insulating gaps II that divide the second metal coating of the second high-resistance region. The T-shaped insulating gaps II include a plurality of T-shaped insulating gap monomers arranged at intervals, and adjacent two T-shaped insulating gap monomers are connected by a safety gate II.

[0010] Preferably, in the inner series edge-thickened high-resistance safety metallized pair film: adjacent two T-shaped insulating gaps I divide the first metal coating into several unit blocks I, and the area of a single unit block I is 500-1000mm 2 .

[0011] Preferably, in the inner series edge-thickened high-resistance safety metallized pair film: the width of the T-shaped insulating gap I is 2-3mm.

[0012] Preferably, in the inner series edge-thickened high-resistance safety metallized pair film: the width of the edge-retaining region is 3-6mm.

[0013] Preferably, in the inner series edge-thickened high-resistance safety metallized pair film: the edge-retaining region includes a thin film edge-retaining portion and a wavy slitting portion provided on one side of the thin film edge-retaining portion.

[0014] Preferably, in the inner series edge-thickened high-resistance safety metallized pair film: adjacent two T-shaped insulating gaps II divide the second metal coating into several unit blocks II, and the area of a single unit block II is 500-1000mm 2 .

[0015] Preferably, in the inner series edge-thickened high-resistance safety metallized pair film: an edge-thickened electrode layer is provided on the side of the second low-resistance region away from the second medium-resistance region.

[0016] Advantages of the present invention:

[0017] The inner series edge-thickened high-resistance safety metallized pair film of the present invention adopts a high-resistance design, and the self-healing performance of the capacitor is better; by setting an inner series structure, the nominal voltage of the component is higher, and the equivalent series resistance and equivalent series inductance are extremely low; the heat generation of the component is relatively small; by setting equal small unit blocks, the capacity loss is smaller; by setting a wavy slitting portion on the edge-retaining thin film, it is beneficial to improve the gold spraying strength, reduce the loss, and the large current impact resistance performance is better; by setting a low-resistance region at the electrode lead-out part, the connection loss is reduced, it is resistant to large currents, and has impact resistance. Description of the Drawings

[0018] Figure 1 This is a schematic structural diagram of the double-edge-retained safety film in the present invention.

[0019] Figure 2 This is a sheet resistance diagram of the double-edge-retained safety film in the present invention.

[0020] Figure 3 This is a schematic structural diagram of the middle-edge-retained safety film in the present invention.

[0021] Figure 4 This is a sheet resistance diagram of the middle-edge-retained safety film in the present invention. Detailed Description of the Invention

[0022] The present invention will be further described below in conjunction with specific drawings and embodiments.

[0023] Embodiment 1

[0024] As Figures 1-4 shown, this embodiment provides an inner-series edge-thickened high-sheet-resistance safety metallized pair film, wherein: the inner-series edge-thickened high-sheet-resistance safety metallized pair film includes a middle-edge-retained safety film and a double-edge-retained safety film disposed on the middle-edge-retained safety film. The double-edge-retained safety film includes a base film 15, a retained-edge area 14 is provided on one side of the base film 15, a first metal coating is plated on the base film 15, and a first low-sheet-resistance area 11, a first middle-sheet-resistance area 12, and a first high-sheet-resistance area 13 are symmetrically provided on the first metal coating with respect to the central axis;

[0025] The double-edge-retained safety film further includes a plurality of T-shaped insulating gaps 5 that separate the first high-sheet-resistance area 13 of the first metal coating. The T-shaped insulating gap 5 includes a plurality of spaced-apart T-shaped insulating gap monomers 51, and adjacent two of the insulating gap monomers 51 are connected by a first safety gate 3;

[0026] The middle-edge-retained safety film includes a second base film 20, a second metal coating is plated on the second base film 20, an inner-series edge gap 16 that longitudinally separates the second metal coating is provided in the middle of the second metal coating, and a second high-sheet-resistance area 17, a second middle-sheet-resistance area 18, and a second low-sheet-resistance area 19 are symmetrically provided on the second metal coating with respect to the inner-series edge gap 16;

[0027] The middle-edge-retained safety film further includes a plurality of T-shaped insulating gaps 10 that separate the second high-sheet-resistance area 17 of the second metal coating. The T-shaped insulating gap 10 includes a plurality of spaced-apart T-shaped insulating gap monomers 101, and adjacent two of the T-shaped insulating gap monomers 101 are connected by a second safety gate 8.

[0028] Wherein: Two adjacent T-shaped insulation gaps 5 divide the first metal coating into several unit blocks 4, and the area of a single unit block 4 is 500-1000 mm 2 .

[0029] Wherein: The width of the first T-shaped insulation gap 5 is 2-3 mm.

[0030] Wherein: The width of the reserved edge area 14 is 3-6 mm.

[0031] Wherein: The reserved edge area 14 includes a thin film reserved edge 2 and a wavy slitting part 1 arranged on one side of the thin film reserved edge 2.

[0032] Wherein: Two adjacent T-shaped insulation gaps 10 divide the second metal coating into several unit blocks 9, and the area of a single unit block 9 is 500-1000 mm 2 .

[0033] Wherein: An edge thickened electrode layer 7 is arranged on the side of the second low square resistance area 19 away from the second medium square resistance area 18.

[0034] The metallized film electrode plate includes a middle reserved edge safety film and a double reserved edge safety film arranged on the middle reserved edge safety film, and is divided into several unit blocks 4 and unit blocks 9 of equal size. The unit block 4 is connected in parallel with the electrode plates of other unit blocks through a safety gate 3, and the unit block 9 is connected in parallel with the electrode plates of other unit blocks through a safety gate 8. After the middle reserved edge safety film and the double reserved edge safety film overlap, each unit block electrode plate is insulated from the corresponding position electrode plate of the opposite film through a base film and forms a small capacitor.

[0035] The safety film is a two-string structure, and the nominal voltage of the component can be designed higher. The capacitor designed with an internal series connection has a smaller equivalent series inductance and equivalent series resistance than that designed with a single series connection. In this way, the heat generation of the capacitor will be relatively small, and heat generation will have a relatively serious impact on the operating life and operating safety of the capacitor.

[0036] The middle reserved edge film is as Figure 4 shown. The second low square resistance area 19 adopts a low square resistance design, the evaporated metal layer is thickened, and it has a strong overcurrent withstand capacity and can resist large inrush current impacts; the first high square resistance area 13 and the second high square resistance area 17 adopt a high square resistance design of 25-65 Ω / square, zinc-aluminum alloy, and a gradually changing square resistance design for evaporating metal to adapt to the transition change of the current of the capacitor component from large to small under ripples.

[0037] According to performance requirements, both the middle-edge safety film and the double-edge safety film adopt a structural design with 1 to n safety gates at the plate part of each unit block. The capacity formed by the plates of each unit block accounts for a very small proportion of the capacity of a single component. Therefore, even if the insulation between the plates of a certain unit block is damaged and needs to be isolated, the resulting capacity loss accounts for a negligible change in the capacity of the entire capacitor and does not affect the performance requirements of the capacitor during normal operation.

[0038] Each unit block 4 is protected by a safety gate 3, and each unit block 9 is protected by a safety gate 8. When self-healing fails in the small-capacitance metallized plates of unit block 4 and unit block 9, the safety gate 3 and the safety gate 8 will act to protect and isolate the faulty unit block small capacitor, ensuring the safe and reliable operation of the entire capacitor. Even if the capacity of the entire capacitor is lost to less than 90%, the capacitor will not experience serious bulging and explosion.

[0039] Working principle: When a certain part of the metallized safety film breaks down, the energy on the unit block where the breakdown point is located and the surrounding unit blocks will all flow towards the breakdown point, and then there will be energy passing through the safety gate; if the breakdown point is self-healing normally, then the self-healing energy consumed at the breakdown point is very small, the current flowing through the safety gate will be very small, and the energy generated by it will not cause the safety gate to act; if the self-healing of the breakdown point fails, due to the relatively small short-circuit resistance at the fault point, the current and energy flowing through the safety gate will increase significantly, and the larger energy will cause the safety gate of the unit block corresponding to the fault point to act, thus isolating and preventing the further expansion of the fault part and playing a safety protection role for the capacitor.

[0040] Finally, it should be noted that the above specific implementation manners are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An inner series edge-thickened high sheet resistance safety metallized facing film, characterized in that: The inner series edge thickened high sheet resistance safety metallized film includes a middle-edge-retained safety film and a double-edge-retained safety film disposed on the middle-edge-retained safety film. The double-edge-retained safety film includes a first base film (15). A retained-edge area (14) is provided on one side of the first base film (15). A first metal coating is plated on the first base film (15). The first metal coating is symmetrically provided with a first low sheet resistance area (11), a first middle sheet resistance area (12), and a first high sheet resistance area (13) about the central axis; The double-edge-retained safety film further includes a plurality of T-shaped insulating gaps one (5) that separate the first metal coating of the first high sheet resistance area (13). The T-shaped insulating gaps one (5) include a plurality of T-shaped insulating gap monomers one (51) arranged at intervals. Adjacent two of the insulating gap monomers one (51) are connected by a first safety gate (3); The middle-edge-retained safety film includes a second base film (20). A second metal coating is plated on the second base film (20). An inner series edge gap (16) that longitudinally separates the second metal coating is provided in the middle of the second metal coating. The second metal coating is symmetrically provided with a second high sheet resistance area (17), a second middle sheet resistance area (18), and a second low sheet resistance area (19) about the inner series edge gap (16); The middle-edge-retained safety film further includes a plurality of T-shaped insulating gaps two (10) that separate the second metal coating of the second high sheet resistance area (17). The T-shaped insulating gaps two (10) include a plurality of T-shaped insulating gap monomers two (101) arranged at intervals. Adjacent two of the T-shaped insulating gap monomers two (101) are connected by a second safety gate (8); Each adjacent pair of the T-shaped insulating gaps 1 (5) divides the first metal coating into a plurality of first unit blocks (4), and the area of a single first unit block (4) is 500-1000 mm 2 ; The retained-edge area (14) includes a thin film edge (2) and a wavy slitting portion (1) provided on one side of the thin film edge (2); An edge thickened electrode layer (7) is provided on the side of the second low sheet resistance area (19) away from the second middle sheet resistance area (18); Each unit block one (4) is protected by a first safety gate (3), and each unit block two (9) is protected by a second safety gate (8). When the small capacitance metallized plates of the unit block one (4) and the unit block two (9) suffer from self-healing failure, the first safety gate (3) and the second safety gate (8) will act; When a certain part of the metallized safety film is punctured, the energy on the unit block where the puncture point is located and the surrounding unit blocks will flow towards the puncture point. Then, there will be energy passing through the safety gate; If the puncture point is self-healed normally, the self-healing energy consumed by the puncture point is very small, the current flowing through the safety gate is very small, and the energy generated by it will not cause the safety gate to act; If the self-healing of the puncture point fails, due to the relatively small short-circuit resistance of the fault point, the current and energy flowing through the safety gate increase significantly. The larger energy will cause the safety gate of the unit block corresponding to the fault point to act.

2. The inner string type edge thickened high sheet resistance safety metallized pair film according to claim 1, characterized in that: The width of the T-shaped insulating gap one (5) is 2-3 mm.

3. The inner string type edge thickened high sheet resistance safety metallized pair of films according to claim 1, wherein: The width of the retained-edge area (14) is 3-6 mm.

4. The inner string type edge thickened high sheet resistance safety metallized facing film according to claim 1, wherein: Two adjacent T-shaped insulating gaps two (10) divide the second metal coating into several unit blocks two (9), and the area of a single unit block two (9) is 500-1000 mm 2 .

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