A film capacitor

Abstract

The utility model relates to the technical field of film capacitors, and specifically discloses a film capacitor, comprising a capacitor housing and a capacitor core sealed in the capacitor housing, the capacitor core comprising two metallized films stacked up and down and wound, the metallized film comprising a dielectric layer and a metal coating evaporated on at least one side of the dielectric layer, the surface of the metal coating is coated with anti-oxidation oil, so that moisture erosion of the metal coating can be reduced to a certain extent, and its oxidation rate under the influence of moisture is reduced, so as to reduce the degree of electrochemical corrosion of the metal coating in a harsh environment, thereby achieving a better moisture-proof and moisture-resistant effect, so that the film capacitor can also have good stability in a harsh environment, avoid rapid failure of the product capacity, and thus ensure the life and reliability of the product.

Description

Technical Field

[0001] The utility model relates to the technical field of film capacitors, in particular to a film capacitor. Background Art

[0002] Film capacitors are indispensable components in power conversion modules and are often used in DC filtering, AC filtering, absorption, resonance and other lines. With the development of new energy and electricity, the high humidity and hot harsh environment of outdoor applications has put forward more stringent requirements on the moisture resistance of capacitors. Film capacitors and other products made of conventional metallized films have general moisture resistance. In a harsh environment, moisture will more easily lead to accelerated capacity failure. Since the metallized film coating is made of materials such as zinc or aluminum, it is more active. When moisture enters the body, it comes into contact with the surface metal and, under the action of the electric field, it will accelerate the electrochemical corrosion of the coating electrode, affecting the life and reliability of the product. Utility Model Content

[0003] The utility model aims to provide a metallized film to solve the above-mentioned technical problems.

[0004] To achieve the above-mentioned purpose, the technical solution of the utility model is: a film capacitor, including a capacitor housing and a capacitor core sealed in the capacitor housing, the capacitor core including two metallized films stacked up and down and wound, the metallized film including a dielectric layer and a metal coating evaporated on at least one side of the dielectric layer, the surface of the metal coating is coated with anti-oxidation oil, which can reduce moisture erosion of the metal coating to a certain extent, reduce the oxidation rate of the metal coating under the influence of moisture, so as to reduce the degree of electrochemical corrosion of the metal coating in harsh environments, thereby achieving better moisture-proof and moisture-resistant effects, so that the film capacitor can also have good stability in harsh environments, avoid rapid failure of the product's capacity, and thus ensure the life and reliability of the product.

[0005] Preferably, the two metallized films are an upper metallized film and a lower metallized film, respectively. The upper metallized film has two metal coatings, which are evaporated side by side on the same side of the dielectric layer of the upper metallized film, and a gap is formed between the two metal coatings, which forms a center edge of the upper metallized film. The lower metallized film has one metal coating, which is evaporated on one side of the dielectric layer of the lower metallized film. The upper metallized film and the lower metallized film are stacked up and down and separated into a C1 capacitor and a C2 capacitor connected in series after winding.

[0006] Preferably, the anti-oxidation oil on the surfaces of the two metal coatings of the upper metallized film contacts and fuses with each other at the gap to form a whole.

[0007] Preferably, the anti-oxidation oil is coated on the surface of the metal coating by a double 85 moisture-heat resistant coating process.

[0008] Preferably, the metallized film is a metallized polypropylene zinc aluminum film, the metal coating is a zinc aluminum coating, and the dielectric layer is a polypropylene film layer.

[0009] Preferably, the metallized film is wound at the front and end of the winding to generate high temperature by high voltage and low current to evaporate the metal coating to form a clean end.

[0010] The utility model has the following beneficial effects:

[0011] The utility model comprises a capacitor housing and a capacitor core sealed in the capacitor housing, the capacitor core comprises two metallized films stacked up and down and wound, the metallized film comprises a dielectric layer and a metal coating evaporated on at least one side of the dielectric layer, the surface of the metal coating is coated with anti-oxidation oil, which can reduce moisture erosion of the metal coating to a certain extent, reduce the oxidation rate of the metal coating under the influence of moisture, and reduce the degree of electrochemical corrosion of the metal coating in harsh environments, thereby achieving better moisture-proof and moisture-resistant effects, so that the film capacitor can also have good stability in harsh environments, avoid rapid reduction and loss of product capacity, and thus ensure the life and reliability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of winding of capacitor core of an embodiment of the utility model;

[0013] Figure 2 is a cross-sectional view of a stack of an upper metallized film and a lower metallized film according to an embodiment of the utility model;

[0014] Figure 3 is a cross-sectional view of an upper metallized film of an embodiment of the utility model;

[0015] Figure 4 is a cross-sectional view of a lower metallized film of an embodiment of the utility model;

[0016] Figure 5 It is a circuit diagram of an embodiment of the utility model;

[0017] The attached figure is marked with: 1 dielectric layer, 2 metal plating layer, 3 anti-oxidation oil, 4 middle edge, 5 cleaning end. DETAILED DESCRIPTION

[0018] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0019] In the description of the present invention, unless otherwise specified, "multiple" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] See also Figure 1-5 As shown, as an embodiment of the utility model, a film capacitor is provided, including a capacitor housing and a capacitor core sealed in the capacitor housing, the capacitor core includes two metallized films stacked up and down and wound, the metallized film includes a dielectric layer 1 and a metal coating 2 evaporated on one side of the dielectric layer 1, the surface of the metal coating 2 is coated with anti-oxidation oil 3, which can reduce moisture erosion of the metal coating 2 to a certain extent, reduce the oxidation rate of the metal coating 2 under the influence of moisture, so as to reduce the degree of electrochemical corrosion of the metal coating 2 in harsh environments, thereby achieving better moisture-proof and moisture-resistant effects, and thus making the film capacitor have better stability in harsh environments, avoiding rapid failure of the product's capacity, thereby ensuring the life and reliability of the product.

[0022] In this embodiment, the metallized film is a metallized polypropylene zinc aluminum film, the metal coating 2 is a zinc aluminum coating, and the dielectric layer 1 is a polypropylene film layer, which increases the product's ability to resist high temperature and high humidity.

[0023] In this embodiment, the two metallized films are an upper metallized film and a lower metallized film, the upper metallized film has two metal coatings 2, the two metal coatings 2 are vapor-deposited side by side on the same side of the dielectric layer 1 of the upper metallized film, and a gap is formed between the two metal coatings 2, the gap forms a middle margin 4 of the upper metallized film, the lower metallized film has one metal coating 2, the metal coating 2 is vapor-deposited on one side of the dielectric layer 1 of the lower metallized film, the upper metallized film and the lower metallized film are stacked up and down and separated into a series capacitor C1 and a series capacitor C2 after winding, thereby increasing the withstand voltage level of the film capacitor, and at the same time, the metallized polypropylene zinc aluminum film series structure is adopted, which can increase the dielectric electric field strength of the product, reduce the edge electric field voltage of the metal coating 2, and reduce the probability of corona occurring on the end face of the capacitor core, and can cope with the harmonic changes of complex power grids to ensure its stability.

[0024] In this embodiment, the anti-oxidation oil 3 on the surfaces of the two metal coatings 2 of the upper metallized film contact and fuse with each other at the gap, further enhancing the protective effect between the two metal coatings 2 and the whole, and effectively preventing moisture corrosion and oxidation.

[0025] In this embodiment, the anti-oxidation oil 3 is coated on the surface of the metal coating 2 through a double 85 moisture-resistant and heat-resistant coating process, and the coating effect is more firm and stable, thereby further improving the moisture-proof and humidity-resistant effect of the metal coating 2.

[0026] Preferably, the metallized film is wound at the front and end thereof and high voltage and low current are used to generate high temperature to evaporate the metal coating 2 to form a clean end 5, thereby ensuring the insulation performance of the product.

[0027] Of course, in other cases, the metal coating layer 2 can also be evaporated on two opposite sides of the dielectric layer 1 .

[0028] Although the present invention has been specifically demonstrated and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes made to the present invention in form and detail, without departing from the spirit and scope of the present invention as defined in the appended claims, shall fall within the scope of protection of the present invention.

Claims

1. A film capacitor, characterized in that: The invention comprises a capacitor housing and a capacitor core sealed in the capacitor housing, wherein the capacitor core comprises two metallized films stacked up and down and wound, wherein the metallized film comprises a dielectric layer and a metal coating evaporated on at least one side of the dielectric layer, wherein the surface of the metal coating is coated with anti-oxidation oil; the metallized film is a metallized polypropylene zinc aluminum film, the metal coating is a zinc aluminum coating, and the dielectric layer is a polypropylene film layer.

2. The film capacitor according to claim 1, characterized in that: The two metallized films are an upper metallized film and a lower metallized film. The upper metallized film has two metal coatings, which are vapor-deposited side by side on the same side of the dielectric layer of the upper metallized film, and a gap is formed between the two metal coatings, which forms a center edge of the upper metallized film. The lower metallized film has one metal coating, which is vapor-deposited on one side of the dielectric layer of the lower metallized film. The upper metallized film and the lower metallized film are stacked up and down and separated into a C1 capacitor and a C2 capacitor connected in series after winding.

3. The film capacitor according to claim 2, characterized in that: The anti-oxidation oil on the surfaces of the two metal coatings of the upper metallized film contacts and fuses with each other at the gap to form a whole.

4. The film capacitor according to claim 1, characterized in that: The anti-oxidation oil is coated on the surface of the metal coating through a double 85 moisture-resistant heat-resistant coating process.

5. The film capacitor according to claim 1, characterized in that: The metallized film is wound at the front and end of the winding process, generating high temperature through high voltage and low current to evaporate the metal coating to form a clean end.

Images