Low-temperature-rise filter capacitor

Abstract

The utility model relates to a low temperature rise filter capacitor which comprises a circular aluminum shell, the top of the aluminum shell is provided with an installation opening, a cover assembly is packaged at the installation opening, and a capacitor cavity is defined between the cover assembly and the aluminum shell. The capacitor cavity is internally provided with more than one group of inner string cores which are overlapped up and down along the height direction and an insulating combined component which is arranged at the periphery of the inner string cores in a surrounding manner, the inner string cores are connected in parallel, the cover assembly is provided with two groups of leading-out ends, the two groups of leading-out ends are respectively connected with a conductive wire, and the conductive wire is connected with the capacitor cavity. The two conductive wires penetrate through the insulating combined component and are electrically connected with the upper-layer metal spraying surface and the lower-layer metal spraying surface of one group of inner string cores respectively; and a filling material consisting of insulating oil is canned in the capacitor cavity. The capacitor is simple in structure, easy to assemble and high in production efficiency, and has the advantages of high voltage resistance, low temperature rise, long service life and the like.

Description

Technical Field

[0001] The utility model relates to the field of capacitors, in particular to a low-temperature rise filter capacitor. Background Art

[0002] With the refinement of electrical equipment and the improvement of power quality requirements, there is an increasing demand for capacitors with long life and high withstand voltage. However, ordinary capacitors cannot meet the requirements of high current, ultra-high voltage and high temperature resistance. When capacitors are exposed to excessive temperature rise, overvoltage and overcurrent for a long time, the internal pressure will be too high, thereby damaging the capacitor. Therefore, it is necessary to make improvements. Summary of the invention

[0003] The utility model aims to solve the above existing problems and provide a low temperature rise filter capacitor with simple and reasonable structure.

[0004] A low-temperature rise filter capacitor comprises a circular aluminum shell, a mounting opening is provided on the top of the aluminum shell, a cover assembly is encapsulated at the mounting opening, and a capacitor cavity is defined between the cover assembly and the aluminum shell, wherein the capacitor cavity is provided with one or more inner string cores stacked up and down in the height direction and an insulating composite component arranged around the outer periphery of the inner string cores, wherein the inner string cores are connected in parallel with each other, two groups of lead terminals are provided on the cover assembly, each of the two groups of lead terminals is connected with a conductive wire, the two conductive wires pass through the insulating composite component and are respectively electrically connected to the upper gold-sprayed surface and the lower gold-sprayed surface of one group of the inner string cores, and the capacitor cavity is filled with a filler composed of an insulating oil agent.

[0005] The purpose of the utility model can also be solved by the following technical measures:

[0006] As a more specific solution, the insulating combination component includes an insulating seat, which is divided into an upper insulating seat with an opening facing downward and a lower insulating seat with an opening facing upward. The upper insulating seat is nested in the upper end of the inner string core of the highest layer, and the lower insulating seat is nested in the lower end of the inner string core of the lowest layer.

[0007] As a further solution, the insulating composite component also includes insulating paper, the width of the insulating paper is the same as or close to the height of the stacked inner string cores, the insulating paper is wrapped around the outer side of the inner string core, and the side edges of the upper insulating seat and the lower insulating seat are wrapped between the insulating paper and the inner string core.

[0008] As a further solution, when there are more than two groups of inner string cores, the upper gold-sprayed surface of the highest layer of inner string cores is welded to the lower gold-sprayed surface of the lowest layer of inner string cores through a yellow wax tube; the upper gold-sprayed surface and the lower gold-sprayed surface of two adjacent inner string cores are welded to each other through a woven copper strip.

[0009] As a further solution, the inner string core includes a hollow core rod and two layers of film. The inner string core is made by winding the two layers of film around the core rod. The two layers of film include an outer film and an inner film.

[0010] As a further solution, one end of one of the conductive wires is welded to the upper gold-sprayed surface, and the other end is electrically connected to one group of lead ends; another conductive wire is passed through the hollow part of the core rod, and one end of it is welded to the lower gold-sprayed surface, and the other end is electrically connected to another group of lead ends.

[0011] As a further solution, the bottom of the aluminum shell is closed and has a bottom wall, and the thickness of the bottom wall of the aluminum shell is greater than the thickness of the side wall of the aluminum shell, and the thickness of the bottom wall increases from the edge to the center.

[0012] As a further solution, two inner metal coatings are symmetrically arranged on the inner surface of the inner film, and the two inner metal coatings are separated; an outer metal coating is arranged on the inner surface of the outer film, and the outer metal coating is connected in series with the left and right inner metal coatings.

[0013] As a further solution, the cover assembly includes:

[0014] A metal cover plate, wherein the edge of the metal cover plate is provided with a curling edge, and the metal cover plate is buckled at the installation opening through the curling edge;

[0015] An insulating cover, the insulating cover is placed on the upper side of the metal cover plate, and the insulating cover is provided with at least one oil filling hole connected to the capacitor cavity;

[0016] An explosion-proof block, which is placed on the lower side of the metal cover plate and has holes corresponding to the lead-out ends;

[0017] A copper foil sheet, wherein the copper foil sheet is arranged on the bottom surface of the explosion-proof block corresponding to the hole, and the copper foil sheet is electrically connected to the other end of the conductive wire;

[0018] Two lead-out electrodes, the two lead-out electrodes are fixed on the insulating seat at intervals, the upper ends of the two lead-out electrodes are located on the upper side of the explosion-proof block and constitute the lead-out ends, and the lower ends of the two lead-out electrodes pass through the holes and are electrically connected to the copper foil;

[0019] A sealing ring is sleeved between the lead-out electrode and the metal cover plate.

[0020] As a further solution, a connecting screw is connected to the bottom surface of the aluminum shell, the connecting screw is arranged at the center of the bottom wall of the aluminum shell, and a fastening nut for fixing the capacitor is movably provided on the connecting screw.

[0021] The beneficial effects of the utility model are as follows:

[0022] The utility model discloses a low-temperature rise filter capacitor, which has the advantages of simple structure, easy assembly, high production efficiency, high withstand voltage, low temperature rise, long service life and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 and Figure 2 This is a schematic cross-sectional structure diagram of Example 1 of the present utility model.

[0024] Figure 3 It is a schematic diagram of the expanded structure of the inner string core in the utility model.

[0025] Figure 4 It is a schematic diagram of the cross-sectional structure of the outer film and the inner film in the utility model.

[0026] Figure 5 This is a schematic diagram of the top view structure of the capacitor in the utility model.

[0027] Figure 6 This is a schematic diagram of the cross-sectional structure of Example 2 of the present utility model.

[0028] Figure 7 This is a schematic diagram of the cross-sectional structure of Example 3 of the present utility model. DETAILED DESCRIPTION

[0029] The utility model is further described below in conjunction with the accompanying drawings and embodiments. Embodiment 1:

[0030] like Figures 1 to 5 As shown, a low-temperature rise filter capacitor includes a circular aluminum shell 1, a mounting opening 101 is opened on the top of the aluminum shell 1, a cover assembly 2 is encapsulated at the mounting opening 101, and a capacitor cavity 201 is defined between the cover assembly 2 and the aluminum shell 1, a group of inner string cores 3 and an insulating composite member 4 arranged around the outer periphery of the inner string core 3 are arranged in the capacitor cavity 201, two groups of lead terminals 5 are arranged on the cover assembly 2, and the two groups of lead terminals 5 are respectively connected to a conductive wire 6, the two conductive wires 6 pass through the insulating composite member 4 and are respectively electrically connected to the upper gold-sprayed surface 301 and the lower gold-sprayed surface 302 of the inner string core 3, and the capacitor cavity 201 is filled with a filler 7 composed of an insulating oil agent.

[0031] This capacitor is mainly suitable for photovoltaic DC to AC filtering or harmonic circuits, or capacitor power systems, or inductive circuits. It has a simple structure, easy assembly, high production efficiency, and has the advantages of high voltage resistance, low temperature rise, and long life.

[0032] The insulating assembly component 4 includes an insulating seat, which is divided into an upper insulating seat 41 with an opening facing downward and a lower insulating seat 42 with an opening facing upward. The upper insulating seat 41 is nested in the upper end of the inner string core 3, and the lower insulating seat 42 is nested in the lower end of the inner string core 3.

[0033] The insulating assembly 4 also includes insulating paper 43, the width of which is the same as or close to the height of the inner string core 3 stacked together, the insulating paper 43 is wrapped around the outer side of the inner string core 3, and the sides of the upper insulating seat 41 and the lower insulating seat 42 are wrapped between the insulating paper 43 and the inner string core 3.

[0034] The above structure utilizes the upper insulating seat 41, the lower insulating seat 42 and the insulating paper 43 to block the connection between the inner string core 3 and the aluminum shell 1, thereby improving the safety of the capacitor.

[0035] The inner string core 3 includes a hollow core rod 31 and two layers of film. The inner string core 3 is made by winding two layers of film around the core rod 31 . The two layers of film include an outer film 32 and an inner film 33 .

[0036] One end of one of the conductive wires 6 is welded to the upper gold-sprayed surface 301, and the other end is electrically connected to one group of lead-out terminals 5; another conductive wire 6 is passed through the hollow part of the core rod 31, and one end of it is welded to the lower gold-sprayed surface 302, and the other end is electrically connected to another group of lead-out terminals 5; the conductive wire 6 is passed through the hollow part of the core rod 31, which can reduce the distance between the aluminum shell 1 and the inner string core 3, making the capacitor more compact.

[0037] The bottom of the aluminum shell 1 is closed and formed with a bottom wall 11, and the thickness of the bottom wall 11 of the aluminum shell 1 is greater than the thickness of the side wall 12 of the aluminum shell 1, and the thickness of the bottom wall 11 increases from the edge to the center; the bottom strength of the aluminum shell 1 can be increased, and when the capacitor heats up and expands, its pressure can only be released in the direction of the cover assembly, thereby pulling off the conductive wire to disconnect the capacitor furnace.

[0038] The inner surface of the inner film 33 is symmetrically provided with two inner metal coatings 331, and the two inner metal coatings 331 are separated from each other; the inner surface of the outer film 32 is provided with an outer metal coating 321, and the outer metal coating 321 is connected in series with the left and right inner metal coatings 331; the outer metal coating 321 is connected in series and in parallel with the left and right inner metal coatings 331, thereby realizing an internal series connection.

[0039] In addition, the inner metal coating 331 covers the edge of the inner film 33, and a thickened area 332 is arranged close to the edge of the inner metal coating 331; the width of the outer film 32 is smaller than the width of the inner film 33, and the outer metal coating 321 is arranged in the middle position of the outer film 32, and a margin 322 is formed at the edge of the outer film 32, and the margin 322 is arranged corresponding to the thickened area 332.

[0040] In the above single-phase or two-phase capacitor, the edge square resistance of the film is between 2Ω and 4Ω.

[0041] In addition, specifically;

[0042] The diameter of the inner string core 3 is ΦD, and 14.2mm±2mm≤ΦD≤51mm±2mm;

[0043] The length of the inner string core 3 is H, and 32mm±2mm≤H≤102mm±2mm;

[0044] The cover assembly 2 comprises:

[0045] A metal cover plate 21, wherein the edge of the metal cover plate 21 is provided with a curling edge 211, and the metal cover plate 21 is buckled at the installation opening 101 through the curling edge 211;

[0046] An insulating cover 22, the insulating cover 22 is placed on the upper side of the metal cover plate 21, and the insulating cover 22 is provided with at least one oil filling hole 221 connected to the capacitor cavity 201;

[0047] An explosion-proof block 23, which is placed on the lower side of the metal cover plate 21 and has a hole 231 corresponding to the lead-out terminal 5;

[0048] A copper foil sheet 24, wherein the copper foil sheet 24 is disposed on the bottom surface of the explosion-proof block 23 and corresponds to the hole 231, and the copper foil sheet 24 is electrically connected to the other end of the conductive wire 6;

[0049] Two lead-out electrodes 25, the two lead-out electrodes 25 are fixed on the insulating seat at intervals, the upper ends of which are located on the upper side of the explosion-proof block 23 and constitute the lead-out end 5, and the lower ends thereof pass through the hole 231 and are electrically connected to the copper foil 24; in this embodiment, the lead-out electrodes 25 are mainly composed of lead-out bolts, nuts and rivets.

[0050] The sealing ring 26 is sleeved between the lead-out electrode 25 and the metal cover plate 21 .

[0051] Through the cover assembly 2 of the above structure, the explosion-proof block 23 fixes the position of the conductive wire 6. When the capacitor is damaged and causes heat expansion to a certain extent, the metal cover plate 21 arches upward from the weak point of the metal cover plate 21, so that the conductive wire 6 or the soldering point between the copper foil 24 and the conductive wire 6 is broken, avoiding further temperature rise, thereby playing an explosion-proof role.

[0052] The bottom surface of the aluminum shell 1 is connected with a connecting screw 10, which is arranged at the center of the bottom wall 11 of the aluminum shell 1, and a fastening nut 13 for fixing the capacitor is movably provided on the connecting screw 10; by using the connecting screw 10 and the fastening nut 13, the capacitor can be more conveniently assembled into the electrical equipment. Embodiment 2:

[0053] The difference between the second embodiment and the first embodiment is that: Figure 6 As shown, when two groups of inner cores 3 are included, the two groups of inner cores 3 are stacked up and down in the capacitor along the height direction, and the two groups of inner cores 3 are connected in parallel with each other;

[0054] The specific connection method is: the upper gold-sprayed surface 301 of the highest layer of inner string core 3 is welded to the lower gold-sprayed surface 302 of the lowest layer of inner string core 3 through the yellow wax tube 8; the upper gold-sprayed surface 301 and the lower gold-sprayed surface 302 of two adjacent inner string cores 3 are welded to each other through a woven copper belt 9.

[0055] In addition, the upper insulating seat 41 is nested in the upper end of the inner string core 3 of the highest layer, and the lower insulating seat 42 is nested in the lower end of the inner string core 3 of the lowest layer. Embodiment three:

[0056] The difference between the third embodiment and the first embodiment is that: Figure 7 As shown, when three groups of inner string cores 3 are included, the structure and principle of the three groups of inner string cores 3 are basically the same as those in Example 2, so they are not repeated here. In addition, the three groups of inner string cores 3 form a three-phase capacitor, and the edge square resistance of the film in the three-phase capacitor is not higher than 3Ω.

[0057] The above is a preferred embodiment of the utility model, which shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principle of the utility model. The utility model may have various changes and improvements without departing from the spirit and scope of the utility model, and these changes and improvements fall within the scope of the utility model to be protected, and the scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A low temperature rise filter capacitor, characterized in that: The invention comprises a circular aluminum shell (1), wherein a mounting opening (101) is provided at the top of the aluminum shell (1), a cover assembly (2) is encapsulated at the mounting opening (101), and a capacitor cavity (201) is defined between the cover assembly (2) and the aluminum shell (1), wherein the capacitor cavity (201) is provided with one or more inner string cores (3) stacked up and down in a height direction and an insulating composite component (4) arranged around the outer periphery of the inner string cores (3), wherein the inner string cores (3) are connected in parallel to each other, and wherein two groups of lead terminals (5) are provided on the cover assembly (2), wherein each of the two groups of lead terminals (5) is connected to a conductive wire (6), wherein the two conductive wires (6) pass through the insulating composite component (4) and are respectively electrically connected to an upper gold-sprayed surface (301) and a lower gold-sprayed surface (302) of one group of the inner string cores (3), and wherein a filler (7) composed of an insulating oil agent is contained in the capacitor cavity (201).

2. A low temperature rise filter capacitor according to claim 1, characterized in that: The insulating assembly component (4) comprises an insulating seat, which is divided into an upper insulating seat (41) with an opening facing downward and a lower insulating seat (42) with an opening facing upward, the upper insulating seat (41) being nested in the upper end of the highest layer of the inner string core (3), and the lower insulating seat (42) being nested in the lower end of the lowest layer of the inner string core (3).

3. A low temperature rise filter capacitor according to claim 2, characterized in that: The insulating assembly component (4) further comprises insulating paper (43), the width of the insulating paper (43) being the same as or close to the height of the inner string cores (3) when stacked, the insulating paper (43) being wrapped around the outer side of the inner string cores (3), and the side edges of the upper insulating seat (41) and the lower insulating seat (42) being wrapped between the insulating paper (43) and the inner string cores (3).

4. The low temperature rise filter capacitor according to claim 1, characterized in that: When two or more groups of inner string cores (3) are included, the upper gold-sprayed surface (301) of the highest layer of inner string cores (3) is welded to the lower gold-sprayed surface (302) of the lowest layer of inner string cores (3) through a yellow wax tube (8); and the upper gold-sprayed surface (301) and the lower gold-sprayed surface (302) of two adjacent inner string cores (3) are welded to each other through a braided copper strip (9).

5. The low temperature rise filter capacitor according to claim 1, characterized in that: The inner string core (3) comprises a hollow core rod (31) and two layers of film. The inner string core (3) is made by winding the two layers of film around the core rod (31). The two layers of film comprise an outer film (32) and an inner film (33).

6. A low temperature rise filter capacitor according to claim 5, characterized in that: One end of one of the conductive wires (6) is welded to the upper gold-sprayed surface (301), and the other end is electrically connected to one group of lead-out terminals (5); another conductive wire (6) is passed through the hollow portion of the core rod (31), and one end of the conductive wire (6) is welded to the lower gold-sprayed surface (302), and the other end is electrically connected to another group of lead-out terminals (5).

7. The low temperature rise filter capacitor according to claim 1, characterized in that: The bottom of the aluminum shell (1) is closed and forms a bottom wall (11), the thickness of the bottom wall (11) of the aluminum shell (1) is greater than the thickness of the side wall (12) of the aluminum shell (1), and the thickness of the bottom wall (11) increases from the edge to the center.

8. The low temperature rise filter capacitor according to claim 5, characterized in that: The inner surface of the inner film (33) is symmetrically provided with two inner metal coatings (331), and the two inner metal coatings (331) are separated from each other; the inner surface of the outer film (32) is provided with an outer metal coating (321), and the outer metal coating (321) is connected in series with the left and right inner metal coatings (331).

9. The low temperature rise filter capacitor according to claim 1, characterized in that: The cover assembly (2) comprises: A metal cover plate (21), wherein an edge of the metal cover plate (21) is provided with a curling edge (211), and the metal cover plate (21) is buckled at the installation opening (101) via the curling edge (211); An insulating cover (22), the insulating cover (22) being placed on the upper side of the metal cover plate (21), and the insulating cover (22) being provided with at least one oil filling hole (221) communicating with the capacitor cavity (201); An explosion-proof block (23), the explosion-proof block (23) being placed on the lower side of the metal cover plate (21), and the explosion-proof block (23) being provided with a hole (231) corresponding to the lead-out end (5); A copper foil sheet (24), the copper foil sheet (24) being arranged on the bottom surface of the explosion-proof block (23) and corresponding to the hole (231), and the copper foil sheet (24) being electrically connected to the other end of the conductive wire (6); Two lead electrodes (25), the two lead electrodes (25) are fixed on the insulating seat at intervals, the upper ends of the two lead electrodes (25) are located on the upper side of the explosion-proof block (23) and constitute the lead end (5), and the lower ends of the two lead electrodes pass through the hole (231) and are electrically connected to the copper foil (24); A sealing ring (26), wherein the sealing ring (26) is sleeved between the lead-out electrode (25) and the metal cover plate (21).

10. The low temperature rise filter capacitor according to claim 1, characterized in that: The bottom surface of the aluminum shell (1) is connected to a connecting screw (10), the connecting screw (10) is arranged at the center of the bottom wall (11) of the aluminum shell (1), and a fastening nut (13) for fixing the capacitor is movably provided on the connecting screw (10).

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