Secondary filter capacitor for bullet train

Abstract

The utility model relates to the technical field of railway vehicles, in particular to a secondary filter capacitor for a bullet train. Comprising a polypropylene metalized grid film, a core, a core group, a rack-shaped copper bar, a circular copper braided wire, an insulator, a shell, an electrode and a flat copper braided wire, the polypropylene metalized grid film is wound into a single core through a winding machine, a plurality of cores are stacked and subjected to heat setting and then are subjected to metal spraying to form the core group, and the rack-shaped copper bars and the circular copper braided wires are connected in parallel in a welding manner to form the core group leading-out end; and the plurality of core groups are connected in parallel and welded to the electrode through the flat copper braided wires, so that the secondary filtering loop capacitor is highly adaptive to the high-speed motor train unit, the anti-surge capability of the capacitor is improved, and the service life of the capacitor is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of rail vehicles, in particular to a secondary filtering capacitor for a motor car. Background Art

[0002] In the prior art, in the secondary filtering circuit of a 25 kV multiple unit train, an LC filtering method is generally adopted, and the capacitor usually consists of a plurality of secondary filtering capacitors connected in parallel. However, this configuration often faces the problem of capacitor failure, triggering system protection actions, which not only affects the normal operation of the train, but also has a too short service life of the capacitor, greatly increasing the additional maintenance time and cost. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a secondary filtering capacitor for a motor car aiming at the defects existing in the prior art, so as to achieve the effect that the capacitor in the secondary filtering circuit is highly adapted to a high-speed multiple unit train while improving the surge resistance and service life of the capacitor.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is: a compact explosion-proof voltage transformer, comprising a polypropylene metallized mesh film, a core, a core group, a rack-shaped copper bar, a circular copper braid, an insulator, a housing, an electrode, and a flat copper braid; the polypropylene metallized mesh film is wound into a single core by a winding machine, several cores are stacked and heat-set and then sprayed with gold to form the core group, the rack-shaped copper bar and the circular copper braid are connected in parallel by welding to form the lead-out end of the core group, and several core groups are connected in parallel and welded to the electrode by the flat copper braid.

[0005] Further, the capacitor is internally wrapped with an insulating film and filled with silicone oil for insulation sealing.

[0006] Further, a single rack-shaped copper bar and a single core are fixedly connected by welding.

[0007] Further, a loop is added to each core on the core group in parallel with the circular copper braid.

[0008] Further, the polypropylene metallized mesh film adopts a hexagonal metal mesh film to increase the contact area between the metal film and the rack-shaped copper bar.

[0009] Further, the insulator is arranged outside the housing.

[0010] Further, the electrode is arranged above the insulator and penetrates the insulator.

[0011] By including a polypropylene metallized mesh film, a core, a core group, a rack-shaped copper bar, a round copper braid, an insulator, a housing, an electrode, and a flat copper braid; the polypropylene metallized mesh film is wound into a single core by a winding machine, and several cores are stacked and heat-set and then sprayed with gold to form the core group. The rack-shaped copper bar and the round copper braid are connected in parallel by welding to form the lead-out end of the core group, and several core groups are connected in parallel and welded to the electrode through the flat copper braid, achieving the effect that the secondary filter circuit capacitor is highly adapted to the high-speed EMU while also improving the surge resistance and service life of the capacitor. Brief Description of the Drawings

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0013] Figure 1 Internal structure diagram of the present invention;

[0014] Figure 2 External shape diagram of the present invention;

[0015] Figure 3 Polypropylene film mesh diagram of the present invention;

[0016] Figure 4 Schematic diagram of the core of the present invention;

[0017] Reference numerals:

[0018] Polypropylene metallized mesh film 1, core 2, core group 3, rack-shaped copper bar 4, round copper braid 5, insulator 6, housing 7, electrode 8, flat copper braid 9. Detailed Description of the Embodiments

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0020] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0021] A secondary filtering capacitor for a bullet train, as Figure 1 , 2 , shown in Figure 4, includes a polypropylene metallized mesh film 1, a core 2, a core group 3, a rack-shaped copper row 4, a circular copper braid 5, an insulator 6, a housing 7, an electrode 8, and a flat copper braid 9. The polypropylene metallized mesh film 1 is wound into a single core 2 by a winding machine. After several cores 2 are stacked and heat-set, they are sprayed with gold to form the core group 2. The rack-shaped copper row 4 and the circular copper braid 5 are connected in parallel by welding to form the lead-out end of the core group 2. Several core groups 2 are connected in parallel and welded to the electrode 8 through the flat copper braid 9.

[0022] Specifically, by using the polypropylene metallized mesh film 1 as the core medium of the capacitor, the risk of capacitor failure due to dielectric breakdown is significantly reduced, and the stability and reliability of the entire filtering circuit are improved. After the cores 2 are stacked to form the core group 3, the rack-shaped copper row 4 and the circular copper braid 5 are used as parallel connections and lead-out ends, effectively increasing the heat dissipation area of the capacitor, optimizing the current distribution, and promoting the rapid dissipation of heat, avoiding performance degradation or damage caused by overheating. Multiple core groups 3 are connected in parallel and welded to the electrode 8 through the flat copper braid 9, achieving high capacitance and low equivalent series resistance of the capacitor, enhancing the load-bearing capacity of the capacitor under high-current conditions, and ensuring its stable operation in application scenarios such as bullet trains that require frequent starting and braking. Due to the improved reliability and durability of the overall capacitor design, the system downtime and maintenance requirements caused by failures are reduced. The compact stacking design, i.e., the cores 2 are stacked into the core group 3, and the efficient heat management, i.e., heat dissipation through the rack-shaped copper row 4 and the circular copper braid 5, enable the capacitor to achieve high capacitance and high performance in a smaller space, further suitable for application scenarios with limited space such as bullet trains.

[0023] As a preference of the above embodiment, as Figure 1 , 3 , shown in the figure, the inside of the capacitor is wrapped with an insulating film and filled with silicone oil for insulation and sealing.

[0024] Specifically, the use of the insulating film provides an additional insulating layer inside the capacitor, effectively isolating the direct contact between the internal components of the capacitor and the external environment, and reducing the risk of insulation performance degradation caused by environmental factors. At the same time, the insulating film can also prevent short circuits or discharge phenomena from occurring between the internal components of the capacitor, improving the overall insulation level of the capacitor. The poured silicone oil, as an insulating and sealing material, not only has excellent insulation performance but also good fluidity and permeability. The silicone oil can penetrate into every corner inside the capacitor, fill the tiny gaps and holes, and form a dense protective film.

[0025] As a preference of the above embodiment, as Figure 1 , 3 shown, a single rack-shaped copper busbar 3 and a single core 2 are fixedly connected by welding.

[0026] Specifically, through the structure in which a single rack-shaped copper busbar 3 and a single core 2 are fixedly connected by welding, it is used to ensure the tight combination between the rack-shaped copper busbar 3 and the core 2. This firm connection not only enhances the stability of the internal structure of the capacitor but also helps to reduce the loosening or falling-off phenomena caused by vibration or impact, improving the overall durability of the capacitor. The welded connection minimizes the contact resistance between the rack-shaped copper busbar 3 and the core 2, thereby optimizing the current transmission path, reducing the energy loss during the operation of the capacitor, improving the electric energy conversion efficiency, and at the same time reducing the heating problem caused by poor contact.

[0027] As a preference of the above embodiment, as Figure 4 shown, the circular copper braid 5 is connected in parallel to each core 2 on the core group 2 to add a loop.

[0028] Specifically, by connecting the circular copper braid 5 in parallel to each core 2, it can ensure the uniform distribution of current among the cores in the core group 2, helping to reduce the problems of local overheating or performance degradation caused by uneven current distribution, and improving the overall stability and reliability of the capacitor. Increasing the parallel loop actually increases the total current channels of the capacitor, thereby improving its current-carrying capacity, and further being applicable to application scenarios such as EMUs that need to handle large currents. It can ensure that the capacitor can still operate stably under high-load conditions and meet the current requirements of the system. Due to the uniform distribution of current among the cores, the heat generated by each core will also be relatively uniform. At the same time, the circular copper braid 5, as a part of the parallel connection, also has a certain heat dissipation effect, helping to optimize the heat dissipation performance of the capacitor, reduce the internal temperature, and extend the service life. By increasing the parallel loop, when some cores or connection lines of the capacitor fail, it can still continue to work through other loops. This design improves the redundancy and reliability of the capacitor and reduces the risk of system downtime caused by single-point failures.

[0029] As a preference of the above embodiment, as Figure 3 shown, the polypropylene metallized mesh film 1 adopts a hexagonal metal mesh film and increases the contact area between the metal film and the rack-shaped copper row 4.

[0030] Specifically, compared with mesh films of other shapes, the hexagonal metal mesh film can provide a longer edge length under the same area, thereby increasing the contact points with the rack-shaped copper row 4. This design enables the current to be transmitted more smoothly between the metal film and the copper row, reduces the contact resistance, improves the conduction efficiency. The increased contact area is not only beneficial to the transmission of current, but also helps with heat dissipation. When the capacitor is working, certain heat will be generated on the metal film, and the increased contact area enables this heat to be more effectively transferred to the external environment through the rack-shaped copper row 4, thereby reducing the temperature inside the capacitor, improving its heat dissipation performance and service life. The special shape of the hexagonal metal mesh film helps to optimize the electric field distribution inside the capacitor. In high-voltage applications, the non-uniformity of the electric field distribution may lead to partial discharge or breakdown phenomena. The hexagonal mesh film can guide the electric field lines to be more evenly distributed throughout the capacitor, reducing the risk of partial discharge and improving the insulation performance and reliability of the capacitor.

[0031] As a preference of the above embodiment, as Figure 1 、 3 shown, the insulator 6 is arranged on the outer side of the housing 7.

[0032] As a preference of the above embodiment, as Figure 1 shown, the electrode 8 is arranged above the insulator 6 and penetrates the insulator 6.

[0033] Specifically, through the structure that the insulator 6 is arranged on the outer side of the housing 7 and the electrode 8 is arranged above the insulator 6 and penetrates the insulator 6, electrical insulation protection is provided and the structural compactness of the capacitor is improved. By directly arranging the electrode 8 above the insulator and penetrating the insulator to connect with the external circuit, the need for additional connecting parts and wiring space can be reduced, making the overall structure of the capacitor more compact and efficient, and further suitable for use in a moving train.

[0034] The above has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A secondary filtering capacitor for a bullet train, characterized in that: It includes a polypropylene metallized mesh film (1), a core (2), a core group (3), a rack-shaped copper busbar (4), a round copper braid (5), an insulator (6), a housing (7), an electrode (8), and a flat copper braid (9); The polypropylene metallized mesh film (1) is wound into a single core (2) by a winding machine. After several cores (2) are stacked and heat-set, gold spraying is performed to form the core group (3). The rack-shaped copper busbar (4) and the round copper braid (5) are connected in parallel by welding to form the lead-out end of the core group (3). Several core groups (3) are connected in parallel and welded to the electrode (8) through the flat copper braid (9).

2. The secondary filtering capacitor for a bullet train according to claim 1, wherein The inside of the capacitor is wrapped with an insulating film and filled with silicone oil for insulation and sealing.

3. The secondary filtering capacitor for motor cars according to claim 1, characterized in that A single rack-shaped copper busbar (4) and a single core (2) are fixedly connected by welding.

4. The secondary filtering capacitor for bullet train according to claim 1, wherein, The round copper braid (5) adds a loop in parallel to each core (2) on the core group (3).

5. The secondary filtering capacitor for bullet train according to claim 1, wherein The polypropylene metallized mesh film (1) uses a hexagonal metal mesh film to increase the contact area between the metal film and the rack-shaped copper busbar (4).

6. The secondary filtering capacitor for EMU according to claim 1, characterized in that The insulator (6) is arranged outside the housing (7).

7. The secondary filtering capacitor for EMU according to claim 6, characterized in that, The electrode (8) is arranged above the insulator (6) and penetrates the insulator (6).

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