Novel tandem type water-cooled resonant capacitor

Abstract

The utility model provides a novel tandem type water-cooled resonant capacitor, comprising capacitor cores and copper electrodes, the upper and lower end faces of the capacitor cores are respectively welded with one copper electrode, the whole capacitor cores are cylindrical, the number of the capacitor cores is two, and the capacitor cores comprise a first copper foil, a second copper foil, a polypropylene optical film and a metallized polypropylene film. The first copper foil and the second copper foil are used as extraction electrodes, the metallized layer of the metallized polypropylene film is used as an intermediate electrode, the two layers of electrodes are separated by the metallized film, a polypropylene medium is arranged in a gap between the first copper foil and the second copper foil, and the capacitor core is formed by winding the copper foil, the polypropylene optical film and the metallized polypropylene film around the hard core rod. Spraying metal layers at two ends, welding the core and the copper electrodes together by using low-temperature soldering tin, and encapsulating a sealing material around the core; the copper electrode is provided with six water through holes, and the six holes are communicated through a connecting pipe to conduct internal water circulation. The power output and reliability of the capacitor are greatly improved, and the service life of the capacitor is greatly prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of capacitor technology, and in particular relates to a novel series-type water-cooled resonant capacitor. Background Technology

[0002] The key power component in a high-frequency induction heating device is the resonant capacitor. During operation, it works in conjunction with other components in the circuit to generate a resonant current, driving the heating element to heat up under these conditions. Therefore, the frequency is very high, and the amount of heat generated is substantial. The quality and lifespan of the resonant capacitor directly determine the reliability and service life of the induction heating equipment. Because the resonant capacitor generates a large current and high frequency during operation, the heat generated is considerable. If measures are not taken to dissipate the heat in time, severe heat accumulation during operation can lead to excessively high capacitor temperatures, significantly reducing its lifespan.

[0003] This solution incorporates a water cooling circulation system within the product itself, which dissipates the heat generated during operation through water cooling, thereby reducing the product's temperature and improving the capacitor's reliability and lifespan. Summary of the Invention

[0004] In view of this, the present invention aims to overcome the shortcomings of the above-mentioned problems in the prior art and proposes a novel series water-cooled resonant capacitor.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] A novel series-type water-cooled resonant capacitor includes a capacitor core and copper electrodes. A copper electrode is welded to each of the upper and lower end faces of the capacitor core. The capacitor core is cylindrical and consists of two layers, including a first copper foil, a second copper foil, a polypropylene film, and a metallized polypropylene film. The first and second copper foils serve as lead-out electrodes, and the metallized layer of the metallized polypropylene film serves as the intermediate electrode. The two electrode layers are separated by the metallized film. A polypropylene dielectric is placed between the gaps of the first and second copper foils. The capacitor core is formed by winding copper foil, polypropylene film, and metallized polypropylene film around a rigid core rod. Metal layers are sprayed at both ends and soldered to the copper electrodes using low-temperature solder. The core is surrounded by a sealing material. Six water holes are provided on the copper electrodes, and internal water circulation is achieved by connecting pipes to these six holes.

[0007] Furthermore, the copper electrode is a square copper block, and each capacitor uses three electrodes, which serve as the lead-out electrodes of the capacitor and as the heat conduction medium of the core.

[0008] Furthermore, the polypropylene medium is 2-5 mm wide and has the same thickness as the first copper foil and the second copper foil.

[0009] Furthermore, the two copper electrodes are led out from the same side or from both sides.

[0010] Furthermore, the first copper foil, the second copper foil, and an intermediate electrode constitute two capacitors connected in series, forming an internal series structure.

[0011] Furthermore, the gold-plated end face of the capacitor core has a pre-reserved groove as a channel for core gas discharge.

[0012] Furthermore, it also includes installing a temperature sensor and a water cooling system on the outside of the capacitor core for circulating cooling.

[0013] Furthermore, the sealing material is epoxy resin.

[0014] Compared with the prior art, the novel series-cooled resonant capacitor of this utility model has the following advantages:

[0015] This invention uses copper foil as the electrode. Copper foil electrodes have very high electrical conductivity, enabling efficient current transfer. Furthermore, copper foil has a high melting point and excellent heat transfer properties, effectively reducing heat generation during product use and significantly lowering the power consumption at high frequencies. Self-heating at high frequencies is greatly reduced. Copper foil also possesses high tensile strength and yield strength, allowing it to withstand the mechanical stress generated during charging and discharging, thus extending the product's lifespan.

[0016] This invention incorporates a water cooling circulation system within the product itself, which dissipates the heat generated during operation through water cooling, thereby reducing the product's temperature and improving the reliability and lifespan of the capacitor. Attached Figure Description

[0017] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0018] Figure 1 This is a schematic diagram of the copper electrode structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the capacitor core of this utility model;

[0020] Figure 3 This is a schematic diagram of the structure of the capacitor core of this utility model;

[0021] Figure 4 This is a schematic diagram of the capacitor structure of this utility model;

[0022] Figure 5 This is a side view of the capacitor of this utility model;

[0023] Figure 6 This is a schematic diagram of the thin film structure of the capacitor of this utility model;

[0024] Figure 7 This is a schematic diagram of the groove structure of this utility model;

[0025] Figure 8 This is a schematic diagram of the water circulation device of this utility model.

[0026] Explanation of reference numerals in the attached figures

[0027] 1-Capacitor core; 2-Copper electrode; 3-Sealing material; 4-First copper foil; 5-Second copper foil;

[0028] 6-Polypropylene film; 7-Metalized polypropylene film; 8-Polypropylene medium; 9-Water passage hole. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0030] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] This utility model provides a novel series-type water-cooled resonant capacitor, including a capacitor core 1 and copper electrodes 2. A copper electrode 2 is welded to each of the upper and lower end faces of the capacitor core 1. The capacitor core 1 is cylindrical in shape and consists of two parts, including a first copper foil 4, a second copper foil 5, a polypropylene film 6, and a metallized polypropylene film 7. The first copper foil 4 and the second copper foil 5 serve as lead-out electrodes, and the metallized layer of the metallized polypropylene film serves as the intermediate electrode. The two electrode layers are separated by the metallized film. A polypropylene dielectric 8 is disposed between the gaps of the first copper foil 4 and the second copper foil 5. The capacitor core 1 is formed by winding copper foil, polypropylene film, and metallized polypropylene film around a rigid core rod. Metal layers are sprayed at both ends, and the core is welded to the copper electrodes using low-temperature solder. A sealing material 3 is applied around the core. The copper electrodes 2 have six water holes 9, which are connected by connecting pipes to allow for internal water circulation.

[0034] The specific structure of a capacitor is as follows: Figure 4 As shown, a copper electrode is welded to the top and bottom faces of each of the two capacitor cores, with the middle copper electrode connecting the two cores. The capacitor core faces are welded to the copper electrodes using a welding process, and then the lower electrode is connected via... Figure 5 The copper pillar on the right leads the electrode to the same side as the copper electrode above, so that the electrodes are led out on the same side. Instead of leading out from both sides of the copper rod, the rest of the product is filled with epoxy resin as an encapsulation and fixing material.

[0035] In this embodiment, the copper electrode is as follows: Figure 1 As shown, it is a square copper block with a polished surface. Each capacitor uses three electrodes, which serve as both capacitor leads and heat conduction medium for the core.

[0036] The capacitor core is the main body of the capacitor, and is cylindrical in shape. Its structure uses two copper foils as lead electrodes, and a metallized layer of a metallized polypropylene film as the intermediate electrode, with the two electrode layers separated by a metallized film. The core structure is as follows: Figure 2 and Figure 3 As shown, the core is made of copper foil, polypropylene film, and metallized polypropylene film wound around a rigid mandrel, with metallized layers sprayed at both ends. It is soldered to copper electrodes using low-temperature solder, and the core is encapsulated with resin. The copper electrodes serve as the lead electrodes and heat conduction medium when used in a capacitor.

[0037] The core experiences severe self-heating under high-power conditions, primarily due to its weak internal current-carrying capacity, high series resistance, and high heating power under high current. This invention utilizes copper foil as the electrode. Copper foil electrodes possess very high conductivity, effectively transferring current. Furthermore, copper foil has a high melting point and excellent heat transfer properties, effectively reducing heat generation during use and significantly lowering heating power at high frequencies. Copper foil also exhibits high tensile strength and yield strength, enabling it to withstand mechanical stresses generated during charging and discharging, thus extending the product's lifespan.

[0038] Figure 6 This is a schematic diagram of the thin-film structure of the capacitor according to an embodiment of the present invention. The capacitor is basically a series-connected structure, consisting of two copper foil leads and a central electrode forming two capacitors connected in series. Due to the structure, there are gaps of varying widths (2-5 mm) between the copper foil leads to separate the two capacitors connected in series. When the core is polymerized, the polypropylene film shrinks due to heat, and the gaps collapse. As a result, the polypropylene film in the middle of the core deforms and stretches. The deformed and compressed polypropylene film causes uneven dielectric thickness, and the electric field is distorted near the deformed film, which can easily lead to breakdown. After prolonged operation, the capacitor will be damaged due to numerous breakdowns. The present invention inserts a 2-5 mm wide polypropylene dielectric with the same thickness as the copper foil into the gaps. After inserting the dielectric into the gaps, it fills the gaps between the copper foil electrodes, reduces the deformation of the polypropylene dielectric during the shaping process, significantly reduces electric field distortion, and improves the reliability of the core.

[0039] After the capacitor core is rolled up and heat-set to remove internal moisture and gases, the conventional process involves immediate gold plating, followed by polishing after metal spraying onto the end faces, and then welding. However, resonant capacitors are constructed by overlapping and winding multiple layers of electrodes and dielectrics of different materials, including copper foil, thermoplastic polypropylene film, and polyester film. Different materials have different shrinkage rates, and copper foil hardly shrinks when heated. The end result is that after heat setting, the capacitor core still has a large number of voids inside, containing residual moisture and corrosive gases. The gold plating process covers the end faces of the core with metal, sealing these gases inside and preventing their escape. These gases will continue to corrode the core plates and dielectric during product operation, shortening the product's lifespan.

[0040] This invention provides a groove 3-3.5mm wide and 45-65mm long (depending on the core diameter) pre-reserved on the gold-plated end face of the core. Figure 7 As shown, it serves as the core gas exhaust channel.

[0041] The heat generated by the product itself cannot be dissipated due to the resin seal, so it can only be transferred out through the two poles of the copper electrode. The core itself is made of copper foil and has a large contact area with the copper plate, which can effectively conduct heat away from here. However, because the product has a series structure, a lot of heat is generated, and there is a concern that the product's lifespan may be reduced if the heat is not dissipated in time. Therefore, this invention adds water channels inside the copper electrode, using flowing water to carry away the heat generated during product operation, thereby achieving the effect of reducing the product temperature.

[0042] This invention incorporates a water channel within the copper electrode, using a water circulation device to remove heat generated by the product, thereby improving heat dissipation efficiency and extending service life. Simultaneously, the bonding strength between the electrode and the core is not reduced. The water circulation device, as... Figure 8 As shown, the product adopts a series structure, which improves the voltage withstand capability compared to ordinary products. It can be flexibly installed using either two-sided or same-sided mounting. The copper electrodes have six water passage holes. Figure 8 As shown, water is circulated through six holes via connecting pipe 3 to achieve cooling. External water circulation cannot cool both cores simultaneously and would result in uneven cooling; therefore, an internal circulation system is used to achieve the desired cooling effect. A temperature sensor and water cooling system are installed externally to assist the circulation system in cooling. Water flows through the external water inlet (labeled 6), then through inlets (labeled 5-8-7-10), and finally out through inlet (labeled 9), completing a circulation cycle to stabilize the temperature.

[0043] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A novel series water-cooled resonant capacitor characterized by: The capacitor core (1) includes a capacitor core (1) and copper electrodes (2). A copper electrode (2) is welded to the upper and lower ends of the capacitor core (1). The capacitor core (1) is cylindrical in shape and consists of two parts, including a first copper foil (4), a second copper foil (5), a polypropylene film (6), and a metallized polypropylene film (7). The first copper foil (4) and the second copper foil (5) serve as lead-out electrodes, and the metallized layer of the metallized polypropylene film serves as the intermediate electrode. The two electrodes are separated by a metallized film. A polypropylene dielectric (8) is provided between the gaps of the first copper foil (4) and the second copper foil (5). The capacitor core (1) is made by winding copper foil, polypropylene film, and metallized polypropylene film around a rigid core rod. Metal layers are sprayed at both ends and welded to the copper electrodes using low-temperature solder. The core is surrounded by a sealing material (3). The copper electrode (2) has six water holes (9), which are connected by a connecting pipe to allow internal water circulation.

2. A novel series water-cooled resonant capacitor as claimed in claim 1, wherein: The copper electrode (2) is a square copper block. Each capacitor uses three electrodes, which serve as the lead-out electrodes of the capacitor and as the heat conduction medium of the core.

3. A novel series water-cooled resonant capacitor as claimed in claim 1, wherein: The polypropylene medium (8) is 2-5 mm wide and has the same thickness as the first copper foil (4) and the second copper foil (5).

4. A novel series-cooled water-cooled resonant capacitor according to claim 1, characterized in that: The two copper electrodes (2) are drawn out from the same side or from both sides.

5. A novel series water cooled resonant capacitor as claimed in claim 1, wherein: The first copper foil (4), the second copper foil (5), and a middle electrode form two capacitors connected in series, forming an internal series structure.

6. A novel series water cooled resonant capacitor as claimed in claim 1, wherein: The gold-plated end face of the capacitor core (1) has a pre-reserved groove as a channel for core gas discharge.

7. A novel series water cooled resonant capacitor as claimed in claim 1, wherein: It also includes setting a temperature sensor and a water cooling system on the outside of the capacitor core (1) for circulating system cooling.

8. A novel series water-cooled resonant capacitor as claimed in claim 1, wherein: The sealing material (3) is epoxy resin.

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