JPH06504410A - power capacitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] power capacitor The invention relates to power capacitors, particularly those wrapped with at least two metallized dielectric films. A tag constituted by at least one capacitive element obtained by Regarding the power capacitor in A1. In fact, the invention more particularly relates to power capacitors of the above type used in filter elements installed in equipment. related. This type of capacitor has a very high specific energy, typically 100 joules. / liter or more, as light as possible, and with non-negligible vibration Must be resistant to stress.

Currently, capacitors of the above type use metallized paper as the dielectric film. This metallized paper is impregnated with wax. Metallized paper is expensive material, making the manufacturing cost of the capacitor prohibitive. Also the density of metallized paper is approximately 1.3, which makes the final product heavy. Furthermore, it is impregnated with wax. The performance of the capacitor is determined by considering the is limited in both temperature and voltage.

For this reason, especially for specific applications such as those mentioned above, the applicant has decided to experiment with manufacturing power capacitors using types of materials other than metallized paper. saw.

The purpose of the invention is to achieve a non-negligible specific energy and a significant reduction in energy consumption compared to conventional capacitors. Improved motion gradient? By providing a new type of power capacitor with be.

Accordingly, the present invention provides for wrapping at least two metallized dielectric films. constituted by at least one capacitive element obtained by attaching A type of power capacitor in which the dielectric film is replaced by a plastic film. The capacitive element is a flat element with a guaranteed thickness. The flat element is impregnated with a liquid dielectric. The metallized film is formed by local demetallization of the metallized film. A power cord characterized by having a recessed part (indent) It is ndensa.

According to a preferred embodiment, the plastic film is a polymer film with a rough surface. The use of a rough surface results in better impregnation. In addition, the dented part can be constituted by a linear or T-shaped recess.

Furthermore, it is essential that the liquid dielectric is composed of a plant-based dielectric. the The reason is that such dielectrics do not damage aluminum metallization and do not damage polypropylene metallization. This is because they only penetrate very unevenly into plastic films.

According to another feature of the invention, for safety reasons the capacitive elements constituting the 5 capacitors are The ment is placed in a metal can with a filler made of insulating material in between. insulation material A filler made of The capacitor can be grounded. can be done.

The invention further provides a method of manufacturing a power capacitor comprising: - at least two gold The plastic film is placed on the spindle in a circular manner with continuous control of expansion. winding to obtain a cylindrical capacitive element, - having a predetermined thickness; flattening the cylindrical element to form a flattened element; - baking the flat element under vacuum; - the side of the flat element; spraying metal on the opposite end using a scoop method; wiring one connection point; Step 1: Put one flat element into a can and impregnate it with liquid dielectric.

Concerning a method of characterizing and.

Preferably at the beginning of the winding to provide a short circuit between the metallized dielectric films. After ML and ML, a non-metallized dielectric film is inserted between the two metallized films.

The features and advantages of the pond of the invention can be seen with reference to the accompanying drawings. will become apparent upon consideration of the following description of a preferred embodiment of the server.

Figure IA and Figure IB are respectively a perspective view and a perspective view of a capacitive element of the present invention. FIG.

- Figure 2 shows multiple capacitive elements before metal spraying using the scoop method. FIG.

- Figure 3 shows the configuration of a capacitor as given in Figure 2 after wiring the various capacitive elements. FIG.

- Figure 4 is a cross-sectional view of a capacitive element in a can;

A preferred embodiment of the power capacitor of the present invention will be described with reference to FIGS. 1-4.

As shown in Figure IA, the capacitive elements constituting the capacitor are metallized Zone 2 and non-! on the edge opposite these! IL attached end 3 Both are obtained by winding two films 1 around a spindle M. Book The metallized film used within the scope of the invention is a polymeric film, in particular a biaxially oriented polymeric film. It is a repropylene film.

To enable this subsequent impregnation, a polypropylene film was prepared as shown in Figure IB. A sea urchin rough surface film is preferred. Films can be rough on one or both sides Ru. In a known method, this film is previously treated with corona discharge and then coated with gold. Metallized using metals such as aluminum under vacuum in metallization equipment (gold resistivity of genus 1 to 5 square ohms).

Furthermore, it is possible to demetallize locally to obtain the desired results, especially during operating gradients. A metallized film is used which has a recess formed by. This kind of dent The self-healing properties can be particularly improved by using a hollow part, and the test results show that it is even more effective. It has been found that a nominal working slope can be obtained.

In order to properly spray metal onto the edges of the roll using the scoop method, two metal The film is wound with one side displaced relative to the other. In addition, non-metalized rough surface plate Place the plastic film between the two films, at both the beginning and end of the wrap. Insert instead.

According to the invention, it is possible to wrap around the spindle with continuously controlled expansion. In the embodiment, this control is approximately 15% in weight thickness of the metallized film. A roll outer diameter corresponding to the adhesive tension is obtained on the mandrel M.

Expansion refers to the gap created between the eyebrows by wrapping. do. In order to obtain good impregnation and good performance, the 1 m tension is as constant as possible There is a need.

After the winding is completed, the cylindrical capacitive element C thus obtained is spun. Remove it from M and obtain the flat element C° shown in Fig. 2. In the example, it is flattened and pressed to mechanical dimensions corresponding to 12% expansion. @flat When using an element, the thickness e can be completely controlled, i.e. the expansion is complete. You can get elements that are completely limited.

As shown in Figure 2, to obtain a capacitor with a specific capacitance value; For this purpose, several flat elements C°, namely eight flat elements in the example shown in FIG. Stack the components one above the other and place them in two The assembly is further secured by two plastic bundts 5. and hold them tightly together to form the bound S itself (loaf).

According to the method of manufacturing a power capacitor of the present invention, the dielectric film is mechanically stabilized. For this purpose, the assembly of flat elements is baked in an open vacuum.

This baking is carried out at a temperature of approximately 80°C and under a vacuum of less than 10-2 mm Hg. Once the desired temperature and vacuum are reached, the assembly is preferably placed in an oven for 24 hours. The temperature was then lowered to 20°C and the aggregate was left for 16 hours before , remove to ambient temperature.

Once the above operations have been carried out, the various flattened elements can be lateralized using the scoop method. In the embodiment shown in Figure 0, where the edges can be metal sprayed, the metal spraying is Those known using the scoop method by spraying a metal such as lead onto the surface 6 (zinc layer thickness: 20.6 μm) After performing the irradiation, the various capacitive elements C are wired. Wiring work is done using fine zinc powder. This is carried out after cleaning the aggregate to remove. This cleaning is carried out at a pressure of 4 bars, for example. This is done by pumping it into compressed air. This wiring is first done at the address of the aggregate. Tin-plated copper foil may be soldered to the center of the assembly to make it more rigid. A copper braid 9 is then soldered to each element.

As shown in Figure 3, in each half of the assembly to obtain a better current distribution. Connecting the various elements symmetrically above and below the midplane. At this moment, capacity The sexual elements are mounted in parallel. Capacitive elements are connected in parallel and/or It will be clear to those skilled in the art that the two can be mounted in series.

Further, as shown in FIG. 3, the leads 10 are soldered to the portions 8. this lead is for connecting the capacitive aggregate to the external connection terminal as shown in Figure 4. Ru.

In the embodiments of the present invention, an aggregate of capacitive elements obtained in this way is included. Before soaking, perform a predetermined number of regeneration tests. Such dry testing eliminates weaknesses. This results in a more homogeneous population and can increase final yield. The first test is , equivalent to charging a 500 μF capacitor at 500 volts, for example 62 It consists of discharging the surplus power of the unit to each aggregate. This test opens It is possible to carry out an air short circuit.

Next, a voltage regeneration test is performed under voltage. For example, a 200V/μ filter is applied to each aggregate. Apply a DC voltage corresponding to the gradient across the lumen. Apply this voltage for about 10 seconds Ru. During this period, numerous regenerations are observed. If playback does not stabilize after 30 seconds, Aggregations are considered unusable.

Once the above tests have been carried out, the assembly is ready to be placed into the can as shown in Figure 1. According to the invention, for example steel, stainless steel or aluminum A metal parallelepiped gauge made of is used as a can. metal coos it This allows you to easily connect the capacitor to ground, and also for safety reasons. used. [As shown in Z4, the metal can 11 has plates 11, 12 and 12 on the inside. It is lined with a retaining plate 14 which is inserted later. These are e.g. Manufactured from an insulating material such as Lopyrene. These plays made of insulating material In one example, the bottom of the can serves to electrically insulate the assembly from the can. The plate 13 located at Rate 12 has a thickness of 2 mm.

Next, an assembly of one or more capacitive elements C° is placed inside a metal can l1 and an insulating material Fixing the three bodies in the can using one or more sets of plates 15 made of This is essential for the capacitive element to resist vibrations. Insert the holding plate 14. Two L-shaped members 16 to secure the assembly. Solder to the top of the can.

Next, as shown in FIG. 4, the opening 18 is opened for passing the connecting terminal 19 and for impregnation. Attach a lid 17 to the can.

Once the capacitive assemblies are installed in the can, they are impregnated. This impregnation is a liquid This is carried out using a dielectric, preferably an N-based dielectric such as rapeseed oil. plant-based lure The electrolyte does not damage the metallization and penetrates the polypropylene film very little. It has the main advantage of not being

However, it is possible to mix rapeseed oil with aromatic synthetic liquids, provided that the metallization is not impaired. It is also clear to those skilled in the art that compounds can also be used. Like antioxidants and epoxies Additives are added to the composition in an amount of 1%. These additives, especially epoxies, Capacitor life can be extended.

Impregnation is carried out in two stages. First, the capacitor is preferably heated to 10-2 Dry under vacuum at mm HH.

When carried out for 24 hours at a combination of 50°C, -’io)mmHg, Sa is considered to have been properly dried.

The actual impregnation is then carried out. For this, the liquid is degassed under vacuum at 60 °C and first impregnating the liquid to remove contaminants on the base material or activated alumina column. Immersing the capacitive assembly into a can under a vacuum of 10”’mmHg Impregnate with. If the capacitance increase does not exceed 1% in 8 hours, the capacitor The sensor is considered completely impregnated. At this stage, break the vacuum with nitrogen at atmospheric pressure. , discontinue keeping warm. Once the assembly has cooled, drain the liquid from the can and replace the cap with is impregnated by soldering a pressure gauge preset to 0.7 bar. Close the holes. Pressure regulator detects internal pressure increase due to unspecified defect can contribute to safety functions.

The capacitor thus obtained is subjected to a sealing test, an electrical test at ambient temperature and Perform normal final manufacturing inspections such as final processing tests.

Using the manufacturing method described above, high specific energy, i.e. more than 100 Joules/liter It is possible to obtain a power condenser with a specific energy of . Furthermore, such controls The capacitor may also be subjected to vibrational stress.

Claims (9)

[Claims] 1. Obtained by wrapping at least two metallized dielectric films A type of power capacitor consisting of at least one capacitive element. Therefore, the dielectric film is made of a plastic film, and the front The storage element forms a flat element with a guaranteed thickness. the flat element is impregnated with a liquid dielectric, and the flat element is impregnated with a liquid dielectric; The metallized film has an indentation formed by local demetallization of the metallized film. A power capacitor characterized by having a grooved portion. 2. The plastic film is a polymer film with a rough surface. A capacitor according to claim 1, characterized in that: 3. The liquid dielectric is made of a plant-based dielectric. A capacitor according to claim 1 or 2. 4. 4. An additive according to claim 3, wherein an additive is added to the liquid dielectric. capacitor. 5. can include several capacitive elements mounted in parallel and/or in series. The capacitor according to any one of claims 1 to 4, characterized in that: 6. The capacitive element is placed in a metal can with a filler made of insulating material in between. 6. The coil according to any one of claims 1 to 5, further comprising: Ndensa. 7. A method for manufacturing a power capacitor according to any one of claims 1 to 6. So, - At least two metallized plastic films on the spindle with continuous expansion winding in a controlled manner to obtain a cylindrical capacitive element; - said cylindrical element so as to form a flat element with a predetermined thickness; and - baking the flattened element under vacuum. - a step of metal spraying the lateral ends of said flat element using a scoop method; and - wiring the connection points; - placing the flat element in a can and immersing it in a liquid dielectric; A method characterized by: 8. At the beginning and end of winding, a non-metalized dielectric film is placed between the two metalized films. 8. The method according to claim 7, further comprising inserting a program. 9. To obtain the desired capacitance, some flat oxides are added before the baking operation. 9. A method according to claim 7, characterized in that the elements are placed in parallel.