JPH0610662Y2 - High voltage capacitors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Purpose of the Invention [Field of Industrial Application] This invention relates to a high-voltage capacitor used for electric power.

[Prior Art] A so-called wound type capacitor, in which a plastic film is used as a dielectric and metallized films obtained by vapor-depositing metal are stacked and wound, is nonpolar and has a small dielectric loss. Used for. However, when used under a high voltage, corona discharge is generated at both end faces of the winding, and it is required to improve the dielectric strength characteristics.

By the way, 59
There is a high-voltage capacitor device disclosed in Japanese Patent Laid-Open No. 107131.

In this high-voltage capacitor, an insulating gas is filled in a capacitor element formed by integrally winding an electrode and a dielectric, and the outer peripheral portion of the capacitor element is surrounded by a flame-retardant synthetic resin portion. This high-voltage capacitor has a structure in which terminals are led out from the electrodes on the outer surface of the synthetic resin part, and this high-voltage capacitor is manufactured by the following manufacturing method.

First, the metallized film is wound in air while being stacked, and the electrodes are formed by spraying metal on both end surfaces of the wound element, and lead wires are connected to this electrode to obtain a capacitor element. A plurality of the obtained capacitor elements are put together in a mold and vacuum-dried, and an insulating gas is injected and filled into the mold in a vacuum state at a pressure of 0 to ² kg / cm ² G to wind each capacitor element. Insulation gas is injected and filled in the gap between both end surface parts, and then while the insulating gas is flowing in the mold with the ventilation hole open (while the internal pressure is always positive), the flame-retardant resin from the lower resin injection port A manufacturing method is used in which a synthetic resin liquid is injected, the synthetic resin liquid is heated to a curing temperature, and after the curing reaction, the mold is removed and the high voltage capacitor is taken out.

The high-voltage capacitor manufactured by such a method can be expected to retain a small amount of insulating gas in the uneven portions on both end faces of the winding of each capacitor element, and the corona discharge characteristics are improved at the same time as compared with the capacitor element not filled with the insulating gas. There is an advantage that the dielectric strength is improved.

[Problems to be Solved by the Invention] However, in the above high-voltage capacitor, SF ₆ gas is injected into each capacitor element at a pressure of 0 to ² kg / cm ² G and then this pressure is temporarily released, and Since the SF ₆ gas pressure in the mold is always made positive by burying the insulating gas in the upper part, and it is embedded in the synthetic resin liquid, when each capacitor element enters the synthetic resin liquid, The insulating gas that had accumulated in the irregularities on both ends of the winding of the capacitor element gained buoyancy by the synthetic resin liquid, and part of the insulating gas went out as bubbles in the synthetic resin liquid. At the initial stage of curing by heating to the curing reaction temperature, the viscosity of the synthetic resin liquid decreases, and the remaining insulating gas is warmed and expands to further increase the buoyancy. And go out I will go.
Therefore, there is a problem in that it is not possible to expect much retention of the insulating gas in the uneven portions on both end faces of the winding of each capacitor element.

Therefore, the present invention intends to provide a high-voltage capacitor capable of improving the corona discharge characteristics by allowing the insulating gas to stay at a high density in the weak points of the dielectric strength around the edges of the metal thin film on both ends of the winding of the capacitor element. is there.

(B) Configuration of the Invention [Means for Solving the Problems] In order to solve the above problems, this invention forms the cylinder chamber between the inner wall and the outer wall by forming the peripheral wall of the storage chamber into a double structure. Then, an opening toward the outside is formed at the lower end of this cylinder chamber,
One or a plurality of winding type capacitor elements are respectively wound in the storage chamber of the container having a through hole which is formed at the upper end portion toward the inner wall and communicates with the storage chamber. At least form a container-containing capacitor, collect a plurality of container-containing capacitors, and fill each container housing chamber and cylinder chamber of this assembly with an insulating gas, and at the same time, fill the cylinder chamber of each container with a synthetic resin liquid. The insulating gas in each storage chamber is pressurized to a positive pressure state and molded with a synthetic resin to seal the insulating gas in the storage chamber to a positive pressure state to be integrated.

[Operation] One or more capacitor elements are accommodated in the accommodating chamber to form a container accommodating capacitor, a plurality of the container accommodating capacitors are assembled, and an insulating gas is provided in each accommodating chamber and cylinder chamber of the aggregate. When the synthetic resin liquid is filled around the container and is filled with the insulating resin, first, the lower opening of the cylinder chamber is sealed with the synthetic resin liquid, so that the insulating gas is filled in the accommodating chamber and the cylinder chamber when the insulating gas is filled. Can be filled with gas pressure. Further, when the synthetic resin liquid is further injected around the container, the gravity of the injected synthetic resin liquid is applied to the free surface of the synthetic resin liquid generated in the lower part of the cylinder chamber, so that the pressurized state is obtained.
It is possible to raise the gas pressure of the insulating gas in the accommodating chamber by pushing up the synthetic resin liquid in the upward direction of the cylinder chamber to flow it in.

Further, after the synthetic resin liquid is filled around the container, the synthetic resin liquid can be further injected while being pressurized by an external force. In this case, a pressure pouring force is added to the free surface of the synthetic resin liquid, and a larger pressure is applied. By being pressurized, the synthetic resin liquid invades while pushing the insulating gas upward in the cylinder tube against the compressive repulsive force of the insulating gas. The gas pressure of the insulating gas can be further increased by being compressed by the amount.

When the gas pressure of the insulating gas in the housing chamber reaches a desired value, the injected synthetic resin liquid is cured by reaction while maintaining the pressurized state, whereby the insulating gas can be sealed at a desired high pressure in the housing chamber.

Since the insulation gas can be sealed to the desired high pressure in the housing chamber, the corona discharge starting voltage at the weak point of the dielectric strength of the wound capacitor element can be increased according to the Paschen's law. Can be improved.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6 of the drawings. 1 is a cross-sectional view of a high-voltage capacitor for explaining an embodiment, FIG. 2 is a vertical cross-sectional view of a container for accommodating one wound-type capacitor element used in the high-voltage capacitor of the present invention, and FIG. III-III 'sectional view of FIG. 2, 4th
FIG. 5 is a vertical sectional view of a container accommodating four wound type capacitor elements, FIG. 5 is a sectional view taken along line VV 'of FIG. 4, and FIG. 6 is a casting mold apparatus used for manufacturing a high voltage capacitor. It is a cutaway sectional view.

In the high-voltage condenser, the peripheral wall of the housing chamber 1 has a double structure to form a cylinder chamber 2 between an inner wall and an outer wall, an opening toward the outside is formed at a lower end of the cylinder chamber 2, and an inner wall is formed at an upper end. One or a plurality of winding type capacitor elements 6 are provided in the housing chamber 1 of the container 4 having the through hole 3 communicating with the housing chamber 1, and the winding both end surfaces 6a, 6a, ..., 6b, 6b ,. , A container housing type capacitor element 8 which is housed with a separate gap is formed, a plurality of the container housing type capacitor elements 8 are assembled, and the housing chamber 1 of each container 4, 4, ... , 1, ... and the cylinder chambers 2, 2, ... Are filled with an insulating gas, for example, SF ₆ gas 9, and each of the containers 4, 4 ,.
Mold cylinder chamber 2, 2, ... synthetic resin solution in, for example, by introducing the epoxy resin solution 10 'around the aggregates allowed the SF ₆ gas 9 of each of the accommodating chamber to pressurize the positive pressure state by the epoxy resin By doing so, the SF ₆ gas 9 in the storage chambers 2, 2, ... Is sealed in a positive pressure state and integrated.

The following method can be used to seal the SF ₆ gas 9 in the respective containers 4, 4, ... In a positive pressure state.

First, a cylinder wall 2 is formed between an outer wall and an inner wall by forming the peripheral wall of the storage chamber 1 into a double structure, an opening toward the outside is formed at a lower end of the cylinder chamber 2, and a storage chamber facing an inner wall is formed at an upper end. A plurality of containers 4 each having a through hole 3 communicating with 2 are prepared, and the winding type capacitor elements 6, 6, ... Are positioned and housed in the housing chambers 1, 1 ,. Then, the container-containing capacitors 8, 8, ... Are formed. Storage chamber 1 for container 4
The number of the wound-type capacitor elements 6 accommodated in 1 is one in the container 4 shown in FIG. 2, and is four in the case of the container 4 shown in FIG.

The accommodation chamber 1 of the container 4 has an inner wall divided into two parts for inserting the winding type capacitor element 6, and the lead wires 7a and 7b of the winding type capacitor element 6 are inserted into each of the divided inner walls and sealed by soldering. Eyelets 5a and 5b are provided to enable the above. The accommodating chamber 1 has an inner diameter slightly larger than the outer diameter of the wound-type capacitor element 6 and faces the winding both end surfaces 6a and 6b of the housed wound-type capacitor element 6 and has a gap therebetween. It is set to the inner dimension of the height that forms the.

The winding type capacitor element 6 is placed in the accommodation chamber 1 of the container 4 as described above.
Is positioned and fixed, the inner wall divided into two is fixed in a sealed state, and the lead wires 7a and 7b inserted into the eyelets 5a and 5b of the inner wall are soldered and housed in a sealed state,
A container type capacitor 8 is formed.

Next, a plurality of container-containing capacitors 8 are assembled, and this assembly is set in a mold 11 having an inner diameter larger than its outer diameter, as shown in FIG.
14 and 15 are closed, valve 13 is opened, vacuum pump 16
Is operated to evacuate the inside of the mold 11 in vacuum.

The air in the accommodating chambers 1, 1, ...
... is degassed through the cylinder chambers 2, 2, ...
1, ... and the inside of the cylinder chambers 2, 2, ... To a vacuum degree of about 10 ^-2 mmHg.

Next, the valve 14 is closed and the valve 15 is opened to allow SF ₆ gas 9 to flow into the mold 11 in a vacuum state.
SF ₆ gas 9 is filled in the cylinders 1, 2, and the cylinder chambers 2, 2 ,. After that, the epoxy resin liquid 10 'is injected between the mold 11 and the containers 4, 4, ....

As the epoxy resin liquid 10 ', for example, an epoxy resin mixed with an inorganic filler and having a density ρ of 1.3 g / cc is used. When this epoxy resin liquid 10 'was poured between the mold 11 and the containers 4, 4, ...
The cylinder chamber 2 ₁ , of the containers 4 ₁ , 4 ₁ , ...
The lower openings of 2 ₁ , ... Are sealed with an epoxy resin liquid 10 ', and the accommodating chambers 1 ₁ , 1 ₁ , ... And the cylinder chambers 2 ₁ , 2 ₁ ,.
SF ₆ gas 9 can be enclosed inside. FIG. 3 illustrates almost this state. Further, when the epoxy resin liquid 10 'is injected, the lower openings of the second-stage cylinder tubes 2 ₂ , 2 ₂ , ... Are sealed with the epoxy resin liquid 10'. In this way, the uppermost third-stage cylinder tubes 2 ₃ , 2 ₃ , ...
The lower opening of the mold is sealed with epoxy resin liquid 10 ', and the mold 1
1 is filled with the epoxy resin liquid 10 '.

The filling pressure P _x of the SF ₆ gas 9 in the cylinder chamber is such that the free surface of the epoxy resin liquid 10 ′ generated in each of the cylinder tubes 2, 2, ...
Ρgh _x per unit area depending on the height h _x to the surface
Since the gravity of the epoxy resin liquid 10 'of [dyn / cm ² ] is applied, the SF ₆ gas 9 is introduced into the mold 11 and the storage chamber 1 and the cylinder chamber 2 are filled with the SF ₆ gas 9. When the pressure is P _o [Torr], it can be calculated by P _x = P _o + ρgh _x × 10 ⁻⁶ [Torr].

Now, when the filling pressure P _o is set to 1.0 Torr and the height of the container-containing capacitors 8 is 12 cm and the whole is assembled in three stages, the first-stage container-containing capacitors 8 ₁ , 8 ₁ , ... The enclosed pressure P _x of the SF ₆ gas 9 in the inside is about P _x ≈1.0 + 0.06 = 1.06 [Torr], and the container-accommodating capacitor 8 ₂ located in the second stage
The enclosed pressure P _x of the SF ₆ gas 9 in 8 ₂ , ... Is about P _x ≈1.0 + 0.04 = 1.04 [Torr], and the container-containing condenser 8 ₃ located in the third stage is The enclosed pressure P _x of the SF ₆ gas 9 in 8 ₃ , ... Is about P _x ≈1.0 + 0.02 = 1.02 [Torr]. Therefore, from the filling pressure P _o = 1.0 [Torr], the pressure is increased and balanced.

When the epoxy resin liquid 10 'is filled into the mold 11 in such a pressurized state while further injecting the epoxy resin liquid 10' while applying an external force, a pressing force by an external force acts on the free surface. while pushing the SF ₆ gas 9 into by compression, epoxy resin liquid 10 'of the cylinder tube 2, 2, continue to invade ... in the direction of the top of, SF ₆ in the gas 9 cylinder tube 2,
2, ... is compressed by the amount of epoxy resin liquid that has entered,
The gas pressure P _x of the SF ₆ gas 9 in the inside is in a pressurized state in which it is further increased.

The injection pressure of the epoxy resin liquid 10 'is set to, for example, 1.4
Two types of × 10 ⁶ dyn / cm ² and 1.9 × 10 ⁶ dyn / cm ² were set, and the internal volume of the cylinder chamber 2 was subtracted from the internal volume of the accommodating chamber 1 by subtracting the volume of the wound-type capacitor element 6. If set to a value that is almost equal to the value, the container housing type capacitor 8 located in the third stage
The gas pressure P _x of the SF ₆ gas 9 in ₃ , 8, ₃ ... Is about 1.
From 02Torr, about 1.42Torr and 1.92Torr, respectively
Will rise to.

In this way, the epoxy resin liquid 10 'can be injected to raise the gas pressure of the SF ₆ gas 9 in the storage chambers 1, 1, ... To a desired positive pressure state value. When the injected synthetic resin liquid 10 'is cured by reaction while maintaining the value of the state, the SF ₆ gas 9 can be sealed in the housing chambers 1, 1, ... At a desired high pressure. Thereafter, the high-voltage capacitor of the present invention can be obtained by taking it out from the mold 11 and subjecting it to post-processing.

Container-contained capacitors 7 ₃ , 7 ₃ , ... Located in the third stage
The gas pressure P _x of the SF ₆ gas inside is 1.02 Torr, 1.4
Torr and 1.9 Torr three types of high voltage capacitors of the present invention were set, and the corona discharge inception voltage was about 1.2 times that of the high voltage capacitors produced by the conventional manufacturing method. It was possible to improve the value by about 1.7 times and about 2.3 times.

The above is a description of the case of a container-type capacitor 8 in which one winding type capacitor element 6 is stored in the storage chamber 1. However, the container-type capacitor 8 in which a plurality of winding type capacitor elements 6 are stored in the storage chamber 1 is described. The same can be said in the case of. FIG. 4 is a drawing showing an example of the container 4 when the number of wound-type capacitor elements 6 accommodated is four.

(C) Effect of the Invention The high-voltage capacitor of this invention is insulated from the accommodating chamber for accommodating the winding type capacitor element by injecting the synthetic resin liquid for molding into the cylinder chamber from the lower opening under pressure. Since the gas is sealed in a positive pressure state, it is possible to interpose insulating gas at a high density in the weak points of the dielectric strength of both ends of the winding of the winding type capacitor element, and to improve the corona discharge starting voltage. It is possible.

[Brief description of drawings]

1 is a cross-sectional view of a high-voltage capacitor for explaining an embodiment, FIG. 2 is a vertical cross-sectional view of a container for accommodating one winding type capacitor element used in the high-voltage capacitor of the present invention, and FIG. 3 is FIG. III-III ′ sectional view of FIG. 4, FIG. 4 is a longitudinal sectional view of a container accommodating four wound type capacitor elements, FIG. 5 is a sectional view taken along line VV ′ of FIG. 4, and FIG. Is a cutaway sectional view of the casting mold apparatus used in the production of FIG. 1 ... Accommodation chamber, 2 ... Cylinder chamber, 3 ... Communication hole, 4 ... Container, 5a, 5b ... Eyes respectively, 6 ... Wound type capacitor element, 6a, 6b ... Each winding end face, 7a,
7b ... Leader wire, 8 ... container type capacitor, 9 ... SF ₆ gas, 10 ... epoxy resin, 1
0 '... Epoxy resin liquid, 11 ... Mold, 12, 13,
14, 15 ... Valve, 16 ... Vacuum pump,
17 ... Synthetic resin liquid tank, 18 ... SF ₆ gas cylinder.

Claims (1)

[Scope of utility model registration request] 1. A cylinder chamber is formed between an inner wall and an outer wall by forming a peripheral wall of the accommodating chamber into a double structure, an opening toward the outside is formed at a lower end portion of the cylinder chamber, and an accommodating chamber is formed at an upper end portion toward the inner wall. One or more wound-type capacitor elements are respectively housed in the housing chamber of the container having a through hole communicating therewith facing the opposite end faces of the winding with respective gaps therebetween to form a container-contained capacitor. , A plurality of container-contained capacitors are assembled, and the accommodating chamber and the cylinder chamber of each container of this assembly are filled with an insulating gas, and a synthetic resin liquid is caused to flow into the cylinder chamber of each container so as to A high-voltage capacitor characterized in that insulating gas in a storage chamber is hermetically sealed in a positive pressure state by pressurizing the insulating gas to bring it into a positive pressure state and molding the periphery of the assembly with a synthetic resin.