JPH0610663Y2 - 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 likely to occur on both end faces of the winding, and improvement in dielectric strength characteristics is required.

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 rolled up in the air while being stacked, the electrodes are formed by spraying metal on both end faces of the rolled up element, and a lead wire is 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 face parts, and then the insulation gas is allowed to flow in the mold with the ventilation holes open (while the internal pressure is always positive), the flame-retardant property is lower than that of the resin injection port below. 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. In the initial stage of curing by heating to the curing reaction temperature, the clay of the synthetic resin liquid falls, and the remaining insulating gas is warmed and expands, further increasing the buoyancy, and further bubbles in the synthetic resin liquid. And go out It becomes Kukoto. 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-mentioned problems, this invention is a winding method in which a band-shaped dielectric layer and an electrode layer are alternately wound around a cylindrical bobbin. -Type capacitor element is housed in a container that surrounds the outer peripheral surface of the cylindrical bobbin excluding the lower end hole and faces both winding end surfaces of the wound-type capacitor element to form a separate gap to form a container-containing capacitor. Then, a plurality of the container-contained capacitors are assembled, and the insulating gas is filled in each container and the hole of the cylindrical bobbin of this assembly, and the synthetic resin liquid is filled in the hole of each cylindrical bobbin. Since the insulating gas in the container is pressurized to bring it into a positive pressure state and molded around the assembly with a synthetic resin, the insulating gas in the container is sealed in a positive pressure state so as to be integrated. is there.

[Operation] When the insulating gas is filled into the holes of the container-containing capacitor and the cylindrical bobbin and the synthetic resin liquid is injected around the container, first, the lower part of the hole of the cylindrical bobbin is filled with the synthetic resin liquid. By sealing with, the insulating gas can be filled into the holes of the container and the cylindrical bobbin at the gas pressure when the insulating gas is filled.

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 hole of the cylindrical bobbin, so that the pressurized state is generated. The gas pressure of the insulating gas in the container can be increased by pushing up the synthetic resin liquid in the upward direction inside the hole of the cylindrical bobbin and flowing 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 pressurizing pouring force is applied to the free surface of the synthetic resin liquid, resulting in a larger pressure. By being in a pressurized state, the synthetic resin liquid enters while pushing the insulating gas upward in the hole of the cylindrical bobbin against the compressive repulsive force of the insulating gas,
The insulating gas is compressed by the amount of the synthetic resin liquid that has entered the hole of the cylindrical bobbin, and the gas pressure of the insulating gas can be further increased.

When the gas pressure of the insulating gas in the container 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 in the container at a desired high pressure.

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

[Embodiment] Hereinafter, the invention of the present application will be described with reference to FIGS.
This will be described with reference to FIG. Note that FIG. 1 is a cutaway sectional view of a high-voltage capacitor for explaining an embodiment, FIG. 2 is a cutaway sectional view of a container-containing capacitor in an intermediate stage of the present invention, and FIG. 3 is used for manufacturing a high-voltage capacitor. The cutaway sectional view of a die-mold apparatus is shown.

The high-voltage capacitor is a winding type capacitor in which a winding type capacitor element 2 in which a band-shaped dielectric layer and an electrode layer are alternately wound around a cylindrical bobbin 1 is surrounded by an outer peripheral surface portion of the cylindrical bobbin 1 excluding a lower end hole portion. The container 2 is housed in a container 4 facing both winding end faces of the element 2 to form a special gap to form a container-containing capacitor 6,
A plurality of the container-containing capacitors 6 are assembled, and an insulating gas, for example, SF ₆ gas 7 is filled in the containers 4, 4, ... And the holes of the cylindrical bobbins 1, 1 ,. At the same time, a synthetic resin liquid, for example, an epoxy resin liquid 8'is caused to flow into the holes of the respective cylindrical bobbins 1, 1, ... And the SF ₆ gas 7 in the containers 4, 4, ... Is pressurized to bring them into a positive pressure state. The insulating gas 7 in the containers 4, 4, ... Is hermetically sealed in a positive pressure state by molding the periphery of the assembly with an epoxy resin 8.

The SF ₆ gas 7 can be hermetically sealed in the respective containers 4, 4, ... In the following manner.

First, a cylindrical bobbin 1 is used as the winding core of the winding type capacitor element 2, and the outer peripheral surface of the winding type capacitor element 2 excluding the lower end hole of the cylindrical bobbin 1 is surrounded by a container 4 to form a winding type A plurality of container-containing capacitors 6 are prepared by separately forming gaps facing both ends of the winding of the capacitor element 2.

The container 4 used for the container-containing capacitor 6 has a container body 4a and a lid 4 for containing the winding type capacitor element 2 therein.
b, has an inner diameter slightly larger than the outer diameter of the wound capacitor element 2, and is set to an inner dimension of a height facing both end faces of the winding to form a gap therebetween. . The lid 4b is fixed to the outer periphery of the lower end of the cylindrical bobbin 1 in a sealed state, and one lead wire 3a of the winding type capacitor element 2 is inserted into the container body 4a to enable soldering and sealing. An eyelet 5a is attached. Further, the cylindrical bobbin 1 is provided with an eyelet 5a for allowing the other lead wire 3b of the winding type capacitor element 2 to be inserted and soldering and sealing. Cylindrical bobbin 1 of winding type capacitor element 2
After attaching the lid 4b to the container, positioning and accommodating it in the container body 4a, the lid 4b is fixed in a sealed state, and a lead wire inserted through the container body 4a and the eyelets 5a, 5b of the tubular bobbin 1 3a and 3b are soldered and kept in a sealed state.

Next, a plurality of container-containing capacitors 6 are assembled, and this assembly is set in a mold 9 having an inner diameter larger than its outer diameter as shown in FIG.
12 and 13 are closed, valve 11 is opened, vacuum pump 14
Is operated to evacuate the inside of the mold 9 in vacuum.

The air inside the containers 4, 4, ...
Degassed through the holes of 1, ..., And the inside of the holes of the containers 4, 4, ... And the cylindrical bobbins 1, 1, ... Is pulled to a vacuum degree of about 10 ⁻² mmHg.

Next, the valve 11 is closed, the valve 12 is opened, and the SF ₆ gas 7 is flown into the mold 9 in a vacuum state so as to enter the holes of the cylindrical bobbins 1, 1, ... And the containers 4, 4 ,. S
The F ₆ gas 8 is filled, and then the epoxy resin liquid 8 ′ is injected between the mold 9 and the respective containers 4, 4, ....

As the epoxy resin liquid 8 ', 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 8'is poured into the mold 9, first, the cylindrical bobbins 1 ₁ , 1 ₁ , ... of the container-containing capacitors 6 ₁ , 6 ₁ , ... located at the first stage from the bottom. The lower opening of the hole is sealed with the epoxy resin liquid 8 ', and S is placed in the containers 4 ₁ , 4 ₁ , ... And the cylindrical bobbins 1 ₁ , 1 ₁ ,.
F ₆ gas 7 can be enclosed. FIG. 3 illustrates almost this state. Furthermore, when the epoxy resin liquid 8'is injected,
Next, the lower openings of the holes of the cylindrical bobbins 1 ₁₂ , 1 ₂ , ... Of the second-stage container housing type capacitors 6 ₂ , 6 ₂ , ... Are sealed with the epoxy resin liquid 8'and the containers 4 ₂ , 4 _2, ... and the cylindrical bobbin ₁ 2, _{1 2,} ... exits encapsulating SF ₆ gas 7 inside. In this way, the lower openings of the cylindrical bobbins 1 ₃ , 1 ₃ , ... of the uppermost third-stage container-containing capacitors 6 ₃ , 6 ₃ , ... are sealed with the epoxy resin liquid 8 ', The mold 9 is filled with the epoxy resin liquid 8 '.

By the height hx from the lower opening surface of the hole of the cylindrical bobbin to the surface of the epoxy resin liquid 8'on the free surface of the synthetic resin liquid 8'generated in the hole of each cylindrical bobbin 1, 1, ... , Ρghx [dyn / cm ² ], per unit area, the gravity of the epoxy resin liquid 8 ′ is applied, so that S in the cylindrical bobbin 1
Filling pressure of F ₆ gas 7 Px is the filling pressure of the SF ₆ gas 8 in the state filled with SF ₆ gas 8 introduced and in the container cylindrical bobbin SF ₆ gas 7 in the mold 9 _P 0 [ Torr], it can be calculated by Px = Po + ρghx × 10 ⁻⁶ [Torr].

Now, when the filling pressure P ₀ is 0.3 Torr and the height of the container-containing capacitor 6 is 12 cm and the whole is assembled in three stages, the first-stage container-containing capacitors 6 ₁ , 6 ₁ , ... The enclosed pressure Px of the SF ₆ gas 7 in the inside is about Px≈0.3 + 0.06 = 0.36 [Torr], and the second-stage cylinder-container-equipped container-type condenser 6 ₂ ,
The enclosed pressure Px of the SF ₆ gas 8 in 6 ₂ , ... becomes Px≈0.3 + 0.04 = 0.34 [Torr], and the third-stage cylinder-container-equipped container-type condenser 6 ₃ ,
The enclosed pressure Px of the SF ₆ gas 7 in 6 ₃ , ... Is Px≈0.3 + 0.02 = 0.32 [Torr], and the increased pressure state from P ₀ = 0.3 [Torr], respectively. It is in balance.

When the mold 9 was filled with the epoxy resin liquid 8'in such a pressurized state and the epoxy resin liquid 8'was further injected while being pressurized by an external force, a pressing force by an external force was further applied to the free surface. As a result, the SF ₆ gas 7 is compressed and pushed in, whereby the epoxy resin liquid 8 ′ intrudes upward in the holes of the cylindrical bobbins 1, 1 ,. _{The 6} gas 7 is compressed by the amount of the epoxy resin liquid that has entered the holes of the cylindrical bobbins 1, 1, ..., Therefore, the gas pressure Px of the SF ₆ gas 7 therein is further increased.

The injection pressure of the epoxy resin liquid 9 ′ is, for example, 1.2 ×
Two types of 10 ⁶ dyn / cm ² and 1.5 × 10 ⁶ dyn / cm ² are set, and the volume of the hole of the cylindrical bobbin 1 is subtracted from the inner volume of the container 4 by the volume of the wound-type capacitor element 2. When set to half of the value
The gas pressure Px of the SF ₆ gas 8 in ₃ , 6, ₃ ... Is about 1.
From 02 Torr, it will rise to about 1.4 Torr and 1.9 Torr, respectively.

In this manner, the epoxy resin liquid 8'is injected to fill the container 4
The gas pressure of the SF ₆ gas 7 in the inside can be raised to a desired positive pressure state value, and when the injected synthetic resin liquid 8 ′ is reacted and cured while maintaining the desired positive pressure state value, the container 4
The SF ₆ gas 7 can be sealed therein to a desired high pressure. afterwards,
The high-voltage capacitor of the present invention can be obtained by taking it out of the mold 9 and subjecting it to post-processing if necessary.

The high pressure condenser of the embodiment of the present invention was prepared in which the gas pressure Px of the SF ₆ gas 7 in the third-stage container housing type condenser 6 was set to three kinds of 1.02 Torr, 1.4 Torr, and 1.9 Torr. The corona discharge inception voltage could be increased to about 1.2 times, about 1.7 times, and about 2.3 times higher than that of the high voltage capacitor produced by the conventional manufacturing method.

(C) Effect of the device In the high voltage capacitor of the device, a synthetic resin liquid for molding is introduced under pressure from the lower opening of the cylindrical bobbin so that insulating gas is supplied to the container surrounding the wound capacitor element. Since it is hermetically sealed in a positive pressure state, it is possible to interpose an insulating gas at a high density in the weak points of the dielectric strength of both ends of the winding type capacitor element, and to improve the corona discharge inception voltage. Is.

[Brief description of drawings]

FIG. 1 is a cutaway sectional view of a high voltage capacitor in an embodiment, FIG. 2 is a cutaway view of a container-containing capacitor that occurs at an intermediate stage of the high voltage capacitor of the present invention, and FIG. 3 is used for manufacturing a high voltage capacitor. It is a cutaway sectional view of the casting mold apparatus. 1 ... Cylindrical bobbin, 2 ... Winding type capacitor element, 3
a, 3b ... Leader lines, 4 ... container, 5a,
5b ... Eyelets, 6 ... Container type condenser, 7 ... SF ₆ gas, 8 '... epoxy resin liquid, 8 ...
… Epoxy resin, 9 …… Mold, 10,11,12,13
...... Valve, 14 ... Vacuum pump, 15 ... Synthetic resin liquid tank, 16 ... SF ₆ gas cylinder.

Claims (1)

[Scope of utility model registration request] 1. A winding-type capacitor element comprising a cylindrical bobbin, in which a band-shaped dielectric layer and an electrode layer are alternately wound, and a winding-type capacitor element surrounding the outer peripheral surface of the cylindrical bobbin excluding a lower end hole. A container housing type capacitor is formed by accommodating the container housing type capacitors by accommodating them in respective containers facing the both end faces of the winding and forming a gap, and each of the container housing type capacitors in the container and in the cylindrical shape. Insulation gas is filled in the bobbin holes, and synthetic resin liquid is made to flow into the holes of each cylindrical bobbin to pressurize the insulating gas in the container to a positive pressure state. A high-voltage capacitor characterized in that the insulating gas in the container is hermetically sealed in a positive pressure state by molding to be integrated.