JP5458047B2 - Anti-layering prevention device for oil-immersed paper capacitor core and oil-impregnated paper capacitor bushing - Google Patents

Description

  The present invention relates to a delamination prevention device for oil-coated paper capacitor cores and an oil-coated paper capacitor bushing.

  The oil-impregnated paper capacitor bushing used for the insulation support of the high-voltage power line is formed by forming a capacitor core for electric field relaxation around the center conductor. As described in Patent Document 1, the capacitor core is an insulating layer. This is a structure in which several dozen layers of oil-impregnated paper and metal foil as electrode layers are alternately laminated.

  During production, oil-coated paper and metal foil are alternately wound around the outer periphery of the central conductor installed horizontally, but the use of adhesives that may adversely affect electrical characteristics must be kept to a minimum. The layers are only simply bonded, not firmly bonded. For this reason, there is a risk that the interlayer of the oil-impregnated paper capacitor core is shifted downward due to gravity in the process of lifting the center conductor after the winding of the capacitor core is vertically lifted and assembling the bushing.

  In the case of a relatively small bushing, the oil-immersed paper capacitor core is small and lightweight, so even when it is lifted vertically, the gap between the layers can be reduced by simple adhesion when winding the core and the frictional force between the insulating papers There will be no drop. However, when a large bushing of 500 kV or more is used, the oil-immersed paper capacitor core itself is a heavy article exceeding 300 kg, and there is a risk of slipping off.

  If such interlayer displacement of the oil-immersed paper capacitor core occurs, the designed electric field relaxation ability cannot be exhibited. In addition, there is a possibility that the safety of the work may be lost due to a heavy object falling during the assembly work. However, large bushings of 500 kV or more may be produced in a small number, and there is no prior art document that focuses on this problem.

JP 2006-107895 A (paragraph 0014)

  Accordingly, the object of the present invention is to solve the above-mentioned conventional problems, and even when the center conductor after the winding of the capacitor core is made vertical, the oil-impregnated paper can easily and reliably prevent the slippage between the layers. An object of the present invention is to provide a capacitor core interlayer slip prevention device and an oil-impregnated paper capacitor bushing.

In order to solve the above-mentioned problems, an interlayer displacement prevention device for oil-immersed paper capacitor cores according to the present invention includes a plurality of ring-shaped members that receive the lower surface of the stepped portion of the capacitor core formed in steps, and these ring-shaped members A plurality of columnar members are arranged between the members at regular intervals in the circumferential direction, and are fixed to the outer periphery of the capacitor core. These members are made of an insulating material.

  The relative dielectric constant of the insulating material is preferably in the range of 0.8 to 1.3 times the relative dielectric constant of the oil-immersed paper forming the capacitor core. The insulating material is preferably a press board impregnated with oil. Moreover, it is preferable to make it the structure which gave the hole or the groove | channel to the upper-lower end part of the columnar member.

  The oil-impregnated paper capacitor bushing according to the present invention is characterized in that the lower end portion of the capacitor core is formed in a multi-stage shape, and the above-mentioned interlayer displacement prevention tool for oil-impregnated paper capacitor core is mounted. In addition, the interlayer displacement prevention tool for oil-immersed paper capacitor cores can be attached to a portion of the lower end portion of the capacitor core on the smaller diameter side.

  Furthermore, the manufacturing method of the oil-absorbing paper capacitor bushing according to the present invention comprises the capacitor core is formed on the outer periphery of the center conductor, and the interlayer slip prevention device for the oil-immersed paper capacitor core according to claim 1 is left dry on the lower surface of the stepped portion. After that, the oil-impregnated paper capacitor core and the oil-impregnated paper capacitor core delamination prevention device are simultaneously impregnated with the oil by vacuum drying impregnation method. It is characterized by being attached to the inside of the.

According to the present invention, the lower surfaces of the plurality of step portions of the capacitor core formed in a step shape are provided with a plurality of ring members made of an insulating material, and a plurality of them at regular intervals in the circumferential direction between these ring members. Since they are arranged and supported by columnar members fixed to the outer periphery of the capacitor core, even if the central conductor after the winding of the capacitor core is lifted vertically, the layers of the capacitor core do not shift. Note that the lowermost end of the interlayer displacement prevention tool for oil-immersed paper capacitor core is supported by a disk fixed to the central conductor. The oil-immersed paper capacitor core shrinks in the drying process before impregnating with the insulating oil. However, since the interlayer misalignment prevention device of the present invention is composed of a large number of parts, it can be easily rearranged according to the shrinkage.

  If the relative permittivity of the insulating material is in the range of 0.8 to 1.3 times the relative permittivity of the oil-impregnated paper forming the capacitor core as in claim 2, it is controlled by the capacitor core. There is no significant disturbance in the electric field.

  If an insulating material in which a press board is impregnated with oil is used as an insulating material, it has an insulation strength comparable to that of oil-impregnated paper and is electrically adversely affected in an electric field controlled by a capacitor core Will not affect.

  If the structure is such that holes or grooves are processed in the upper and lower ends of the columnar member as in claim 4, the work of unwinding and reassembling the cotton tape or the like that has passed through these holes or grooves even after impregnation with oil It can be done easily.

  Further, the oil-impregnated paper capacitor bushing of the present invention is formed by forming the lower end portion of the capacitor core in a multi-stage shape and mounting the above-mentioned interlayer slip prevention tool for the oil-impregnated paper capacitor core. It can support reliably and can prevent a gap between layers.

  According to the sixth aspect of the present invention, if the anti-slipping tool is configured to be mounted only on the smaller diameter portion of the lower end portion of the capacitor core, the mounting and recombination workability is improved. In addition, since a part with a large diameter is short in length and lightweight, there is little possibility that an interlayer shift will occur.

  Furthermore, according to the manufacturing method of the oil-impregnated paper capacitor bushing of the present invention, it is not necessary to perform the work of mounting the interlayer displacement prevention device inside the oil-impregnated tank, and the assembly workability can be improved.

It is a typical sectional view showing a capacitor core. It is typical sectional drawing which shows the capacitor | condenser core with which the interlayer shift | offset | difference prevention tool was mounted | worn. It is a perspective view which shows only an interlayer displacement prevention tool. It is a horizontal sectional view which shows the state tied with the tape. It is sectional drawing of the lower part of a bushing.

Hereinafter, preferred embodiments of the present invention will be described.
FIG. 1 is a schematic cross-sectional view showing a state in which a capacitor core 2 is wound around a central conductor 1. As described above, the capacitor core 2 is for laminating oil-impregnated paper and metal foil (aluminum foil) alternately to form a capacitor of several tens of layers, thereby relaxing the electric field. In general, the lower end of the capacitor core 2 is formed in a multi-stage shape as shown in FIG. The winding of the capacitor core 2 is performed in a state where the central conductor 1 is installed horizontally as in the conventional case. At this stage, the capacitor core 2 is in a dry state.

  Next, as shown in FIG. 2, the interlayer shift prevention device for oil-immersed paper capacitor core of the present invention is attached to the lower end portion of the capacitor core 2. This is composed of a plurality of ring-shaped members 3 and columnar members 4 arranged between these ring-shaped members 3 as shown in FIG. 3 and subsequent figures, all of which are made of an insulating material. Yes. The ring-shaped member 3 is a member that is in close contact with the lower end portion of the capacitor core 2, that is, the lower surface of the step portion. . Note that the ring-shaped member 3 does not have to be attached to all the lower surfaces of the stepped portions of the lower end portion of the capacitor core 2 and may be attached only to the portion having a relatively small diameter. This is because the large-diameter portion is light and has no fear of slipping off. By limiting the mounting portion in this way, the workability can be improved and the cost can be reduced.

A plurality of columnar members 4 are members that support a load and are arranged between the adjacent upper and lower ring-shaped members 3 and 3 at a predetermined interval in the circumferential direction . In this embodiment, the four columnar members 4 are arranged at intervals of 90 °, but three or five or more may be used. Holes 5 are formed in the upper and lower ends of the columnar member 4, and the whole can be fixed to the outer periphery of the capacitor core 2 by passing a string or tape 6 through these holes 5 as shown in FIG. 5. . A groove may be processed at the end instead of the hole 5. By adopting a configuration in which a large number of parts are assembled in this way, recombination can be easily performed. For example, recombination can be easily performed in response to contraction of the capacitor core 2 due to vacuum heating and drying.

  Since the ring-shaped member 3 and the columnar member 4 are incorporated into the bushing as they are, it is necessary that the ring-shaped member 3 and the columnar member 4 be made of a material that does not adversely affect the electrical characteristics of the bushing. Needless to say, the material is required to have no part that causes electric field concentration such as contamination of metal foreign matter, flaking, fraying, cracking, and cracking. In particular, the risk of flashing increases when metallic foreign objects are mixed in, so take precautions such as X-ray inspection at the time of shipment from the manufacturer. Further, it is required that the compressibility is small and the compressive strength, bending strength, and shear strength are high. As for the compressive strength, a material having a compressive strength of 10 times or more of the pressure by the capacitor core is adopted by considering the likelihood of 5 times in consideration of the inertial force 2G when moving up and down. Furthermore, it is required to have a service life of at least 30 years.

  In this embodiment, a press board (two types (PB2) defined by JIS_C2305) in which high-purity pulp is pressure-laminated is used as a material that satisfies the above characteristics. This press board is an insulator that is also used in transformers, and is a proven material that does not change when used in insulating oil for many years. In addition, it has a high strength and can support a load, and can be cut into a required size on site. In order to prevent the moisture from affecting the insulating oil, it is preferable to remove the moisture by vacuum heating and drying before impregnating the oil.

  The relative dielectric constant of the insulating material used for the ring-shaped member 3 and the columnar member 4 is preferably in the range of 0.8 to 1.3 times the relative dielectric constant of the oil-impregnated paper forming the capacitor core 2. By using a material having a close relative dielectric constant in this way, the electric field controlled by the capacitor core 2 is not greatly disturbed. A press board impregnated with insulating oil has an insulation strength comparable to that of oil-impregnated paper.

  The ring-shaped member 3 and the columnar member 4 described above are attached to the lower end portion of the capacitor core 2 in a dry state while the center conductor 1 is in a horizontal state. As shown in FIG. 2, the lowermost end portion of the interlayer displacement prevention tool is brought into close contact with a ring-shaped jig 7 screwed and fixed to the center conductor 1 so as to receive a load. Note that the material of the string or tape 6 for connecting the columnar members 4 must also be insulative and not cause electric field concentration. In this embodiment, pure cotton tape is used.

  Next, the whole is lifted by a crane or the like and transferred to a vacuum heating and drying apparatus. Thus, even if it lifts up vertically, since the lower surface of the step part of the capacitor core 2 is supported by the ring-shaped jig 7, it does not fall off. After the moisture in the capacitor core 2 and the interlayer displacement prevention device is sufficiently extracted by vacuum heating and drying, the capacitor core 2 and the interlayer displacement prevention device are impregnated with insulating oil.

  After the impregnation with the insulating oil, the ring-shaped jig 7 is removed from the central conductor 1 and the number of the ring-shaped members 3 is increased or decreased, and the lowermost metal fitting 9 is attached to adjust the ring-shaped member 3 so that it does not shift. At this time, the thickness can be adjusted by tearing the ring-shaped jig 7 in the thickness direction. As shown in FIG. 5, a set screw 10 is cut in the lowermost metal fitting 9, and the lower end portion of the center conductor 1 is screwed. In this state, the center conductor 1 provided with the capacitor core 2 and the soot tube 8 are assembled. Although the center conductor 1 is lifted vertically during this operation, there is no risk of slipping off. Thereafter, insulating oil is injected into the bushing.

  It should be noted that buoyancy occurs when the entire capacitor core 2 is immersed in oil, so that even if there is no interlayer displacement prevention device, the capacitor core 2 will not fall thereafter, but the interlayer displacement prevention device in oil. In order to eliminate the man-hours to remove, the finished product is left with the anti-slipping tool attached.

  As described above, according to the present invention, even when the center conductor 1 that has been wound around the capacitor core 2 is moved vertically or assembled, it is possible to easily and reliably prevent the capacitor core 2 from slipping off between the layers. Therefore, the designed electric field relaxation capability can be exhibited, and the danger of heavy objects falling during assembly work can be eliminated.

DESCRIPTION OF SYMBOLS 1 Center conductor 2 Capacitor core 3 Ring-shaped member 4 Column-shaped member 5 Hole 6 String or tape 7 Ring-shaped jig 8 Fence pipe 9 Bottom-most metal fitting 10 Stop screw

Claims (7)

A plurality of ring-shaped members that receive the lower surface of the stepped portion of the capacitor core formed in a step shape, and a plurality of ring-shaped members that are arranged at regular intervals in the circumferential direction between these ring-shaped members and fixed to the outer periphery of the capacitor core An anti-layer shift tool for oil-immersed paper capacitor cores, characterized in that these members are made of an insulating material.   2. The oil-impregnated paper capacitor core according to claim 1, wherein a relative dielectric constant of the insulating material is in a range of 0.8 to 1.3 times a relative dielectric constant of oil-immersed paper forming the capacitor core. Anti-slipping tool.   The interlayer insulation prevention tool for oil-immersed paper capacitor cores according to claim 2, wherein the insulating material is a press board impregnated with oil.   The anti-layering prevention tool for oil-coated paper capacitor cores according to claim 1, wherein holes or grooves are formed in the upper and lower ends of the columnar member.   An oil-impregnated paper capacitor bushing, wherein the lower end portion of the capacitor core is formed in a multi-stage shape, and the anti-interlayer displacement prevention device for oil-impregnated paper capacitor core according to claim 1 is mounted.   6. The oil-immersed paper capacitor bushing according to claim 5, wherein an interlayer displacement prevention device for oil-immersed paper capacitor core is attached to a portion of the lower end portion of the capacitor core having a smaller diameter.   A capacitor core is formed on the outer periphery of the center conductor, and the interlayer displacement prevention device for oil-impregnated paper capacitor core according to claim 1 is mounted on the lower surface of the stepped portion in a dry state. The oil-impregnated paper capacitor bushing is characterized in that the capacitor core and the oil-impregnated paper capacitor core interlayer slip prevention device are impregnated with oil at the same time, and the oil-impregnated paper capacitor core interlayer slip prevention device is attached to the inside of the soot tube Manufacturing method.

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