JP5317930B2 - Static induction machine - Google Patents

Description

  The present invention relates to a static induction appliance such as a transformer or a reactor, and more particularly to a static induction appliance in which a surge protection measure is taken for a static induction winding.

In static induction appliances such as transformers, the most common cause of failure or breakage is the dielectric strength within the static induction winding that constitutes the static induction appliance as a result of the invasion of overvoltage (surge) caused by lightning The above overvoltage occurs transiently and leads to dielectric breakdown . Transient overvoltages (potential vibration) generated inside the stationary induction winding against surge invasion, tables in the square root of the ratio of the total earth capacitance C of the windings relative to the total capacitance K of the internal stationary induction winding As the value of α = (square root of (C / K)) is smaller, the maximum value is smaller. Therefore, as a method of suppressing the potential oscillation, there is a method of increasing the electrostatic capacity inside the static induction winding. Generally used.

  As a means of increasing the electrostatic capacity inside the static induction winding of the static induction electric machine, the conductive conductors are used to electrostatically couple the winding conductors at different potentials, and equivalently increase the electrostatic capacity. The method is often used.

  As shown in FIG. 5, as a method of increasing the electrostatic capacity inside the static induction winding by the conductive shield material, a magnetic iron core 1, a cylindrical low-voltage winding 2 wound around the outer periphery of the magnetic iron core 1, A transformer having a cylindrical high-voltage winding 3 in which a plurality of layers of concentric high-voltage winding layers 3A to 3D are formed on the outer periphery of the cylindrical low-voltage winding 2 via a gap, and a storage tank 4 for collectively storing these. In, for example, the conductive shield material 5 that is electrically directly connected to the line end 3T is disposed on the inner peripheral side of the high-voltage winding layer 3A connected to the line end 3T via a gap.

  As a related technique, there is Patent Document 1 as a patent document.

JP-A-63-209112

  In the transformer disclosed in the background art, since the electrostatic capacity inside the cylindrical high voltage winding 3 by the conductive shield material 5 increases, transient overvoltage can be suppressed. However, since the cylindrical low voltage winding 2 exists on the inner diameter side of the cylindrical high voltage winding 3 on which the conductive shield material 5 is disposed, the conductive shield material 5 having the same potential as the line end 3T of the high voltage winding layer 3A. And the cylindrical low-voltage winding 2 must have an insulation distance. As a result, the gap between the cylindrical high-voltage winding 3 and the cylindrical low-voltage winding 2 is widened. As a result, the outer diameter of 3 increased and there was a problem of increasing the size of the entire transformer.

  An object of the present invention is to provide a static induction electric appliance capable of suppressing a transient overvoltage while suppressing an increase in the outer diameter of the static induction winding.

In order to achieve the above object, the present invention provides a cylindrical high voltage winding formed concentrically with a plurality of layers on the outer periphery of a cylindrical low voltage winding mounted around a magnetic iron core via a gap, and the cylindrical high voltage winding. And a conductive shield material that is discontinuous in the circumferential direction of the magnetic iron core between and a member having a potential difference is supported by an insulating material, and the conductive shield material is disposed in the longitudinal direction of the cylindrical high-voltage winding. The static induction machine is configured by making the distance between the conductive shield material and the cylindrical high-voltage winding narrower than the distance between the layers of the cylindrical high-voltage winding .

  With the above-described configuration, the conductive shield material is not electrically connected directly to any conductive portion in the static induction appliance, and is electrostatically connected to the cylindrical winding in which the conductive shield material is disposed. Since they are coupled, the potential of the conductive shield material is an average value of the winding conductor potential of the cylindrical winding located in a range facing the conductive shield material.

  As a result, the potential of the conductive shield material is lower than the line potential of the cylindrical winding, and the insulation distance between the conductive shield material and the other winding facing the conductive shield material is the same as the line potential. Compared to the case of the electric potential, it can be made smaller, and the outer diameter of the cylindrical winding can be reduced to reduce the size of the stationary induction device.

  As described above, according to the present invention, it is possible to obtain a static induction device that can suppress a transient overvoltage with a conductive shield material while suppressing an increase in the outer diameter of the static induction winding.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic longitudinal cross-sectional view of the transformer which shows 1st Embodiment of the static induction appliance by this invention. The enlarged view of the upper end part vicinity of the cylindrical winding which shows the modification of 1st Embodiment. The schematic longitudinal cross-sectional view of the transformer which shows 2nd Embodiment of the static induction appliance by this invention. FIG. 3 is an equivalent view of FIG. 3 showing the operation of the first embodiment of the static induction electric machine according to the present invention. The equivalent figure of FIG. 1 which shows the conventional transformer.

  Hereinafter, a first embodiment of a static induction electric machine according to the present invention will be described based on a transformer shown in FIG.

  The transformer includes a magnetic iron core 1, a cylindrical low-voltage winding 2 wound around the outer circumference of the magnetic iron core 1, and a plurality of cylindrical winding layers disposed on the outer circumference of the cylindrical low-voltage winding 2 with a gap therebetween. A cylindrical high-voltage winding 3 in which 3A to 3D are arranged concentrically and a storage tank 4 that collectively stores them are provided.

  A cylindrical conductive shield material 5 is disposed between the cylindrical low-voltage winding 2 and the cylindrical high-voltage winding 3 at a position approaching the inner diameter side of the cylindrical high-voltage winding 3. The conductive shield material 5 does not form one turn with respect to the circumferential direction of the magnetic iron core 1, in other words, the conductive shield material 5 discontinuous in the circumferential direction of the magnetic iron core 1 is not illustrated. The material is supported and arranged. That is, at least one place in the circumferential direction of the cylindrical conductive shield material 5 is cut away and separated so that a circulating current does not flow through the conductive shield material 5. Further, the conductive shield material 5 is disposed so as to face the entire length of the cylindrical high-voltage winding 3 in the longitudinal direction (the height direction in the case of FIG. 1).

According to the present embodiment, the conductive shield 5 is not electrically directly connected to any of the cylindrical high voltage winding 3 and the conductive portion of the transformer, and the cylindrical low voltage winding 2 Since the cylindrical conductive shield material 5 is disposed between the cylindrical high voltage winding 3 and a position close to the inner diameter side of the cylindrical high voltage winding 3, the potential of the conductive shield 5 is static. It becomes equal to the average potential of the winding conductor in the longitudinal direction in the cylindrical winding layer 3A located on the innermost diameter side of the cylindrical high-voltage winding 3 that is electrically coupled. As a result, the transient overvoltage (potential oscillation) of the cylindrical high-voltage winding 3 is suppressed by the effect of the conductive shield 5, so that the potential distribution is close to a straight line distribution from the line end 3T to the ground end.

  Since the potential of the conductive shield 5 becomes equal to the average potential of the longitudinal winding conductor in the cylindrical winding layer 3A located on the innermost diameter side of the cylindrical high-voltage winding 3 that is electrostatically coupled, The potential is lower than the potential at the line end 3T, and the potential difference between the conductive shield material 5 and the cylindrical low-voltage winding 2 facing the conductive shield material 5 is electrically connected directly to the line end 3T. It becomes smaller than the case where it becomes the same potential as 3T. As a result, the necessary insulation distance between the conductive shield material 5 and the cylindrical low-voltage winding 2 can be shortened.

  In addition, since it is necessary to produce a big electrostatic coupling between the electroconductive shield material 5 and the cylindrical winding layer 3A, it is necessary to arrange both closely. Further, electrostatic coupling is also generated between the cylindrical winding layers 3A and 3B, but in order to generate an electrostatic coupling of the same level or higher between the conductive shielding material 5 and the cylindrical winding layer 3A, the conductive shielding material is used. It is appropriate that the insulation distance W1 between 5 and the cylindrical winding layer 3A is equal to or less than the insulation distance W2 between the cylindrical winding layers 3A and 3B. The potential of the conductive shield material 5 is the average potential of the winding conductors adjacent in the longitudinal direction (height direction) in the cylindrical winding layer 3A, and the conductive shield material 5 and the cylindrical winding layer 3A Since the difference voltage between them is less than or equal to half of the difference voltage between the cylindrical winding layers 3A and 3B, the insulation distance W1 is more preferably about half of the insulation distance W2.

  By the way, as a material of the conductive shield material 5, a sheet-like thin plate conductor, a foil-like conductor, a braided wire of a fine metal wire, a conductive paint sprayed or applied to the surface of an insulator, and the like are suitable.

  Furthermore, in the first embodiment, the conductive shield material 5 has an integrated structure in the longitudinal direction of the cylindrical high-voltage winding 3, but the same effect can be obtained even if the structure is divided into a plurality of parts in the longitudinal direction. It is done. In addition, the cylindrical conductive shield material 5 may be divided into a plurality of parts in the circumferential direction, and this may be combined with the division in the longitudinal direction.

  As described above, according to the first embodiment, the necessary insulation distance between the conductive shield material 5 and the cylindrical low-voltage winding 2 can be shortened. The overvoltage generated in the wire 1 can be suppressed, and an increase in the insulation distance between the high-voltage side cylindrical winding 1 and the cylindrical low-voltage winding 2 is suppressed, and the static induction appliance can be downsized.

  In addition, since it is not necessary to directly connect the conductive shield material 5 and any conductive portion in the static induction appliance, it is possible to simplify the arrangement work of the conductive shield material 5 and improve productivity. Can be achieved.

  Next, a modification of the first embodiment will be described with reference to FIG.

  In this modification, cylindrical winding is provided at both ends of the longitudinal dimension (height dimension) of the conductive shield material 6 facing the cylindrical winding layer 3A located on the inner diameter side of the cylindrical high-voltage winding 3 with a gap. An electric field relaxation portion 6E extending beyond the longitudinal dimension (height dimension) of the line layer 3A is provided.

  That is, the cylindrical winding layer 3A is formed by winding a winding conductor 3a covered with an insulating layer 3b. When the section of the winding conductor 3a is viewed, the cross-section corner is formed at a small curvature radius R1. Since the electric field concentrates there and the insulating layer 3b is deteriorated, and there is a risk that the insulation layer 3b may be broken down. Therefore, the surrounding components (the yoke extending from the cylindrical low-voltage winding 2 and the magnetic iron core 1) (Not shown)).

  In order to solve such a problem, it extends beyond the longitudinal dimension (height dimension) of the cylindrical winding layer 3A at both ends of the longitudinal dimension (height dimension) of the conductive shield material 6. An electric field relaxation portion 6E having a radius of curvature R2 larger than the small curvature radius R1 of the cross-sectional corner portion of the winding conductor 3a is provided, and the longitudinal end portion of the cylindrical winding layer 3A is spaced by an interval between the electric field relaxation portions 6E. I covered it.

  With this configuration, the electric field concentrated on the cross-sectional corner of the winding conductor 3a can be relaxed by the electric field relaxation portion 6E of the conductive shield material 6. As a result, the insulation distance from the surrounding constituent members can be reduced. Therefore, the transformer can be reduced in size.

According to this modification, the same effects as those of the first embodiment can be achieved, and the transformer can be miniaturized.
As a result, the insulation distance from the cylindrical low-voltage winding 2 and the insulation distance from the iron core yoke (not shown) located above the cylindrical winding layer 3A can be shortened.

  FIG. 3 is a transformer showing a second embodiment of a static induction electric machine according to the present invention, and a configuration different from the first embodiment is that a cylindrical low-voltage winding 2 is composed of a plurality of sheet conductors 2A to 2C. It is a point that is configured.

When the cylindrical low-voltage winding 2 is composed of sheet conductors 2A to 2C, for example, an eddy current Ia flows through the outermost sheet conductor 2A during operation of the transformer. The eddy current Ia generates a magnetic flux ( denoted as magnetic flux repulsive force Fa ) toward the cylindrical high voltage winding 3, and the magnetic flux repulsive force Fa passes between the cylindrical low voltage winding 2 and the cylindrical high voltage winding 3. A part of the leakage magnetic flux Φ is pushed out to the cylindrical high-voltage winding 3 side and linked to the longitudinal end of the cylindrical high-voltage winding 3. However, when the amount of interlinkage of the leakage magnetic flux Φ with respect to the winding conductor at the longitudinal end portion of the cylindrical high voltage winding 3 increases, stray loss of the cylindrical high voltage winding 3 increases, thereby reducing the transformer performance. Become.

However, in this embodiment, like the first embodiment, since the conductive shielding material 5 on the inner diameter side of the cylindrical high-voltage winding 3 is placed, the sheet conductors 2A in the transformer running The eddy current Ib in the direction opposite to the eddy current Ia flows through the conductive shield material 5, and the eddy current Ib generates a magnetic flux ( denoted as magnetic flux repulsive force Fb ) toward the cylindrical low-voltage winding 2 side. The magnetic flux repulsive force Fb generated by the conductive shield material 5 reduces or cancels the magnetic flux repulsive force Fa generated by the sheet conductor 2A, thereby causing a chain of leakage magnetic flux Φ at the longitudinal end portion of the cylindrical high-voltage winding 3 by the magnetic flux repulsive force Fa. The amount of crossing is reduced, and the stray loss generated in the cylindrical high-voltage winding 3 can be reduced to improve the performance of the transformer. By the way, since the conductive shield material 5 is not directly electrically connected to any conductive portion in the transformer, the eddy current Ib flowing at the end of the conductive shield material 5 is limited to the inside of the conductive shield material 5. Therefore, an increase in stray loss due to the eddy current Ib is minimized.

  According to this embodiment, in addition to the same effects as those of the above-described embodiment, stray loss generated in the cylindrical high-voltage winding 3 can be reduced, and the efficiency of the transformer can be improved.

  FIG. 4 explains the effect of reducing the amount of interlinkage of the leakage magnetic flux Φ with respect to the cylindrical high-voltage winding 3 in the first embodiment shown in FIG.

  That is, when the cylindrical low-voltage winding 2 is formed by winding each of the winding conductors in a disk shape like the cylindrical high-voltage winding 3, the cylindrical low-voltage winding 2 has a leakage flux Φ. The magnetic flux repulsion force that pushes out toward the cylindrical high-voltage winding 3 is not generated. However, there is a leakage magnetic flux Φ linked to the end of the cylindrical high-voltage winding 3. Therefore, according to the first embodiment, the leakage flux Φ interlinked by the magnetic flux repulsive force Fb by the conductive shield material 5 described above is pushed back to the cylindrical low-voltage winding 2 side, so that the cylindrical height of the leakage flux Φ is increased. The amount of linkage to the end of the winding 3 can be reduced to reduce stray loss and improve the performance of the transformer.

  Although the above explanation has explained a transformer in which a cylindrical low voltage winding is mounted around a magnetic iron core as a static induction electric appliance and a cylindrical high voltage winding is mounted on the outer periphery thereof, it is not limited to these, The present invention can also be applied to a transformer having a cylindrical intermediate voltage winding between a cylindrical low voltage winding and a cylindrical high voltage winding.

  Further, in the above description, the conductive shield material is disposed on the inner diameter side of the cylindrical high-voltage winding. However, depending on the connection method of the winding, the conductive shield material is provided between the cylindrical high-voltage winding and the storage tank. The conductive shield material may be disposed on both the inner diameter side and the outer diameter side of the cylindrical high-voltage winding.

  In the above description, a transformer has been described as an example of a static induction electric appliance. However, the present invention can also be applied to a reactor including a single magnetic induction winding on a magnetic iron core.

  DESCRIPTION OF SYMBOLS 1 ... Magnetic iron core, 2 ... Cylindrical low voltage winding, 2A-2C ... Sheet conductor, 3 ... Cylindrical high voltage winding, 3A-3D ... Cylindrical winding layer, 3a ... Winding conductor, 3b ... Insulating layer, 3T ... Line ends, 4 ... storage tanks, 5, 6 ... conductive shield material, 6E ... electric field relaxation part.

Claims (8)

A magnetic iron core, a cylindrical low-voltage winding mounted around the magnetic iron core, a cylindrical high-voltage winding formed concentrically on the outer periphery of the cylindrical low-voltage winding via a gap, and these are housed In a static induction appliance comprising a storage tank, a conductive shield material that is discontinuous in the circumferential direction of the magnetic iron core is disposed between the cylindrical high-voltage winding and a member having a potential difference by an insulating material. In addition, the conductive shield material is opposed over the entire length in the longitudinal direction of the cylindrical high-voltage winding, and the interval between the conductive shield material and the cylindrical high-voltage winding is set between each layer of the cylindrical high-voltage winding. A static induction machine characterized in that it is formed narrower than the interval. 2. The static induction device according to claim 1, wherein the conductive shield material is disposed between the cylindrical low-voltage winding and the cylindrical high-voltage winding. The static induction device according to claim 1, wherein the conductive shield material is installed between the cylindrical high-voltage winding and the storage tank. The static induction appliance according to any one of claims 1 to 3, wherein the conductive shield material extends in a range exceeding a length of the cylindrical high-voltage winding. The portion of the conductive shield material that exceeds the length of the cylindrical high-voltage winding is bent toward the winding conductor with a radius of curvature larger than the radius of curvature of the winding conductor corner of the cylindrical high-voltage winding. The static induction machine according to claim 4, wherein a relaxation part is formed. The stationary conductive material according to any one of claims 1 to 5, wherein the conductive shield material is a thin plate-like or foil-like conductor, a braided wire of a fine metal wire, or a conductive paint coated on a substrate. Induction machine. The static induction machine according to claim 1, wherein the cylindrical low-voltage winding is a sheet-like conductor. A magnetic iron core, a cylindrical low-voltage winding mounted around the magnetic iron core, a cylindrical high-voltage winding formed concentrically on the outer periphery of the cylindrical low-voltage winding via a gap, and these are housed In a static induction appliance comprising a storage tank, a conductive shield material that is discontinuous in the circumferential direction of the magnetic iron core is insulated between the inner periphery of the cylindrical high voltage winding and the outer periphery of the cylindrical low voltage winding. And supporting the conductive shield material over the entire length in the longitudinal direction of the cylindrical high voltage winding, and the interval between the conductive shield material and the cylindrical high voltage winding is: A static induction machine characterized in that it is formed narrower than the interval between the layers of the cylindrical high-voltage winding.

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