JP6656187B2 - Stationary inductor - Google Patents

Description

  The present invention relates to a stationary inductor, and more particularly, to a stationary inductor including a shield so as to be sandwiched between a plurality of windings constituting the stationary inductor, such as a reactor.

  Since the transmission line is installed at a higher position than the surrounding buildings, it is installed in an environment that is subject to natural phenomena over long distances. When a transmission line receives a lightning strike and an impact voltage such as a lightning surge propagates through the transmission line, the impact voltage may enter a stationary inductor such as a transformer or a reactor. During normal operation of the stationary inductor, the potential of the coil included in the stationary inductor has a uniform potential distribution proportional to the number of turns. However, when the impact voltage enters the stationary inductor, the potential of the coil included in the stationary inductor is proportional to the number of turns due to the circuit constant between the stationary inductor and the circuit breaker. It becomes steeper than the distribution and oscillates around a potential distribution proportional to the number of turns. This phenomenon is called potential oscillation. In the stationary inductor, when the potential of the coil becomes non-uniform in this way, the potential of the coil becomes higher than that in the normal operation, and dielectric breakdown easily occurs.

  To solve this problem, for example, in Japanese Patent Application Laid-Open No. Hei 9-17658 (Patent Document 1), a shield is arranged between a pair of adjacent windings constituting a coil, so that a pair of windings and a shield are used. The configured capacitance is increased. As a result, the potential distribution when an impact voltage such as a lightning surge enters is improved.

  Also, for example, in Japanese Patent Application Laid-Open No. 2002-164227 (Patent Document 2), a shield is provided between the first coil and the second coil, and in the shield, the interval between the wound individual windings is provided. There is disclosed a configuration including a conductor portion having a larger width. An insulating portion is wound around a conductor portion included in the shield. Such a shield reduces the inductance of the shield and improves its shielding effect.

  In addition, as described above, in the following description, the “wire” also means a linear material constituting a wound member such as a coil, and the “coil” means a wire wound. It means the entirety of the formed inductive member. Further, the term "winding" is intended to mean a part of each individual turn included in a single coil. That is, one coil is formed by winding one element wire a plurality of times to form a plurality of windings.

JP-A-9-17658 JP 2002-164227 A

  In Japanese Patent Application Laid-Open No. 9-17658, the shield is constituted only by a single hollow conductor and an insulating part covering the surface thereof. For this reason, the shielding effect of the magnetic flux in the shield is not sufficient, and eddy current is easily generated in the shield. Since eddy currents increase the power loss of the entire stationary inductor and reduce the efficiency of power conversion, it is desirable to reduce this as much as possible.

  In Japanese Patent Application Laid-Open No. 2002-164227, the shield itself is single, and only a single-layer insulating member that covers the surface of the conductor winding included in the single shield is disposed. That is, there is no configuration in which the adjacent windings are individually insulated from each other by individually covering the adjacent windings. Therefore, for example, if the windings of the conductive material contact each other in the shield, eddy currents are likely to be generated in the shield.

  Furthermore, unlike Japanese Patent Application Laid-Open No. 9-17658, a shield is provided between a plurality of coils, not between a pair of adjacent windings constituting a coil, unlike Japanese Patent Application Laid-Open No. Hei 9-17658. That is, since there is no magnetic flux shielding effect between the plurality of windings in the coil, there is a concern that eddy current may be generated in the shield due to a leakage magnetic flux in a portion between the plurality of windings in the coil.

  The present invention has been made in view of the above problems, and an object of the present invention is to reliably increase a magnetic flux shielding effect between individual windings constituting a coil, reduce power loss due to eddy current, and reduce an impact voltage. An object of the present invention is to provide a stationary inductor capable of improving a potential distribution at the time of intrusion.

The stationary inductor of the present invention includes an iron core, a coil, and an inner shield. The coil is formed to have a plurality of windings in which a wire is wound around an iron core. The inner shield is arranged at a position sandwiched between windings adjacent to each other in the radial direction in which the coil is wound, and is wound around an iron core. The inner shield includes a plurality of conductors and an insulating coating that individually covers the surfaces of the plurality of conductors. The plurality of conductor portions of the inner shield are wound concentrically so as to overlap each other in the radial direction in which the coil is wound, and are arranged so as to be arranged in a direction intersecting the radial direction.

  In the present invention, an inner shield is arranged between a plurality of windings included in a coil, the inner shield is constituted by a plurality of independent conductors, and the surfaces of the plurality of conductors are individually insulated and coated. . As a result, the effect of shielding magnetic flux and the effect of reducing power loss can be improved, and the potential distribution at the time of impact voltage penetration can be improved.

FIG. 1 is a perspective view illustrating an appearance of a stationary inductor according to Embodiment 1 of the present invention. FIG. 2 is a partial cross-sectional view of the stationary inductor according to Embodiment 1 of the present invention. FIG. 3 is a schematic perspective view of a region III surrounded by an alternate long and short dash line in FIG. 2. FIG. 4 is a schematic enlarged perspective view showing a region IV surrounded by a dashed line in FIG. 3 in more detail than FIG. 3. FIG. 5 is a schematic sectional view of a portion along the line VV in FIG. 4. A schematic perspective view (A) of one of the windings of the wound inner shield according to the second embodiment of the present invention being extracted, and the extension of the wound inner shield according to the second embodiment of the present invention. It is the schematic diagram (B) which shows the aspect of one end part and the other end part regarding a direction. FIG. 9 is a partial cross-sectional view of a stationary inductor according to Embodiment 3 of the present invention. FIG. 8 is a schematic perspective view of a region VIII surrounded by a dashed line in FIG. 7. FIG. 13 is a sectional view of a first example of an inner shield according to Embodiment 4 of the present invention. FIG. 13 is a sectional view of a second example of the inner shield according to Embodiment 4 of the present invention. It is a perspective view which shows the external appearance of the stationary inductor which concerns on Embodiment 5 of this invention. FIG. 12 is a schematic cross-sectional view of a portion along the line XII-XII in FIG. 11. FIG. 13 is a schematic cross-sectional view of a portion along the line XIII-XIII in FIG. 11. FIG. 14 is a schematic cross-sectional view showing details of a region XIV surrounded by a certain chain line in FIG. 13. FIG. 14 is a schematic perspective view of a region XV surrounded by a dashed line in FIG. 13.

Hereinafter, the present embodiment will be described with reference to the drawings.
Embodiment 1 FIG.
The stationary inductor 100 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing the appearance of the entire stationary inductor according to Embodiment 1 of the present invention. FIG. 2 is a partial cross-sectional view of the stationary inductor according to Embodiment 1 of the present invention, and shows only a region above iron core 110 in an enlarged manner from FIG. FIG. 3 is a schematic perspective view in which a region III surrounded by a dashed line in FIG. 2 is further enlarged than FIG. FIG. 4 is a schematic enlarged perspective view showing a region IV surrounded by a dashed line in FIG. 3 in more detail than FIG. FIG. 5 is a schematic sectional view of a portion along the line VV in FIG.

  Referring to FIG. 1, stationary inductor 100 according to Embodiment 1 is a shell-type transformer. The stationary inductor 100 includes an iron core 110, and a low-voltage coil 120 and a high-voltage coil 130 wound around the main leg of the iron core 110 as a central axis and arranged coaxially. The high-voltage coil 130 is arranged so as to be sandwiched between the low-voltage coils 120 in the central axis direction of the low-voltage coil 120 and the high-voltage coil 130.

  The stationary inductor 100 further includes a tank 135. The tank 135 is filled with an insulating medium and an insulating oil that is a cooling medium. As the insulating oil, for example, mineral oil, ester oil, and silicone oil are used. The iron core 110, the low-voltage coil 120, and the high-voltage coil 130 are housed in a tank 135.

  As shown in FIG. 2, the low-voltage coil 120 is configured such that a plurality of low-voltage coil layers 121 and 122 formed by winding a rectangular electric wire in a substantially rectangular shape are coaxially arranged and electrically connected to each other. It is configured. The high-voltage coil 130 is configured such that a plurality of high-voltage coil layers 131, 132, 133, and 134 formed by winding a rectangular electric wire in a substantially rectangular shape are coaxially arranged and electrically connected to each other. I have.

  That is, the low-voltage coil layer 121 and the low-voltage coil layer 122 may be originally separate and independent coils, but they are electrically connected to each other, for example, at the lowermost part of the low-voltage coil 120 in FIG. Similarly, the high-voltage coil layers 131 to 134 may be originally separate and independent coils, in which case they are electrically connected to each other. For example, in FIG. 2, the lowermost part of the high-voltage coil layer 131 and the lowermost part of the high-voltage coil layer 132, the uppermost part of the high-voltage coil layer 132 and the uppermost part of the high-voltage coil layer 133 correspond to the lowermost part of the high-voltage coil layer 133. The lowermost part of the coil layer 134 is connected to each other. Here, from the viewpoint of narrowing the interval in the left-right direction of FIG. 2 in the connected portion and making the connection easier, the high-voltage coil layers 131 to 134 extend obliquely to the vertical direction of FIG. It is wound around.

  The stationary inductor 100 further includes an inter-coil insulating plate 140, an inter-layer insulating plate 160, an inter-coil insulating spacer 150, an inter-layer insulating spacer 170, and an electrostatic shield 190.

  The electrostatic shield 190 has a substantially rectangular outer shape when viewed from the center axis direction of the low-voltage coil 120 and the high-voltage coil 130, and has an opening at the center. The electrostatic shield 190 is arranged so as to face an end surface of the high-voltage coil 130 in the central axis direction of the high-voltage coil 130. The electrostatic shield 190 includes a conductor portion and an insulating portion that covers a surface of the conductor portion. Note that the electrostatic shield 190 does not necessarily have to be provided.

  The inter-coil insulating plate 140 has a substantially rectangular outer shape when viewed from the center axis direction of the low-voltage coil 120 and the high-voltage coil 130, and has an opening at the center. The inter-coil insulating plate 140 is arranged coaxially with the low-voltage coil 120 and the high-voltage coil 130. The inter-coil insulating plate 140 is formed by, for example, a press board.

  In the present embodiment, three inter-coil insulating plates 140 are arranged between the low-voltage coil 120 and the high-voltage coil 130. The number of inter-coil insulating plates 140 disposed between the low-voltage coil 120 and the high-voltage coil 130 is appropriately changed according to the magnitude of the potential difference generated between the low-voltage coil 120 and the high-voltage coil 130.

  The inter-coil insulating spacer 150 is provided between the low-voltage coil 120 and the inter-coil insulating plate 140, between the adjacent inter-coil insulating plates 140, and between the high-voltage coil 130 and the inter-coil insulating plate 140, respectively. And extends along an extending direction parallel to the central axis. As the inter-coil insulating spacer 150, for example, a press board or a resin laminate is used.

  The inter-coil insulating spacer 150 is provided between the adjacent low-voltage coil layer 122 and the inter-coil insulating plate 140, between the adjacent inter-coil insulating plates 140, and between the adjacent electrostatic shield 190 and the coil. In each of the spaces between the inter-insulation plate 140 and the inter-insulation plate 140, they are arranged at equal intervals in the circumferential direction of the central axis. Between adjacent low-voltage coil layers 122 and inter-coil insulating plates 140, between adjacent inter-coil insulating plates 140, and between adjacent electrostatic shields 190 and inter-coil insulating plates 140 , The portion where the inter-coil insulating spacer 150 is not located serves as a flow path of the insulating oil.

  The circumferential arrangement intervals of the inter-coil insulating spacers 150 are not limited to equal intervals, and may be between the adjacent low-voltage coil layers 122 and the inter-coil insulating plates 140, between the adjacent inter-coil insulating plates 140, In addition, it is only necessary that the distance between the adjacent electrostatic shield 190 and the inter-coil insulating plate 140 be determined so as to be maintained.

  The interlayer insulating plate 160 has a substantially rectangular outer shape when viewed from the center axis direction of the low-voltage coil 120 and the high-voltage coil 130, and has an opening at the center. The interlayer insulating plate 160 is spaced apart from each of the adjacent low-voltage coil layers 121 and 122 so as to block between the adjacent low-voltage coil layers 121 and 122 in the low-voltage coil 120. Position. The interlayer insulating plate 160 is spaced apart from each of the adjacent high-voltage coil layers 131 to 134 so as to block between the adjacent high-voltage coil layers 131 to 134 in the high-voltage coil 130. .

  In the present embodiment, one interlayer insulating plate 160 is disposed between the low-voltage coil layer 121 and the low-voltage coil layer 122 adjacent to the low-voltage coil 120. One interlayer insulating plate 160 is arranged between each of the adjacent high voltage coil layers 131 to 134 of the high voltage coil 130 and between each of the adjacent electrostatic shields 190 and the high voltage coil layer 131. ing. As the interlayer insulating plate 160, for example, a press board is used.

  The number of interlayer insulating plates 160 disposed between the adjacent low-voltage coil layers 121 and 122 depends on the magnitude of the potential difference generated between the adjacent low-voltage coil layers 121 and 122. It is changed appropriately according to the situation. The number of interlayer insulating plates 160 arranged between the adjacent high voltage coil layers 131 to 134 is appropriately changed according to the magnitude of the potential difference generated between the adjacent high voltage coil layers 131 to 134. Is done. For example, one interlayer insulating plate 160 is arranged between the high voltage coil layers 131 and 132 adjacent to each other, but a plurality of interlayer insulating plates 160 are spaced apart from each other (or (To be in contact with each other). Alternatively, the interlayer insulating plate 160 may not be disposed in the area.

  The interlayer insulating spacer 170 is disposed between the adjacent low-voltage coil layers 121 and 122 and between the high-voltage coil layers 131 to 134 in each of the low-voltage coil 120 and the high-voltage coil 130 and is parallel to the central axis. It extends along the extending direction. As the interlayer insulating spacer 170, for example, a press board or a resin laminate is used.

  The interlayer insulating spacer 170 is provided between the adjacent low-voltage coil layers 121 and 122 of the low-voltage coil 120, between the adjacent high-voltage coil layers 131 to 134 and the interlayer insulating plate 160, and between the adjacent high-voltage coil layers 131 and 134. In each of the spaces between the insulating plates 160, they are arranged at equal intervals in the circumferential direction of the central axis. Between the adjacent low-voltage coil layers 121 and 122 of the low-voltage coil 120, between the adjacent high-voltage coil layers 131 to 134 and the interlayer insulating plate 160, and between the adjacent interlayer insulating plates 160. , The portion where the interlayer insulating spacer 170 is not located serves as a flow path of the insulating oil.

  The spacing between the interlayer insulating spacers 170 in the circumferential direction is not limited to an equal interval, and is between the adjacent low-voltage coil layers 121 and 122 of the low-voltage coil 120 and between the adjacent high-voltage coil layers 131 to 134. It suffices that the distance is determined so as to maintain the respective intervals between the plate 160 and between the adjacent interlayer insulating plates 160.

  The number of interlayer insulating spacers 170 arranged between the adjacent high voltage coil layers 131 to 134 is appropriately changed according to the magnitude of the potential difference generated between the adjacent high voltage coil layers 131 to 134. . For example, two interlayer insulating spacers 170 are arranged between the high voltage coil layers 131 and the high voltage coil layers 132 adjacent to each other so as to sandwich the interlayer insulating plate 160 in FIG. Alternatively, only three interlayer insulating spacers 170 may be arranged at intervals (or in contact with each other).

  As described above, for example, between the high-voltage coil layers 131 to 134 adjacent to the high-voltage coil 130, both the interlayer insulating plate 660 and the interlayer insulating spacer 670 may be provided, or only the interlayer insulating spacer 670 may be provided. Good. The same applies to the low-voltage coil layers 121 and 122 adjacent to each other.

  As shown in FIG. 2, the coil in stationary inductor 100 of the present embodiment is formed so as to have a plurality of windings 13 c in which a wire is wound around iron core 110. That is, for example, when the direction in which the iron core 110 extends is viewed as the axial direction, the high-voltage coil layer 131 of the high-voltage coil 130 is configured such that the plurality of wound windings 13c are mutually radially intersecting in the axial direction. It is wound concentrically so as to overlap. Referring to FIG. 3, in FIG. 3, the outermost turn of the plurality of windings 13c is formed as winding 13c1, and the turns of the element wires are turned inward from the windings 13c2 and 13c3. Are formed in this order. The same applies to the high voltage coil layers 132, 133, and 134.

  An inner shield 13s is disposed at a position between the windings 13c1 and 13c2 adjacent to each other in the coil, that is, the high-voltage coil layer 131 in FIG. 3 in the radial direction (vertical direction in FIG. 3). Have been. The inner shield 13s is a shield wound around the iron core 110 so as to overlap the winding 13c. The inner shield 13s is similarly disposed at a position between the windings 13c2 and 13c3 adjacent to each other in the radial direction (vertical direction in FIG. 3) around which the high-voltage coil layer 131 is wound. Although not shown, the inner shield 13s is also arranged at a position inside the winding 13c3 (on the side of the iron core 110) between the pair of windings 13c adjacent to each other as described above.

  More specifically, referring to FIG. 4, a wire constituting winding 13 c has a substantially rectangular electric wire portion 13 a and a wire coating portion 13 b covering electric wire portion 13 a in a cross section intersecting with the extending direction. And The electric wire portion 13a and the electric wire covering portion 13b have a shape extending in a thin line shape. The low-voltage coil layers 121 and 122 and the high-voltage coil layers 132 to 134 constituting the low-voltage coil 120 have the same configuration as described above.

  In the inner shield 13s, the high-voltage coil layers 131 and the high-voltage coil layers 132, 133, and 134 shown in FIG. 2 are independently disposed. The inner shield 13s includes a plurality of conductors 13d and an insulating coating 13e that individually covers the surfaces of the plurality of conductors 13d in a cross section that intersects the extending direction. The conductor portion 13d and the insulating coating portion 13e have a shape extending in a thin line shape. In FIG. 4, four conductor portions 13d are arranged so as to be arranged in the horizontal direction in the figure, and these are independent of each other. The number of the conductors 13d is not limited to four and is arbitrary. Insulating covering portions 13e are arranged so as to cover the surfaces of the independent conductor portions 13d extending in the respective extending directions. Referring to FIG. 5, the shield member constituted by conductor portion 13d and insulating coating portion 13e is preferably arranged such that insulating coating portions 13e are in contact with each other, but is not limited thereto.

  In the inner shield 13 s, each of the plurality of thin conductors 13 d and the insulating coating 13 e is bundled together, and another insulating coating made of, for example, insulating paper or the like is provided so as to cover the surfaces thereof. 13f is further formed. In other words, in the inner shield 13s, the insulating coating 13e and the other insulating coating 13f are formed in two layers in this order so as to cover the surfaces of the plurality of conductors 13d.

It is preferable that the dielectric constant of the other insulating covering portion 13f that covers the insulating covering portion 13e is higher than the dielectric constant of the constituent material of the insulating covering portion 13e that directly covers the surface of the conductor portion 13d. Specifically, the dielectric constant of the insulating cover portion 13e and epsilon _1, if the dielectric constant of the other insulating coating portion 13f and epsilon _2, it is preferred that ε _2> ε ₁ relation holds. For example, the insulating coating portion 13e dielectric constant epsilon ₁ is used 3-4 polyimide, preferably kraft paper dielectric constant epsilon ₂ 2.2 is used for the other insulating cover portion 13f.

  Referring to FIG. 4 again, the plurality of conductor portions 13d constituting the inner shield 13s are arranged so as to be arranged in a direction intersecting the radial direction in which the coil, that is, the high-voltage coil 130 (the high-voltage coil layer 131) is wound. Here, the radial direction in which the high-voltage coil 130 is wound means a direction B indicated by an arrow in FIG. 4, and a direction intersecting the radial direction means a direction A indicated by an arrow in FIG. Here, the angle between the direction A and the direction B in FIG. 4 may be, for example, a right angle, or may be an angle close to the right angle but different from the right angle.

  Next, the operation and effect of the present embodiment will be described while explaining the background art and the like of the present invention.

  When a shock voltage such as a lightning surge enters the stationary inductor, the potential distribution of the high-voltage coil becomes non-uniform, and the high-voltage coil is likely to cause dielectric breakdown. From the viewpoint of solving this problem, the inner shield may be disposed at a position sandwiched between the windings constituting the high-voltage coil so as to be wound around the high-voltage coil. The thickness of the insulating portion included in the inner shield in a cross section that intersects the extending direction is reduced by the arrangement of the conductor portion included in the inner shield. For this reason, by sandwiching the inner shield between, for example, a pair of mutually adjacent windings of the high-voltage coil, it is possible to equivalently increase the capacitance formed in the portion by the winding and the inner shield. If the capacitance increases, the potential difference at that portion becomes relatively small, so that the potential difference can be kept below a threshold at which a discharge phenomenon due to an impact voltage or the like occurs. Therefore, if the inner shield is provided, even if an impact voltage is input, the insulation performance of the winding can be enhanced by keeping the potential distribution of the winding uniform and suppressing its dielectric breakdown.

  However, in the conventional stationary inductor, the inner shield is constituted only by a single conductor portion and an insulating portion covering the surface thereof. In this case, a leakage magnetic flux generated by driving the low-voltage coil and the high-voltage coil passes through the inside of the inner shield, and an eddy current is easily generated inside the inner shield. If the conductor portion is single, for example, the cross-sectional area is larger than when the conductor portion is divided into a plurality of portions, and the eddy current tends to increase because the area of the region where the eddy current can flow is large. It is.

  Alternatively, another conventional stationary inductor has a structure in which the inner shield does not have a configuration in which the surface of the conductor portion is directly covered with the insulating portion and the individual windings are electrically insulated by the insulating portion. It only has a configuration in which a bundle of wires is collectively covered with an insulating portion. In this case, the insulation breakdown of the coil is likely to occur when the impact voltage enters. If only a single layer of insulation is provided outside the conductor, the electric field tends to concentrate at the boundary between the conductor and the insulation, and a large potential difference is generated in that portion. This is because it is easy to cause the change.

  Therefore, in the stationary inductor 100 of the present embodiment, between the windings 13c, that is, between the windings 13c1 and 13c2 adjacent to each other, the plurality of conductors 13d and each of the plurality of conductors 13d are provided. And an inner shield 13s including an insulating coating portion 13e that individually covers the surface of the inner shield 13s. In this way, the plurality of conductors 13d are provided, and the respective surfaces are individually covered with the insulating covering portions 13e, so that the plurality of conductors 13d are electrically insulated in the inner shield 13s. Thereby, in the inner shield 13s, the area of the portion where the eddy current of each of the conductor portions 13d can flow becomes smaller than, for example, a case where only a single large conductor portion is provided. This is because the conductor 13d is individually covered with the insulating coating 13e, so that the eddy current is cut off at that portion and the conductor 13d cannot greatly spread beyond the insulating coating 13e. For this reason, the eddy current can be reduced, and the loss such as a reduction in power conversion efficiency due to the eddy current can be reduced.

  The conductors 13d are individually covered with insulating coatings 13e. For this reason, the conductor portions of the plurality of conductor portions 13d come into contact with each other and the vortex of the conductor portion 13d as compared with, for example, a case where the plurality of conductor portions 13d are bundled and the whole is covered with one insulating coating portion. A very large area of a portion through which current can flow is suppressed. Therefore, according to the inner shield 13s, an increase in the eddy current in the conductor portion 13d can be suppressed by the shielding effect of the magnetic flux, and a loss such as a reduction in power conversion efficiency due to the eddy current can be reduced.

  Such an inner shield 13s is arranged between a plurality of windings 13c included in a single high-voltage coil 131 (eg, between adjacent windings 13c1 and 13c2). Therefore, it is possible to suppress the generation of the eddy current in the winding 13c due to the leakage magnetic flux in a portion between the plurality of windings 13c constituting the high-voltage coil layer 131.

  The inner shield 13s of the present embodiment has another insulating coating 13f that covers the plurality of insulating coatings 13e in addition to the insulating coating 13e that directly covers the conductor 13d. The dielectric constant between the insulating coating 13e and the other insulating coating 13f has the above relationship. For this reason, the concentration of the electric field around the conductor 13d inside the inner shield 13s due to the voltage applied to the region between the adjacent windings 13c can be reduced.

  The inner shield 13s has a configuration in which each surface of the plurality of conductors 13d is covered with an insulating covering portion 13e, and a bundle of these is collectively covered with another insulating covering portion 13f. For this reason, the inner shield 13s has plasticity and can improve workability. Here, the plasticity of the inner shield 13s means that, due to its presence, the inner shield 13s does not deform after winding the inner shield 13s so as to return to a linear shape.

  In addition, in the present embodiment, similarly to the comparative example and the like, the thickness of the insulating material portion is reduced by the inner shield 13s and a large capacitance is provided, so that the potential of the winding 13c when an impact voltage enters is provided. By making the distribution uniform, the insulation breakdown can be suppressed, and the insulation performance of the winding 13c can be enhanced.

  As shown in FIG. 4, the plurality of conductors 13d of the inner shield 13s are arranged so as to be arranged in a direction A intersecting the radial direction B around which the high-voltage coil 130 is wound. The direction A is a direction intersecting the direction of the magnetic flux generated by the current flowing through the high voltage coil 130 (the direction of arrow B). Therefore, with this configuration, the insulating covering portion 13e formed on the surface of the conductor portion 13d receives the magnetic flux generated by the current flowing through the high-voltage coil 130 from the front. Therefore, the effect of the insulating coating portion 13e to reduce the eddy current due to the magnetic flux can be enhanced.

Embodiment 2 FIG.
In the present embodiment, a method of connecting a plurality of conductor portions 13d included in the inner shield 13s will be described. Basically, each feature other than the above in the present embodiment is similar to that of the first embodiment, and therefore, description thereof will not be repeated. FIG. 6A is a schematic perspective view of one of the wound inner shields 13s according to Embodiment 2 of the present invention, in which one of the windings is removed. FIG. 6B shows the state of one end and the other end in a state before winding of the inner shield 13s in FIG. 6A or a state where the inner shield 13s is cut open along the line CC. .

  Referring to FIGS. 6A and 6B, one end (first end) of first conductor 13d, which is one of a plurality (four in this case) of conductors 13d included in inner shield 13s. The upper end in FIG. 6) and one end of the second conductor 13d other than those described above among the plurality of conductors 13d are electrically insulated from each other. The one end portions that are insulated from each other are shown as non-connection portions O in FIG. On the other hand, the other end (the lower end in FIG. 6) of the first conductor 13d, which is one of the plurality (here, four) of conductors 13d included in the inner shield 13s, The other end of the second conductor 13d other than those described above among the plurality of conductors 13d is electrically connected to each other. The other end portions insulated from each other are shown as connection portions S in FIG.

  As shown in FIG. 6, one end of each of the plurality of conductors 13d may be insulated and the other end may be connected. However, in the present embodiment, one end of each of the plurality of conductors 13d may be insulated, and the other end may be insulated. In any case, in the present embodiment, at least one of one end and the other end of the plurality of conductors 13d are electrically insulated from each other.

Next, the operation and effect of the present embodiment will be described.
If one end and the other end of the plurality of conductors 13d are connected to each other to form a connection portion S, a closed circuit is formed between the plurality of conductors 13d. Therefore, an eddy current that circulates through the closed circuit so as to flow between the conductors 13d through the connection portion S, for example, between the conductors 13d in FIG.

  Therefore, in the present embodiment, at least on one end side (upper side) of FIG. 6B, the conductor portions 13d are not connected to each other. As a result, a closed circuit is not formed between the plurality of conductors 13d, so that formation of an eddy current can be suppressed.

  In addition, since at least one of the one and the other ends of each conductor 13d is electrically insulated from each other, the potential of each conductor 13d can be determined. This is because there is no room for generating a potential difference because no current flows through each conductor portion 13d, and each potential is fixed. Generally, by arranging the inner shield 13s so as to be sandwiched between the windings 13c of the high voltage coil 130 (high voltage coil layer 131), the electric field concentrates on the end of the conductor 13d of the inner shield 13s. However, by fixing the potential of each conductor portion 13d, the electric field concentration in the inner shield 13s due to the voltage generated between the windings 13c can be reduced.

  Furthermore, in the present embodiment, since the inner shield 13s has a plurality of independent conductor portions 13d, a configuration in which a closed circuit is not formed therebetween can be achieved. If the conductors 13d arranged in the horizontal direction in the drawing in the inner shield 13s are not independent but are integrated, a closed circuit is often formed in the conductor 13d, and eddy current is easily generated. From this viewpoint as well, the eddy current is suppressed by forming a bundle of a plurality of independent wires (as in the first embodiment), rather than using only one conductor portion 13d included in the inner shield 13s. be able to.

Embodiment 3 FIG.
The stationary inductor 200 of the present embodiment is different from the stationary inductor 100 of the first embodiment in that the location of the inner shield 13s is limited. Hereinafter, the stationary inductor 200 according to the present embodiment will be described with reference to FIGS. 7 and 8. FIG. 7 is a partial cross-sectional view of a stationary inductor according to Embodiment 3 of the present invention, and shows only a region above iron core 110 in an enlarged manner from FIG. FIG. 8 is a schematic perspective view of a region VIII surrounded by a dashed line in FIG. 7 further enlarged than FIG.

  Referring to FIGS. 7 and 8, in stationary inductor 200, inner shield 13 s is located on the outermost periphery of high-voltage coil layer 131 as the first high-voltage coil portion of high-voltage coil 130, which is farthest from iron core 110. It is arranged between the wound first outermost winding OC1 and a first adjacent winding AC1 adjacent inside the first outermost winding OC1. The first outermost winding OC1 corresponds to the winding 13c1 of the high-voltage coil layer 131 in FIG. 2, and the first adjacent winding AC1 corresponds to the winding 13c2 of the high-voltage coil layer 131 in FIG. Further, in the stationary inductor 200, the inner shield 13s is provided with the second outermost layer wound around the outermost periphery of the high-voltage coil layer 132 as the second high-voltage coil portion of the high-voltage coil 130 adjacent to the first high-voltage coil portion. It is arranged between the outer peripheral winding OC2 and a second adjacent winding AC2 adjacent inside the outer peripheral winding OC2. The second outermost winding OC2 corresponds to the winding 13c1 of the high-voltage coil layer 132 in FIG. 2, and the second adjacent winding AC2 corresponds to the winding 13c2 of the high-voltage coil layer 132 in FIG.

  One line end of the entire high-voltage coil 130 is an end adjacent to the first outermost winding OC1 (winding 13c1) wound on the outermost circumference in the high-voltage coil layer 131 arranged on the leftmost side in the drawing. . That is, in the high-voltage coil 130, it can be said that the high-voltage coil layer 131 among the four high-voltage coil layers 131 to 134 includes the line end. For this reason, the first outermost winding OC1 is shown as a line end winding TE in FIG.

  In the present embodiment, the inner shield 13s is not arranged at a position between the pair of adjacent windings 13c other than the above-described location. In this point, the present embodiment is structurally different from the first embodiment in which the inner shield 13s can be arranged at a position sandwiched between an arbitrary pair of adjacent windings 13c. However, since each feature of the present embodiment other than the above is the same as that of the first embodiment, the same components are denoted by the same reference numerals and description thereof will not be repeated.

Next, the operation and effect of the present embodiment will be described.
In a core-type transformer such as the stationary inductor 200, the magnitude of the magnetic flux is highest in the high-voltage coil 130, particularly in the line-end winding TE of the high-voltage coil layer 131, and as the distance from the line-end winding TE increases. Become smaller. More specifically, the high-voltage coil 130 is electrically connected to the high-voltage coil layers 131, 132, 133, and 134 and is substantially integrated, so that the high-voltage coil layer 131 is apart from the line end winding TE. As the magnetic flux decreases, the magnetic flux gradually decreases. Therefore, among the high voltage coils 130, the first outermost winding OC1 (line end winding TE), the first adjacent winding AC1, the second outermost winding OC2, and the second adjacent winding AC2 shown in FIG. The magnetic flux becomes large in the region where the is arranged and the region adjacent thereto. When the magnetic flux is high, an eddy current generated by the magnetic flux easily flows in the region.

  Therefore, by arranging the inner shield 13s similar to the first embodiment between the adjacent windings 13c in the region where the magnetic flux is large, the power loss due to the eddy current can be reduced as in the first embodiment. it can.

  Further, when a steep surge voltage such as a VFT (Very Fast Transient) surge enters the stationary inductor 200, the first outermost periphery is determined from the relationship between the capacitance of the stationary inductor 1 and the high frequency of the VFT surge. The voltage generated between the winding OC1 and the first adjacent winding AC1 is the highest. For this reason, by arranging the inner shield 13s between the line end winding TE and the first adjacent winding AC1 adjacent thereto as in the present embodiment, a large electrostatic capacity is obtained as in the first embodiment. Potential oscillation is suppressed by the capacitance, and high insulation performance can be obtained.

  The work of incorporating the inner shield 13 s between the windings of the high-voltage coil 130 and connecting the inner shield 13 s from the windings of the high-voltage coil 130 is performed in a portion of the high-voltage coil 130 distant from the iron core 110. Will be For this reason, by arranging the inner shield 13s only in a region adjacent to the line end winding TE remote from the iron core 110 as in the present embodiment, for example, between the windings 13c as in the first embodiment. The operation of pulling out and connecting the inner shield 13s can be simplified as compared with the case where the inner shield 13s is arranged. That is, according to the present embodiment, the workability of the stationary inductor 200 can be improved as compared with the first embodiment.

Embodiment 4 FIG.
The present embodiment is different from the first to third embodiments in the cross-sectional shape of the conductor 13d included in the inner shield 13s. Hereinafter, the cross-sectional shape will be described with reference to FIGS. 9 and 10. Basically, each feature other than the above in the present embodiment is similar to that of the first embodiment, and therefore, description thereof will not be repeated.

  FIG. 9 is a sectional view of a first example of the inner shield according to Embodiment 4 of the present invention. FIG. 10 is a sectional view of a second example of the inner shield according to Embodiment 4 of the present invention. Referring to FIG. 9, in the inner shield 13 s here, each of the plurality of conductors 13 d has a rectangular cross section crossing the extending direction thereof. That is, the inner shield 13s has a cross-sectional shape having a dimension longer in the up-down direction of FIG. 9 than in the left-right direction of FIG. 9 so that the plurality of conductor portions 13d have a substantially rectangular shape.

  Referring to FIG. 10, in inner shield 13s here, each of a plurality of conductor portions 13d has a flat cross section that crosses the extending direction. That is, in the inner shield 13s, the plurality of conductor portions 13d have a dimension longer in the vertical direction of FIG. 10 than in the horizontal direction of FIG. 10, but the angle extending in the vertical direction is slightly oblique and substantially parallel sides. It has a cross-sectional shape.

  In this respect, the inner shield 13s in FIGS. 9 and 10 differs from the inner shield 13s in which each of the plurality of conductors 13d has a circular cross-sectional shape as in FIG. 2 of the first embodiment, for example. Although the number of the conductors 13d is eight in FIGS. 9 and 10, any of them is optional.

  As described above, the cross-sectional shape of the conductor portion 13d may be any of a circular shape, a rectangular shape, and a flat shape. 2, 9, and 10, the cross-sectional shape of each of the plurality of conductors 13d included in one inner shield 13s is unified to one of a circular shape, a rectangular shape, and a flat shape. However, the plurality of conductor portions 13d included in one inner shield 13s may be a mode in which two or more types of conductor portions having different cross-sectional shapes are mixed.

Embodiment 5 FIG.
The stationary inductor 600 according to the present embodiment will be described with reference to FIGS. Since the stationary inductor according to the present embodiment is mainly different in that it is a core-type transformer, the description of the same configuration as that of the stationary inductor according to the first embodiment will not be repeated. FIG. 11 is a perspective view showing the appearance of the entire stationary inductor according to Embodiment 5 of the present invention. FIG. 12 is a schematic cross-sectional view of a part along the line XII-XII in FIG. 11, and particularly a schematic cross-sectional view of a part where a high-voltage coil layer configuring the high-voltage coil 630 is arranged. FIG. 13 is a schematic cross-sectional view of a portion along the line XIII-XIII in FIG. 11, and particularly shows a positional relationship between the iron core and the coil. FIG. 14 is a schematic perspective view showing an example of the configuration of a region XIV surrounded by a dashed line and omitted in FIG. 13 in more detail than FIG. FIG. 15 is a schematic perspective view in which a region XV surrounded by a dashed line in FIG. 13 is further enlarged than FIG.

  Referring to FIGS. 11 to 13, stationary inductor 600 according to Embodiment 5 includes iron core 610, low-voltage coil 620 and high-voltage coil 630 concentrically wound around the main leg of iron core 610 as a central axis. And The high voltage coil 630 is located outside the low voltage coil 620. The low-voltage coil 620 and the high-voltage coil 630 are each configured as a single coil by stacking a plurality of disk-shaped windings formed by winding a flat electric wire in a disk shape in a direction along the central axis. I have. That is, in each of these coils, a flat wire is wound concentrically at a portion of the core 610, and is stretched from there to a position at a small interval in a direction along the central axis of the core, and the core is again placed at that position. 610 is formed by repeating concentric winding.

  The stationary inductor 600 includes a tank (not shown), and the tank is filled with an insulating medium and an insulating oil serving as a cooling medium. As the insulating oil, for example, mineral oil, ester oil or silicone oil is used. The iron core 610, the low-voltage coil 620, and the high-voltage coil 630 are housed in a tank.

  The stationary inductor 600 further includes an inter-coil insulating plate 640, an inter-layer insulating plate 660, an inter-coil insulating spacer 650, and an inter-layer insulating spacer 670.

  The inter-coil insulating plate 640 is provided between the iron core 610 and the low-voltage coil 620 so as to block between the opposing surfaces of the iron core 610 and the low-voltage coil 620 and between the opposing surfaces of the low-voltage coil 620 and the high-voltage coil 630. It is spaced apart from each of the high voltage coils 630. The inter-coil insulating plate 640 is also located outside the high-voltage coil 630 with an interval from the high-voltage coil 630. More specifically, the inter-coil insulating plate 640 blocks between the outer peripheral surface of the iron core 610 and the inner peripheral surface of the low-voltage coil 620, and between the outer peripheral surface of the low-voltage coil 620 and the inner peripheral surface of the high-voltage coil 630. , The core 610, the low-voltage coil 620, and the high-voltage coil 630. Further, the inter-coil insulating plate 640 is spaced from the high voltage coil 630 so as to surround the outer peripheral surface of the high voltage coil 630 from the outside. The inter-coil insulating plate 640 is formed by, for example, a press board.

  The inter-coil insulating plate 640 has a cylindrical outer shape. The inter-coil insulating plate 640 is arranged concentrically with the low-voltage coil 620 and the high-voltage coil 630. Referring to FIG. 14, in the present embodiment, as an example, six inter-coil insulating plates 641, 642, 643, 644, 645, as inter-coil insulating plates 640 between low-voltage coil 620 and high-voltage coil 630. 646 are spaced from one another in the circumferential direction. However, the number of inter-coil insulating plates 640 disposed between the low-voltage coil 620 and the high-voltage coil 630 is appropriately changed according to the magnitude of the potential difference generated between the low-voltage coil 620 and the high-voltage coil 630. For this reason, in FIGS. 11 to 13, the inter-coil insulating plate 640 disposed between the low-voltage coil 620 and the high-voltage coil 630 shows a plurality of bundles collectively. Not shown.

  The intervals between the circumferential positions of the inter-coil insulating plates 640 are not limited to equal intervals, but may be between the low-voltage coil 620 and the inter-coil insulating plate 640, between the adjacent inter-coil insulating plates 641 to 646, and between the high-voltage coil. It suffices that the distance between the coil 630 and the inter-coil insulating plate 640 is determined so as to be maintained.

  The stationary inductor 600 is disposed between the low-voltage coil 620 and the inter-coil insulating plate 640 and between the high-voltage coil 630 and the inter-coil insulating plate 640, and extends in a direction parallel to the central axis. Further, a plurality of inter-coil insulating spacers 650 extending along the plurality of coils are further provided. In the present embodiment, the stationary inductor 600 includes the inter-coil insulating plates 640 in which the plurality of inter-coil insulating plates 641 to 646 are arranged at intervals in the circumferential direction. The inter-coil insulating plates 640 that match each other (641 to 646) are also arranged. As the inter-coil insulating spacer 650, for example, a press board or a resin laminate is used.

  Some of the plurality of inter-coil insulating spacers 650 are sandwiched between adjacent low-voltage coils 620 and inter-coil insulating plates 640. Another part of the plurality of inter-coil insulating spacers 650 is sandwiched between adjacent inter-coil insulating plates 640 (641 to 646). Still another part of the plurality of inter-coil insulating spacers 650 is sandwiched between the adjacent high-voltage coil 630 and the outer inter-coil insulating plate 640.

  The inter-coil insulating spacer 650 is provided between the adjacent low-voltage coil 620 and the inter-coil insulating plate 640, between the adjacent inter-coil insulating plates 640 (641 to 646), and between the adjacent high-voltage coils. In each of between the 630 and the inter-coil insulating plate 640, they are arranged at equal intervals in the circumferential direction. Between the adjacent low-voltage coil 620 and the inter-coil insulating plate 640, between the adjacent inter-coil insulating plates 640, and between the adjacent high-voltage coil 630 and the inter-coil insulating plate 640; In each case, the part where the inter-coil insulating spacer 650 is not located serves as a flow path for insulating oil. The spacing between the inter-coil insulating spacers 650 in the circumferential direction is not limited to equal intervals, and may be between the adjacent low-voltage coil 620 and the inter-coil insulating plate 640, between the adjacent inter-coil insulating plates 640, In addition, it is sufficient that the distance between the adjacent high voltage coil 630 and the inter-coil insulating plate 640 can be maintained.

  Next, with reference to FIG. 13, the coil in stationary inductor 600 of the present embodiment is formed to have a plurality of windings 13 c in which element wires are wound around iron core 610. That is, the high-voltage coil layer constituting the high-voltage coil 630 has a plurality of wound windings 13c in a radial direction in which the wound plurality of windings 13c intersect in the axial direction when the vertical direction in FIG. Are wound concentrically so as to overlap each other. A plurality of such concentrically wound high-voltage coil layers are stacked in the axial direction, and are electrically connected to form one high-voltage coil layer.

  In FIG. 13, the interlayer insulating spacer 670 is arranged in a region sandwiched between a plurality of high-voltage coil layers that are stacked at intervals in the axial direction. The interlayer insulating spacer 670 is made of, for example, a press board or a resin laminate. Thus, the intervals between the plurality of high-voltage coil layers are determined so as to be maintained. In addition, only the interlayer insulating spacer 670 may be arranged in a region between the plurality of stacked high-voltage coil layers. However, as shown in FIG. 13, an interlayer insulating plate 660 is arranged in addition to the interlayer insulating spacer 670. You may. For example, a press board is used as interlayer insulating plate 660.

  In FIG. 13, both the interlayer insulating spacer 670 and the interlayer insulating plate 660 are arranged in only one of the regions (there are a plurality) between the stacked high voltage coil layers in the vertical direction. In this region, only the interlayer insulating spacer 670 is arranged. That is, in a region between the stacked high-voltage coil layers and the like, both the interlayer insulating plate 660 and the interlayer insulating spacer 670 may be arranged, or only the interlayer insulating spacer 670 may be arranged. Although not shown, the same applies to a region between a plurality of low-voltage coil layers of the low-voltage coil 620 and the like. The number of the interlayer insulating plates 660 and the interlayer insulating spacers 670 to be arranged is also arbitrary. This is appropriately changed according to the magnitude of the potential difference generated between the regions.

  Referring to FIG. 15, the coil according to stationary inductor 600 of the present embodiment, that is, the high-voltage coil layer forming high-voltage coil 630 in FIG. 13, is wound in the radial direction (left-right direction in FIGS. 13 and 15). The inner shield 13s is disposed at a position between the adjacent windings 13c1 and 13c2. Although not shown, the inner shield 13s is also disposed at a position inside the winding 13c2 (on the side of the iron core 110) between the pair of windings 13c adjacent to each other as described above.

  The configurations of the winding 13c and the inner shield 13s are the same as those of the winding 13c and the inner shield 13s of the first embodiment. In other words, in FIG. 15, the plurality of conductors 13 d constituting the inner shield 13 s are arranged so as to be arranged in the direction A intersecting the radial direction B in which the coil, that is, the high-voltage coil 630 (high-voltage coil layer) is wound.

  The operation and effect of this embodiment are basically the same as those of the first embodiment. As for the core-type transformer as in the present embodiment, similarly to the core-type transformer as in Embodiment 1, if the inner shield 13s is arranged at a position sandwiched between the adjacent windings 13c. Thus, the same effect as in the first embodiment can be obtained. That is, also in the present embodiment, it is possible to obtain an effect of reducing a loss such as a reduction in efficiency of power conversion due to eddy current, an effect of suppressing insulation breakdown of the winding 13c and increasing insulation performance, and the like.

  Although the stationary inductor in each of the above embodiments uses insulating oil, the inner shield of the present invention may be applied to a stationary inductor using an insulating gas instead.

  The features described in the respective embodiments (each example included therein) may be applied so as to be appropriately combined within a technically consistent range.

  The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  13a wire portion, 13b wire cover portion, 13c, 13c1, 13c2, 13c3 winding, 13d conductor portion, 13e insulating cover portion, 13s inner shield, 100, 200, 600 stationary inductor, 110, 610 iron core, 120, 620 low pressure Coil, 121, 122 Low voltage coil layer, 130,630 High voltage coil, 131, 132, 133, 134 High voltage coil layer, 135 tank, 140, 640, 641, 642, 643, 644, 645, 646 Coil insulating plate, 150 , 650 inter-coil insulating spacer, 160,660 interlayer insulating plate, 170,670 interlayer insulating spacer, 190 electrostatic shield, AC1 first adjacent winding, AC2 second adjacent winding, OC1 first outermost winding, OC2 first 1 Outermost winding, TE line end winding.

Claims (8)

Iron core,
A coil formed to have a plurality of windings in which a wire is wound around the iron core;
An inner shield wound around the iron core is disposed at a position sandwiched between the windings adjacent to each other in a radial direction around which the coil is wound,
The inner shield includes a plurality of conductor portions, and an insulating coating portion that individually covers respective surfaces of the plurality of conductor portions,
Wherein said plurality of conductor portions of the inner shield, the wound concentrically as wound coils overlap each other in the radial direction, are arranged side by side in a direction crossing before Ki径direction, stationary Inductor.   One end of a first conductor of the plurality of conductors included in the inner shield and one end of a second conductor other than the first conductor of the plurality of conductors The stationary inductor according to claim 1, wherein the ends are electrically insulated from each other.   The inner shield is a first outermost winding wound around an outermost periphery of a first high-voltage coil portion including a line end of the high-voltage coil constituting the coil, and is adjacent to the inside of the first outermost winding. Of the second outermost winding and the second outermost winding wound around the first adjacent winding and the outermost periphery of the second high voltage coil adjacent to the first high voltage coil. The stationary inductor according to claim 1, wherein the stationary inductor is disposed between a second adjacent winding adjacent to the inside. The inner shield further includes another insulating coating portion covering a surface of the insulating coating portion,
The stationary inductor according to any one of claims 1 to 3, wherein a dielectric constant of the other insulating coating portion is higher than a dielectric constant of the insulating coating portion.   The stationary inductor according to any one of claims 1 to 4, wherein the inner shield has plasticity.   The stationary inductor according to any one of claims 1 to 5, wherein each of the plurality of conductors has a circular cross-sectional shape.   The stationary inductor according to claim 1, wherein each of the plurality of conductors has a rectangular cross-sectional shape.   The stationary inductor according to any one of claims 1 to 5, wherein each of the plurality of conductors has a flat cross-sectional shape.

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