JP2005277298A - Electrostatic shielding structure for stationary induction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic shielding structure for a stationary induction apparatus which is resistant to a mechanical force in the radial direction of a acting on a shielding plate and is capable of suppressing rise in the local field. <P>SOLUTION: The electrostatic field structure of the stationary induction apparatus provided with the electrostatic shielding plate 4 between a coaxially wound primary coil and a coaxially wound secondary coil. The electrostatic shielding plate 4 is divided into a plurality of plates in a direction of the periphery. Side ends 10a, 10b, 11a, 11b, adjacent to the divided electrostatic shielding plate 4, are superimposed by having each sandwiching an insulating material 12 therebetween. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrostatic shielding structure for a stationary induction device.

  In a transformer, which is a static induction device, electrostatic shielding, if necessary, to alleviate internal local electric field concentration and to suppress electrostatic transition from the primary winding to the secondary winding A plate is provided. That is, as shown in FIG. 12, by placing the electrostatic shielding plate 53 at the ground potential between the primary winding 51 and the secondary winding 52, the electric field at the winding end is shielded. The concentration has been relaxed, and the electrostatic transfer voltage between the windings 51 and 52 has been suppressed. By the way, in general, leakage magnetic flux exists inside the transformer, and when a metal (copper wire, iron core, tank) is linked to the leakage magnetic flux, an induced voltage is generated and eddy current loss occurs. Therefore, when the electrostatic shielding plate 53 is disposed, there is a problem that the electrostatic shielding plate 53 is linked to the leakage magnetic flux, causing a loss due to eddy current and increasing heat generation. In FIG. 12, reference numeral 50 denotes an iron core disposed in the axial center portion.

Therefore, conventionally, as shown in FIG. 11, the electrostatic shielding plate 53 is formed by bending a thin metal foil partially provided with slits 54 into a cylindrical shape. In this case, the eddy current loss can be reduced by narrowing the width of the metal portion by the slit 54 and reducing the interlinkage area with the magnetic flux. In addition, there is a type in which the electrostatic shielding plate 53 is formed of a metal net (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 50-21221 (page 1-2, figure)

  However, when the electrostatic shielding plate 53 shown in FIG. 11 is used and the electrostatic shielding plate 53 is installed outside the secondary winding 52 as shown in FIG. When the inner surface of the shielding plate 53 and the secondary winding 52 are opposed to each other, it is difficult to fix in a predetermined position and adjust the dimensions, and when a mechanical force in the radial direction is received due to a positioning error during assembly work. There is a drawback that the metal foil constituting the electrostatic shielding plate 53 is deformed or torn. Further, in the gap of the slit 54 and the insulating portion 55 for suppressing eddy current, the local electric field at the end portion of the electrostatic shielding plate (metal foil) 53 may rise due to the surge voltage, and partial discharge may occur. was there.

  Further, as described in Patent Document 1, even if the electrostatic shielding plate 53 is formed of a metal mesh body, the local electric field at the end of the mesh body may increase and partial discharge may occur. is there.

  The present invention has been made to solve the above-mentioned conventional drawbacks, and its object is to provide resistance to a radial mechanical force acting on the electrostatic shielding plate and to suppress a local electric field rise. It is an object of the present invention to provide an electrostatic shielding structure for a static induction device capable of achieving the above.

  Accordingly, the electrostatic shielding structure of the static induction device according to claim 1 is the static electricity of the static induction device in which the electrostatic shielding plate 4 is provided between the primary winding 1 and the secondary winding 2 wound coaxially. The shielding structure is characterized in that the electrostatic shielding plate 4 is divided into a plurality in the circumferential direction.

  In the electrostatic shielding structure of the static induction device according to the first aspect, even if a radial mechanical force acts on the electrostatic shielding plate 4, the electrostatic shielding plate 4 is divided into a plurality of portions in the circumferential direction. The divided pieces 5 of the electrostatic shielding plate 4 are displaced following the directional mechanical force, and the mechanical force applied to the divided pieces 5 can be reduced. Moreover, the dimension adjustment of this electrostatic shielding board 4 is attained, without setting the dimension of each division | segmentation piece 5 which comprises the electrostatic shielding board 4 with high precision. Further, in this electrostatic shielding structure, since it is possible to assemble each divided piece 5, the assembly workability is higher than the assembling work of inserting an integral cylindrical type into a predetermined position. improves.

  The electrostatic shielding structure of the static induction device according to claim 2 is configured such that the side end portions 10a, 10b, 11a, and 11b of the adjacent divided pieces 5 and 5 of the divided electrostatic shielding plate 4 are sandwiched with the insulating material 12 therebetween. It is characterized by overlapping.

  In the electrostatic shielding structure of the static induction device according to claim 2, the insulating material 12 is sandwiched between the side end portions 10a, 10b, 11a, 11b of the adjacent divided pieces 5, 5 of the divided electrostatic shielding plate 4. As a result of the overlapping, the electric field rise at the side end portions 10a, 10b, 11a, and 11b can be suppressed.

  The electrostatic shielding structure of the static induction device according to claim 3 is configured such that the electrostatic shielding plate 4 is composed of a plurality of metal foils, and an inner surface of each metal foil is covered with an inner insulating sheet 15 and an outer surface of each metal foil. Are coated with the outer insulating sheet 16, and tapered surfaces 17a, 17b, 18a, 18b are formed on the side edge portions of the inner insulating sheet 15 and the outer insulating sheet 16, respectively, and the adjacent tapered surfaces 17a, 17b, The feature is that 18a and 18b face each other.

  In the electrostatic shielding structure of the static induction device according to claim 3, taper surfaces 17a, 17b, 18a, and 18b are formed on the side edge portions of the inner insulating sheet 15 and the outer insulating sheet 16, respectively, and the adjacent taper. Since the surfaces 17a, 17b, 18a, and 18b are abutted with each other, the insulating sheets 15 and 16 and so on can be slid and abutted with the tapered surfaces 17a, 17b, 18a, and 18b during assembly. For example, the electrostatic shielding plate 4 can be displaced in the radial direction, and the influence of the mechanical force in the radial direction can be reduced.

  The electrostatic shielding structure of the stationary induction device according to claim 4 is configured such that the electrostatic shielding plate 4 is formed of a metal mesh body, and a folded portion 19 is provided at an end portion in the axial direction of the metal mesh body. It is a feature.

  In the electrostatic shielding structure of the static induction device according to the fourth aspect, since the electrostatic shielding plate 4 is made of a metal mesh, the resistance to mechanical force is improved by the stretchability of the metal mesh. Further, by bending the axial end portion of the metal net, the axial end portion of the electrostatic shielding plate 4 can be rounded, and the local electric field rise can be suppressed.

  According to the electrostatic shielding structure of the static induction device according to claim 1, even if a radial mechanical force acts on the electrostatic shielding plate, the electrostatic shielding plate is divided into a plurality in the circumferential direction. The influence of the mechanical force applied to the piece can be reduced. As a result, damage to the electrostatic shielding plate due to radial mechanical force can be prevented, and a stable shielding effect can be exhibited over a long period of time. In addition, it is possible to adjust the size of the electrostatic shielding plate without setting the size of each divided piece constituting the electrostatic shielding plate with high accuracy, and the productivity is excellent. Further, since it is possible to assemble each divided piece, the assembling workability is improved as compared with the assembling work of inserting the integral cylindrical type into a predetermined position.

  According to the electrostatic shielding structure of the static induction device according to the second aspect, the local electric field rise can be suppressed, the occurrence of partial discharge can be prevented, and the function of the static induction device can be stably exhibited.

  According to the electrostatic shielding structure of the static induction device according to the third aspect, the influence of the mechanical force applied to the electrostatic shielding plate can be reduced, and the electrostatic shielding structure having excellent durability can be obtained.

  According to the electrostatic shielding structure of the static induction device according to the fourth aspect, the resistance to mechanical force is improved by the stretchability of the metal net. In addition, by bending the axial end of the metal mesh body, the axial end of the electrostatic shielding plate can be rounded, the local electric field rise at this end can be suppressed, and partial discharge can be prevented. Can be prevented.

  Next, specific embodiments of the electrostatic shielding structure of the static induction device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional plan view showing a first embodiment of an electrostatic shielding structure for a static induction device according to the present invention, and FIG. 2 is a sectional front view thereof. The static induction device in this case is a transformer, and includes a primary winding 1 and a secondary winding 2 wound coaxially as shown in FIGS. 1 and 2, and an iron core in the shaft center portion. 3 is arranged. A cylindrical electrostatic shielding plate 4 is disposed between the primary winding 1 and the secondary winding 2.

  As shown in FIG. 3, the electrostatic shielding plate 4 in this case is composed of two divided pieces 5 and 5 made of metal foil, and an insulating sheet 6 whose both surfaces (inner surface and outer surface) are made of an insulating film or the like. , 6. And the clearance gaps 7 and 7 are formed between a pair of halves 8 and 8 comprised by the division piece 5 and the insulating sheets 6 and 6. FIG. Further, as shown in FIG. 2, shield wires (metal bars) 9 are attached to the axial ends of the halves 8, 8. At this time, the electrostatic shielding plate 4 may be divided into three as shown in FIG.

  In this way, by dividing the electrostatic shielding plate 4, even if a radial mechanical force acts on the electrostatic shielding plate 4, each of the electrostatic shielding plates 4 follows the radial mechanical force. The division | segmentation piece 5 can displace and the mechanical force added to each division | segmentation piece 5 can be reduced. Thereby, damage to the electrostatic shielding plate 4 and the like can be prevented. Further, since it is possible to assemble each divided piece 5, the assembling workability is improved as compared with the assembling work of inserting the integral cylindrical type into a predetermined position. Moreover, since the shield wire (metal bar) 9 is provided at the axial ends of the halves 8 and 8 as necessary, electric field concentration at the axial ends can be reduced. In addition, it is possible to adjust the dimensions of the electrostatic shielding plate 4 without setting the dimensions of the divided pieces 5 constituting the electrostatic shielding plate 4 with high accuracy.

  Further, as in the second embodiment shown in FIG. 5, the side end portions 10a, 10b, 11a, 11b of the pair of split pieces 5a, 5b constituting the electrostatic shielding plate 4 may be overlapped (wrapped). . That is, one side end portion 10a of the first divided piece 5a and one side end portion 10b of the second divided piece 5b are overlapped, and the other side end portion 11a of the first divided piece 5a and the second divided piece 5b are overlapped. The other side end portion 11b of 5b is overlapped. In this case, in the illustrated example, one side end portion 10a of the first divided piece 5a and the other side end portion 11b of the second divided piece 5b are arranged on the outer diameter side, but the side end portions 10a, 11b Either one may be arranged on the inner diameter side, or both may be arranged on the inner diameter side. At this time, in consideration of receiving the mechanical force in the radial direction, the overlapping portion is not fixed. And also in this electrostatic shielding board 4, the inner surface and outer surface of the metal foil are covered with the insulating sheets 6 and 6. Also in the second embodiment, the electrostatic shielding plate 4 may be divided into three parts, or even more.

  Note that the rise in the electric field can also be suppressed by overlapping the ground metal foil electrically insulated from the electrostatic shielding plate 4 in the gap portion of the metal foil of the electrostatic shielding plate 4 instead of such a wrap. Furthermore, even if a slit as shown in FIG. 11 is formed in the electrostatic shielding plate 4, an increase in the electric field at the slit can be suppressed by insulating and overlapping another ground metal foil on the slit.

  By the way, as shown in the said FIG. 5, if the side edge part 10a, 10b, 11a, 11b of the division | segmentation piece 5a, 5b is wrapped, the electric field rise in each side edge part 10a, 10b, 11a, 11b can be suppressed. . Further, since only the side end portions 10a, 10b, 11a, and 11b of the divided pieces 5a and 5b are wrapped, even if a radial mechanical force acts on the electrostatic shielding plate 4, it follows this mechanical force. Thus, damage to the electrostatic shielding plate 4 can be prevented.

  By the way, when it wraps, as shown in FIG. 6, you may make it interpose the insulating material 12 between the side edge part 10a, 10b etc. which the division | segmentation piece 5a, 5b faces. Also in this case, in consideration of receiving the mechanical force in the radial direction, the insulating material 12 is fixed to the first divided piece 5a side, and the insulating material 12 is not fixed to the second divided piece 5b side. On the contrary, the insulating material 12 may be fixed to the second divided piece 5b side and the insulating material 12 may not be fixed to the first divided piece 5a side.

  7 and FIG. 8 (enlarged view of the A part in FIG. 7) show the third embodiment. In this case, as in FIG. 6, between the side end portions 10a and 10b facing the divided pieces 5a and 5b. The insulating material 12 is interposed, and the inner surface of the metal foil constituting the split piece 5 is covered with the inner insulating sheet 15, and the outer surface of the metal foil is covered with the outer insulating sheet 16, and the inner insulating sheet 15 and Tapered surfaces 17a, 17b, 18a, and 18b are formed on the side edge portions of the outer insulating sheet 16, respectively. Then, on the inner side, one tapered surface 17a of the first inner insulating sheet 15a and the other tapered surface 17b of the second inner insulating sheet 15b corresponding to each other are abutted, and the first inner insulating sheet 15a The other tapered surface (not shown) and one corresponding tapered surface (not shown) of the second inner insulating sheet 15b are abutted against each other. Also, on the outside, the one outer surface 16a of the first outer insulating sheet 16a and the other outer surface 16b of the second outer insulating sheet 16b corresponding to each other face each other, and the first outer insulating sheet 16a. The other tapered surface (not shown) and the corresponding one tapered surface (not shown) of the second outer insulating sheet 16b are abutted against each other. Here, abutting means that the facing tapered surfaces are overlapped.

  In this way, the tapered surfaces 17a, 17b, 18a, and 18b are formed on the side edge portions of the inner insulating sheet 15 and the outer insulating sheet 16, and the adjacent tapered surfaces 17a, 17b, 18a, and 18b are butted against each other. If it is, the electrostatic shielding plate 4 can be displaced in the radial direction by sliding the two insulating sheets 15 and 16 together with the tapered surfaces 17a, 17b, 18a and 18b during assembly. Thus, the influence of the mechanical force in the radial direction can be reduced.

  Further, as shown in FIG. 9 showing the fourth embodiment, the electrostatic shielding plate 4 does not use a metal foil, and is a metal net (metal mesh) made of a metal having low conductivity (for example, stainless steel). You may comprise. At this time, a plurality of metal nets are arranged along the circumferential direction to form a cylindrical shape, and a folded portion 19 that is folded back is formed at the axial end portion as shown in FIG. Here, the metal net-like body is a frame made up of a plurality of longitudinal members 21... And a plurality of transverse members 22. At this time, whether the longitudinal member 21 is disposed on the inner diameter side, or conversely, the lateral member 22 is disposed on the inner diameter side, further, The vertical direction member 21 and the horizontal direction member 22 may be alternately arranged on the inner diameter side and the outer diameter side at a portion where the direction member 22 intersects. Moreover, you may comprise with the 1st inclination member which inclines at a predetermined angle with respect to an axial direction, and the 2nd inclination member which inclines at about 90 degree | times with respect to this 1st inclination member.

  In the fourth embodiment, as shown in FIG. 10A, the folded portion 19 is formed by folding it in a single layer, and an insulating member (insulating sheet) 20 is additionally provided so as to cover the folded portion 19. . When the folded portion 19 is formed, the folded portion 19 may be folded back to the inner diameter side or the outer diameter side. When the folded portion 19 is formed, the folded portion 19 may be formed by being folded twice as shown in FIG.

  Thus, by using a metal net, the resistance to mechanical force applied in the radial direction is improved by the stretchability of the metal net. Further, by providing the folded portion 19, the end portion in the axial direction of the electrostatic shielding plate 4 is rounded, and the local electric field rise at this end portion can be suppressed. Moreover, the round bar shield wire 9 shown in FIG. 2 and the like is not required, and the assembly workability is improved. A large curvature electrostatic shielding plate 4 with high withstand voltage performance can be configured by providing a structural member having a required curvature at the end of the electrostatic shielding plate 4 and covering it with a metal mesh (metal mesh). Needless to say.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, when the electrostatic shielding plate 4 is divided, the circumferential lengths of the divided pieces 5 may be different. Further, as the insulating sheets 6, 15, 16 and the insulating material 12, insulating paper or the like can be used. That is, the insulating sheet 6 or the like can be formed of various materials having insulating properties, and can exhibit insulating properties even in the thickness dimension, and can be stored in the stationary induction device to be used. If it is. Moreover, as long as the material and thickness of the metal foil constituting the electrostatic shielding plate 4 have shielding properties and can be interposed between the primary winding 1 and the secondary winding 2, Various things can be selected. Note that the static induction device is not limited to a transformer, and may be another device having windings with different voltages.

It is a section top view showing a 1st embodiment of an electrostatic shielding structure of a static induction device of this invention. It is a cross-sectional front view of the electrostatic shielding structure of the static induction device. It is a simplified cross-sectional top view of the electrostatic shielding board of the electrostatic shielding structure of the said static induction apparatus. It is a simplified cross-sectional top view which shows the modification of the electrostatic shielding structure of the said static induction apparatus. The 2nd Embodiment of the electrostatic shielding structure of the said static induction apparatus is shown, and it is a simple perspective view of the electrostatic shielding board. It is a principal part expanded sectional view which shows the modification of the electrostatic shielding board of the said 2nd Embodiment. 3rd Embodiment of the electrostatic shielding structure of the said static induction apparatus is shown, and it is a simplified perspective view of the electrostatic shielding board. It is the A section enlarged view of the said FIG. The 4th Embodiment of the electrostatic shielding structure of the said static induction apparatus is shown, and it is an expanded view of the electrostatic shielding board. The 4th Embodiment of the electrostatic shielding structure of the said static induction apparatus is shown, (a) is the principal part expanded sectional view of an electrostatic shielding board, (b) is the principal part expanded cross section of the modification of an electrostatic shielding board. FIG. It is a simple perspective view of the electrostatic shielding board of the electrostatic shielding structure of the conventional static induction apparatus. It is a cross-sectional top view of the electrostatic shielding structure of the conventional static induction apparatus.

Explanation of symbols

  1 .... primary winding, 2 .... secondary winding, 4 .... electrostatic shielding plate, 5 .... split piece, 10a ... side end, 10b ... side end, 11a ... side end 11b..Side end, 12..Insulating material, 15..Inner insulating sheet, 17a..Tapered surface, 17b..Tapered surface, 16..Outer insulating sheet, 18a..Tapered surface, 18b..Taper Face, 19 ... Folded part

Claims (4)

In the electrostatic shielding structure of a static induction device in which an electrostatic shielding plate (4) is provided between a primary winding (1) and a secondary winding (2) wound coaxially, the electrostatic shielding plate An electrostatic shielding structure for a stationary induction device, wherein (4) is provided by being divided into a plurality in the circumferential direction. Side edges (10a), (10b), (11a), and (11b) of adjacent divided pieces (5) and (5) of the divided electrostatic shielding plate (4) are overlapped with an insulating material (12) interposed therebetween. The electrostatic shielding structure for a stationary induction device according to claim 1. The electrostatic shielding plate (4) is composed of a plurality of metal foils, and the inner surface of each metal foil is covered with an inner insulating sheet (15), and the outer surface of each metal foil is covered with an outer insulating sheet (16). Then, taper surfaces (17a), (17b), (18a), and (18b) are formed on the side edge portions of the inner insulating sheet (15) and the outer insulating sheet (16), and the adjacent tapered surfaces (17a) are formed. (17b) (18a) (18b) abutting each other, The electrostatic shielding structure for a static induction device according to claim 1 or 2. The said electrostatic shielding board (4) is comprised with a metal mesh body, and the folding | turning part (19) was provided in the axial direction edge part of this metal mesh body, The Claim 1 or Claim 2 characterized by the above-mentioned. Electrostatic shielding structure for stationary induction equipment.