JP2008177325A - Stationary induction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stationary induction apparatus capable of suppressing rising of temperature at an iron core connecting bracket part with a simple structure, for a reduced loss. <P>SOLUTION: The stationary induction apparatus comprises an iron core consisting of a plurality of iron core legs 1 and yokes 2 above and below it, and a winding 4 which is wound on the iron core legs. The iron core connecting bracket 3 arranged on both sides of the yokes 2 comprises a vertical member 3A that pressurizes the yoke 2 and a horizontal member which is fixed on one end of the vertical member 3A and is opposite to the end face of the winding 4. Non-magnetic shields 5 and 6 extending in the length direction of the iron core connecting bracket are arranged on the surface of the horizontal member 3B and the other end side of the vertical member 3A. At the horizontal member 3B of the iron core connecting bracket 3 that corresponds to the position between the windings 4, auxiliary non-magnetic shields 7 and 8 for making an eddy current flow toward the non-magnetic shield 6 on the other end side of the vertical member 3A are arranged. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a stationary induction device such as a transformer or a reactor, and more particularly to a stationary induction device having a non-magnetic shield on an iron core fastening bracket.

  Static induction machines such as transformers and reactors have an increasing capacity. For example, in the case of a transformer, the overall structure is enlarged. Increasing the size of the transformer also increases the leakage magnetic flux from the windings housed in the tank and the lead wires drawn from the windings during operation. Leakage magnetic flux penetrates into the structure of the transformer, induces eddy currents, causes a local temperature rise based on the eddy currents, and increases losses. This causes problems in terms of product performance and reliability. .

  Transformer iron cores formed by laminating silicon steel sheets are constructed integrally by placing and tightening L-shaped or U-shaped iron core fasteners on the upper and lower yokes connecting the core legs. ing. The upper and lower iron core fastening brackets are formed of a vertical member that normally presses the yoke portion, and a horizontal member that is fixed to one end of the vertical member and faces the end face of the winding.

  Since the horizontal member of the iron core clamp is close to and opposed to the end face of the winding, it is necessary to reduce the local temperature rise due to the intrusion of the leakage magnetic flux as much as possible. For this reason, the iron core clamp is made of copper that is smaller than the electrical resistance of the iron core clamp on the horizontal member that directly faces the winding end face, and on the other end of the vertical member or the horizontal member on the non-winding side. It has been proposed to arrange a nonmagnetic shield of aluminum or aluminum so as to extend in the longitudinal direction of the iron core fastener (see Patent Document 1).

  The non-magnetic shield placed on the surface of the horizontal member of the iron core clamp, etc., when leakage magnetic flux enters the eddy current due to the leakage magnetic flux flows into this non-magnetic shield, and the magnetic flux generated by the eddy current becomes the leakage magnetic flux. Therefore, the intrusion of leakage magnetic flux can be suppressed, the temperature of the iron core fastener can be prevented from rising locally, and the loss can be prevented from increasing.

Japanese Patent No. 2924448

  When a non-magnetic shield is arranged on the horizontal member of the iron core fastener as in Patent Document 1, when the leakage magnetic flux enters the horizontal member of the iron core fastener, particularly near the position facing the winding, the non-magnetic material is used. An eddy current flows in the horizontal direction in a direction that cancels out the leakage flux to the shield. The magnetic flux generated by the eddy current can be counteracted to prevent the leakage magnetic flux from entering the iron core fastening bracket, thereby preventing a local temperature rise.

  However, since the eddy current does not flow properly through the non-magnetic shield so as to cancel the leakage magnetic flux flowing in the longitudinal direction near the position between the windings of the horizontal member of the iron core clamp, the core clamp There is a problem that a local temperature rise is caused at a position facing between the windings, and loss cannot be reduced. This is because the eddy current flows from the horizontal direction to the vertical direction in the vicinity of the position between the windings of the horizontal member of the iron core clamp, so that the generated magnetic flux does not cancel the leakage flux. ing.

  An object of the present invention is to provide a static induction electric appliance that can suppress a temperature rise of an iron core fastening bracket portion with a simple structure and can reduce loss.

  The static induction electric machine of the present invention has an iron core composed of a plurality of iron core legs and upper and lower yoke portions, and a winding wound around each of the iron core leg portions, and is disposed on both sides of each of the yoke portions. The iron core fastening bracket includes a vertical member that presses at least the yoke portion, and a horizontal member that is fixed to one end of the vertical member and faces an end face of the winding, and faces the winding of the horizontal member. When the non-magnetic shield extending in the longitudinal direction of each of the iron core clamps is disposed on the other surface and the other end of the vertical member, the iron core clamp corresponding to the gap between the windings is formed It is characterized in that an auxiliary non-magnetic shield that allows an eddy current to flow toward the non-magnetic shield on the other end of the vertical member is provided at the position of the horizontal member of the metal fitting.

  Preferably, the auxiliary nonmagnetic shield includes a flat auxiliary nonmagnetic shield extending in the longitudinal direction and a flat auxiliary nonmagnetic shield extending toward the nonmagnetic shield on the other end of the vertical member. It is characterized by the construction.

  Preferably, the iron core fastening bracket has a horizontal member that is fixed to the other end side of the vertical member and that is on the non-winding side, and is formed in a U-shaped cross section, and the horizontal member on the anti-winding side It is characterized in that a non-magnetic shield is provided on the surface.

  Further preferably, the iron core fastening bracket includes a reinforcing member for connecting the horizontal member and the vertical member, and the auxiliary nonmagnetic shield having an L-shaped cross section is provided on both side surfaces of the reinforcing member. It is characterized by being configured.

  If the static induction electric machine is configured as in the present invention, it is possible to prevent intrusion of leakage magnetic flux with a simple structure without complicating the iron core clamp part, and therefore between the windings of the horizontal member of the iron core clamp. There is an effect that a local temperature rise in the vicinity of the corresponding position can be significantly suppressed, and an increase in loss can be reduced.

  The static induction electric machine according to the present invention has a plurality of core leg portions and upper and lower yoke portions, and an iron core in which an iron core fastener is disposed on both sides of each of the yoke portions, and is wound around each of the iron core leg portions. And a winding to rotate. The iron core clamp includes at least a vertical member that presses the yoke portion, and a horizontal member that is fixed to one end of the vertical member and faces the end face of the winding, and the horizontal member faces the winding. A non-magnetic shield extending in the longitudinal direction of the iron core clamp is disposed on the other end of the surface and the vertical member. In addition, an auxiliary nonmagnetic shield that allows eddy current flowing toward the nonmagnetic shield on the other end of the vertical member is provided.

  The present invention will be described with reference to FIGS. 1 (a), 1 (b) and FIG. 2 in which the present invention is applied to a three-phase / three-leg transformer. As is well known, a three-phase tripod transformer contains a transformer body inside a tank (not shown) and insulates insulating oil and gas used for insulation and cooling medium in the tank. Enclose the medium and make it.

  As shown in FIGS. 1 (a) and 2, the three-phase / three-leg transformer body includes an iron core leg portion 1 for each phase, a yoke portion 2 disposed above and below each iron core leg portion 1, and upper and lower yokes. A laminated iron core in which silicon steel plates are laminated is formed by the iron core fastening fittings 3 that are arranged and fixed on both sides of the part 2, and each U-phase is formed on each iron core leg 1 as shown in FIG. 1 (b). , V-phase and W-phase primary and secondary windings 4 are arranged.

In the example of FIGS. 1A, 1B, and 2, the upper and lower iron core fastening fittings 3 are fixed to the vertical member 3A that presses the yoke portion 2 and fixed to one end of the vertical member 3A. It is comprised by the substantially L shape which consists of the horizontal member 3B which opposes the end surface of the line | wire 4. As shown in FIG. In the horizontal member 3B of the upper and lower iron core fasteners 3, a nonmagnetic shield 5 extending in the longitudinal direction of the iron core fastener 3 is disposed on a plane portion directly opposite to the windings. Similarly, a nonmagnetic shield 6 is disposed on the other end side. As is well known, the nonmagnetic shields 5 and 6 are made of a highly conductive material such as copper or aluminum, which has a remarkably lower electrical resistance than the iron core fastening fitting 3.
In addition, the horizontal member 3B of the iron core clamp 3 has a specific position on a surface different from the plane on which the nonmagnetic shields 5 and 6 are provided according to the present invention, that is, a position corresponding to the space between the left and right windings 4 (interphase portion). ) Is provided with a flat auxiliary nonmagnetic shield 7, and the vertical member 3 </ b> A of the iron core clamp 3 is provided with a flat auxiliary nonmagnetic shield 8 in the same position. Since it arrange | positions in this way, the auxiliary | assistant nonmagnetic body shields 7 and 8 and the nonmagnetic body shield 6 will be in the state couple | bonded electrically. The auxiliary nonmagnetic shields 7 and 8 are also made of the same highly conductive material as the nonmagnetic shields 5 and 6 and fixed by the same means.

  With this configuration, as indicated by broken line arrows, leakage magnetic flux Φ1 of the U-phase, V-phase, and W-phase windings 4 is generated, and when attempting to enter the iron core fastening bracket 3, the nonmagnetic shield 5 and 6, that is, both the non-magnetic shields 5 and 6 are blocked by the repulsive force of the magnetic flux generated by the eddy current flowing in the direction to cancel out the leakage magnetic flux Φ 1, and the leakage magnetic flux Φ 1 hardly penetrates into the core clamp 3. .

  When a circulating eddy current flows between the vertical member 3A and the horizontal member 3B of the iron core fastening bracket 3 as indicated by solid arrows, most of the current flows through the non-magnetic shields 5 and 6 made of a highly conductive material. Local temperature rise is suppressed. In addition, since the auxiliary nonmagnetic shields 7 and 8 are arranged at positions corresponding to the positions between the windings 4 of each phase, the leakage magnetic flux that flows in the horizontal member 3B of the iron core fastening bracket 3 as indicated by the broken line arrow The eddy current based on Φ2 flows through the auxiliary nonmagnetic shields 7 and 8 made of a highly conductive material as shown by arrows in FIGS. For this reason, in the position (interphase part) corresponding to between the left and right windings 4 in the horizontal member 3B of the iron core clamp 3, it is possible to eliminate a problem due to a local temperature rise, and to suppress an increase in loss. .

  3 and 4 which are other embodiments of the present invention, the same parts as those in the first embodiment are denoted by the same reference numerals. FIG. 3 shows an example in which the iron core fastening fitting 3 is formed in a U-shaped cross section by fixing a horizontal member 3 </ b> C on the opposite side to the other end side of the vertical member 3 </ b> A. Then, a non-magnetic shield 6 is provided on the surface of the horizontal member 3C on the side opposite to the winding, and the horizontal member 3B of the iron core clamp 3 is positioned between the windings 4 of each phase in the same manner as in the above embodiment. Auxiliary non-magnetic shields 7 and 8 are arranged at corresponding locations.

  Also in this embodiment, the leakage magnetic flux Φ1 can be effectively prevented from entering the iron core fastening fitting 3, and the eddy current due to the leakage magnetic flux Φ2 flowing in the longitudinal direction between the windings 4 (interphase portion) of the horizontal member 3B. However, since the auxiliary nonmagnetic shields 7 and 8 flow as shown by solid arrows in FIGS. 3 and 4, the same effects as in the above embodiment can be achieved.

  Similarly, a three-phase three-leg transformer shown in FIGS. 5 and 6 which is another embodiment of the present invention is denoted by the same reference numerals as those in the first embodiment. In FIG. 5, the iron core fastening fitting 3 has a U-shaped cross section as in FIG. 3, and a reinforcing member 9 is disposed between the vertical member 3 </ b> A and the horizontal member 3 </ b> B, and the gap between the two members. It is connected to increase the mechanical strength. In this structure, the reinforcing member 9 positioned between the windings 4 (interphase part) is utilized, and the auxiliary nonmagnetic shield 10 whose cross section is processed into an L shape is disposed on both side surfaces of the reinforcing member 9. .

  Also in this embodiment, the eddy current flows through the auxiliary nonmagnetic shields 7 and 8 as indicated by solid arrows in FIGS. 3 and 4, so that the same effect as in each of the above embodiments can be achieved.

  In each of the above-described embodiments, the present invention has been described with reference to an example in which the present invention is applied to a three-phase three-leg transformer. However, the present invention is applied to a single-phase transformer, a three-phase five-leg transformer, and a reactor. It is clear that an auxiliary non-magnetic shield that allows eddy current to flow toward the non-magnetic shield on the other end of the vertical member can be provided at the position of the corresponding horizontal member of the iron core clamp. Effects can be achieved.

(A) And (b) is the schematic perspective view and schematic vertical sectional view which show only the upper part of the three-phase three-leg transformer which is one Example of this invention. It is a schematic side view which shows the principal part of FIG. It is a schematic perspective view which shows only the upper part of the three-phase three-leg transformer which is another Example of this invention. It is a schematic side view which shows the principal part of FIG. It is a schematic perspective view which shows only the upper part of the three-phase tripod transformer which is another Example of this invention. It is a schematic side view which shows the principal part of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Iron core leg part, 2 ... Joint part, 3 ... Iron core fastening metal fitting, 3A ... Vertical member, 3B, 3C ... Horizontal member, 4 ... Winding, 5, 6 ... Nonmagnetic shield, 7, 8, 10 ... auxiliary nonmagnetic shield, 9 ... reinforcing member.

Claims (4)

  An iron core fastening bracket having an iron core composed of a plurality of iron core leg portions and upper and lower yoke portions, and a winding wound around each iron core leg portion, and disposed on both sides of each yoke portion, It comprises at least a vertical member that presses the yoke part, and a horizontal member that is fixed to one end of the vertical member and faces the end face of the winding. In the stationary induction device in which the non-magnetic shield extending in the longitudinal direction of each of the iron core fasteners is disposed on the end side, the vertical member is positioned at the position of the horizontal member of the iron core fastener corresponding to between the windings. A static induction appliance comprising an auxiliary nonmagnetic shield that allows an eddy current to flow toward the nonmagnetic shield on the other end side.   2. The auxiliary nonmagnetic shield according to claim 1, wherein the auxiliary nonmagnetic shield extends in a longitudinal direction and a flat auxiliary nonmagnetic shield extends toward the nonmagnetic shield on the other end of the vertical member. A static induction machine characterized by comprising   2. The iron core fastening bracket according to claim 1, wherein the iron core fastening member has a horizontal member that is fixed to the other end of the vertical member and that is on the non-winding side, and is formed in a U-shaped cross section. A static induction device characterized in that a nonmagnetic shield is provided on the surface.   4. The auxiliary nonmagnetic shield according to claim 1, wherein the iron core clamp includes a reinforcing member that connects the horizontal member and the vertical member, and the L-shaped cross section is formed on both side surfaces of the reinforcing member. A static induction electric appliance characterized by comprising the above.

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