JP2010093104A - Three-phase transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-phase transformer capable of suppressing an increase in loss and reduction in efficiency by surely preventing the displacement of an iron core joint part in the longitudinal direction of an iron core of a transformer. <P>SOLUTION: A transformer body 9 is constituted of: three-leg iron cores 1 to 3; windings 4; an upper yoke 5, a lower yoke 6; upper core clamps 7, and lower core clamps 8. The transformer body 9 with the constitution is dipped and stored in a tank 11 into which a cooling medium 10 (mineral oil, gas, silicone liquid, etc.) is sealed. Pairs of brackets 13 made of a non-magnetic material are arranged so as to bridge the end faces of both ends of a pair of upper iron core clamps 7 and a pair of lower ion core clamps 8. Each bracket 13 is connected to an inner wall of the tank 11 by a support metal fitting 15 made of a non-magnetic material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a three-phase transformer that improves earthquake resistance against earthquakes.

  In recent years, transformers have a tendency to increase in capacity, and accordingly, there is a demand for improvement in earthquake resistance against earthquakes.

  As is well known, the upper and lower yokes are arranged at the upper and lower ends of the leg core around which the winding is wound, and the transformer is arranged opposite to the upper and lower ends of the winding to support the winding. A transformer body having an upper core fastening bracket and a lower core fastening bracket is housed in a tank. A cooling medium is sealed in the tank. The leg iron core, upper yoke, and lower yoke are formed by laminating silicon steel plates.

  Conventionally, as a seismic structure of such a transformer, it is known that a reinforcing member or a spring member is provided on the transformer body and connected to a tank. Providing a reinforcing member is described in Patent Document 1 below, and providing a spring member is described in Patent Document 2 below. This seismic structure is intended to improve the seismic resistance of the silicon steel sheet in the laminating direction, that is, the width direction (thickness direction) of the iron core, and is mainly for preventing overturning.

  By the way, in order to join the leg iron core to the upper and lower yokes, both ends of the central leg are cut at an angle of 45 degrees and protruded into a V shape, and the upper and lower yokes combined therewith are combined. A V-shaped notch is provided to provide an overlapped surface. Moreover, the joining of the silicon steel plate of the end legs and the silicon steel of the upper yoke and the lower yoke is performed by cutting the silicon steel plate at 45 degrees into a butt joint like a corner of the frame, and the upper and lower yokes. It is made to protrude to the side from the right and left leg parts which join.

  About joining such a leg iron core, an upper yoke, and a lower yoke, it is described in the following patent document 3, for example, and is well known. Hereinafter, in this specification, such a butt joint is referred to as a butt joint provided with an overlapping surface.

JP-A-6-61065 Japanese Patent Laid-Open No. 3-129709 JP-A-6-181120

  In the prior art, a reinforcing member or a spring member is provided to improve the earthquake resistance in the width direction (thickness direction) of the iron core to prevent the collapse. For this reason, there is a problem that a displacement of the overlapping surface of the iron core joints, that is, a displacement in the longitudinal direction of the transformer core occurs due to a shake in the longitudinal direction of the transformer core due to a large earthquake. Longitudinal displacement of the transformer core is likely to occur at the end legs at the joint between the end legs and the upper and lower yokes, and if the displacement of the overlapping surface occurs, the loss of the transformer increases and the efficiency decreases. .

  This technical problem was discovered by the present inventors who investigated the cause of the increase in transformer loss after an earthquake, and is a completely new technical problem that has not been raised in the past.

  An object of the present invention is to provide a three-phase transformer that can reliably prevent displacement in the longitudinal direction of a transformer core at an iron core joint and suppress increase in loss and decrease in efficiency.

  A feature of the present invention is that a transformer for connecting both end faces of a pair of upper iron core fasteners and both end faces of the pair of lower iron core fasteners to the inner wall of the tank by a nonmagnetic material support metal fitting The feature is that a longitudinal displacement control mechanism for the iron core is provided.

  Specifically, a non-magnetic receiving bracket is provided so as to bridge the end faces on both sides of the pair of upper core clamping brackets and the pair of lower core clamping brackets. They are connected by non-magnetic support brackets.

  The present invention provides a longitudinal displacement restriction of a transformer core in which both side end surfaces of a pair of upper core fastening metal fittings and each side end face of a pair of lower iron core fastening metal fittings are connected to the tank inner wall by a nonmagnetic material support metal fitting. A mechanism is provided. Therefore, even if vibration is applied to the transformer core due to a large earthquake, the longitudinal length of the transformer core can be kept constant, so that the longitudinal displacement of the transformer core can be surely prevented, and transformer loss can be reduced. Reduction and efficiency improvement can be achieved.

  An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show a first embodiment of the present invention. FIG. 1 is a front view showing a section of a tank of a three-phase transformer according to an embodiment of the present invention, FIG. 2 is a partial sectional view of the tank with a ceiling plate (lid) removed, and FIG. It is the side view which cut the surface.

  1 to 3, reference numerals 1, 2, and 3 denote three leg iron cores. The iron core leg 2 is a central leg, and the two iron core legs 1 and 3 are end legs. A winding 4 is wound around each of the three-legged iron cores 1 to 3. An upper yoke 5 and a lower yoke 6 are arranged on the upper and lower ends of the three-legged iron cores 1, 2 and 3.

  An upper iron core fastening fitting 7 and a lower iron core fastening fitting 8 which are arranged opposite to the upper and lower ends of the winding 4 and support the winding 4 are arranged. Both the iron core fastening fittings 7 and 8 are formed in a U-shape, and their vertical surfaces are brought into contact with the upper yoke 5 or the lower yoke 6 and are provided in pairs on the front side and the rear side as viewed from the front. .

  The transformer body 9 is composed of the three-legged iron cores 1, 2 and 3, the winding 4, the upper yoke 5, the lower yoke 6, the upper iron core fastening fitting 7 and the lower iron core fastening fitting 8. The transformer body 9 configured in this manner is immersed and stored in a tank 11 in which a cooling medium 10 (mineral oil, gas, silicone liquid, etc.) is enclosed.

  The lower iron core fastening bracket 8 is fixed to the core base 12 by bolts (not shown), and the core base 12 is fixed by pins (not shown) planted on the bottom plate of the tank 11. The transformer body 9 is firmly fixed to the tank 11 so as not to be displaced in the longitudinal direction of the iron core.

  Receiving metal fittings 13 made of a non-magnetic material such as stainless steel are fixed to both side ends of the upper iron core fastening metal fitting 7 by welding. The receiving metal fitting 13 is arrange | positioned so that the end surface of a pair of upper iron core fastening metal fitting 7 may be bridged as shown in FIG. 2, FIG. Similarly, receiving metal fittings 13 made of a non-magnetic material are fixed to both side ends of the lower iron core fastening metal fitting 8 by welding. The receiving metal fitting 13 is disposed so as to bridge the end surfaces of the pair of lower iron core fastening metal fittings 8.

  The receiving metal fitting 13 is fixed to both side end faces of the upper core fastening metal fitting 7 and both side edge faces of the lower iron core fastening metal fitting 8, but substantially at both side ends of the upper yoke 5 and the lower yoke 6 in the longitudinal direction. It will be provided.

  The receiving metal 13 constitutes a longitudinal displacement regulating mechanism 14 of the iron core provided by the present invention. An example of the longitudinal displacement regulation mechanism 14 of the transformer core is shown in FIG.

  The support fitting 15 is composed of a bolt with a right screw cut at one end on the left side in the figure and a left screw cut at the other end on the right side. A long nut 16 is fixed to the metal fitting 13. The nut 16 is right-handed. One end of the bolt 15 is screwed into the nut 16 by rotating in the direction indicated by the arrow a.

  A nut 17 is screwed to the other end of the bolt 15. The nut 17 is left-handed. The other end of the bolt 15 is screwed into the nut 17 by rotating it in the direction indicated by the arrow b.

  The bolt 15 and the nuts 16 and 17 are adjusted in screwing depth so that the tip of the nut 17 is brought into close contact with the inner wall of the tank 11. The length of the support fitting 15 can be adjusted. The metal fitting 13 is connected to the tank inner wall 11 by a longitudinal displacement regulating mechanism 14 of the iron core. The support fittings (bolts) 15 are arranged in parallel.

  As described above, according to the present invention, the nonmagnetic member receiving metal fittings are provided at both longitudinal ends of the upper yoke and the lower yoke, and each receiving metal fitting is connected to the tank inner wall by the support metal fitting. For this reason, even if vibration is applied to the transformer core due to a large earthquake, the length in the longitudinal direction of the transformer core can be kept constant, so that displacement of the silicon steel sheet at the core joint can be reliably prevented. As a result, the loss of the transformer can be reduced and the efficiency can be improved.

  FIG. 5 shows a second embodiment of the present invention. In the embodiment of FIG. 5, a non-magnetic receiving bracket 20 is formed in a U shape and is sandwiched and welded to both ends of a pair of upper iron core fastener 7 and lower iron core fastener 8. Support metal fittings 21 are provided on the outer surfaces of both legs of the U-shaped metal fittings 20 to prevent overturning in the width direction. The support bracket 21 has the same configuration as the support bracket 15 of the first embodiment.

  In the second embodiment as well, the longitudinal displacement of the transformer core can be reliably prevented, and the transformer core can be prevented from falling.

  In the above embodiment, a three-phase tripod transformer is taken as an example, but it goes without saying that the same effect can be obtained even with a three-phase five-leg transformer.

  Moreover, although the above-mentioned Example has provided one support metal fitting in the both ends of a pair of iron core fastening metal fittings, it is clear that a several support metal fitting may be provided. When a plurality of support fittings are provided, the force applied to the support fittings can be dispersed.

  Furthermore, although the above-mentioned Example has given the example of U shape and L shape as an iron core fastening metal fitting, of course, you may comprise by shapes, such as a hollow rectangular shape.

It is the front view which carried out the cross section of the front of the tank of the three phase transformer concerning one example of the present invention. It is a fragmentary sectional view in the state where the ceiling board (lid) of the tank was removed. It is the side view which cut the left side of a tank. It is an example block diagram of the longitudinal direction displacement control mechanism of the transformer core in this invention. It is a top view of the state which removed the ceiling board (lid) of the tank of the three-phase transformer which concerns on the other Example of this invention.

Explanation of symbols

1, 2, 3 ... iron core legs, 4 ... winding, 5 ... upper yoke, 6 ... lower yoke, 7 ... upper iron core clamp, 8 ... lower iron core clamp, 9 ... transformer body, 10 ... Cooling medium, 11 ... tank, 12 ... core base, 13 ... receiving bracket, 14 ... longitudinal displacement regulating mechanism of iron core, 15 ... support fitting (bolt), 16, 17 ... nut

Claims (3)

  An upper yoke and a lower yoke are arranged at the upper and lower ends of the leg iron core around which the winding is wound, and a pair of upper iron core fasteners and a pair of the upper iron core and the lower yoke that are arranged opposite to the upper and lower ends of the winding to support the winding A transformer body having a lower iron core fastening bracket is housed in a tank, and the leg iron core and the both yokes are formed by laminating silicon steel plates, and a butt joint is provided by providing an overlapping surface at the joint. In the three-phase transformer, the both end surfaces of the pair of upper iron core clamps and the both end surfaces of the pair of lower iron core fasteners are connected to the tank inner wall by a nonmagnetic material support metal fitting. A three-phase transformer provided with a longitudinal displacement regulating mechanism.   An upper yoke and a lower yoke are arranged at the upper and lower ends of the leg iron core around which the winding is wound, and a pair of upper iron core fasteners and a pair of the upper iron core and the lower yoke that are arranged opposite to the upper and lower ends of the winding to support the winding A transformer body having a lower iron core fastening bracket is housed in a tank, and the leg iron core and the both yokes are formed by laminating silicon steel plates, and a butt joint is provided by providing an overlapping surface at the joint. In the three-phase transformer, a pair of upper iron core clamps and a pair of lower iron core clamps are provided with nonmagnetic material receiving metal parts arranged so as to bridge both end faces, 3. The three-phase transformer, wherein the tank inner walls are connected by a non-magnetic support bracket.   The three-phase transformer according to any one of claims 1 and 2, wherein the length of the support metal fitting is adjustable.

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