JPH08148352A - Three-phase transformer and reactor with gap in magnetic circuit - Google Patents

Abstract

PURPOSE: To reduce vibration and noise at a gap part in the magnetic circuit of a three-phase transformer and a reactor. CONSTITUTION: A non-magnetic spacer with an adhesive or an elastic non- magnetic plate are inserted and cure in a gap 4 at a joining part between an upper core 1 and a lower core 2 in a three-phase three-leg core. In addition, a non-magnetic high-resistance metallic plate 3 is welded to each gap part of U-phase and W-phase core legs in an MIG welding step to join these upper and lower cores 1 and 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase transformer and a reactor provided with a gap in a magnetic circuit constituting an inverter device or a static power supply device.

[0002]

2. Description of the Related Art Some three-phase transformers and reactors used in inverter devices and static power supply devices are provided with a gap in an iron core forming a magnetic circuit according to the purpose of use. It is as shown in 4. FIG. 4 is a cross-sectional view of an inner iron type three-phase three-leg iron core, in which a gap 4 is provided at the joint between the upper iron core 1 and the lower iron core 2, and the gap 4 is fixed by a spacer or an adhesive. There is.

When a voltage is applied to a three-phase transformer or a reactor having a gap in a magnetic circuit, the power supply frequency is doubled in each of the U-phase, V-phase and W-phase gaps forming a three-phase three-leg iron core. A magnetic attraction force alternating in frequency is generated between the upper iron core 1 and the lower iron core 2. That is, since the leg portions of the upper iron core 1 and the lower iron core 2 are connected by the yoke portion and are regarded as one rigid body, the U-phase gap portion and the W-phase gap portion are attracted by the V-phase gap portion as a fulcrum. Reaction forces are generated alternately, and a relative displacement motion is generated.

FIG. 5 is a characteristic curve showing the relationship between the applied voltage and the magnetic attraction force in each phase. From the change curve of the magnetic attraction force in FIG. 5, the attraction force and reaction force in each phase are as follows. Time U phase V phase W phase t ₁ Suction force (max) Support point reaction force (maximum) t ₂ Reaction force (maximum) Support point suction force (maximum) t ₃ Suction force (small) Suction force (maximum) Suction force ( Small) As a result, the upper iron core 1 and the lower iron core 2 vibrate due to the repetitive suction force and reaction force sandwiching the U-phase and W-phase gap portions. Also, if a minute gap is generated between the iron core in the gap portion and the spacer due to the reaction force,
During suction, not only noise is generated due to collision between the two, but it also increases with time.

[0005]

As a method of suppressing the vibration and noise generated by the collision due to the relative displacement motion of the upper iron core and the lower iron core described above, a metal rod, a plate, a band, a bolt or the like may be used to suppress the vibration. There are a method of suppressing the relative motion by pressurizing between the lower iron cores, a method of adhering the gap portion, and the like, as shown in FIGS. 2 and 3. FIG. 2 is a cross-sectional view of the upper and lower cores showing an example of a pressing method between the upper and lower cores,
The gap 4 between the upper iron core 1 and the lower iron core 2 is fixed to the spacer with an adhesive or the like, and the metal fasteners 10, 11,
Pressure is applied between the upper and lower iron cores by the bolts 12, 13 and the bolts 14, 15. Next, FIG. 3 shows another pressing method for the upper and lower iron cores. The gap 4 between the upper iron core 1 and the lower iron core 2 is fixed by a spacer and an adhesive or the like, and the non-magnetic iron core pressing plate is used. Tightening bolt 2 through 20 and 21
The front and rear surfaces of the upper and lower iron cores are fastened by 2,23,24,25 and the upper and lower iron cores are fixed.

In the pressurizing method shown in FIGS. 2 and 3,
The pressure applied to the gap portion decreases due to changes over time such as the expansion of bolts due to the repeated thermal expansion of the iron core and the loosening between the iron core and the clamp, or the slip between the iron core and the retainer plate, and vibration and noise increase. Also, U-phase iron core and W
This may cause a change in the adhesive or the like due to repeated attraction and reaction forces of the companion core, or peeling of the bond due to heat deterioration due to the temperature of the core, resulting in increased vibration and noise.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and is a non-magnetic spacer in the gap portion between the upper core and the lower core in a three-phase three-leg core. It is fixed with an adhesive or a flexible non-magnetic plate, and the side surfaces of the gap between the U-phase iron core and the W-phase iron core are welded by applying a non-magnetic / high-resistance metal plate to the upper and lower iron cores. Combine.

[0008]

[Operation] By applying MIG welding to the side surfaces of the U-phase iron core and the W-phase iron core by applying a non-magnetic / high-resistance metal plate, three-phase three-phase
Firmly connect the leg iron core. Therefore, the relative displacement motion of the upper and lower iron cores due to the suction force and the reaction force applied to the gap between the U phase and the W phase does not occur, and the vibration and noise are suppressed. Further, due to heat deterioration of the adhesive or the like due to the temperature of the iron core, even when the bonded portion is peeled off, the relative displacement motion of the upper and lower iron cores does not occur due to the welded metal plates, so that vibration and noise do not increase.

[0009]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a three-phase three-leg iron core portion in a three-phase transformer and a reactor having a gap in a magnetic circuit. In FIG. 1, the U-phase, V-phase and W-phase of an inner iron type three-phase three-leg iron core are divided into an upper iron core 1 and a lower iron core 2, and a gap 4 is provided at the joint between the upper and lower iron cores to form a magnetic circuit. There is. The gap 4 is fixed by filling a non-magnetic spacer with an adhesive or an adhesive, or by inserting a flexible non-magnetic plate (such as plastics) and pressing between the upper and lower iron cores. I will let you.
Further, as is apparent from FIG. 1, the laminated cores forming the three-phase three-leg iron core are superposed, and the non-magnetic and high-resistance metal plate 3 is formed on the side surface of the gap portion of the U-phase iron leg and the W-phase iron leg. Then, MIG welding (Metal Inert Gas Arc Welding) is performed between the U-phase and W-phase iron core legs and the metal plate 3.

By welding the metal plates 3 to the U-phase iron core legs and the W-phase iron core legs, not only the upper and lower iron cores of the three-phase three-leg iron core are joined through the gaps 4, but also the respective laminated cores are connected to the metal plate 3. It will be bonded and molded into one body via. Therefore, the reinforcement by the metal fasteners and the iron core pressing plate as in the prior art is simplified.

[0011]

As is apparent from the above description, the three-phase transformer and reactor having the magnetic circuit provided with the cap according to the present invention has a non-magnetic adhesive or a flexible material for each gap portion in the three-phase three-leg iron core. It is fixed by inserting a non-magnetic plate with a magnetic property, and then the side of the gap part of the U-phase and W-phase iron core legs is applied with a non-magnetic / high-resistance metal plate and welded to join the upper and lower iron cores. There is. Therefore,
Not only can vibration and noise generated in the gap portion be suppressed, but also increase in vibration and noise due to heat deterioration or time deterioration of the adhesive or the like in the gap portion can be suppressed. Also,
Reinforcement by metal fasteners or the like for jointly molding the three-phase three-leg iron core into one body is also simplified.

[Brief description of drawings]

FIG. 1 is a perspective view of a three-phase three-leg iron core in a three-phase transformer and reactor having a gap in a magnetic circuit according to the present invention.

FIG. 2 is a sectional view showing an example of a conventional pressing method between upper and lower iron cores.

FIG. 3 is a cross-sectional view showing another example of a conventional pressing method between upper and lower iron cores.

FIG. 4 is a cross-sectional view of an inner iron type three-phase three-leg iron core.

FIG. 5 is a characteristic curve showing a relationship between an applied voltage and a magnetic attraction force in each phase.

[Explanation of symbols]

 1 Upper iron core 2 Lower iron core 3 Metal plate 4 Gap

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location H01F 37/00 A 9375-5E S 9375-5E (72) Inventor Hiroki Shirato 1 Tsutsudori, Sumida-ku, Tokyo Chome 19-9 NIPPON SEIKI CO., LTD.

Claims (2)

[Claims] 1. A three-phase transformer in which a three-phase three-leg iron core is divided into an upper iron core and a lower iron core, and a gap is provided in each of the joints of the divided iron cores to form a magnetic circuit. In the reactor and the reactor, the gap portions of the three-phase three-leg iron core are fixed by filling a non-magnetic spacer and an adhesive or an adhesive, and the side surfaces of the gap portions of the U-phase iron core and the W-phase iron core are fixed. A three-phase transformer and a reactor having a gap in a magnetic circuit, characterized in that an upper core and a lower core are joined by applying a non-magnetic and high resistance metal plate and welding them. 2. A U-phase iron core and a W-phase iron core are fixed by inserting a flexible non-magnetic plate into each gap portion of a three-phase three-leg iron core and applying pressure between the upper iron core and the lower iron core. 2. The magnetic circuit according to claim 1, wherein the upper iron core and the lower iron core are joined together by applying a non-magnetic / high-resistance metal plate to the side surfaces of the gap portion and welding them. 3 phase transformer and reactor.