JPH04303904A - Iron-core type reactor provided with gap - Google Patents

Abstract

PURPOSE:To provide an iron-core type reactor, provided with a gap, which prevents an unreasonable compressive stress from being generated in the central part of a yoke iron core and which can make a noise low. CONSTITUTION:An upper yoke iron core and a lower yoke iron core 4, 5 whose cross section is rectangular are arranged at the upper part and the lower part of an iron-core leg 1 provided with gaps. The yoke iron cores 4, 5 are fixed collectively to the iron-core leg 1 provided with the gaps by using upper and lower clamping plates 6 and upper and lower clamping studs 7. The iron-core leg 1 provided with the gaps is formed by stacking block iron cores 1a via the gaps 2. The clock iron cores 1a at their outside-diameter side 1b are constituted of stamped plates from silicon steel plates whose permeability is relatively high with reference to inside-diameter sides 1c, 1d. As a result, when a reactor is operated, the difference in a permeability between both end parts and the central part in the lamination direction of the yoke iron core 4 becomes equal, the movement of a magnetic flux is suppressed and it is possible to prevent a noise from being generated.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gapped core reactor whose block core has been improved to reduce noise.

0002

2. Description of the Related Art As a reactor used as a shunt reactor, an iron core reactor with a gap is generally used.

[0003] This gapped core reactor has a plurality of block cores made of laminated silicon steel plate strips.
The core legs are stacked so that a plurality of magnetic gaps are formed by sandwiching an insulating gap member between them, and are provided with gapped iron core legs having a circular cross section as a whole. Above and below this gapped core leg, yoke cores having a rectangular cross section and configured in the same manner are arranged. Further, a winding wire is wound around the gapped core leg.

[0004] In the gapped iron core reactor constructed as described above, reduction of noise generated from the reactor body is a major problem. Noise causes can be broadly classified into those caused by mechanical vibration and those caused by magnetostriction.

The phenomenon caused by mechanical vibration is a phenomenon in which a magnetic attraction force acts between the upper and lower block iron cores due to the magnetic flux passing through the magnetic gap, and the resulting vibration generates noise. Therefore, in order to prevent this vibration noise, a structure is required in which the yoke core and the block core are firmly tightened together through a gap.

On the other hand, magnetostrictive noise includes magnetostrictive noise caused by magnetic flux flowing inside the core, and magnetostrictive noise that increases further as a result of applying excessive compressive stress to the punched plate inside the core. The latter is particularly influential. To deal with this, it is possible to appropriately set the magnetic flux density and to adopt an iron core structure that does not apply unreasonable compressive stress to the punched plate inside the iron core when tightening the iron core and during operation.

Now, the distribution of magnetic flux density in the yoke core will be explained with reference to FIG. As shown in FIG. 4, in the gapped core reactor, magnetic flux flows from the gapped core leg 1 with a circular cross section to the yoke core 4 with a rectangular cross section, so the magnetic flux density is low at both ends 4a in the yoke core stacking direction. Similarly, the central portion 4b has a high magnetic flux density. Therefore, there is a difference in the magnetic permeability of the silicon steel plate strip between both ends 4a and the center part 4b, and as a result, the magnetic flux 8 in the center part 4b is transferred to both ends 4a.
The main feature of the gapped iron core reactor is that it moves.

[0008]

[Problems to be Solved by the Invention] However, in the gapped core reactor as described above, the loss generated at the center of the yoke core 4 becomes increasingly large due to the movement of magnetic flux, and a temperature difference occurs between the ends 4a. . As a result, yoke core 4
The central part 4b of the yoke tries to extend in the direction of the punched plate, but both ends 4a of the yoke core act in a direction to prevent this, and in the end,
The punched plate in the central portion 4b of the yoke core 4 is compressed, and magnetostrictive noise increases.

[0009] As a means for preventing this, there is a means to ease the clamping pressure in the stacking direction of the yoke core 4 so that the central portion 4b of the yoke core 4 can easily expand, but it is difficult to manage the clamping force and is not practical.

The present invention was proposed to solve the problems of the prior art as described above, and its purpose is to prevent excessive compressive stress from occurring in the center of the yoke core during operation, and to reduce the stress. An object of the present invention is to provide an iron core reactor with a gap that can reduce noise. [Structure of the invention]

[0011]

[Means for Solving the Problems] In order to achieve the above object, the gapped core reactor of the present invention has a yoke core with a rectangular cross section, which is constructed by laminating gapped core legs with a circular cross section and silicon steel plate strips. In a gap core type reactor consisting of a combination of, the outer diameter side of the block core is
It is characterized by being constructed from a punched silicon steel plate having a relatively high magnetic permeability on the inner diameter side.

0012

[Operation] In the gapped core reactor of the present invention having such a configuration, the punched plate on the outer diameter side of the block core constituting the gapped core leg is relatively transparent with respect to the punched plate on the inner diameter side. Since it is constructed from a punched silicon steel plate with high magnetic flux, the magnetic flux distribution within the core leg has a high magnetic flux density on the outer diameter side and a low magnetic flux density on the inner diameter side. As a result, the magnetic flux distribution within the yoke core becomes substantially uniform, the movement of the magnetic flux within the yoke core is suppressed, and the generation of compressive stress in the yoke core is prevented. As a result, the generation of noise caused by compressive stress is prevented.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 3. Note that the same members as those in the prior art shown in FIG. 4 are given the same reference numerals. Further, in this embodiment, the present invention is applied to a single-phase three-leg iron core.

As shown in FIG. 1, a plurality of block iron cores 1a formed by stacking punched silicon steel plates are stacked with magnetic gaps 2 made of insulating gap members interposed therebetween to form a circular cross-section. A core leg 1 with a gap is constructed. A winding 3 is wound around this core leg 1 with a gap.

Upper and lower yoke cores 4 and 5 each having a rectangular cross section are arranged above and below this gapped core leg 1 so as to sandwich it therebetween. These yoke cores 4 and 5 are connected to the gapped core leg 1 by means of upper and lower clamping plates 6 and clamping studs 7.
is fixed integrally.

As shown in FIG. 2, the block iron core 1a has a circular cross section made by laminating punched silicon steel plates in a radial manner. It is composed of 1c and 1d. Among these, the punched plate on the outer diameter side 1b is made of a silicon steel plate having a relatively higher magnetic permeability than the punched plates on the inner diameter side 1c and 1d.

For example, as an example, the punched plates on the inner diameter side 1c and 1d are made of non-oriented silicon steel plate strips, and the punched plates on the outer diameter side 1b
The punched plate is made of a oriented silicon steel sheet strip having a relatively higher magnetic permeability than a non-oriented silicon steel sheet strip. In addition, as another example, the punched plates on the inner diameter side 1c and 1d are composed of a non-oriented silicon steel plate strip or a grain-oriented silicon steel plate strip of ordinary material, and the punched plates on the outer diameter side 1b are made of a non-oriented silicon steel plate strip or a plain grain-oriented silicon steel plate strip. It is also made of a high-compound silicon steel sheet strip with relatively high magnetic permeability or an amorphous magnetic material.

In this embodiment having such a configuration, when magnetic flux flows from the block core 1a having a circular cross section to the yoke core 4 having a rectangular cross section, the block core located at the center of the yoke core 4 has a high magnetic flux density. Inner diameter side 1 of 1a
c and 1d are the outer diameter sides 1b of the block core located at both ends of the yoke core 4, where the magnetic permeability is low and the magnetic flux density is low.
has high magnetic permeability.

Therefore, during operation of the reactor, the magnetic flux flowing from the block core 1a with a circular cross section to the yoke core 4 with a rectangular cross section is made uniform as a whole, and the magnetic flux from the center of the yoke core 4 in the stacking direction to both ends is uniformized. Movement is suppressed. As a result, as shown in FIG. 3, the punched plates at each section of the yoke core 4 are elongated uniformly, and generation of unreasonable compressive stress due to differences in thermal expansion is prevented. Therefore, the generation of magnetostrictive noise due to unreasonable compressive stress is suppressed, and it is possible to reduce the noise of the reactor.

It should be noted that the present invention is not limited to the above-described embodiments, but can be similarly applied to a three-phase, three-legged core (including one with a wound core yoke) and a five-phase, five-legged core. It can also be applied to the side legs of an iron core with side legs. Furthermore, in the embodiment, the inner diameter sides 1c, 1d of the block core 1b
Although it is assumed that the magnetic permeability is the same, it is also possible to make a difference in magnetic permeability here.

[0021]

[Effects of the Invention] As described above, according to the present invention, the punched plate on the outer diameter side of the block iron core is simply constituted of a silicon steel plate having a higher magnetic permeability than the punched plate on the inner diameter side. As a result, it is possible to provide a gapped core reactor that prevents the generation of unreasonable compressive stress in the central portion of the yoke core and achieves low noise.

[Brief explanation of drawings]

[Fig. 1] A front view showing an embodiment of the gapped iron-core reactor of the present invention.

[Figure 2] Cross-sectional view of the block core of the gapped core reactor in Figure 1

[Figure 3] Plan view of the yoke core portion of the gapped core reactor in Figure 1.

[Figure 4] A plan view showing the state of magnetic flux within the yoke core in a conventional gapped core reactor.

[Explanation of symbols]

1... Core leg with gap 1a...Block core 1b...Outer diameter side of block iron core 1c, 1d...inner diameter side of block iron core 2...Gap 3... Winding wire 4, 5...Yoke iron core 8...Moving magnetic flux

Claims (1)

[Claims] Claim 1: A plurality of block cores each having a circular cross section are constructed by laminating punched silicon steel plates in a radial manner, and gapped core legs are constructed by stacking the block cores through magnetic gaps. In a gapped core type reactor in which a winding is wound around a gapped core leg, and the gapped core leg with a circular cross section and a yoke core with a rectangular cross section are integrally combined, the outer diameter side of the block core is An iron-core reactor with a gap characterized by being constructed from a punched silicon steel plate that has a relatively high magnetic permeability on the inner diameter side.