JPH0582360A - Gapped iron core-type reactor - Google Patents

Abstract

PURPOSE:To realize the low noise of gapped iron core-type reactor by a method wherein the generation of an unreasonable compressive stress exerted on the central part of a yoke iron core is prevented and a magnetostrictive noise is reduced. CONSTITUTION:At least one oil passage 8 is installed within the range of 50 to 75% of a lamination thickness up to both ends 4a of a yoke by using the lamination-thickness center in the lamination direction of a yoke iron core 4 as a reference. The movement of a magnetic flux caused by a difference in a permeability is restrained. The generation of a compressive stress in the yoke iron core 4 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cored reactor with a gap, and more particularly to improvement of a yoke core.

[0002]

2. Description of the Related Art As a reactor used for a shunt reactor or the like, a cored reactor with a gap is generally used. This core-reactor with a gap has a circular cross-section that is formed by stacking a plurality of magnetic gaps between a plurality of block cores formed by stacking silicon steel strips to stack them through a plurality of magnetic gaps. An iron core with a core is formed, and a yoke iron core having a rectangular cross section, which is also formed by laminating silicon steel strips, is arranged below the core, and a winding is wound around the core with a gap.

By the way, in the iron core type reactor with a gap constructed as described above, one of the major problems is reduction of noise generated from the reactor body. The factors of noise can be roughly classified into those caused by mechanical vibration and those caused by magnetostriction. What is due to mechanical vibration?
This is a phenomenon in which a magnetic attraction force acts between the block cores above and below the gap by the magnetic flux passing through the gap, and noise is generated due to the vibration caused by the magnetic attraction force. Therefore, it is necessary to have a structure in which the yoke core and the block core are integrally and firmly tightened via the gap. On the other hand, due to magnetostriction, it consists of magnetostrictive noise generated due to the flow of magnetic flux in the iron core, and magnetostrictive noise that further increases as a result of applying an unreasonable compressive stress to the iron core blank at that time, and the latter effect in particular is large. For this purpose, it is conceivable to appropriately set the magnetic flux density and to adopt an iron core structure that does not apply unreasonable compressive stress to the iron core inner blank during tightening and during operation. here,
Looking at the magnetic flux density in the yoke core, as shown in FIG.
Since magnetic flux flows from the iron core leg 1 having a circular cross section with a gap to the yoke core 4 having a rectangular cross section, the central portion 4b in the stacking direction of the yoke cores 4b.
Has a high magnetic flux density, and both ends 4a also have a low magnetic flux density. Therefore, as a result of the difference in the magnetic permeability of the silicon steel strip between the central portion 4b and the both end portions 4a, the magnetic flux in the central portion largely moves to both end portions is one of the major features of the cored reactor with a gap. is there.

[0004]

In the iron core type reactor with a gap, as described above, since the magnetic flux distribution of the yoke iron core is non-uniform, the loss of the generated magnetic flux in the central portion of the yoke increases due to the movement of the magnetic flux, which causes a temperature difference. Central part 4b of the yoke core 4
Tries to extend in the direction of the blanking, but both ends 4 of the yoke core 4
Often, a acts in the direction of blocking it, and eventually, the blank of the central portion 4b of the yoke core 4 is compressed and the magnetostrictive noise increases. As a means for preventing this, there is a means for relaxing the tightening pressure of the yoke core in the stacking direction so that the yoke core central portion 4b can easily extend, but it is difficult to control the tightening force and is not practical.

In view of the above points, an object of the present invention is to provide an iron core reactor with a gap, which prevents generation of an unreasonable compressive stress in the central portion of the yoke iron core during operation, and which has reduced noise. To do.

[0006]

According to the present invention, there is provided a core iron reactor with a gap, which comprises a core iron leg with a gap having a circular cross section and a yoke iron core having a rectangular cross section formed by laminating silicon steel strips. 50 to 75% of the laminated thickness up to both ends of the yoke, based on the laminated thickness center in the laminated direction
In this range, at least one oil passage is provided.

[0007]

With this, the movement of the magnetic flux due to the difference in magnetic permeability resulting from the non-uniform distribution of the magnetic flux between the both ends and the center of the yoke core in the stacking direction is suppressed by providing an oil passage at an appropriate position. However, the generation of compressive force in the yoke is prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a case of a single-phase three-leg iron core, in which a plurality of block iron cores 1a formed by laminating silicon steel strips are connected via a magnetic gap 2 made of an insulating gap member. Are stacked to form an iron core leg 1 with a circular cross section, and a winding 3 is wound around the iron core leg 1 with a gap. Above and below this iron core leg 1 with a gap, upper and lower yoke cores 4 and 5 are arranged with a rectangular cross section in which silicon steel strips are laminated so as to sandwich it, and upper and lower tightening plates 6 The iron core leg with a gap 1 by the tightening stud 7 through
The upper and lower yoke cores 4 and 5 are integrally tightened.
In the present invention, as shown in FIG. 2, the upper and lower yoke cores 4 and 5 (only the upper yoke core 4 is shown in the figure) are stacked up to both ends of the yoke with reference to the center of the stacking thickness in the stacking direction. At least one oil passage is provided in the range of 50 to 75% of the laminated thickness of.

With such a configuration, during operation, the movement of the magnetic flux from the laminated central portion of the yoke core 4 to both ends thereof is suppressed, the generated loss is reduced, and the yoke core 4 as shown by the arrow in FIG. The difference in the thermal expansion of the blanks at the respective cross-sections is reduced to prevent the generation of unreasonable compressive stress.

In the above embodiment, the case of the single-phase three-leg iron core has been described, but the present invention similarly applies to other three-phase three-leg iron cores (including winding core yokes) and three-phase five-leg iron cores. Applicable. Further, the present invention can be applied to the side leg portion even for the side leg portion.

[0012]

As described above, according to the present invention, there is provided a core iron reactor with a gap formed by combining a core iron leg with a gap having a circular cross section and a yoke iron core with a rectangular cross section formed by laminating silicon steel strips. An oil passage is provided in the stacking direction to suppress the movement of the magnetic flux from the stacking center of the yoke core to both ends, reducing the generated loss and generating unreasonable compressive stress in the center of the yoke core during operation. It is possible to obtain a cored reactor with a gap that further prevents noise and further reduces noise.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

FIG. 3 is a plan view showing a part of a yoke iron core of a conventional core iron reactor with a gap.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Iron core with a gap, 1a ... Block iron core, 2 ... Gap, 3 ... Winding, 4, 5 ... Yoke iron core, 4a ... Both ends of the yoke iron core, 4b ... Central part of the yoke iron core, 8 ... Oil passage, 9
… Moving magnetic flux.

Claims (1)

[Claims] 1. An iron core type reactor with a gap formed by combining an iron core leg with a gap having a circular cross section and a yoke iron core with a rectangular cross section formed by laminating silicon steel strips, wherein a laminated thickness center is formed in a laminated direction of the yoke iron core. A cored reactor with a gap, characterized in that at least one oil passage is formed in a range of 50 to 75% of a laminated thickness up to both ends of the yoke.