JPH0779053B2 - Iron core type reactor with gap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a cored reactor with a gap,
In particular, it relates to improvement of the iron core structure for making the magnetic flux density distribution uniform.

(Prior Art) As a reactor used for a shunt reactor or the like, a cored reactor with a gap has been generally used. This core core reactor with a gap is made by sandwiching a grain-formed silicon steel sheet with a gap member having an insulating property between a plurality of block cores each having a circular cross section and formed by radially stacking the directionally aligned with the main magnetic flux. By stacking the block cores through a plurality of magnetic gaps to form a core leg with a gap, and arranging a yoke core having a rectangular cross section formed by laminating silicon steel plates on the bottom of the core core. It is constructed by winding a winding around the attached iron core leg.

(Problems to be Solved by the Invention) By the way, in the cored reactor with a gap configured 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. The mechanical vibration is a phenomenon in which a magnetic attraction force acts between the block cores above and below the gap due to the magnetic flux passing through the gap, which causes noise due to vibration. Therefore, it is necessary to have a structure in which the yoke core and the block core are firmly and integrally fastened 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 unreasonable compressive stress to the iron core internal 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 the iron core structure so that excessive compressive stress is not applied to the iron core inner blank during operation and iron core tightening magnetism. Considering the magnetic flux density distribution in the yoke core, the magnetic flux flows from the core core with a gap with a circular cross section to the yoke core with a rectangular cross section. Has a low magnetic flux density. Therefore, a temperature difference occurs due to the loss generated in the yoke core itself, a difference in thermal expansion occurs between the central portion and both ends of the cross section of the yoke core, and the magnetostriction due to the internal compressive stress increases, which may increase noise during operation. There is.

In view of the above points, an object of the present invention is to provide a cored reactor with a gap in which the magnetic flux density distribution of the yoke core is made uniform and the generation of internal compressive stress is suppressed to further reduce noise. .

[Structure of the Invention] (Means for Solving Problems) The cored reactor with a gap of the present invention has a directionality of a silicon steel sheet blank of a block core located at the upper and lower ends of the core leg with a gap in contact with the yoke core. Is perpendicular to the direction of flow of the main magnetic flux, and the main magnetic flux is moved radially in the block iron core so that it enters the yoke iron core, thereby making the magnetic flux density distribution of the yoke iron core uniform and generating internal compressive stress. Is suppressed and noise due to magnetostriction is reduced.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings for a case of a single-phase three-leg iron core with a gap-shaped core type reactor. In FIG. 1, a plurality of block iron cores 1a each having a circular cross section formed by stacking punched silicon steel plates are stacked via a magnetic gap 2 made of a gap member having an insulating property to form a core leg 1 with a gap. The winding core 3 is wound around the core leg 1 with a gap. The upper and lower yoke cores 1 and 4 are arranged above and below the gap core core leg 1 so as to sandwich the silicon steel plates, and the lower and upper yoke cores 4 and 5 are arranged. Tightening studs 7 through the plate 6,
The upper and lower yoke cores 4, 5 and the gapped core leg 1 are integrally tightened by a tightening nut 8. Reference numeral 9 is a side leg.

Further, in the present invention, the directionality 10a of the blank of the block core 1a located at the upper and lower ends of the core legs with gaps 1 in contact with the upper and lower yoke cores 4 and 5 is made perpendicular to the direction in which the main magnetic flux 11 flows. The block iron core 1b has a directionality 10b that is the same as the direction in which the main magnetic flux 11 flows. As a result, the main magnetic flux moves radially inside the block cores 1a and then enters the yoke cores 4,5 as shown by the arrows in FIG. 2, and at the cross-sectional center and both ends of the yoke cores 4,5. Has a uniform magnetic flux density distribution and can suppress generation of magnetostriction to a low level.

[Effects of the Invention] As described above, according to the present invention, the directionality of the block core punching plates located at the upper and lower ends of the iron core legs with gaps in contact with the yoke core is set to be perpendicular to the direction in which the main magnetic flux flows. It is possible to obtain a cored reactor with a gap in which the magnetic flux density distribution is made uniform, the generation of internal compressive stress is suppressed, and the noise is further reduced.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention, and FIG. 2 is a plan view of the same. 1 …… Gap iron core leg, 1a …… Block iron core, 2 ……
Gap, 3 ... Winding, 4,5 ... Yoke iron core, 6 ... Tightening plate, 7 ... Stud, 8 ... Tightening nut, 9 ... Side leg.

Claims (1)

[Claims] 1. A core iron leg with a gap is formed by stacking a plurality of block iron cores having a circular cross section, which are formed by laminating blanks of grain-oriented silicon steel plates in a radial pattern, through magnetic gaps, and with this gap. A winding iron is wound around the core leg, and a yoke core with a rectangular cross section is formed by stacking silicon steel sheets on the top and bottom of the core leg with a gap. The yoke core and the core with a gap are tightened by tightening studs. In a cored reactor with a gap in which the legs are clamped together, the direction of the blanks of the block cores located at the upper and lower ends of the cored legs with gaps in contact with the yoke core is made perpendicular to the direction of the main magnetic flux. Iron core type reactor with a gap.