JPS63233511A - Iron-core reactor with cap - Google Patents

Abstract

PURPOSE:To prevent generation of the compression stress in the central part of a yoke iron core for lowering a noise by forming both end parts in the direction of lamination of the yoke iron cores of a silicon steel band having a large generation loss and the rest central part of a silicon steel band having only a small generation loss in the direction of lamination. CONSTITUTION:Both end parts 4a in the lamination direction of the upper and lower yoke iron cores 4 and 5 are formed of a silicon steel band having relatively many generation losses and the central part 4b in the other lamination direction is formed of the silicon steel band having relatively less generation losses. At the time of operation, a temperature rise due to the generation loss of both end parts in the lamination direction and the central part of the yoke iron core 4 is almost levelled by negating the part due to inequality of a magnetic flux portion through the choice of a kind of the silicon steel band. A batten of each section part of the yoke iron core 4 is evenly extended to prevent generation of excessive compression stress due to a difference of thermal expansion. Thereby, noise can be lowered.

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention relates to a gapped iron core reactor.
Especially regarding improvements to the yoke core.

(Prior Art) As a reactor used for a shunt reactor or the like, an iron core reactor with a gap is generally used. This gapped core reactor is made by sandwiching an insulating gap member between multiple block cores formed by stacking silicon steel strips, stacking them together via multiple magnetic gaps to form a gap with a circular cross section. A yoke core with a rectangular cross section formed by forming one layer of another insulator band is arranged above and below the core leg with a bridge, and a winding is arranged on the core leg with a gap. be done.

By the way, in the gapped iron core reactor configured in this way, one major problem is the reduction of noise generated from the reactor body. Noise causes can be broadly classified into those caused by mechanical vibration and those caused by magnetostriction. This is caused by mechanical vibration, which is caused by the magnetic flux passing through the gap that causes a magnetic attraction force to act between the block iron cores above and below the gap! This is a phenomenon in which noise is generated due to 1 livJ. Therefore, there is a need for a structure in which the yoke core and block core are firmly tightened together through a gap. On the other hand, magnetostrictive noise consists of magnetic flux noise caused by magnetic flux flowing within the core, and magnetostrictive noise that increases further as a result of applying unreasonable compressive stress to the punched core inside the core.The latter effect is particularly important. big. 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 excessive compressive stress even if the iron core is pulled out when the iron core is tightened or during operation. Here, looking at the magnetic flux density in the yoke core, as shown in FIG.
Since magnetic flux flows through the yoke core, the central portion 4b in the yoke core lamination direction has a high magnetic flux density, and both end portions 4a have a low magnetic flux density.

Therefore, one of the major features of the gapped iron core reactor is that a temperature difference occurs between the center portion 4b and both ends 4a due to the generated loss, and a difference in thermal expansion occurs.

(Problems to be Solved and Attempted by the Invention) In the gapped core type reactor, due to the non-uniform magnetic flux distribution of the yoke core as described above, the central portion 4b of the yoke core 4 tends to extend in the root extraction direction, but the yoke core Both end portions 4a of the yoke core 4 act in a direction to prevent this, and as a result, the punched portion of the central portion 4b of the yoke core 4 is compressed, often resulting in an increase in magnetostrictive noise. As a means to prevent this, the clamping pressure in the stacking direction of the yoke core is relaxed and the yoke core central portion 4b is
There is a way to make it easier to extend, but it is difficult to manage the tightening force and is not practical.

In view of the above points, it is an object of the present invention to provide a gapped core reactor that prevents the generation of unreasonable compressive stress in the center of a yoke core during operation and reduces noise.

[Structure 1 of the Invention (Means for Solving the Problems) The present invention provides a gapped iron core formed by combining a gapped core leg with a circular cross section and a yoke core with a rectangular cross section formed by a single layer of silicon steel strip. In an iron core reactor, both ends of the yoke core in the stacking direction are made of silicon steel strips that have a relatively high loss, and the rest of the center part in the stacking direction is made of silicon steel strips that have a relatively low loss. It is characterized by being composed of.

(Function) As a result, the temperature rise due to loss generated at both ends and the center in the stacking direction of the yoke core due to uneven magnetic flux distribution is canceled out by using different types of silicon steel strips, making the temperature almost uniform. Prevents compressive force due to shape W & difference.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figure 1 shows single phase 311! This figure shows the case of the 11 iron core, in which several block iron cores 1a each made of 4 layers of silicon steel strips are stacked with a magnetic gap 2 made of an insulating gap member interposed therebetween to form a circular cross-section. A core leg 1 with a gap is constructed, and a winding 4!3 is formed on this core leg 1 with a gap.
is wrapped. Upper and lower yoke cores 4.5 each having a rectangular cross section made of laminated silicon steel strips are arranged above and below this gapped core leg 1, and upper and lower clamping plates 6 The gapped core leg 1 and the upper and lower yoke cores 4 and 5 are integrally tightened by the tightening stud 7 via the gap. Therefore, in the present invention, as shown in FIG.
Upper and lower yoke cores 4 and 5 (upper yoke core 4 in the figure)
Both end portions 4a in the lamination direction of the lamination direction (only shown) are composed of silicon steel bands with a relatively large loss generated, and the other central portion 4b in the lamination direction is made of a silicon steel band with a relatively low loss generated. It consists of For example, both ends 4a of the yoke core are made of non-oriented silicon steel strips, and the rest of the yoke core center section 4b is made of non-oriented silicon steel strips, which produce less loss than the non-oriented silicon steel strips. Constructed of silicon steel strip.

Alternatively, both end portions 4a of the yoke core are made of a non-oriented silicon steel strip or a grain-oriented silicon steel strip made of ordinary material, and the other yoke core center portion 4b is constructed with relatively less loss than the silicon steel strip. Consists of a small number of highly oriented silicon steel strips.

With this configuration, during operation, the thermal loss caused by the loss generated between both ends and the center of the yoke core 4 in the stacking direction is canceled out by the non-uniform magnetic flux distribution by using different types of silicon steel strips. As shown by the arrows in FIG. 2, the punched parts of the cross-section of the iron core 4 extend evenly, thereby preventing the generation of unreasonable compressive stress due to differences in thermal expansion.

In the above embodiment, the case of an 11-phase 3rIA core has been described, but the present invention can be similarly applied to other 3-phase, 3-legged cores (including those with wound core yokes) and 3-phase, 5-legged cores. Further, the present invention can also be applied to the side legs.

[Effects of the Invention] As described above, the present invention provides an iron core leg with a gap having a circular cross section,
In a gapped core reactor that combines a yoke core with a rectangular cross section formed by laminating silicon steel strips, both ends in the stacking direction of the yoke core are grooved with silicon steel strips that generate relatively large losses. , the rest of the central part in the stacking direction is made of silicon steel strip, which generates less loss than the other silicon steel strips, which prevents the occurrence of unreasonable compressive stress in the central part of the yoke core during operation. It is possible to use a gapped iron-core reactor that further reduces noise.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a plan view showing a part of a yoke core of a conventional gapped core reactor. 1... Core leg with gap, 1a... Block core,
2... Gisep, 3... Winding, 41, 5... Yoke core, 4a... Both ends of the yoke core, 4b... Center portion of the yoke core. Applicant's agent Patent attorney Takehiko Suzue Figure 1 a Figure 2 Figure 3

Claims (4)

[Claims] (1) In a gapped core type reactor that combines a gapped core leg with a circular cross section and a yoke core with a rectangular cross section formed by laminating silicon steel strips, both ends of the yoke core in the stacking direction are An iron-core reactor with a gap, characterized in that it is made of a silicon steel strip that generates a lot of loss, and the rest of the central part in the stacking direction is made of a silicon steel strip that generates a relatively small loss. (2) Claim 1, characterized in that both ends in the lamination direction of the yoke core are made of non-oriented silicon steel strips, and the other central portion in the lamination direction is made of grain-oriented silicon steel strips. Iron core reactor with gap. (3) Both ends of the yoke core in the lamination direction are made of non-oriented silicon steel strips or grain-oriented silicon steel strips, and the other central part in the lamination direction is made of highly oriented silicon steel strips. An iron core reactor with a gap. (4) The end of the yoke core, which is made of silicon steel strip with relatively high loss, is set to 1/1/2 of the outer diameter of the core leg with a gap.
An iron-core reactor with a gap according to any one of claims 1 to 3, characterized in that the reactor has a dimension of 4 or less.