JP3357705B2 - Iron core type reactor with gap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gapped iron core type reactor in which noise is reduced by improving the arrangement of a magnetic gap or the configuration of a yoke core in a gapped iron core leg.

[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 iron core reactor with a gap is provided with an iron core leg with a circular cross section, and is configured as shown in FIG. That is, as shown in FIG. 3, the core 1 with a gap is composed of a plurality of block cores 2 having a circular cross section.
Are coaxially stacked such that a plurality of magnetic gaps 3 are formed by sandwiching a magnetic gap material made of an insulator therebetween. in this case,
The block core 2 is configured by laminating annularly in a form of radially arranging blanked silicon steel plates. A winding 4 is wound around the iron core leg 1 with a gap.
Further, upper and lower yoke cores 5 and 6 having a rectangular cross section are arranged above and below the iron core with gap 1 so as to sandwich the core. The yoke cores 5 and 6 are formed by laminating punched silicon steel sheets, similarly to the block core 2, and are integrally formed with the iron core legs 1 with the gap by the upper and lower clamping plates 7 and the clamping studs 8. Fixed.

[0003] In the iron core reactor with the gap configured as described above, reduction of noise generated from the reactor body is an important issue. Such noise can be roughly classified into noise due to mechanical vibration and noise due to magnetostriction according to the factors. Among them, the noise due to the mechanical vibration is generated by the magnetic flux passing through the magnetic gap 3 and the magnetic attractive force acts between the block cores 2 above and below the magnetic gap 3, and the vibration generated due to the vibration due to the magnetic attractive force It is noise. In order to prevent such vibration noise, the block core 2 of the iron core with gap 1 is tightened via the magnetic gap 3, and the iron core with gap 1 and the yoke iron cores 5 and 6 above and below are tightened. It is necessary to have a tightening structure for integrally and firmly tightening.

On the other hand, noise due to magnetostriction is magnetostriction noise generated due to the flow of magnetic flux inside the iron core, and magnetostriction noise further enhanced as a result of an excessive compression force acting on a punched plate in the iron core. Among such magnetostrictive noises, in the iron core reactor with the gap, the effect of the magnetostrictive noise caused by the compressive force is particularly large. In order to suppress such magnetostrictive noise, to appropriately set the magnetic flux density, and
It is conceivable to adopt an iron core structure that does not apply excessive compressive force to the punched plate in the iron core at the time of iron core tightening and during operation.

Considering the iron core structure of the conventional iron core reactor with a gap, as shown in FIG. 3, the magnetic gap 3 is disposed inside the winding 4 and the leakage flux to the winding 4 is reduced. The core structure to suppress is common. Next, the magnetic flux density B in each block core 2 will be described with reference to FIG. In the figure, R indicates the position of the block core 2 in the stacking direction. As shown in FIG. 4, the block core 2 located outside the upper and lower ends of the winding 4 is more likely to concentrate magnetic flux than the block core 2 inside the winding 4, so that the generated loss is large and the The temperature can be quite high.

FIG. 5 shows another example of a conventional cored reactor with a gap. As shown in FIG. 5, the upper and lower yoke cores 5 and 6 are generally divided into a plurality of parts via a lap joint 9 in order to improve the tightness of tightening with the core leg 1 with a gap, which is the main leg. The yoke cores 5a, 5b, 6a, and 6b are respectively divided. In this case, the main magnetic flux 11 flows from the gapped iron core leg 1, which is the main leg, into the upper and lower split yoke iron cores 5a, 6a.
Since 2 is orthogonal to the main magnetic flux 11, the generated loss is large, and the temperature locally rises considerably.

That is, in the conventional iron core structure of the iron core type reactor with a gap, as described above, the upper and lower ends of the winding 4 are determined by the concentration of the magnetic flux or the relationship between the magnetic flux and the directionality of the core punching plate. The loss generated in the magnetic flux inflow portions of the block core 2 and the yoke cores 5 and 6 outside the portion becomes large, and the temperature locally becomes considerably high. This is a major feature of the cored reactor with a gap.

[0008]

However, in the above-mentioned conventional iron core reactor with a gap,
Local temperature increases can significantly increase magnetostrictive noise. That is, due to local temperature rise in the block core 2 outside the upper and lower ends of the winding 4 or the magnetic flux inflow portion of the yoke core 4, excessive thermal stress is generated in these cores, and magnetostrictive noise is generated. May increase significantly. This tendency is observed when the insulation distance between the upper and lower ends of the winding is increased for high voltage reactors for domestic use of 500 kV or more.
Most noticeable. Further, in order to prevent the generation of thermal stress in the magnetic flux inflow portion of the yoke core 4, for example, it is conceivable that the tightening pressure in the laminating direction of the yoke core 4 is relaxed so that the yoke core 4 is easily extended. This method
It is difficult to control the tightening pressure and is not practical.

The present invention has been proposed to solve the problems of the prior art as described above.
An object of the present invention is to provide a gapped iron core reactor capable of suppressing generation of magnetostrictive noise and preventing noise by preventing generation of excessive thermal stress in a block core and a yoke core during operation.

[0010]

In order to achieve the above-mentioned object, a gapped iron core reactor according to the present invention comprises a plurality of silicon steel plates which are radially arranged in a ring shape to form a plurality of circular sections. A block core is formed, the block cores are stacked via a magnetic gap to form a gapped core leg, and a winding is wound around the gapped core leg. A cored reactor with a gap, which is integrally fixed to a yoke core having a cross section, has the following features. First, the iron core reactor with a gap according to claim 1, wherein at least three magnetic gaps each having a size of 30 mm or less are arranged at outer portions of both ends of the winding in the iron core with a gap. Features. In addition, the gapped iron core type reactor according to claim 2 is configured such that the directionality of the silicon steel plate in a portion of the yoke iron core opposite to both ends of the gapped iron core leg is determined by a magnetic flux direction of the gapped iron core leg. It is characterized by the same direction.

[0011]

The operation of the cored reactor with a gap according to the present invention having the above-described structure is as follows. That is,
First, in the configuration of claim 1, three or more magnetic gaps each having a size of 30 mm or less are arranged on the outer portions of both ends of the winding in the iron core leg with a gap. The concentration of magnetic flux on the block core at the end in the stacking direction can be reduced. Accordingly, it is possible to reduce the generation loss due to the concentration of the magnetic flux and the temperature rise due to the loss, and as a result, it is possible to suppress the generation of excessive thermal stress, so that the generation of magnetostrictive noise can be suppressed. The reason why the magnetic gap dimension is limited to 30 mm or less is that if the dimension is exceeded, the leakage of the main magnetic flux of the iron core leg becomes too large, and the windings and the structural material may be overheated.

In the second aspect of the present invention, the direction of the silicon steel plate in the portion of the yoke core opposite to both ends of the gapped iron leg is the same as the magnetic flux direction of the gapped iron leg serving as the main leg. Since the direction is set as the direction, when magnetic flux flows from this iron core leg with a gap into this part in the yoke iron core, the loss generated in this part and the temperature rise due to this can be reduced. As a result, generation of excessive thermal stress can be suppressed, and generation of magnetostrictive noise can be suppressed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Two embodiments in which the present invention is applied to a single-phase three-legged cored reactor with a gap will be specifically described below with reference to FIGS. Here, FIG. 1 is a front view showing a first embodiment of a cored reactor with a gap according to the present invention, and FIG. 2 is a front view showing a second embodiment of a cored reactor with a gap according to the present invention.

(1) First Embodiment FIG. 1 As shown in FIG. 1, a core leg 1 with a gap according to the first embodiment.
Has a plurality of block cores 2 having a circular cross section,
A plurality of magnetic gaps 3 are formed by sandwiching a magnetic gap material made of an insulator, and are stacked coaxially. In this case, block core 2
Is formed by radially arranging punched silicon steel plates in a ring shape. In addition, iron core with gap 1
, A winding 4 is wound. Further, upper and lower yoke cores 5 and 6 having a rectangular cross section are arranged above and below the iron core with gap 1 so as to sandwich the core. The yoke cores 5 and 6 are formed by laminating punched silicon steel sheets, similarly to the block core 2, and are integrally formed with the iron core legs 1 with the gap by the upper and lower clamping plates 7 and the clamping studs 8. Fixed.

In this embodiment, three or more magnetic gaps 3a each having a size of 30 mm or less (three in the figure) are provided outside the upper and lower ends of the windings 4 in the iron core legs 1 with gaps. ) Is located. On the other hand, inside the winding 4, a magnetic gap 3b having a size larger than 30 mm is arranged.

In this embodiment having the above configuration, the following operation and effect can be obtained. That is, three or more magnetic gaps 3a each having a size of 30 mm or less are arranged outside the upper and lower ends of the winding 4 in the iron core leg 1 with a gap, so that a block core adjacent to the magnetic gap 3a is provided. 2, that is, the magnetic flux density of the block core 2 located outside the upper and lower ends of the winding 4 can be appropriately reduced. Therefore, the loss caused by the concentration of the magnetic flux and the temperature rise due to the loss can be reduced, so that the occurrence of excessive thermal stress can be suppressed. As a result, generation of magnetostrictive noise due to excessive thermal stress can be suppressed, and the noise of the reactor can be reduced.

(2) Second Embodiment--FIG. 2 As shown in FIG. 2, in the second embodiment, the upper and lower yoke cores 5, 6 are main legs similarly to the conventional example shown in FIG. In order to improve the tightness of the fastening with the iron core leg 1 with a gap, it is divided into a plurality of divided yoke iron cores 5a, 5b, 6a, 6b via a lap joint 9.
Among these, the directionality 12 of the punched silicon steel plate constituting the divided yoke iron cores 5a and 6a at the portions opposed to the upper and lower end portions of the iron core leg 1 with a gap is the main iron leg 1 with a gap.
In the same direction as the direction of the main magnetic flux 11. In addition, the directionality 12 of the punched silicon steel plate forming the remaining portion of the divided yoke iron cores 5b and 6b is set to be orthogonal to the main magnetic flux 11 as in the related art. Further, the magnetic gap 3 of the iron core leg 1 with a gap of this embodiment is not arranged characteristically as in the first embodiment, but is arranged similarly to the conventional example as shown in FIG. The parts other than the yoke cores 5 and 6 and the iron core leg 1 with a gap are configured basically in the same manner as in the first embodiment.

In this embodiment having the above configuration, the following operation and effect can be obtained. That is, of the yoke iron cores 5 and 6, the directionality 12 of the silicon steel punched plate constituting the divided yoke iron cores 5 a and 6 a of the portions facing the upper and lower ends of the gapped iron core leg 1 is determined by the gaps which are the main legs Since the direction is the same as the direction of the main magnetic flux 11 of the iron core 1 with a gap, the split yoke irons 5a, 5a,
When a magnetic flux flows into the core 6a, the split yoke core 5
It is possible to reduce the generation loss in the portions a and 6a and the temperature rise due to the loss. As a result, the occurrence of excessive thermal stress can be suppressed, so that the occurrence of magnetostrictive noise can be suppressed, and the noise of the reactor can be reduced.

(3) Other Embodiments The present invention is not limited to the above embodiments, but can be applied to other than the above-described single-phase three-legged cored reactor with a gap. For example, the present invention can be similarly applied to a three-phase three-leg iron core type or a three-phase five-leg iron core reactor with a gap. Further, it is also possible to adopt a configuration in which the two embodiments are combined. That is, in the outer part of the upper and lower ends of the winding 4 in the iron core leg 1 with a gap,
The direction of the blanking plate of silicon steel plate which arranges three or more magnetic gaps 3a each having a size of 30 mm or less and constitutes the divided yoke iron cores 5a and 6a at the portions opposed to the upper and lower ends of the iron core leg 1 with the gap. It is also possible to configure so that the property 12 is in the same direction as the direction of the main magnetic flux 11 of the iron core leg 1 with a gap. In this case, the effect obtained by combining the effects of the two embodiments can be obtained. Can be Furthermore, since the present invention has a feature particularly regarding the arrangement of the magnetic gaps in the gapped iron core legs and the directionality of the silicon steel plate constituting the yoke iron core, the specific configuration of the other parts is appropriately selected. It is possible.

[0020]

As described above, according to the present invention,
In the outer part of both ends of the winding in the core with a gap,
Three or more magnetic gaps each having a dimension of 30 mm or less are arranged, or the directionality of the silicon steel plate in the portion opposed to both ends of the gapped iron core is set to be the same direction as the magnetic flux direction of the gapped iron core. By improving the simple configuration, it is possible to prevent the occurrence of excessive thermal stress in the block core and the yoke core during operation, and to suppress the generation of magnetostrictive noise and provide a cored reactor with a gap that can reduce noise. can do.

[Brief description of the drawings]

FIG. 1 is a front view showing a first embodiment of a cored reactor with a gap according to the present invention.

FIG. 2 is a front view showing a second embodiment of a cored reactor with a gap according to the present invention.

FIG. 3 is a front view showing an example of a conventional iron core reactor with a gap.

FIG. 4 is a magnetic flux density distribution diagram showing a magnetic flux density of each block iron core in the iron core reactor with a gap in FIG. 3;

FIG. 5 is a front view showing another example of a conventional cored reactor with a gap.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Iron leg with gap 2 ... Block iron core 3, 3a, 3b ... Magnetic gap 4 ... Winding 5, 6 ... Yoke iron core 5a, 5b, 6a, 6b ... Split yoke iron core 7 ... Tightening plate 8 ... Tightening stud 9 ... Wrap Joint 11: Main magnetic flux 12: Directionality of punched silicon steel plate

Claims (2)

(57) [Claims] 1. A plurality of block cores having a circular cross section are formed by annularly stacking silicon steel plates in a radially arranged form, and the block cores are stacked via a magnetic gap to form a core leg with a gap. In a cored reactor with a gap formed by winding a winding around the cored leg with a gap and integrally fixing the cored leg with a circular cross section and the yoke core with a rectangular cross section, A gap-type iron core reactor in which three or more magnetic gaps each having a size of 30 mm or less are arranged on outer portions of both ends of the winding in the iron core leg. 2. A plurality of block cores having a circular cross section are formed by annularly stacking silicon steel plates in a radially arranged form, and the block cores are stacked via a magnetic gap to form a core leg with a gap. In a cored reactor with a gap formed by winding a winding around the cored leg with a gap and integrally fixing the cored leg with a circular cross section and a yoke core with a rectangular cross section, the yoke core Wherein the directionality of the silicon steel plate at the portions facing both ends of the iron core with gap is the same as the direction of the magnetic flux of the iron core with gap.