JPS5919457B2 - reactor core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a core structure of a reactor, and more particularly to the studs of a yoke core which are fastened and fixed through stud insertion holes opened in the center of the yoke by stud bolts passing through core leg center holes. This is designed to alleviate the concentrated magnetic flux near the insertion hole to prevent local overheating.

In recent years, ground-to-ground charging capacity has increased due to the expansion of long-distance ultra-high voltage power transmission networks and the installation of high-voltage cables within cities, and shunt reactors are generally used to adjust the rise in grid voltage due to phase advance capacity during light loads. ing.

Among these, in the case of a core-containing reactor, a plurality of core blocks are stacked to form each phase core leg, and yokes are placed above and below the legs to form a magnetic circuit. At this time, in order to reduce the effect of fringe fern on the magnetic flux due to the gap, the core block has an annular structure in which silicon steel plates are arranged radially and a center hole is provided in the center for passing the stud bolt for tightening the core legs. A structure is used in which a non-magnetic stud bolt is passed through the center hole of each phase core leg in which these are stacked, and is fastened integrally with the yoke. Therefore, as shown in Fig. 1, in the center of the yoke, a segmented yoke 4 made of short silicon steel plates laminated with the required dimensions according to the thickness of the stud bolt is sandwiched and arranged. A rectangular stud insertion hole 3 is formed with iron 4 in correspondence with the center hole of each phase core leg 1, and a stud bolt is passed through the stud insertion hole 3 to tighten and secure each phase core leg 1 to the yoke 2. configured. At this time, the segmental yoke 4 arranged in the center of the yoke 2 is separated by the stud insertion hole 3, and each phase iron leg 1
The segmental yoke 4 placed between the adjacent mutual iron core legs 1
A closed magnetic path is formed between the two, and in the case of a relatively small-capacity type with a small number of magnetic fluxes, the magnetic flux flowing into this segmental yoke 4 from one core leg 1 flows to the other adjacent core leg 1. The segmental yoke 4 disposed at both ends does not form a closed magnetic path, and the magnetic flux flowing from the core leg 1 at the end is adjacent to the stud insertion hole 3 opened corresponding to the center hole of the core leg 1. The magnetic flux flows into the laminated steel plate of the yoke, and the passing magnetic flux flows in a concentrated manner near the stud insertion hole 3, resulting in locally high iron loss and local overheating.

Therefore, in a reactor with a relatively small capacity, in order to prevent partial overheating due to this concentrated magnetic flux, a segmented yoke 4 at both ends of the yoke 2, and joints placed on both sides of the segmented yoke 4 sandwiching the segmented yoke 4 are installed at both ends of the yoke 2. A small iron core is made by laminating strip-shaped steel plates having a length that is approximately equal to the stacking thickness of the yoke 2, and the strip-shaped steel plates are placed upright and in close contact with each other in the stacking thickness direction of the yoke 2. A structure in which the magnetic flux that has flowed into the segmental yoke 4 placed at both ends of the yoke 2 is sucked up by the small iron core, which is integrally protruded, and is made to flow into the laminated steel plate of the yoke 2 via the small iron core. has been proposed. However, as the equipment capacity increases, the number of magnetic fluxes flowing through the iron core also increases, and along with this, the number of magnetic fluxes in the segmental yoke 4 disposed between the core legs also increases, causing the flow of magnetic flux to the adjacent yoke laminated steel plates. It also migrates and causes local overheating.

In addition, the iron loss due to the increase in capacity also increases, and the heat generation amount of the iron core also increases, so as shown in Fig. 2,
An oil guide 6 may be formed between the segmental yoke 4 and the adjacent steel plate of the yoke via a spacer 5, or an oil guide v may be formed at any position during the stacking of the steel plates of the yoke 2 as necessary. A structure is used in which the iron core is cooled. In this case, an air gap having a large magnetic resistance is provided between the segmental yoke 4 and the yoke laminated steel plate, and the magnetic flux transferred from the segmental yoke 4 is concentrated particularly in the vicinity of the stud insertion hole 3 and is locally Iron loss increases significantly, impairing electrical characteristics and causing local overheating, which adversely affects equipment. The present invention eliminates the above-mentioned drawbacks associated with an increase in equipment capacity, reduces iron loss without increasing the amount of iron core, and can be manufactured rationally by preventing local overheating near the stud insertion hole. This is how it was done.

The embodiment will be explained below with reference to FIGS. 3 to 5.
Reference numeral 11 denotes a circle in which a conventionally known annular iron core block 14 is stacked with a predetermined gap 15 made of an insulating material or the like, in which silicon steel plates are arranged radially and a center hole 13 is provided in the center to allow a stud bolt 12 to pass through. A columnar core leg 16 is a yoke placed above and below the core leg 11, and a short silicon steel plate with a predetermined thickness is installed in the center of the yoke according to the thickness of the stud bolt 12 that passes through the core leg 11. The stacked sectional yokes 17 are arranged, and stud insertion holes 18 are opened corresponding to the center holes 13 of each phase core legs 11, so that the stud yokes 17 are in contact with the sectional yokes 17 and oil is introduced through spacers 19 on both sides thereof. 20 are provided, yoke steel plates 21 and 2V are arranged, and they are tightened together with tightening bolts (not shown).
It is inserted into and fixed to each phase core leg 11 with sufficient tightening pressure using nuts 22 and 2γ.

Reference numeral 23 denotes an auxiliary yoke for sucking up magnetic flux, which is made by laminating rectangular silicon steel plates having a length approximately equal to the stacking thickness of the yoke 16 and having an appropriate stacking thickness. At both ends of the steel plate laminated end face of the segmental yoke 17 which is clamped in the center via the oil guide 20 and at the intermediate part of each phase core leg 11 (the intermediate part between the stud insertion holes 18), in the direction of the yoke steel plate lamination. Each section yoke 1 is perpendicular to the longitudinal direction of the yoke 16.
A core structure is formed by standing strip-shaped steel plates upright on the laminated end faces of 7 and yoke steel plates 21 and 2V, and protruding the mutually laminated end faces in close contact with each other across the oil guide 20.

FIG. 4 shows a yoke 16 and an auxiliary yoke 23 which are further provided with oil guides 20 at appropriate locations in the adjacent yoke steel plates 21, 2V via the sectional yoke 17 and an oil guide 20 for cooling. An example of a core structure in which the above-described structures are arranged in the same manner as described above is shown. The present invention has the above-described configuration, and of the magnetic flux flowing into the yoke 16 from each phase core leg 11, the magnetic flux flowing into the segmented yoke 17 clamped at the center of the yoke 16 is as shown in FIG. As shown by the arrows in FIG. The oil flows in the longitudinal direction and flows into the adjacent yoke steel plates 21 and 2V via the oil guide 20.

It should be noted that the sectional yoke 1 can be used without providing any particular oil guide to the yoke 16.
Even in the structure in which the yoke steel plates 21 and 2V are arranged in contact with the yoke steel plates 21 and 2V, the magnetic flux flowing from each phase core leg 11 to the segmental yoke 17 passes through the respective auxiliary yokes 23 to the yoke steel plates 21 and 2V, as described above. 2V. As described above, the present invention is designed to prevent the magnetic flux flowing into the sectional yoke from the core legs from being caused by the laminated steel plates of the yoke, even when oil conductors with high magnetic resistance are provided on both sides of the sectional yoke as equipment capacity increases. The oil is sucked up into the auxiliary yoke installed on the end face at both ends and in the middle of each phase core leg, and flows into the yoke steel plate via the auxiliary yoke. Even if the segmental yoke is isolated, the concentration of magnetic flux transferring from the segmental yoke to the yoke steel plate will not occur, and the passing magnetic flux will concentrate near the stud insertion hole, increasing iron loss or There is no chance of localized overheating causing equipment damage, and even in the center of the yoke where a magnetic path is normally not formed due to the stud insertion holes, the sectional yoke effectively forms a magnetic circuit with the help of the auxiliary yoke, reducing the amount of heat generated by the core. It has remarkable features, such as being able to reduce the amount of heat generated and making the equipment economical.

[Brief explanation of the drawing]

FIG. 1 is a top view showing the core of a conventional reactor, FIG. 2 is a top view of a conventional reactor core provided with an oil guide, FIGS. 3 to 5 show the core of the reactor of the present invention, and FIG. The figure shows a top view of a reactor core with a yoke configuration in which a segmented yoke is sandwiched via an oil guide, Figure 4 shows a top view of a reactor core with an oil guide further provided in the yoke steel plate, and Figure 5 shows FIG. 2 is a longitudinal sectional front view of a main part showing a part of the iron core cut away. 11: Iron core leg, 12: Stud bolt, 16: Yoke, 1
7: Segmented yoke, 18: Stud insertion hole, 20, 2 (y:
Oil guide, 23: Auxiliary yoke.

Claims (1)

[Claims] 1 Core blocks are stacked and each phase core leg is provided with a center hole through which a stud bolt passes through, and a short segmented yoke is arranged in the center of the stacked steel yoke plates to correspond to the center hole of the core leg. Insert stud bolts into the stud insertion holes opened and tighten them to the upper and lower yokes. On the laminated end faces of both ends of the yoke and on the end faces of the yoke steel plate at the intermediate position of each phase core leg, apply the appropriate bolts. An auxiliary yoke made of laminated strip-shaped steel plates with a length that is approximately equal to the stacked thickness of the yoke is orthogonal to the yoke in the steel plate stacking direction of the yoke, and the strip-shaped steel plates are orthogonally crossed so that the mutual stacked end faces A reactor core characterized by a protruding structure that is closely attached to the core.