JP2001035733A - Magnetic shield device for stationary induction electrical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic shield device for a stationary induction electrical apparatus of high reliability by providing a slit only on the surface side of a magnetic body shield, and providing a presser bracket which withstands magnetic attraction, for reduced loss of the magnetic body shield itself and prevented local overheating. SOLUTION: A magnetic body shield 10, where magnetic bodies are laminated, is fitted inside tanks 6 and 7 where an induction electric apparatus main body comprising an iron core 3 and coils 4 and 5 is housed. Here, a slit 11 is provided only on the surface side of the magnetic body shield, with presser brackets 20 and 21 which can withstand fully against magnetic attraction being provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic shielding device for stationary induction devices such as transformers and reactors.

[0002]

2. Description of the Related Art Generally, an eddy current flows into a tank such as a transformer or a reactor due to intrusion of leakage magnetic flux from a winding or a lead wire to cause a loss. Since this loss increases as the capacity increases, a magnetic shielding device is usually provided in the tank to reduce the loss.As this magnetic shielding device, a nonmagnetic material such as copper or aluminum, or a silicon steel plate is laminated. Magnetic shields are used.

However, in a conventional magnetic shield device using a magnetic shield, when leakage magnetic flux from a winding vertically penetrates into the magnetic shield surface, an eddy current flows on the magnetic shield surface, and the eddy current flows. However, there is a drawback that the loss caused by the magnetic shield increases and the magnetic shield itself causes local overheating.

On the other hand, Japanese Patent Application Laid-Open No. 52-299 discloses a structure capable of reducing loss in a magnetic shield and preventing local overheating.
Issue 28 has been proposed. Japanese Patent Application Laid-Open No. 52-29928 has slits at the ends where a large amount of magnetic flux leaks from the windings.However, since the eddy current flowing on the surface of the magnetic shield cannot be divided, loss reduction in the magnetic shield itself and local overheating have occurred. Is not enough to prevent In addition, since the slit is provided at the end of the magnetic shield, there are problems such as a decrease in mechanical strength due to a magnetic attraction force when the magnetic shield is attached to the tank and a difficulty in a fixing method.

[0005]

In the above-mentioned conventional magnetic shielding apparatus for a stationary induction device, a machine using a magnetic attraction force acting on a magnetic shield when a magnetic flux leaking from a winding vertically penetrates into the surface of the magnetic shield. Since the reduction in mechanical strength is not considered, there is a problem to be solved with a fixing method that can sufficiently withstand the magnetic attraction force and a structure that can reduce loss of the magnetic shield itself and prevent local overheating.

SUMMARY OF THE INVENTION The present invention effectively solves the problems of the prior art described above, and has as its object to prevent a decrease in mechanical strength of a magnetic shield and to improve the reliability of a fixing method and to reduce loss and local overheating. It is an object of the present invention to provide a magnetic shielding device for a static induction device for preventing static induction.

[0007]

According to the present invention, there is provided a shielding device for a stationary induction electric machine in which a magnetic material shield formed by laminating a magnetic material is mounted inside a tank accommodating an induction electric device main body having an iron core and a winding. A magnetic shielding device for a stationary induction electric appliance, wherein a device provided with a slit only on the surface side of a body shield and a device not provided with a slit are integrated in the laminating direction, and a holding metal is provided so as not to reduce mechanical strength.

According to the magnetic shielding device for a stationary induction device of the present invention, even when a magnetic attraction force acts when the leakage magnetic flux from the winding penetrates perpendicularly into the magnetic material shield surface side, only the magnetic material shield surface side is exposed. The one with the slit and the one without the slit are integrated in the laminating direction and the holding bracket is provided so that the mechanical strength does not decrease, so the strength against magnetic attraction can be sufficiently secured, and the magnetic shield Since the slit is provided on the front surface side, the loss of the magnetic shield itself can be reduced and local overheating can be prevented.

[0009]

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

FIG. 1 is a plan view showing the structure of a magnetic shield in a single-phase center core transformer, and FIG. 2 is a cross-sectional view of a principal part taken along a line TT in FIG. FIG. 3 shows TT of FIG.
FIG. 4 is a cross-sectional view of a main part showing a configuration of a magnetic shield in a cross section. 1, 2, and 3, an inner winding 4 and an outer winding are provided inside a tank 7 that houses a transformer body including a main leg 1 and a side leg 2, an upper yoke 3, an inner winding 4, and an outer winding 5. Pressing bracket with the longitudinal direction of a magnetic shield 8 formed by laminating a thin silicon steel sheet having a width W and a thin thickness at a position facing the winding 5 so as to be vertical.
(Not shown) are arranged side by side with a predetermined gap therebetween, and one slit 11 is provided only on the surface side of the magnetic shield 8 in order to reduce loss in the magnetic shield 8. The magnetic shield 8A provided and the magnetic shield 8B without the slit 11 are integrated in the laminating direction.

According to such a configuration, even if the leakage flux 40 from the inner winding 4 and the outer winding 5 penetrates perpendicularly into the surface side of the magnetic shield 8 as shown by the arrow, the slit 11
Since the magnetic shield 8A provided with the magnetic shield 8A and the magnetic shield 8B not provided with the slit 11 are integrated in the laminating direction, the magnetic shield 8A sufficiently withstands the mechanical strength due to the magnetic attraction acting on the magnetic shield 8, thereby providing reliability. It is possible to provide a highly inductive magnetic shielding device for a static induction device. Moreover, the loss due to the eddy current of the magnetic shield 8 increases with the square of the width. However, since one slit 11 is provided only on the surface of the magnetic shield 8, the width W is １ ／, and the loss is 1 It can be greatly reduced to / 4. On the other hand, the leakage flux 40 from the inner winding 4 and the outer winding 5 vertically enters the surface of the magnetic shield 8 and then flows in the height direction on the surface of the magnetic shield 8, so that the depth of the slit 11 is Only the front side of the magnetic shield 8 is sufficient. In addition, the operation of the magnetic shield 8A in which the slit 11 is provided only on the front surface side of the magnetic shield 8 can be easily performed by using a dedicated machine or a shear line, and the cost is low because the slit 11 is provided only on the front surface side. It is possible to manufacture a magnetic shield 8 that is easy to use.

FIGS. 4 and 5 show another embodiment. FIG. 4 is a plan view showing the configuration of a magnetic shield in a single-phase center core transformer, and FIG. 5 is a cross-sectional view of a main part taken along a line TT in FIG. As can be seen from FIGS. 4 and 5, two slits 11 are provided only on the surface side of the magnetic shield 9 at positions facing the inner winding 4 and the outer winding 5 in order to reduce the loss in the magnetic shield 9. The magnetic shield 9A provided and the magnetic shield 9B without the slit 11 are integrated in the laminating direction. At other positions, a magnetic shield 8A having one slit 11 only on the surface side of the magnetic shield 8 and a magnetic shield 8B having no slit 11 are provided.
Are integrated in the laminating direction.

According to such a configuration, as shown by arrows, the leakage magnetic flux 40 from the inner winding 4 and the outer winding 5 is arranged at a position where the magnetic flux vertically entering the surface side of the magnetic shield 9 becomes largest. Slit 1 on magnetic shield 9
Since two 1s are provided, the width is reduced to 1/3, and the loss is reduced to 1/9. The loss of the magnetic shield 9 itself can be greatly reduced, and local overheating can be prevented. Moreover, since the slits 11 are provided only on the surface side of the magnetic material shield 9, mechanical strength due to magnetic attraction can be sufficiently secured.

FIGS. 6 and 7 show another embodiment. 6 is a plan view showing a configuration of a magnetic shield in a single-phase center core transformer, and FIG. 7 is a cross-sectional view of a main part taken along a line TT in FIG. As can be seen from FIGS. 6 and 7, two slits 11 are provided only on the surface side of the magnetic shield 9 arranged at a position facing the inner winding 4 and the outer winding 5, and the magnets arranged at other positions are provided. The body shield 10 has no slit 11.

According to this configuration, as shown by the arrows, the leakage flux 40 from the inner winding 4 and the outer winding 5 is arranged at a position where the magnetic flux vertically entering the surface side of the magnetic shield 9 becomes largest. Since two slits 11 are provided only on the surface side of the magnetic shield 9 to be formed, the loss of the magnetic shield 9 itself can be greatly reduced and local overheating can be prevented. In addition, the magnetic shield 10 arranged at a position not facing the inner winding 4 and the outer winding 5 separates from the inner winding 4 and the outer winding 5, and vertically enters the surface of the magnetic shield 10. It is not necessary to provide the slit 11 to reduce the leakage magnetic flux 40 as indicated by the arrow. For this reason, the operation of providing the slits 11 in the magnetic shield 10 is not required, so that an inexpensive magnetic shield 10 can be manufactured.

FIGS. 8 and 9 show another embodiment. FIG. 8 is a plan view showing the configuration of a magnetic shield in a single-phase four-leg transformer, and FIG.
Shows front views in the TT section of FIG.
As can be seen from FIGS. 8 and 9, the magnetic body shield 9 having two slits 11 at positions facing the inner winding 4 and the outer winding 5 and a magnetic body having no slit 11 between the windings (interphase portion). It has a configuration in which a shield 10 is arranged.

According to such a configuration, the inner winding 4 and the outer winding 5 are located at positions facing the inner winding 4 and the outer winding 5.
As shown by the arrow, even though the magnetic flux 40 leaks perpendicularly into the surface of the magnetic shield 9, two slits 11 are provided only on the surface of the magnetic shield 9, so the surface of the magnetic shield 9 is As a result, the eddy current flowing through the power supply is cut off, the loss can be greatly reduced, and local overheating can be prevented. Moreover,
Since the slits 11 are provided only on the front surface side of the magnetic shield 9, mechanical strength by magnetic attraction can be sufficiently secured. Also, between the windings (interphase), the leakage flux 40 from the inner winding 4 and the outer winding 5 flows in the width direction of the magnetic shield 10 as shown by the arrow, so that it is not necessary to provide the slit 11 and the There is an advantage that the number of manufacturing steps of the body shield 10 can be reduced.

FIG. 10 shows another embodiment. FIG. 10 is a plan view showing a configuration of a magnetic shield in a three-phase three-leg transformer. As can be seen from FIG. 10, between the magnetic shield 9 having two slits 11 in the tank 7 facing the inner winding 4 and the outer winding 5 and the tank 6 not covered by the side legs, and between the windings (interphase portion). Shield 1 without slit 11
0 is arranged.

According to this configuration, the slit 11 is provided only on the surface of the magnetic shield 9 disposed in the tank 7 facing the inner winding 4 and the outer winding 5 and the tank 6 not covered by the side legs. As a result, the eddy current flowing on the surface side of the magnetic shield 9 is divided even if the leakage magnetic flux 40 vertically enters the surface side of the magnetic shield 9 as shown by the arrow, thereby effectively reducing the loss. Can be reduced and local overheating can be prevented.

FIG. 11 shows another embodiment. FIG. 11 shows FIG.
FIG. 9 is a cross-sectional view of a main part showing a mounting state of the magnetic shield in a cross section taken along line TT of FIG. As can be seen from FIG. 11, on the front surface of the tank 7 facing the inner winding 4 and the outer winding 5 (not shown), the holding member 15 of the magnetic shield 9 having two slits 11 is provided with the slits 11. No magnetic shield 1
The length of the magnetic material shield 9 is made longer than the
It has a structure that firmly holds the whole.

According to this configuration, even if the leakage magnetic flux 40 (not shown) from the inner winding 4 and the outer winding 5 (not shown) enters the surface of the magnetic shield 9 vertically, the magnetic material Since two slits 11 are provided only on the front surface side of the shield 9, the loss of the magnetic shield 9 itself can be significantly reduced, and local overheating can be prevented. Further, since the slits 11 are provided only on the surface side of the magnetic shield 9, there is a concern that the mechanical strength of the magnetic shield 9 may be reduced due to the magnetic attraction acting on the magnetic shield 9. Is firmly pressed by the holding metal 15, so that a reduction in mechanical strength can be prevented and a highly reliable magnetic shielding device can be provided. The magnetic shield 9 and the holding metal 1
5. In order to keep the magnetic shield 10 and the holding member 20 insulated, the magnetic shields 9 and 10 are usually covered with an insulator (not shown).

FIG. 12 shows another embodiment. FIG. 12 is a cross-sectional view of a main part showing a mounting state of the magnetic shield. In the figure, the same parts as those shown in FIG. 11 use the same reference numerals. As can be seen, the inner winding 4 and the outer winding 5
The holding member 21 of the magnetic shield 9 in which two slits 11 are inserted in the front surface of the tank 7 opposite to (not shown) is longer than the holding member 20 of the magnetic shield 10 in which the slit 11 is not inserted, In addition, the structure is such that one is alternately pressed.

According to this configuration, even if the leakage magnetic flux 40 (not shown) from the inner winding 4 and the outer winding 5 (not shown) vertically enters the surface side of the magnetic shield 9, Since the two slits 11 are provided only on the surface side of the shield 9, there is a concern that the mechanical strength is reduced due to the magnetic attraction acting on the magnetic shield 9. Due to the strong pressing, a reduction in mechanical strength can be prevented, and a highly reliable magnetic shielding device can be provided. Moreover, since two slits 11 are provided only on the surface side of the magnetic shield 9, the magnetic shield 9 is provided.
It can greatly reduce its own loss and prevent local overheating.

FIGS. 13 and 14 show another embodiment. FIG.
Fig. 1 is a cross-sectional view of a main part showing a mounting state of a magnetic shield, and Fig. 1
Reference numeral 4 denotes an enlarged view of a main part of the magnetic shield mounting bracket. 13 and 14 which are the same as those shown in FIG. 11 use the same reference numerals. As can be seen from FIGS. 13 and 14, the holding member 21 of the magnetic shield 9 having two slits 11 provided on the front surface of the tank 7 facing the inner winding 4 and the outer winding 5 (not shown) is provided with the slit 11. It has a structure in which only one side is larger than the holding metal fitting 20 for fixing the magnetic material shield 10 which is not provided, and both are overlapped and fixed.

According to this configuration, even if the leakage magnetic flux 40 (not shown) from the inner winding 4 and the outer winding 5 (not shown) vertically enters the surface of the magnetic shield 9, Since two slits 11 are provided only on the front surface side of the shield 9, the loss of the magnetic shield 9 can be greatly reduced and local overheating can be prevented. Further, since the magnetic metal shield 9 is firmly pressed against the tank 7 by superimposing the holding metal fittings 20 and 21, the magnetic shield 9 can sufficiently withstand the mechanical strength due to the magnetic attraction force. Can be provided.

FIGS. 15 and 16 show another embodiment. FIG.
Fig. 1 is a cross-sectional view of a main part showing a mounting state of a magnetic shield, and Fig. 1
Reference numeral 6 denotes an enlarged view of a main part of the magnetic shield mounting bracket. 15 and 16, the same parts as those shown in FIG. 11 use the same reference numerals. As can be seen from FIGS. 15 and 16, a metal plate is provided between the holding members 20 of the magnetic shield 9 having two slits 11 in the front surface of the tank 7 facing the inner winding 4 and the outer winding 5 (not shown). 23 are superimposed and firmly pressed.

According to this configuration, even if the leakage magnetic flux (not shown) from the inner winding 4 and the outer winding 5 (not shown) enters the surface of the magnetic shield 9 vertically, the magnetic shield 9, two slits 11 are provided only on the surface side of
Since the magnetic shield 9 can be firmly pressed while the magnetic shield 9 is interposed between the magnetic shields 9, the loss of the magnetic shield 9 itself and the local overheating can be prevented. The material of the metal plate 23 is a non-magnetic material that does not generate local overheating even when leaked magnetic flux (not shown) from the inner winding 4 and the outer winding 5 (not shown) enters. It is valid. The present invention has been described by taking as an example the case where the number of slits 11 is one or two only on the surface side of the magnetic shields 8 and 9.
It can be applied to two or more, and the effect can be expected similarly. The method of attaching the presser fitting 20 to the tank may be welding or bolting (not shown).

[0028]

According to the magnetic shielding apparatus for a stationary induction device of the present invention, a slit is provided only on the surface side of the magnetic shield disposed inside the tank, and the holding member can sufficiently withstand magnetic attraction. By fixing with a metal fitting, it is possible to significantly reduce the loss of the magnetic shield itself, to prevent local overheating, and to provide a highly reliable magnetic shielding device for a stationary induction device.

[Brief description of the drawings]

FIG. 1 is a plan view of a magnetic shielding device of a stationary induction device showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of a magnetic shielding device for a stationary induction device, showing one embodiment of the present invention.

FIG. 3 is an enlarged view of a magnetic shielding device of a stationary induction device showing one embodiment of the present invention.

FIG. 4 is a plan view of the magnetic shielding device of the stationary induction device showing one embodiment of the present invention.

FIG. 5 is a cross-sectional view of a main part of the magnetic shielding device of the stationary induction device, showing one embodiment of the present invention.

FIG. 6 is a plan view of a magnetic shielding device of a stationary induction device showing one embodiment of the present invention.

FIG. 7 is a cross-sectional view of a main part of a magnetic shielding device for a stationary induction device, showing one embodiment of the present invention.

FIG. 8 is a plan view of the magnetic shielding device of the stationary induction device showing one embodiment of the present invention.

FIG. 9 is a cross-sectional view of a main part of a magnetic shielding device for a stationary induction electric machine according to an embodiment of the present invention.

FIG. 10 is a plan view of a magnetic shielding device of a stationary induction device showing one embodiment of the present invention.

FIG. 11 is a cross-sectional view of a main part of a magnetic shielding device of a stationary induction device showing a holding metal according to an embodiment of the present invention.

FIG. 12 is a cross-sectional view of a main part of a magnetic shielding device of a stationary induction device showing a holding metal according to an embodiment of the present invention.

FIG. 13 is a cross-sectional view of a main part of the magnetic shielding device of the stationary induction device showing the holding metal according to the embodiment of the present invention.

FIG. 14 is an enlarged view showing a holding bracket according to an embodiment of the present invention.

FIG. 15 is a cross-sectional view of a main part of a magnetic shielding device of a stationary induction device showing a holding metal according to an embodiment of the present invention.

FIG. 16 is an enlarged view showing a holding bracket according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main leg, 2 ... side, 3 ... Upper yoke part, 4 ... Inner winding,
5 ... Outer winding, 6, 7 ... Tank, 8, 8A, 8B, 9, 9
A, 9B, 10: magnetic shield, 11: slit, 1
5, 20, 21 ... holding metal, 30 ... metal plate, 40 ... magnetic flux leakage.

Continued on front page (72) Inventor Mitsumasa Hashimoto 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside Kokubu Plant, Hitachi, Ltd. (72) Inventor Tadashi Ki1-1 1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside Hitachi Kokubu Plant (72) Inventor Masanori Mitsui 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside Kokubu Town, Hitachi (72) Inventor Yasunori Ohno 1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Kokubu Plant, Hitachi, Ltd. 1-1-1 1-1 F-term in Kokubu Plant of Hitachi, Ltd. (reference) 5E058 BB05

Claims (8)

[Claims] 1. A static induction device shielding apparatus comprising: a magnetic material shield formed by laminating a magnetic material inside a tank accommodating an induction device main body having an iron core and a winding;
A magnetic shielding device for a stationary induction device, wherein a slit is provided only on the surface side of the magnetic shield. 2. A stationary device according to claim 1, wherein a magnetic shield provided with a slit and a magnetic shield not provided with a slit are integrated in a laminating direction, and a holding metal is provided so as not to reduce mechanical strength. Magnetic shielding device for induction equipment. 3. The magnetic shield provided on the inside of the tank facing the inner winding and the outer winding has a greater number of slits than a magnetic shield provided at another position. A magnetic shielding device for the stationary induction device according to claim 1. 4. A shielding device for a stationary induction electric machine having a magnetic shield provided with a slit inside a tank accommodating an induction electric machine body having an iron core and a winding, wherein a length of a presser fitting for fixing the magnetic shield is provided. A magnetic shielding device for a stationary induction machine, characterized in that it has a longer length and is fixed from both sides. 5. A holding member for fixing a magnetic shield provided with a slit is made larger than a holding member for fixing a magnetic shield not provided with a slit, and is alternately pressed by one. A magnetic shielding device for a stationary induction device according to claim 4. 6. A holding member for fixing a magnetic shield provided with a slit has a larger size on one side than a holding member for fixing a magnetic shield not provided with a slit, and the two are overlapped and fixed. A magnetic shielding device for a stationary induction device according to claim 4. 7. A holding member for fixing a magnetic shield provided with a slit is the same size as a holding member for fixing a magnetic shield having no slit, and is fixed via a metal plate between the holding members. 5. The magnetic shielding device for a stationary induction device according to claim 4, wherein: 8. A magnetic shield for a stationary induction electric device according to claim 7, wherein the metal plate provided between the holding members for fixing the magnetic shield provided with the slit is made of a non-magnetic stainless steel. apparatus.