JPH11176646A - Oil filled stationary induction apparatus and durable driving method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil filled stationary induction apparatus which can prolong its life without causing reduction of its insulation reliability and without requiring any modification. SOLUTION: In the oil-filled stationary induction apparatus, an interior structure 100 including a winding 10 and an ion core 11 is placed in an outer box 50 filled with insulating oil, so that the entire interior structure 100 is immersed with the insulating oil within the outer box to be cooled by the insulating oil in its insulated state. Further first high-voltage lead wires 20a to 20d, second high-voltage lead wires 21a to 21d, a first low-voltage lead wire 25 and a second low-voltage lead wire 26 for connection between the winding 10 and external conductors are led out from both upper and lower parts of the winding 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an oil-filled stationary induction device and a method for extending the life of an oil-filled stationary induction device such as an oil-filled transformer.

[0002]

2. Description of the Related Art In an oil-filled stationary induction device such as an oil-filled transformer, an internal structure including a winding and an iron core is placed in an outer box containing insulating oil, and the entire internal structure is insulated in the outer box. It is immersed in oil and cooled by insulating oil in an insulated state.

FIG. 8 shows the structure of a conventional single-phase oil-immersed transformer. The internal structure 100 has an assembly of a winding 10 and an iron core 11, and this assembly is integrated by being sandwiched between an upper frame 12 and a lower frame 13. A lid member 14 of an outer box is connected to the upper frame 12 by a double screw bolt 15. Although not shown in the drawing, a lead wire connected to a bushing for connecting to an external conductor is drawn out from the upper part of the winding.

[0004]

In a stationary induction machine, such as an oil-immersed transformer, which generates heat during operation and uses mineral oil (insulating oil) for cooling, the insulator gradually decreases due to the heat generated during operation. Deterioration and deterioration of dielectric strength and mechanical strength greatly increase the risk of destruction when subjected to abnormal electrical or mechanical stress such as abnormal voltage due to lightning surge or electromagnetic mechanical force due to external short circuit. And that point is the life. The service life is determined by the highest point temperature in the stationary induction equipment, and it is said that a 30-year regular life can be expected at the highest point temperature of 95 ° C. for oil-filled equipment using Class A insulation.

FIG. 9 is a diagram showing the technical report of the Institute of Electrical Engineers of Japan (part I), part 14.
3 shows the temperature rise characteristics of the oil-filled transformer quoted from No. 3. As shown in this figure, the location where the highest point temperature of the oil-filled equipment is generally located is such that the heat generated during operation causes the insulating oil to convect inside the outer box, so the temperature at the top of the equipment is higher than at the bottom, and Part.

A conventional oil-filled stationary induction machine, for example, an oil-filled transformer as shown in FIG. 8 is based on the premise that the vertical position of the internal structure 100 in the outer case is reversed after manufacturing. It is operated as it is when it is manufactured. For this reason, in this oil-immersed transformer, the life is extended only by the deterioration of the upper part of the winding. According to the temperature rise characteristics shown in FIG. 9, since the temperature rise at the lower part of the winding is lower than at the upper part of the winding, the insulation at the lower part of the winding is not as deteriorated as at the upper part. Despite the remaining life, the overall life is reduced only by the deterioration of the insulation at the top of the winding.

In the oil-immersed transformer as shown in FIG. 8, in order to invert the vertical position of the contents structure 100 in the outer box after the manufacturing, the lower frame 13 is used as the upper frame. In order to make the lower frame 13
It is necessary to make a modification to make a hole through which both screw bolts 15 pass, and even if the modification is made, the lead wire from the winding is pulled out only from the upper part of the winding, so that the internal structure 100 in the outer box is removed. If the vertical position of the wire is reversed, the lead wire must be routed upward from the lower part of the winding, making it difficult to connect to the bushing for connection to the external conductor, and the gap between the winding and the outer box. Therefore, it is inevitable that insulation reliability is reduced.

The present invention has been made in order to solve such a problem, and it is an object of the present invention to provide an oil-filled stationary induction device that does not require modification and can extend the life of the device without lowering insulation reliability. The purpose of the present invention is to obtain a method for extending the life of an oil-filled stationary induction device.

[0009]

In order to achieve the above-mentioned object, an oil-filled stationary induction device according to the present invention has a structure including a winding and an iron core placed in an outer box containing insulating oil,
In an oil-filled stationary induction device having a structure in which the entire content structure is immersed in insulating oil in an outer box and cooled by the insulating oil in an insulated state, a lead wire for connecting the winding and an external conductor is formed by the winding. It is taken from both the top and bottom of the line.

[0010] An oil-filled stationary induction device according to the next invention is characterized in that a relay terminal block for connecting the winding and the external conductor in insulating oil is provided on both the upper part and the lower part of the internal structure. It is.

The oil-filled stationary guidance device according to the next invention has an outer frame that supports the entire contents structure so that it can be turned upside down, and the outer frame is supported by the outer box so as to be rotatable in the horizontal direction. is there.

[0012] In order to achieve the above-mentioned object, a method of extending the life of an oil-filled stationary induction device according to the present invention is as follows: an inner structure including a winding and an iron core is placed in an outer box containing insulating oil; In the method of extending the life of an oil-filled stationary induction device having a structure in which the entire content structure is immersed in insulating oil in the outer box and cooled by the insulating oil in an insulated state, the content structure is turned upside down after a predetermined period of operation. After that, it is driven for a predetermined period, and the content structure is turned upside down every time the predetermined period elapses.

[0013] In the method for extending the life of an oil-filled stationary induction device according to the next invention, the internal structure of the oil-filled stationary induction device according to the above-described invention is turned upside down every time a predetermined period elapses.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an oil-filled stationary induction machine according to the present invention; In the embodiments of the present invention described below, the same components as those of the above-described conventional example are denoted by the same reference numerals as those of the above-described conventional example, and description thereof will be omitted.

Embodiment 1 1 to 4 show Embodiment 1 in which an oil-filled stationary induction device according to the present invention is applied to an oil-filled transformer. First high-voltage leads 20 a to 20 d are drawn out from the upper part of the winding 10, and second high-voltage leads 21 a to 21 d are drawn out from the lower part of the winding 10.

The upper frame 12 has first upward high-voltage leads 20a, 20d and a high-voltage bushing (not shown).
And a first relay terminal block 22 for switching taps with the first high-voltage leads 20b and 20c.

The lower frame 13 relays the second high voltage leads 21a, 21d and a high voltage bushing (not shown) which are directed upward when the content structure 100 of the transformer is turned upside down from the state shown in the figure. , First high-voltage lead wire 21b, 2
A second relay terminal block 23 for switching taps by 1c is attached.

A lead wire 24 for connection to a high-voltage bushing (not shown) is detachably connected to the first relay terminal block 22 or the second relay terminal block 23 located above, that is, the duty relay terminal block. . A first low-voltage lead 25 is drawn out from the upper part of the winding 10, and a second low-voltage lead 26 is drawn out from the lower part of the winding 10.

A lead wire 27 for connection to a low-voltage bushing (not shown) is detachably connected to the first low-voltage lead wire 25 or the second low-voltage lead wire 26 located on the upper side, that is, the low-voltage lead wire. .

As for the low voltage side, similarly to the high voltage side, a relay terminal block is provided on the upper frame 12 and the lower frame 13 and the first low voltage lead wire 25 or the second low voltage lead wire is set with the relay terminal block as a relay point. 26 may be connected to a low-pressure bushing. In FIG. 1, reference numeral 50 denotes an outer box for storing the internal structure of the transformer.

FIG. 2 shows a winding structure in the case where the electric wire is continuously wound in the height direction of the winding 10 or the winding is performed over multiple layers. First high voltage lead wire 20
a, the second high-voltage lead 21a and the first high-voltage lead 20
b, the second high-voltage lead 21b and the first high-voltage lead 20
c, the second high-voltage lead 21c and the first high-voltage lead 20
d and the second high-voltage lead wire 21d are electrically connected to electric wires 28a to 28d of the same potential of the winding 10, respectively.

In manufacturing the winding 10 having this structure, first, the first high-voltage lead wire 20a and the second high-voltage lead wire 21a at the beginning of winding are pulled out from the upper and lower end surfaces of the winding 10, respectively.
Winding of the wire 10 from the wire 28a is started. When there is an intermediate tap, the first high-voltage lead 20b and the second high-voltage lead 21
b, first high-voltage lead 20c and second high-voltage lead 21c
Are respectively drawn from the upper and lower end surfaces of the winding 10.
Similarly to the other leads, the electric wire 28d at the end of winding is the same as the other high-voltage leads 20d and the second high-voltage leads 2d.
1d is pulled out from the upper and lower end surfaces of the winding 10, respectively.

FIG. 3 shows an example of a winding formed by continuously winding a sheet-like electric wire in the circumferential direction of the winding 10. Winding 10
Is constituted by continuously winding a sheet-shaped electric wire 29 in the circumferential direction, and the first low-voltage lead wire 25 and the second low-voltage lead wire 26 of the winding 10 from the sheet-shaped electric wire 29 are upper and lower end surfaces of the winding 10. Each has been drawn out. FIG. 4 shows a low-voltage side connection diagram of the windings of the oil-filled transformer. The sheet-shaped electric wire 29 is often applied to the low-voltage side winding of a transformer, and FIG. 5 shows an example of a single-phase transformer using the sheet-shaped electric wire 29 for AA only.

In the transformer having the above structure,
In order to extend the life of the transformer, when the structure 100 of the transformer is turned upside down, the structure 100 of the transformer is first lifted from the outer case 50, and the high voltage bushing, the low voltage bushing and the winding 1
The lead wires 24 and 27 connected to 0 are disconnected from the duty relay terminal block (first relay terminal block 22) and the duty low-voltage lead wire (first low-voltage lead wire 25).

Next, the internal structure 100 of the transformer is turned upside down. After the upside down, the lead wire 24 is connected to the upper second relay terminal block 22, and the lead wire 27 is connected to the upper second low voltage lead wire 26, respectively. After the connection is completed, the content structure 100 of the transformer is put into the outer case 50 again, and after the lubrication of the insulating liquid, the operation is resumed.

As described above, in particular, the structure 100 of the transformer can be turned upside down without modification, and even if the structure 100 of the transformer is turned upside down, the lead wire 2
Without routing 2, 27 upward from the bottom of the winding,
The connection to the bushing for connection to the external conductor is facilitated, and the gap between the winding 10 and the outer case 50 is
Since the wires 2 and 27 do not pass, the insulation reliability does not decrease. As a result, the life of the transformer can be extended without requiring modification and without reducing insulation reliability.

FIG. 5 (a) shows a state where the product is shipped from the factory. The transformer starts operating in this state, and is operated in this state for a certain period of time, for example, during a periodical inspection (in the case of oil-filled equipment, generally ten years). Winding 1
Regarding the vertical relationship of 0, the mark ○ is up and the mark ● is down. At this time, since the oil temperature of the insulating oil used in this device is Ta> Tb, the deterioration of the upper part (the part marked with a circle) of the winding 10 decreases during the certain period of time. Advances faster than).

After a certain period of time, for example, 10 years later, at the time of oil change, the internal structure 100 of the transformer is turned upside down. As shown in FIG. 5 (b), the vertical relationship of the windings 10 after this operation is performed is as follows: the mark marked side is up and the mark marked side is down, and in the future, the winding 10 is operated in this state for a certain period of time. . Also in this case, since the oil temperature of the insulating oil satisfies Ta> Tb, in this case, the deterioration on the side of the mark proceeds faster on the side of the mark.

By repeating the above operation pattern as illustrated in FIG. 6, the deterioration of the winding 10 due to the thermal influence becomes uniform, and the equivalent temperature from the viewpoint of the highest point temperature throughout the entire operation period, that is, the life. The typical temperature is estimated to be the temperature at the midpoint between the upper and lower windings.

Deterioration of insulators in oil is due to Arrhenius
And in oil, the 6 ° C. half reduction rule is applied, and the degree of acceleration of deterioration is expressed by the following equation.

Acceleration magnification = 2 ⁽ difference from normal temperature ^{/ 6)}

Based on this law and the measured data of the temperature difference between the upper and lower windings during operation, which the inventors have, an example of how the life extension operation method according to the present invention contributes to extending the life will be described below. Shown in

According to the data held by the inventor, the oil temperature at the upper part of the winding, that is, the point B temperature θ ₀ in FIG.
Was 49 ° C., and the oil temperature at the lower part of the winding, that is, the point A temperature in FIG. 9 was 20 ° C. From this data, it is estimated that the R point temperature θ _{0m at the} center of the winding is as follows.

Θ _0m = θ _0- (θ ₀ -point A temperature) /2=34.5° C.

Therefore, the acceleration magnification is as follows: acceleration magnification = 2
^{(34.5-49) /6=0.19} . Assuming that the life of the conventional operation method is 30 years, the operation of the present invention
The calculation result was 30 / 0.19 = 158.

Embodiment 2 FIG. 7 shows a second embodiment in which the oil-filled stationary induction device according to the present invention is applied to an oil-filled transformer. In FIG. 7, portions corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof will be omitted.

The internal structure 100 of the transformer including the winding 10 and the iron core 11 is composed of an upper frame 12 and a lower frame 13, and a left frame 16 and a right frame 17 connecting the upper frame 12 and the lower frame 13. Surrounded and retained by these. Upper frame 12, lower frame 13, left frame 16, right frame 17
Is an integrated structure, and in the following description, the whole is referred to as a vertically inverted frame 30.

The upside down frame 30 is supported by a horizontal rotating frame (outer frame) 32 so that it can be turned upside down by horizontal shafts 31 on both left and right sides. Upside down frame 30
Is the vertical position shown in FIG.
It is fixed to the horizontal rotating frame 32 by the fixing bolt 33 in one of the up and down postures rotated by 0 degrees. The horizontal rotating frame 32 is suspended and supported by a vertical shaft 34 so as to be rotatable in the horizontal direction from the cover member 14 of the outer box.

The arrangement of each lead wire of the winding 10 in this embodiment is the same as that in the first embodiment, and a description thereof will be omitted.

In this embodiment, first, the inner structure 100 of the transformer is taken out of the outer box together with the vertically inverted frame 30 and the horizontal rotating frame 32, and the lead connection of the winding 10 is performed in the same manner as in the first embodiment. Remove. After this,
The fixing bolt 33 is removed, and the contents structure 100 of the transformer is removed.
It is rotated 180 degrees vertically about the horizontal axis 31 as the center of rotation. Thus, the internal structure 100 of the transformer is turned upside down with respect to the horizontal rotating frame 32.

After this upside down is completed, the internal structure 100 of the transformer is fixed by the fixing bolt 33 to the horizontal rotating frame 3.
2 and the leads of the winding 10 are connected in the same manner as in the first embodiment.

In this state, the high-pressure bushing and the low-pressure bushing are reversed left and right.
0 degree horizontal rotation or the cover member 14 is rotated 180 degrees horizontally with respect to the horizontal rotation frame 32, and then the transformer internal structure 100 is placed in an outer box together with the upside down frame 30 and the horizontal rotation frame 32, and the insulating oil Lubricate and resume operation.

In this embodiment, the upside-down operation of the internal structure 100 of the transformer can be easily performed without any heavy load operation.

[0044]

As can be understood from the above description, according to the oil-filled stationary induction machine of the present invention, the lead wire for connecting the winding and the external conductor is taken out from both the upper and lower parts of the winding. Since the lead connection work before and after the internal structure is turned upside down is easily performed, and even when the internal structure is turned upside down, the lead wire does not pass through the gap between the winding and the outer box. In addition, the insulation reliability does not decrease.

According to the oil-filled stationary induction device according to the next invention, the relay terminal block for connecting the winding and the external conductor in the insulating oil is provided on both the upper part and the lower part of the internal structure. In addition, the structure in which the lead wires are drawn out from both the upper and lower portions of the winding is effectively utilized, and the lead connection work before and after the internal structure is turned upside down can be easily and reliably performed.

According to the oil-filled stationary guidance device of the next invention, the entire structure is supported so that it can be turned upside down from the outer frame and the outer frame can be rotated horizontally from the outer box. Upside down work can be easily performed without accompanying heavy load work.

According to the method for extending the life of an oil-filled stationary induction device according to the next invention, after the operation for a predetermined period, the above-mentioned internal structure is turned upside down and placed in an outer box, and thereafter the operation is performed for a predetermined period. Each time the content structure is turned upside down, the life of the oil-filled stationary induction device is not limited to the deterioration of only the upper part of the winding, and the insulation used is made uniform and the life of the device is made effective. Can be extended.

According to the method for extending the life of an oil-filled stationary induction device according to the next invention, the oil-filled stationary induction device according to the above-mentioned invention is used because the internal structure is turned upside down every time a predetermined period elapses. A life prolonging operation method for making the insulation deterioration uniform and effectively extending the equipment life can be performed easily and without impairing the insulation reliability.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment in which an oil-filled stationary induction device according to the present invention is applied to an oil-filled transformer.

FIG. 2 is a high-voltage side connection diagram showing windings of the oil-immersed transformer according to the first embodiment.

FIG. 3 is a configuration diagram illustrating a low-voltage side of a winding of the oil-immersed transformer according to the first embodiment.

FIG. 4 is a low-voltage side connection diagram illustrating windings of the oil-immersed transformer according to the first embodiment.

FIGS. 5 (a) and 5 (b) are explanatory diagrams showing an upside-down state of the oil-immersed transformer according to the first embodiment.

FIG. 6 is an explanatory diagram showing an operation pattern example of a life extension operation method of an oil-filled stationary induction device (oil-filled transformer) according to the present invention.

FIG. 7 is an overall configuration diagram showing a second embodiment in which the oil-filled stationary induction device according to the present invention is applied to an oil-filled transformer. It is a block diagram which shows Embodiment 2 of the oil-filled stationary guidance apparatus by this invention.

FIG. 8 is a configuration diagram showing a content structure of a conventional oil-immersed transformer.

FIG. 9 is a graph showing a temperature distribution around a transformer winding.

[Explanation of symbols]

100 Contents structure, 10 Windings, 11 Iron core, 12
Upper frame, 13 Lower frame, 14 Lid member of outer box, 20a-20d First high-voltage lead wire, 21a-21
d Second high voltage lead wire, 22 First relay terminal block, 23
Second relay terminal block, 24 lead wires, 25 first low-voltage lead wire, 26 second low-voltage lead wire, 27 lead wire 28a
~ 28d electric wire, 29 sheet electric wire, 30 upside down frame, 31 horizontal axis, 32 horizontal rotating frame, 3
3 Fixing bolt, 34 vertical axis.

Claims (5)

[Claims] 1. An inner structure including a winding and an iron core is placed in an outer box containing insulating oil, and the entire inner structure is immersed in insulating oil in the outer box and cooled by the insulating oil in an insulated state. An oil-filled stationary induction device having a structure as described above, wherein a lead wire for connecting the winding to an external conductor is taken out from both upper and lower portions of the winding. 2. The terminal structure according to claim 1, wherein a relay terminal block for connecting the winding and the external conductor in an insulating oil is provided on both the upper part and the lower part of the internal structure. Oil-filled stationary induction equipment. 3. An apparatus according to claim 1, further comprising an outer frame for supporting the entire contents structure in a vertically reversible manner, wherein the outer frame is supported so as to be rotatable in a horizontal direction from the outer box. An oil-filled stationary induction device as described. 4. An inner structure including a winding and an iron core is placed in an outer box containing insulating oil, and the entire inner structure is immersed in insulating oil in the outer box and cooled by the insulating oil in an insulated state. In the method for extending the life of an oil-filled stationary induction device having a structure as described above, the internal structure is turned upside down and placed in an outer box after being operated for a predetermined period, and thereafter, the internal structure is operated for a predetermined period. A method for prolonging the life of an oil-filled stationary induction device, wherein the structure is turned upside down. 5. The oil according to claim 4, wherein the internal structure of the oil-filled stationary induction device according to any one of claims 1 to 3 is turned upside down every time a predetermined period elapses. How to extend the life of stationary stationary guidance equipment.