JP6200637B2 - Oil-filled transformer - Google Patents

Description

  The present invention relates to an oil-filled transformer, and more particularly to an oil-filled transformer provided with a radiator.

In an oil-filled transformer, if an abnormality occurs inside the transformer, an abnormal temperature is generated, the insulating oil and internal materials are decomposed, and various gases are generated. This gas generates a specific gas in response to abnormalities such as dielectric breakdown, local discharge, heating, and loose taps. Here, the internal abnormality of the transformer and the generated gas will be explained. In the case of a short-circuit between the windings (arc discharge), gas such as C ₂ H ₂ , H ₂ , CO, CO ₂ is generated and is generated between the tap contacts. In the case of discharge, C ₂ H ₂ , C ₂ H ₄ , C ₃ H ₆ , C ₄ type hydrocarbon gas, etc. are generated, and in the case of corona discharge in an iron core or the like, H ₂ , CH ₄ , C A gas such as ₂ H ₂ is generated. In addition, when the insulating paper is overheated, CO and CO ₂ become prominent. When the synthetic resin portion is overheated, C ₃ H ₆ and C ₄ hydrocarbon gases are generated, and the iron core portion is overheated. In the case, a hydrocarbon gas such as C ₂ H ₄ or CH ₄ or a gas such as H ₂ is generated, and in the case of a tap switch contact failure, C ₂ H ₄ , C ₃ H ₆ , C ₄ hydrocarbon gas, etc. When the lead connection portion is overheated, hydrocarbon gas such as C ₂ H ₄ is generated.

  In addition, in an oil-filled transformer, when an internal abnormality occurs, the internal pressure rises, and there is a method of reducing the pressure by providing an air layer portion in the transformer body in response to this internal pressure rise. In this method, when the air layer portion cannot be sufficiently secured, it is necessary to provide the air layer portion outside. In addition, there is a pressure relief device as a protective component against an increase in internal pressure. When an internal abnormality occurs, gas and insulating oil may be ejected from the pressure relief device.

  And in order to collect | recover these jetting gas and insulating oil, it was set as the structure as shown in FIG. 5 conventionally. FIG. 5 shows a configuration of an oil-filled transformer that includes an oil recovery tank and recovers gas and insulating oil ejected due to internal abnormality via a pressure relief pipe. In FIG. 5, 1 is a transformer body, 3 is an insulating oil, 4 is an oil surface of the insulating oil, 7 is an air layer portion, 10 is an iron core formed of a silicon steel plate or an amorphous ribbon, 11 is a winding, A primary bushing, 17 is a secondary bushing, 30 is a pressure relief pipe, 31 is an oil recovery tank, and 32 is an oil recovery tank drain valve. When an internal abnormality occurs due to winding inside the transformer, discharge at the iron core, overheating of insulating paper, etc., gas is generated and the internal pressure rises, and the gas and insulating oil pass through the pressure relief pipe 30 and the oil recovery tank 31. To be recovered. When the oil recovery tank 31 is filled with gas or insulating oil, the oil recovery tank drain valve 32 is opened to drain the oil.

  In addition, when the oil-filled transformer shown in FIG. 5 is installed in the tower for offshore wind power generation, since the air layer portion 33 is secured in the oil-filled transformer, the tower is shaken by waves, and accordingly When the oil-filled transformer is also shaken, the air in the air layer portion 33 and the insulating oil 3 may be mixed and bubbles may be generated. When bubbles are generated in the insulating oil 3, there is a possibility that dielectric breakdown may occur due to the bubbles.

Therefore, when an oil-filled transformer is used for offshore wind power generation, it is necessary to adopt a configuration in which bubbles are not generated in the insulating oil even if the oil-filled transformer is shaken by waves.
Also, when used for offshore wind power generation, if an internal abnormality occurs and the pressure relief device operates and insulating oil is ejected, the insulating oil will flow out into the ocean on the environment. It is necessary to make the structure difficult to leak.
Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-126931) communicates the lower part of the conservator located in the information of the transformer main body with the upper part of the transformer main body 1, and the upper end of this connecting part and the transformer main body. It is described that an oil communication pipe that communicates with the upper part of the cooler located on the side of the compressor is provided, and that a pressure relief valve is provided on the upper part of the conservator.

JP 2001-126931 A

  In a conventional oil-filled transformer, if the air layer cannot be secured sufficiently, an air layer is installed outside, and the internal pressure rises due to an internal abnormality, so that the oil recovery tank is oil-filled in response to the ejection of insulating oil. By providing it outside the main body of the transformer, the entire transformer becomes larger and the cost increases. In addition, when used for offshore wind power generation, the oil-filled transformer may generate air bubbles in the insulating oil due to the shaking of the waves, causing dielectric breakdown, etc. May erupt outside the transformer and leak, causing adverse environmental effects. In Patent Document 1, the pressure release valve is installed on the upper part of the conservator and is different from the configuration of the present invention.

  In order to solve the above problems, the present invention provides an oil-filled transformer including a radiator having both internal pressure relaxation, a pressure relief mechanism, and an oil recovery mechanism in the transformer when an internal abnormality occurs in the oil-filled transformer. It is to provide.

In order to solve the above problems, the present invention is an oil-filled transformer in which an iron core and a winding are arranged in a transformer tank and filled with insulating oil, and a lid is provided on the upper part of the transformer tank, A primary bushing and a secondary bushing are arranged on the lid of the transformer tank, and a radiator with corrugated fins is arranged on the side surface of the transformer tank. The transformer tank and the radiator have upper and lower side portions. It is connected at the header part so that the insulating oil can move, and the radiator has a height higher than the lid of the transformer tank, and an air layer part is provided in the upper part of the radiator, and the upper part of the radiator and the Connect the lid of the transformer tank with a connecting pipe with a cooler installed, and position the oil level of the insulating oil of the radiator inside the radiator, where the oil level of the insulating oil is shaken by the wave. However, no bubbles are generated in the transformer tank. As higher position than the height, and characterized by being configured as an air layer portion does not occur at the top of the inside of the transformer tank.

  According to the present invention, even if an internal abnormality occurs in the oil-filled transformer, gas is generated, and the internal pressure rises, the gas in the transformer body is cooled as it moves to the radiator via the connecting pipe and moves. The gas is returned to the liquid and collected. Further, with respect to the internal pressure increase, the pressure can be lowered by a pressure relief device installed at the top of the radiator, and the discharged insulating oil can be reduced by an oil recovery cylinder provided around the pressure relief device.

  Also, when used for offshore wind power generation, the oil surface position of the insulating oil is higher than the cover surface of the oil-filled transformer, and there is no air layer in the transformer body, so the oil surface of the insulating oil is shaken by waves. However, no bubbles are generated. The bubbles generated in the radiator are circulated through the insulating oil. The upper header of the radiator moves from the transformer body side to the radiator side, and the lower header section from the radiator side to the transformer body side. Since the air layer is above the radiator, it is difficult for the transformer body to move. Therefore, the internal abnormality is unlikely to occur.

The front sectional view of the oil-filled transformer of the example of the present invention is shown. The front sectional drawing and top view of the heat radiator of the Example of this invention are shown. The front sectional drawing of the oil-filled transformer of another Example of this invention is shown. A sectional view and a top partial cutaway view of a heat dissipation device installed in a heat sink of an oil-filled transformer are shown. Front sectional drawing of the conventional oil-filled transformer is shown.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Example 1
FIG. 1 shows a front cross-sectional view of an oil-filled transformer having a radiator having an oil recovery mechanism according to an embodiment of the present invention. In FIG. 1, 1 is an oil-filled transformer body, 2 is a radiator attached to the side surface of the oil-filled transformer body 1, 3 is an insulating oil filled in the transformer body and the radiator, and 4 is an oil of the insulating oil. Surface 5 is a connecting pipe connecting the transformer body 1 and the radiator 2, 6 is a pressure relief device, 7 is an air layer portion above the radiator 2, 10 is a silicon steel plate installed in the transformer body 1, An iron core 11 formed of an amorphous ribbon is a winding. Reference numeral 12 denotes a header portion that connects the transformer main body 1 and the radiator 2, and the insulating oil 3 moves. Reference numeral 13 denotes the direction of the insulating oil flow between the transformer main body 1 and the radiator 2. Reference numeral 14 denotes the inside of the connecting pipe 5. , 16 is a primary bushing, and 17 is a secondary bushing.
In FIG. 1, an assembly incorporating an iron core 10 and a winding 11 is installed inside the transformer body 1, and a primary bushing 16 and a secondary bushing 17 are disposed on the top of the lid 41 of the transformer tank 1. . A radiator 2 is installed on the side surface of the transformer body 1, and the transformer body 1 and the radiator 2 are configured so that the header part 12 is connected to the upper part and the lower part of the side surface so that the insulating oil 3 can move to each other. .

  In FIG. 1, one radiator 2 is arranged on one side, but a radiator having the same configuration may be installed on the other side. The height of the radiator 2 is set higher than the surface of the lid 41 of the transformer tank body 1. Then, a U-shaped connecting pipe 5 is installed on the upper part of the transformer body 1 and the upper part of the radiator 2, so that the oil surface of the insulating oil 3 is insulated in the transformer body 1 so that it is higher than the cover of the transformer body 1. Fill with oil. In the radiator 2, the height is higher than that of the transformer body 1, and the insulating oil 3 is provided with the air layer portion 7, so that the upper portion of the radiator 2 is not filled up, and the oil level of the insulating oil 3 is increased. Is higher than the height of the lid 41 surface of the transformer tank body 1 and lower than the height of the radiator 2. The radiator 2 is formed of corrugated fins having a large surface area. In addition, a pressure relief device 6 is installed above the radiator 2. The pressure release device 6 will be described later.

In FIG. 1, the flow 13 of the insulating oil 3 between the transformer main body 1 and the radiator 2 flows from the bottom to the top as the insulating oil is warmed by the heat amount of the iron core or the iron core in the transformer main body 1 in a normal use state. It becomes convection, enters the radiator 2 from the header part at the top of the transformer body, cools and descends, enters the transformer body 1 from the header part at the bottom of the transformer body 1 and circulates, and the transformer is cooled. In the transformer main body 1, when an internal abnormality occurs, gas is generated as described above, and the internal pressure rises, so that the gas moves to the radiator 2 through the connecting pipe 5 as in the flow 14. The generated gas is mostly C ₂ H ₂ and H ₂ gas when accompanied by discharge, and CO and CO ₂ become prominent when the insulating paper is overheated. Further, when the temperature of the insulating oil 3 rises due to an internal abnormality and is gasified and passes through the connecting pipe 5, it is cooled and liquefied to return to liquid and can be recovered as insulating oil in the radiator 2. With such a configuration, there is no need to use a conventional oil recovery tank.

(Example 2)
Next, when using an oil-filled transformer for offshore wind power generation, a configuration in which insulating oil does not flow out to the outside, particularly the open ocean will be described. 2 shows a radiator having a structure in which insulating oil does not leak to the outside, FIG. 2 (a) is a top view of the radiator, and FIG. 2 (b) is a front sectional view of the radiator. 2 (a) and 2 (b) is different from FIG. 1 in that an oil recovery cylinder of a radiator is provided around the pressure relief device 6. FIG.

  An internal abnormality occurs in the oil-filled transformer body, gas is generated, the internal pressure rises, and the gas passes through the connecting pipe 5 connected to the radiator 2 installed on the side surface of the transformer body 1 so that the gas is an air layer portion. The pressure release device 6 operates by raising the pressure of 7 at once, and the gas is released to the outside through the pressure release device 6. At this time, what is discharged from the pressure relief device 6 includes insulating oil in addition to gas. An oil recovery cylinder 8 is provided around the pressure release device 6 so that the released insulating oil does not leak to the outside, and the insulating oil released from the pressure release device 6 is stored. The oil recovery cylinder 8 is provided with a lid so that it can be opened and closed.

It is also possible to arrange a polypropylene sheet or the like that is bonded to the multi-layer structure to absorb the insulating oil in the oil collecting cylinder 8 so that the liquid does not leak to the outside.
Further, there is a method of arranging a material that solidifies the insulating oil in addition to absorbing the insulating oil.
In this way, since the insulating oil rescued around the pressure relief device 6 is stored, absorbed, or solidified, it can be prevented from flowing out of the transformer, particularly into the open ocean.

Here, the configuration of the radiator 2 will be described with reference to FIG.
The heat radiator 2 connected by the oil-filled transformer body 1 and the header portion 12 is formed by a square pole having a width of almost the same size as the header portion 12, and corrugated fins 42 are provided on both sides of the plane continuous to the header portion 12. Installed to increase the surface area of the radiator and improve cooling efficiency. The corrugated fins 42 are formed by bending a steel plate into a corrugated shape, and insulating oil enters the corrugated fins 42 so that it can be circulated by convection and cooled. The radiator 2 forms a flow in which the temperature of the insulating oil rises when the temperature is higher in the central rectangular column main body portion and the corrugated fin portion, and descends when cooled.

(Example 3)
Next, the structure which cools the connecting pipe 5 which connects the oil-filled transformer main body 1 and the heat radiator 2 is demonstrated. FIG. 3 shows a diagram in which a cooling function is arranged in the connecting pipe 5. The cooler 43 winds a hollow pipe around the connecting pipe 5 a predetermined number of times, and sends water, refrigerant gas, air, or the like to the connecting pipe 5. The gas passing through the inside 5, particularly the gas of the oil gasified by the insulating oil is cooled, liquefied and returned to the liquid for recovery.

  In FIG. 3, the cooler 43 of the connecting pipe 5 can detect an increase in internal pressure by a pressure sensor or the like when an internal abnormality occurs, not always, and can be operated by the detected signal. In addition to the above, the cooling may be wind power such as a fan, or a rapid cooling spray may be used.

  Next, the pressure relief device 6 will be described. 4 shows a pressure relief device, FIG. 4 (a) is a top view of the pressure relief device, and FIG. 4 (b) is a sectional view thereof. 4 (a) and 4 (b), 20 is a cover, 21 is a receiving portion of the shaft 26, 22 is a pressure relief device body, 23 is a mounting seat such as an upper wall of the heat dissipation device, and 24 is a pressure relief device as a mounting seat. Bolts to be fixed, 25 is a nut, 27 is a spring provided on the shaft 26, 28 is a hole provided in the pressure relief device main body 22, 29 is a gas in a state where the cover 20 and the pressure relief device main body 22 are closed. An O-ring 30 for preventing leakage indicates an upper wall of the radiator 2.

Next, the operation of the pressure relief device 6 will be described. When the area under the mounting seat 23 of the pressure relief device 6 is filled with a gas or a liquid of insulating oil and the pressure increases, high pressure gas enters the concave portion 31 of the pressure relief device body 22 and enters the pressure relief device body 22. The high pressure gas or insulating oil liquid enters the space 32 surrounded by the cover 20 and the pressure release device main body 22 from the provided hole 28, and the pressure release device main body 22 is fixed, so that the shaft 26 is pushed up. At the same time, the spring 27 is compressed, the shaft 26 pushes up the receiving portion 21 of the cover 20, and the cover 22 is pushed up. When the cover 20 is pushed up, the liquid of high pressure gas or insulating oil in the space 32 formed by the pressure release device main body 22 and the cover 20 is discharged from the space 33 inside the cover 20.
In the above configuration, when an abnormal pressure occurs due to an internal abnormality, the cover of the pressure release device is pushed up to release the internal pressure to the outside. When the internal pressure decreases, the cover 20 is automatically restored to the original state by the spring 27 and airtight. Hold.

  In the present invention, when an internal abnormality occurs in the oil-filled transformer due to the above-described configuration, the insulating oil gasified by the connecting pipe connecting the radiator installed on the side surface of the transformer body is cooled and returned to the liquid. It is possible to collect the insulating oil released around the pressure relief device provided at the top of the radiator, and to prevent the insulating oil liquid from leaking to the outside using a material that absorbs or solidifies. To avoid adverse environmental impacts.

DESCRIPTION OF SYMBOLS 1 ... Oil-filled transformer tank 2 ... Radiator 3 ... Insulating oil 4 ... Oil level of insulating oil 5 ... Connecting pipe 6 ... Pressure release device 7 ... Air layer part 8 ... Oil recovery cylinder 10 ... Iron core 11 ... Winding 12 ... Header part 14 ... Gas flow in the connecting pipe 16 ... Primary bushing 17 ... Secondary bushing 20 ... Pressure relief device cover 21 · Shaft receiving part 22 · Pressure relief device body 23 · Mounting seat 24 · Bolt 25 · Nut 26 · Shaft 27 Spring 28 Hole 29 O-ring 41 Transformer tank lid 42 Wave corrugated fin 43 Cooler

Claims (7)

An oil-filled transformer with an iron core and windings placed in a transformer tank and filled with insulating oil,
A lid is provided on the upper part of the transformer tank, and a primary bushing and a secondary bushing are arranged on the lid of the transformer tank,
Place a radiator with corrugated fins on the side of the transformer tank,
The transformer tank and the radiator are connected to the upper and lower sides of the side surface by a header part so that the insulating oil can move,
The radiator has a height higher than the lid of the transformer tank, and an air layer portion is provided in the upper part of the interior.
The upper part of the radiator and the lid of the transformer tank are connected by a connecting pipe provided with a cooler ,
The position of the oil level of the insulating oil of the radiator is the inside of the radiator, and no bubbles are generated in the transformer tank even if the oil level of the insulating oil is shaken by a wave. An oil-filled transformer for offshore wind power generation, characterized in that an air layer portion is not formed at an upper portion inside the transformer tank as a position higher than the height. The oil-filled transformer according to claim 1,
The oil-filled transformer, wherein the connecting pipe is U-shaped. The oil-filled transformer according to claim 1,
An oil-filled transformer characterized in that a pressure relief device is installed above the radiator. In the oil-filled transformer according to claim 3 ,
An oil-filled transformer, wherein an oil recovery device is installed around the pressure relief device. The oil-filled transformer according to claim 4 ,
An oil-filled transformer, wherein the oil recovery device has a cylindrical shape. The oil-filled transformer according to claim 4 ,
An oil-filled transformer, wherein a material that absorbs insulating oil or a material that solidifies is disposed in the oil recovery device. The oil-filled transformer according to claim 6 ,
The oil-filled transformer, wherein the material that absorbs the insulating oil is a polypropylene sheet that is pressure-bonded to a multilayer structure.

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