JPH05114519A - Gas sending type gas insulated transformer - Google Patents

Abstract

PURPOSE:To reduce cost by a method wherein inexpensive insulation material can be used by decreasing the temperature to which an on-load tap changer is exposed. CONSTITUTION:A diaphragm 8 is installed between an on-load tap changer 4 and transformer contents which are accommodated in a sealed vessel 1, and their spaces are partitioned. From the view point of insulation gas flow, the spaces are made independent. A gas circulation route is constituted in the following manner. Cooling gas sent out from a gas blower 6 installed in a cooling apparatus 5 is firstly made to flow in the space in which the on-load tap changer 4 is installed, and then introduced into a lower space of the transformer contents by using a gas guide 7. Thereby the on-load tap changer 4 is kept at a low temperature without practcally changing the cooling action of the transformer contents 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding or an iron core having a high voltage portion, which is obtained by enclosing an insulating gas made of sulfur hexafluoride, which is abbreviated as SF ₆ , in a hermetically sealed container which serves as an insulating medium and a cooling medium. The present invention relates to a gas-insulated transformer in which the contents of a transformer including the gas-insulated transformer are housed, and more particularly, to a gas-feed type gas-insulated transformer having a load tap changer and adopting a cooling method for forcibly circulating insulating gas.

[0002]

2. Description of the Related Art FIG. 7 is a schematic view showing the contents of a conventional gas-insulated transformer, a tap changer under load, and a cooling structure. In this figure, a sealed container 13 is filled with an insulating gas of several atmospheres, and a transformer core 20 including an iron core 2, a winding 3 and its not-shown accessory parts is housed therein. An on-load tap changer 2 attached to the upper lid 13 is stored.

The cooler 5 is connected to the hermetically sealed container 13, and the insulating gas flows from the upper position of the transformer contents 20 shown in the figure to the upper position of the cooler 5 through a pipe not labeled. While being cooled in a cooler 5 provided with an unillustrated blower, the cooler gas flows downward and flows as a cooling gas from a lower position of the cooler 5 to a lower position of a sealed container 13 indicated by a gas blower 6. Transformer contents 2
The lower part of 0 is covered with a gas guide 73, and a circulating cooling path that returns to the upper position through a cooling duct (not shown) provided in the transformer contents 20 in which the cooling gas flows vertically is provided. It is configured. The pressure at which the insulating gas flows through this cooling path is mostly due to the gas blower 6. The pressure difference due to the tunnel effect within the transformer contents 20 is small. In other words, the transformer contents 20
The cooling effect is enhanced by circulating the insulating gas at a much faster rate than the natural cooling type in which the insulating gas flows due to the pressure difference due to the tunnel effect inside.

A cooling duct is provided in the transformer contents 20, and an insulating gas as a cooling medium is flowed only in the cooling duct to cool the transformer. The heat transfer coefficient is higher as the flow velocity of the insulating gas is higher. This is because the cooling efficiency is greatly improved.
In particular, since the winding 3 generates a lot of heat in the transformer contents 20, the above-mentioned cooling duct is especially provided in the winding 3 so that the insulating gas can effectively flow in the cooling duct. Is taken into consideration.

The insulating gas from the upper portion of the transformer contents 20 cools the transformer contents 20 to take heat and is heated to raise the temperature. The ambient temperature of the insulating gas at this position is 40 degrees. It is about 120 degrees under the condition that the load current is 100%. The upper position of the tap changer 2 under load is exposed to a high temperature close to this temperature. Therefore, the insulating material forming the tap changer 2 under load is one that can withstand this high temperature. Since the heat generated by the load tap changer 2 itself is small, a structure in which a cooling gas is supplied to cool the tap changer 2 is not adopted. As mentioned above 12
The reason why it is exposed to a high temperature of about 0 degrees is that the transformer contents 20 are cooled and exposed to the insulating gas that has become a high temperature. By the way, the temperature of the cooling gas after being cooled by the cooler 5 is about 50 degrees lower than the above-mentioned maximum temperature when the load current is 100%. When the ambient temperature is 40 degrees, it becomes about 70 degrees.

FIG. 8 is a graph showing the temperature distribution of each part. In this figure, the horizontal axis is the position of each part indicated by numerical values in the circles in FIG. 7, and the vertical axis is the temperature of the insulating gas. As described above, since the cooled insulating gas flows at the position, the temperature is low, and the position is the high temperature insulating gas whose temperature has risen after the transformer contents 20 are cooled. It indicates that the temperature is high, which is almost the same as the temperature.

[0007]

As described above, the insulating material forming the tap changer 2 under load that is exposed to a high temperature must be a material that can withstand a high temperature of 120 degrees. In the case of insulating oil, which is the most widely used insulating medium for large-capacity transformers, the temperature to which an insulating material such as a pressboard is exposed is generally 100 degrees or less, and an insulation material that can withstand 120 degrees against this. There are glass fiber reinforced synthetic resin, polyamide paper, etc., but these are about 10 times more expensive than press board, so the load tap changer equipped in the gas cooling type gas insulation transformer is expensive. There is a problem that it becomes.

An object of the present invention is to solve such a problem and to provide a gas-cooled gas-insulated transformer capable of reducing the temperature to which the tap changer under load is exposed and using an inexpensive insulating material. ..

[0009]

In order to solve the above-mentioned problems, according to the present invention, the contents of a transformer, a tap changer at the time of load, a sealed container in which these are housed and an insulating gas is sealed,
A cooler that cools the insulating gas heated by the contents of the transformer to raise its temperature to generate a cooling gas, a gas blower that sends the cooling gas to the sealed container, and a guide that sends the supplied cooling gas to the lower part of the contents of the transformer. In the gas transmission type gas insulation transformer consisting of the gas guide as a plate,
A partition plate is provided for partitioning the space in which each of the transformer contents and the load tap changer is provided, and a cooling gas inlet is provided in the space where the load tap changer is provided,
This space and the space below the transformer contents are connected to each other by providing a flow passage through which the cooling gas passes, and the transformer contents and the load tap changer arranged side by side upright. A partition plate connected to the gas guide is provided therebetween, an inlet for cooling gas is provided in an upper portion of the space where the load tap changer is provided, and a space under the transformer and the load tap changer are provided. The gas guide is provided with a through-hole that connects the space with the space, and a partition plate is provided between the contents of the transformer and a load tap changer horizontally provided above the transformer to provide cooling gas. Is provided at one end of the space where the load tap changer is provided, and a pipe is provided from the other end to connect this space with the space below the transformer contents. Is the external pipe provided outside the sealed container? That Is a, and also, the pipe is assumed to consist of internal pipe which is provided in a sealed container.

[0010]

In the structure of the present invention, a partition plate for partitioning the tap changer under load and the contents of the transformer is provided so that the respective spaces are made independent in terms of the flow of the insulating gas, and the inlet of the cooling gas is switched over under load. Is installed in the space where the transformer is installed so that the tap changer is exposed to the cooling gas at the time of loading, and this space is connected to the space below the transformer contents formed by the gas guide, and the flow path through which the insulating gas passes. By providing the cooling gas, the cooling gas whose temperature hardly rises from the space where the tap changer at load is installed enters the space below the transformer contents, and thereafter rises to the upper part while cooling the transformer contents as in the conventional case. And becomes high-temperature insulating gas.

In addition, a partition plate connected to the gas guide is provided between the contents of the transformer and the load tap changer arranged upright next to the transformer so that the space provided for each of them is independent and the cooling gas By providing the inlet at the upper part of the space where the load tap changer is provided, and by providing the gas guide with a through hole that connects the lower part of the transformer and the space where the load tap changer is provided, The cooling gas flowing into the space provided with the tap changer flows into the space below the contents of the transformer with almost no increase in temperature.

A partition plate is provided between the contents of the transformer and a load tap changer which is horizontally provided above the transformer so that the space in which each partition is provided is independent and the inlet of the cooling gas is loaded. By installing pipes at one end of the space where the tap changer is installed and connecting the other end of this space to the space below the transformer contents, the tap changer under load is exposed to cooling gas Cooling gas flows into the contents of the vessel. In this case, the pipe may be an external pipe arranged outside the sealed container or an internal pipe arranged inside.

[0013]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is a schematic diagram showing the contents of a gas-insulated transformer, a tap changer at the time of load, and a cooling structure according to a first embodiment of the present invention. The same components as those in FIG. Detailed explanation is omitted. Further, FIG. 2 is a graph showing the temperature distribution at each position, and description of the same items as in FIG. 8 will be omitted. In these figures, the cooling gas produced by being cooled in the cooler 5 enters the gas blower 6 at the position of
The cooling gas discharged from the gas blower 6 flows through the pipe 9 and flows into the sealed container 1 from the inlet port indicated by the symbol provided at the upper position of the tap changer 4 under load. A space in which the load tap changer 4 and the transformer contents 20 are provided is partitioned by a partition plate 8. Further, a through hole 74 is provided in a portion of the gas guide 7 that is in contact with the space where the load tap changer 4 is provided, and the cooling gas that has flowed into the space where the load tap changer 4 is provided is the through hole 74. Through the gas guide 7 into the space below the transformer contents 10. Like the conventional transformer, the cooling gas flowing into the gas guide 7 is heated while cooling the transformer contents 20, and its temperature rises to become a high temperature gas, and then flows into the cooler 5.

Since the heat generated by the tap changer 4 under load is much smaller than the heat generated by the winding 2, the temperature change of the cooling gas from position to position is small, and the transformer contents are small. It does not affect the cooling effect of 20. Since the tap changer 4 under load is exposed to the cooling gas, the low temperature state is maintained. Therefore, it is not necessary to use an expensive material that can withstand high temperatures as the insulating material used therefor, and the same material as the oil-filled transformer can be used. As a result, the load tap changer is also inexpensive. Also, since it is shared with the load tap changer of the oil-filled transformer, standardization is possible and cost reduction due to mass production can be expected.

FIG. 3 is a schematic view showing the contents of a gas-insulated transformer, a tap changer at the time of load and a cooling structure according to a second embodiment of the present invention. The same components as those in FIG. To omit detailed explanation. Further, FIG. 4 is a graph showing the temperature distribution at each position, and the description of the same items as in FIG. 2 is omitted. In these figures, the load tap changer 4 is provided on the upper portion of the transformer contents 20 and is divided by a partition plate 81 between them.

It is necessary to reduce the floor area of the transformer by placing the load tap changer 4 horizontally on the upper portion of the transformer contents 20. Instead, the height of the transformer becomes large. If this is allowed, such a configuration is adopted. The cooling gas enters the gas blower 6 at the position of, flows through the pipe 91, and flows in from the position indicated by at the right end of the figure in the space where the load tap changer 4 is provided. The external pipe 92
To the gas guide 71 from the position indicated by. The rest is the same as in FIG. Load tap changer 4
Similar to FIGS. 1 and 2, the position is maintained at a low temperature because the position is exposed to the cooling gas.

FIG. 5 is a schematic view showing the contents of a gas-insulated transformer, a tap changer at the time of loading and a cooling structure according to a third embodiment of the present invention. The difference from FIG. 3 is that the external pipe 92 is sealed. The internal pipe 93 that passes through the inside of the container 12 is adopted, and the other points are the same as in FIG. 6 is a graph showing the temperature distribution of the insulating gas in each part of FIG. 5, which is exactly the same as FIG. The internal pipe 93 is shown as a pipe sharing the left wall of the hermetically sealed container 12 in FIG. 5, but of course, it is not limited to this, and the structure in which the pipe 93 is provided regardless of the wall surface of the hermetically sealed container 12 is adopted. You can also

[0018]

As described above, according to the present invention, the space provided with the partition plate and each of the load tap changer and the transformer contents is made independent in terms of the distribution of the partition insulating gas.
A cooling gas inlet is provided in the space where the load tap changer is provided so that the load tap changer is exposed to the cooling gas, and this space and the space under the transformer formed by the gas guide are separated from each other. By providing the communication passages through which the insulating gas passes, the tap changer under load is exposed to the cooling gas and the low temperature is maintained without changing the function of cooling the transformer contents as in the conventional one. Therefore, the insulating material used for this does not need to use an expensive material that can withstand high temperatures, and the same inexpensive material as the oil-filled transformer can be used. Is obtained. Further, since it becomes common with the load tap changer of the oil-filled transformer, the load tap changer can be standardized, and the cost reduction due to the mass production effect can be expected.

Further, the load tap changer is arranged upright in the transformer contents, and a partition plate connected to the gas guide is provided between the load tap changers and the transformer contents so that the space provided for each of them is independent. By providing a cooling gas inlet at the upper part of the space where the load tap changer is provided, and by providing a through hole that connects the lower part of the transformer contents and the space where the load tap changer is provided in the gas guide. Since the cooling gas that has flowed into the space where the load tap changer is installed flows into the space below the contents of the transformer with almost no temperature rise, the load tap changer is always maintained at the same low temperature as the cooling gas. As a result, the same effect as the above-mentioned configuration can be obtained.

A partition plate is provided between the contents of the transformer and a load tap changer which is horizontally provided above the transformer so that the space in which each partition is provided is independent, and the cooling gas inlet is under load. By installing pipes at one end of the space where the tap changer is installed and connecting the other end of this space to the space below the transformer contents, the tap changer under load is exposed to cooling gas Cooling gas flows into the contents of the vessel. In this case, the pipe may be an external pipe arranged outside the sealed container or an internal pipe arranged inside. In this way, since the tap changer under load is always exposed to the cooling gas, the same effect as the above-described configuration can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a gas-insulated transformer showing a first embodiment of the present invention.

FIG. 2 is a graph showing the temperature distribution at each position in FIG.

FIG. 3 is a schematic diagram of a gas insulation transformer showing a second embodiment of the present invention.

FIG. 4 is a graph showing the temperature distribution at each position in FIG.

FIG. 5 is a schematic diagram of a gas insulation transformer showing a third embodiment of the present invention.

FIG. 6 is a graph showing the temperature distribution at each position in FIG.

FIG. 7 is a schematic diagram of a conventional gas-insulated transformer.

FIG. 8 is a graph showing a temperature distribution of each part of FIG.

[Explanation of symbols]

 1 hermetically sealed container 11 hermetically sealed container 12 hermetically sealed container 13 hermetically sealed container 2 iron core 3 winding 20 transformer contents 4 tap changer under load 5 cooler 6 gas blower 7 gas guide 71 gas guide 72 gas guide 73 gas guide 8 partition plate 81 partition plate 82 Partition plate 9 Piping 91 Piping 92 External piping 93 Internal piping

Claims (5)

[Claims] 1. A transformer contents, a load tap changer, a sealed container in which these are housed and filled with an insulating gas, and an insulating gas which is heated by the contents of the transformer and whose temperature has risen is cooled to generate a cooling gas. A gas-sending gas-insulated transformer comprising a cooler, a gas blower for sending the cooling gas to the sealed container, and a gas guide as a guide plate for sending the sent cooling gas to the lower part of the transformer contents, wherein the transformer contents and the A partition plate for partitioning the space in which each of the load tap changers is provided is provided, and an inlet for cooling gas is provided in the space in which the load tap changer is provided, and this space and the space below the transformer contents are provided. A gas transmission type gas-insulated transformer, characterized in that it is provided with a flow passage that is in communication with and through which cooling gas passes. 2. A partition plate connected to the gas guide is provided between the contents of the transformer and the load tap changer arranged side by side upright, and the cooling gas inlet is provided with the load tap changer. 2. The gas guide is provided with a through hole which is provided in an upper portion of the provided space and which connects a space below the transformer contents and a space in which the load tap changer is provided. Gas transmission type gas insulation transformer. 3. A partition plate is provided between the contents of the transformer and a load tap changer horizontally provided above the transformer, and a cooling gas inlet is provided in the space where the load tap changer is provided. 2. The gas-sending gas-insulated transformer according to claim 1, further comprising a pipe provided at one end and connecting the space to the space below the transformer from the other end. 4. The gas transmission type gas insulated transformer according to claim 3, wherein the pipe is an external pipe provided outside the sealed container. 5. The gas transmission type gas insulated transformer according to claim 3, wherein the pipe comprises an internal pipe provided in a sealed container.