JP2008108802A - Gas insulated transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas insulated transformer that can uniform and improve winding cooling performance by insulating gas and maximize the cooling capacity. <P>SOLUTION: The gas insulated transformer is provided with thin-plate flow regulating plates 14a and 15a that are installed between an inner winding 3 and a spacer 9a and between the lower side of an outer winding 4 and a spacer 9b, respectively. The width of the flow regulating plate 15a under the outer winding in the direction of gas flow is made larger than that of the flow regulating plate 14a under the inner winding in the direction of gas flow. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a gas insulation transformer that performs cooling with an insulating gas such as SF ₆ gas, nitrogen gas, carbon dioxide gas, and air, and more particularly to a technique for improving cooling performance.

A conventional example of a gas-insulated transformer will be described with reference to FIG. That is, an apparatus body comprising an iron core 2 in which a silicon steel plate is laminated in a tank 1 and an inner (low voltage) winding 3 and an outer (high voltage) winding 4 wound around the main leg of the iron core 2 is an SF ₆ gas. And an insulating gas 5 such as nitrogen gas.

  Each of the inner winding 3 and the outer winding 4 is a multi-cylindrical winding formed by winding a copper wire with insulation coating into a cylindrical shape and forming four layers thereof, and is installed on the inner peripheral side and the outer peripheral side. Insulation between the windings and the iron core 2 are maintained by the insulating cylinder 6. Vertical ducts 8 are formed between the respective cylindrical windings and between the cylindrical windings and the insulating cylinders by vertical duct spacers 7. Further, horizontal duct spacers 9 a and 9 b are formed above and below the cylindrical windings. A horizontal duct 10 is formed.

  A plurality of coolers 11 for cooling the insulating gas are installed outside the tank, and a pipe 12 and a blower 13 for circulating gas between the tank 1 and the plurality of coolers 11 are provided. Yes.

  The insulating gas cooled by the cooler cools the iron core and the windings as the temperature rises, and circulates back to the cooler. In particular, in the winding, as shown by the arrows in the figure, the insulating gas flows in from the outside lower part and flows in the vertical duct from the bottom to the top to cool the winding. As described above, the device body composed of the iron core and the winding is cooled and insulated by the insulating gas.

Here, when the capacity | capacitance of a transformer is small, it becomes a natural circulation cooling system without an air blower, but the flow of gas is completely the same.
JP 2003-109825 A

By the way, in recent years, reduction of the amount of SF ₆ gas used in gas insulation equipment has been proposed from the viewpoint of environmental problems, such as reducing the gas pressure of SF ₆ gas, nitrogen gas, carbon dioxide gas, air, or a mixed gas thereof. Development and research of the equipment using is carried out.

Here, in the gas insulated transformer as described above, when the gas pressure of the SF ₆ gas is lowered or when another insulating gas as described above is used, the heat capacity of the gas is larger than that of the SF ₆ gas. Since it is greatly reduced, the cooling capacity is also greatly reduced. In particular, in a gas-insulated transformer of the natural gas circulation type that does not have a blower, the cooling capacity is significantly reduced, which has been a problem.

  As a means for coping with such a problem, it is conceivable to make a cooling design by increasing the winding in the main body tank to reduce the amount of heat generation, or increasing the number of coolers or the number of panels per unit. . However, these measures have a drawback that the size of the equipment is increased.

  In addition, if a cylindrical winding that facilitates gas flow is employed, the gas circulation flow rate is increased, so that the cooling performance is improved. However, in this case as well, there is a drawback that the difference between the winding that tends to flow gas and the winding that does not flow easily becomes remarkable, and the winding temperature rises locally. In particular, in the conventional example shown in FIG. 5, there are cases where a large amount of gas flowing from the outer peripheral side flows into the vertical duct near the entrance and does not flow so much into the vertical duct far from the entrance. In this case, the temperature of the inner cylindrical winding will increase.

  The present invention has been proposed in order to solve the above-described problems of the prior art, and its purpose is to achieve uniform and improved winding cooling performance with an insulating gas to maximize the cooling capacity. It is to provide a gas-insulated transformer that can.

  In order to achieve the above object, a gas-insulated transformer according to the present invention comprises an iron core laminated with silicon steel sheets, a low-voltage inner winding formed by winding a copper wire in a cylindrical shape around the main leg portion of the iron core, and a high-voltage Multiple cylindrical windings each having a plurality of outer windings arranged concentrically, a vertical cooling duct in which vertical spacers are arranged at equal intervals in the circumferential direction between the cylindrical windings, and horizontally above and below the cylindrical windings In a gas-insulated transformer comprising a horizontal duct having spacers arranged radially and at equal intervals, between at least one of the upper and lower ends of the inner winding and the outer winding, and the horizontal spacer, A plate-like flow rate adjusting unit is provided corresponding to the position of the horizontal spacer.

  According to the present invention as described above, a plate-like flow rate adjustment provided corresponding to the position of the horizontal spacer between at least one of the upper and lower ends of the inner winding and the outer winding and the horizontal spacer. Since the cross-sectional area of the flow path is narrowed by the plate and pressure loss occurs, the gas flow in each vertical duct becomes uniform. For this reason, the cooling efficiency of the winding is made uniform and improved, and a local increase in the winding temperature can be suppressed. Thereby, the winding cooling performance of the gas insulated transformer can be maximized.

  According to the present invention as described above, it is possible to provide a gas-insulated transformer that can achieve uniform and improved winding cooling performance with an insulating gas and maximize the cooling capacity.

  Hereinafter, typical embodiments according to the present invention will be described in detail with reference to FIGS.

(1) First Embodiment [Configuration]
As shown in FIG. 1, the gas-insulated transformer according to the first embodiment of the present invention has a cylindrical shape in which a low-voltage side inner winding 3 and a high-voltage side outer winding 4 are respectively coated with insulation. Insulated between the windings and the iron core is maintained by the insulating cylinders 6 installed on the inner and outer peripheral sides.

  A vertical duct 8 is formed between the cylindrical windings and between the cylindrical winding and the insulating cylinder by a vertical duct spacer 7. Also, horizontal duct spacers 9a and 9b are respectively installed on the upper and lower portions of the inner and outer windings, thereby forming a horizontal duct 10. Due to the presence of the horizontal duct 10, a cooling insulating gas flows from the outer peripheral side of the horizontal duct 10.

  In this embodiment, furthermore, thin plate-like flow rate adjusting plates 14a and 15a are installed between the inner winding 3 and the spacer 9a and between the lower portion of the outer winding 4 and the spacer 9b, respectively. The width of the flow rate adjustment plate 15a at the lower part of the wire with respect to the gas flow direction is formed wider than the width of the flow rate adjustment plate 14a at the lower side of the inner winding with respect to the gas flow direction.

[Function and effect]
In the present embodiment configured as described above, the insulating gas flows from the outer peripheral side of the horizontal duct at the lower part of the winding and from the vertical duct on the outer peripheral side to the inner peripheral side as indicated by the arrows in FIG. The air is shunted to the ducts in order, and the windings are cooled by flowing in the vertical ducts from the bottom to the top.

  Here, conventionally, there has been a gas shunting characteristic in which gas easily flows into the vertical duct on the outer peripheral side close to the inlet and hardly flows into the vertical duct on the inner peripheral side far from the inlet.

  On the other hand, in the present embodiment, by installing the wide flow rate adjusting plate 15a on the outer peripheral side where it is easy to flow, the flow passage cross-sectional area of the vertical duct inlet is narrowed, and the flow suddenly shrinks and expands. A large pressure loss will occur. Further, since the flow rate adjusting plate 14a installed on the inner peripheral side which is difficult to flow is narrow, a large pressure loss does not occur, and the flow resistance hardly changes.

  Therefore, gas hardly flows in the vertical duct of the outer winding, which has been easy to flow in the past, and the gas flow in both windings becomes uniform because the vertical duct of the inner winding is not different from the conventional. In particular, by adjusting the widths of the flow rate adjusting plates 14a and 15a, the gas flow rate can be controlled in accordance with the heat generation amount of the winding. Thereby, the cooling efficiency of the winding is averaged, the rise in winding temperature can be suppressed, and the winding cooling performance of the gas insulated transformer can be maximized.

(2) Second Embodiment [Configuration]
A second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a detailed view of a winding portion similar to FIG. 1, and horizontal duct spacers 9a and 9b are respectively installed on the upper and lower portions of the inner and outer windings, and a horizontal duct 10 is formed. Yes. In the present embodiment, the outer peripheral side of the horizontal duct is closed by the insulating cylinder 6a, and the opening 16 is provided between the inner peripheral side spacers as an alternative function. That is, the insulating gas for cooling flows from the opening 16, travels through the horizontal duct from the inner peripheral side to the outer peripheral side of the winding, and flows into the winding.

  Further, thin plate-like flow rate adjusting plates 14c and 15c are installed between the inner winding 3 and the spacer 9a, and between the lower portion of the outer winding 4 and the spacer 9b, respectively. Is wider than the flow rate adjusting plate 15c below the outer winding.

[Function and effect]
In the present embodiment configured as described above, the insulating gas flows from the inner peripheral side of the horizontal duct at the lower part of the winding and from the vertical duct 8 on the outer peripheral side to the outer peripheral side, as indicated by arrows in the drawing. The current is diverted sequentially to the vertical ducts 8 and flows in the respective vertical ducts 8 from below to cool the windings.

  Here, the gas shunting characteristics are also the same in this embodiment as the gas easily flows into the vertical duct 8 close to the inlet and the gas hardly flows into the vertical duct 8 far from the inlet. By installing the wide flow rate adjusting plate 14c on the inner peripheral side where it easily flows, the flow passage cross-sectional area at the entrance of the vertical duct 8 is reduced, and a relatively large pressure loss occurs. Further, since the flow rate adjusting plate 15c installed on the outer peripheral side where it is difficult to flow is narrow, a large pressure loss does not occur.

  Accordingly, the gas does not easily flow in the vertical duct 8 of the inner winding, which is easy to flow, and the gas flow does not change in the vertical duct 8 of the outer winding, so that the gas flows in both windings approach uniformly. In particular, by adjusting the widths of the flow rate adjusting plates 14c and 15c, the gas flow rate can be controlled in accordance with the heat generation amount of the winding. Thereby, the cooling efficiency of the winding is averaged, the rise in winding temperature can be suppressed, and the winding cooling performance of the gas insulated transformer can be maximized.

(3) Third Embodiment [Configuration]
A third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic view of the flow rate adjusting plates 14d and 15d in the present embodiment. Both the flow rate adjusting plate 14d for the inner winding 3 and the flow rate adjusting plate 15d for the outer winding 4 have a donut plate shape that roughly matches the cross-sectional shape of the winding, and holes 17a, 17b are provided at regular intervals and pitches.

  In FIG. 3, it can be seen that the holes 17a in the inner winding 3 are large and dense, and the holes 17b in the outer winding 4 are small and rough. This represents an embodiment where the insulating gas flows from the outer peripheral side of the horizontal duct. On the other hand, when the insulating gas flows from the inner peripheral side of the horizontal duct, it is the reverse of the mode of FIG. Install closely.

[Function and effect]
In the present embodiment configured as described above, when the insulating gas flows from the outer peripheral side of the horizontal duct, a large hole 17a is densely formed in the flow adjustment plate 14d for the inner winding to adjust the flow for the outer winding. By providing the small holes 17b roughly in the plate 15d, the flow passage cross-sectional area can be easily set with high accuracy, and the gas flow rate between the windings can be controlled with high accuracy.

  On the other hand, when the insulating gas flows in from the inner peripheral side of the horizontal duct, the adjustment of the flow path cross-sectional area and the control of the gas flow rate are facilitated by setting the hole relationship in reverse. In the present embodiment, it is preferable to process several fan-shaped flow rate adjusting plates into a donut plate shape in consideration of workability.

(4) Other Embodiments The present invention is not limited to the above embodiments, and includes the following aspects, for example. For example, the thin plate-like flow rate adjusting plates 14a and 15a in the first embodiment can be provided not only at the lower part of the winding but also at the upper part of the winding or at both the upper and lower parts of the winding. When installed on the top and bottom, half of the pressure loss is generated at two locations, but the estimation error of the pressure loss due to dimensional error or assembly error becomes small.

  It is also possible to omit the inner flow rate adjusting plate 14a far from the inlet, or to make the same width smaller than the horizontal duct spacer 9a. In the latter case, the cross-sectional area of the vertical duct inlet is enlarged, and as a result, an effect of facilitating gas flow can be obtained. Furthermore, by adhering the flow rate adjusting plate 14a to the spacer 9a, positioning and assembling accuracy are improved and workability is also improved. As a result, it is possible to eliminate the positional deviation of the flow rate adjusting plate that occurs at the time of winding assembly, and to reduce dimensional errors and performance estimation errors.

  Furthermore, as shown in FIG. 4, the flow rate adjusting plate 14b at the lower part of the inner peripheral winding and the flow rate adjusting plate 15b at the lower part of the outer peripheral winding are configured so that the width gradually increases from the inner peripheral side toward the outer peripheral side. Is also possible. In this case, the cross-sectional area of the flow path between adjacent flow rate adjusting plates gradually decreases from the inner peripheral side toward the outer peripheral side. In other words, the flow path area of the inlet is wide in the vertical duct on the inner circumference side, which is difficult to flow, and the flow path cross-sectional area of the inlet is narrow in the vertical duct on the outer circumference side, which tends to flow, so that a larger pressure loss occurs toward the outer circumference side. It will be.

  Therefore, gas can be made to flow uniformly in the vertical ducts on the inner peripheral side and the outer peripheral side, and gas flow rate control for each vertical duct is possible instead of gas flow rate control for each winding. Further, the flow rate adjusting plate can be configured to have a different width for each vertical duct.

Schematic of the winding part in the 1st Embodiment of this invention. Schematic of the winding part in the 2nd Embodiment of this invention. The top view of the flow volume adjustment board in the 3rd Embodiment of this invention. The top view which shows the shape and arrangement example of the flow volume adjustment board in other embodiment of this invention. The front view of the conventional gas insulation transformer and the detailed drawing of a coil | winding part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tank 2 ... Iron core 3 ... Inner winding 4 ... Outer winding 5 ... Insulating gas 6, 6a ... Insulating cylinder 7 ... Vertical spacer 8 ... Vertical duct 9 ... Horizontal spacer 10 ... Horizontal duct 11 ... Cooler 12 ... Pipe 13 ... Blowers 14a, 14b, 14c, 14d ... Inner flow rate adjustment plates 15a, 15b, 15c, 15d ... Outer flow rate adjustment plates 16 ... Openings 17a, 17b ... Holes

Claims (7)

An iron core in which silicon steel sheets are laminated, and a multi-cylindrical winding in which a plurality of low-voltage inner windings and a plurality of high-voltage outer windings are concentrically arranged around a main leg portion of the iron core in a cylindrical shape. A vertical cooling duct in which vertical spacers are arranged at equal intervals in the circumferential direction between the cylindrical windings, and a horizontal duct in which horizontal spacers are arranged radially and at equal intervals above and below the cylindrical windings, In the gas-insulated transformer provided,
A gas characterized in that a plate-like flow rate adjusting portion is provided between at least one of the upper and lower end portions of the inner winding and the outer winding and the horizontal spacer, corresponding to the position of the horizontal spacer. Isolation transformer.   The gas-insulated transformer according to claim 1, wherein the flow rate adjusting unit is provided at both upper and lower ends of the inner winding and the outer winding. The vertical cooling duct and the horizontal duct are formed so that the gas flow path flows in from the outer peripheral side of the winding and flows out from the inner peripheral side,
The flow rate adjusting unit is formed with a wide plate width with respect to the gas flow direction on the upstream side of the gas flowing through the two ducts, and with a narrow plate width with respect to the gas flow direction on the downstream side of the gas flow. The gas insulation transformer according to claim 1 or 2.   The gas-insulated transformer according to claim 3, wherein a plate width of the flow rate adjusting portion is gradually narrowed from the upstream side to the downstream side of the gas flowing through the two ducts. The flow rate adjusting portion is formed in a donut shape that is concentrically arranged with each cylindrical winding and has substantially the same inner diameter and outer diameter.
The donut-shaped flow rate adjustment unit has a plurality of holes on the surface,
2. The gas-insulated transformer according to claim 1, wherein the plurality of holes are provided densely on the upstream side of the gas flowing through the two ducts, and are provided small and coarse toward the downstream side. The flow rate adjusting unit is arranged in a plurality of fan shapes that are concentrically arranged with the cylindrical windings and have substantially the same inner diameter and outer diameter,
The fan-shaped flow rate adjusting unit includes a plurality of holes on the surface,
2. The gas-insulated transformer according to claim 1, wherein the plurality of holes are provided densely on the upstream side of the gas flowing through the two ducts, and are provided small and coarse toward the downstream side.   The gas-insulated transformer according to claim 1, wherein the flow rate adjusting unit and the horizontal spacer are bonded and fixed.

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