JPS6315730B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil feed type transformer in which insulating oil is cooled in a transformer case by a cooling device such as a unit cooler and the oil is sent into the case from the lower part of the case. .

In conventional oil-fed transformers, insulating oil cooled by a cooling device is sent to the lower part of the case from the lower oil pipe by an oil pump, and is then sent between the windings and into the core of the transformer housed in the case. The oil is distributed through established oil channels. The insulating oil, whose temperature has risen by cooling the windings and iron core, reaches the upper part of the case, is led to a cooling device through an upper oil pipe connected to the upper part of the case, and is cooled again. It is known that in order to increase the cooling effect in this type of transformer, it is possible to increase the flow rate of the insulating oil that comes into contact with the core and windings.
When the flow rate of the insulating oil flowing inside the winding is increased, static electricity is generated due to friction between the insulating material used in the winding and the insulating oil, and the insulating oil becomes electrically charged. This phenomenon is called a flow charging phenomenon, and if a certain amount of charge is accumulated in the insulating oil, discharge may occur and damage the insulator. We believe that the cause of this flow charging phenomenon is not only the flow rate of the insulating oil, but also subtly affected by the characteristics of the insulating oil, the amount of water in the insulating oil, the oil temperature, and the surface condition of the insulating material. However, the most important factor is the flow velocity of the insulating oil within the windings.

On the other hand, since cooling devices such as unit coolers that cool insulating oil have high cooling efficiency, it is preferable to increase the flow velocity within the radiator to some extent in order to achieve sufficient cooling effect; and the cooling effect will be significantly reduced. Therefore, it is desirable to make the flow velocity within the radiator as fast as possible;
In conventional transformers, when the flow velocity in the radiator is increased, the flow velocity of the insulating oil in the windings is also increased by the increase in flow velocity, making it impossible to avoid the occurrence of the fluid charging phenomenon. If an attempt was made to reduce the flow velocity within the winding in order to prevent the flow charging phenomenon, the flow velocity within the radiator would also decrease, resulting in a drawback that the cooling effect would be inhibited.

In addition, by forming a winding cooling channel and an iron core cooling channel in the case of the transformer, and separately providing a cooling device and an oil supply means for both cooling channels, the winding cooling channel A transformer is known in which the flow rate of insulating oil within the transformer can be adjusted, but when configured in this way, the structure of the transformer inevitably becomes extremely complicated.

The object of the present invention is to provide a transformer main body having an iron core and a winding fitted to the iron core, a case for storing the transformer main body together with insulating oil, and an upper oil pipe and an upper oil pipe in the upper and lower parts of the case, respectively. a cooling device connected via a lower oil feeding pipe; and a cooling device for causing insulating oil in the cooling device to flow into the case from the lower oil feeding pipe and causing insulating oil in the case to flow into the cooling device from the upper oil feeding pipe. In an oil feed type transformer equipped with a lower oil feed pipe, an oil feed means for generating an oil flow in an insulating oil circulation system formed by a storage case and an upper oil feed pipe, cooling can be achieved without complicating the structure. To enable insulating oil to be circulated at an optimum flow rate without changing the flow rate of the insulating oil in a device, preventing a flow charging phenomenon and not inhibiting the heat radiation effect of a radiator.

Therefore, the oil-fed transformer of the present invention has a core cooling flow path provided from the lower part of the case to the upper part of the case along the core to flow insulating oil along the core, and a core cooling passage provided inside the winding. A winding cooling channel is provided almost independently from the core cooling channel to flow insulating oil through it, from the lower part of the case through the winding to the upper part of the case, and the lower part of the core cooling channel. and a flow rate adjusting means inserted in the middle of the oil passage to adjust the flow rate of the insulating oil flowing through the oil passage. We are prepared. The lower oil feed pipe is communicated with the lower part of the winding cooling flow path or the lower part of the core cooling flow path, and the insulating oil sent from the cooling device through the lower oil feed pipe is communicated with the lower part of the winding cooling flow path or the core cooling flow path. Let it flow into the bottom of the.

In the above configuration, when the lower oil pipe is connected to the lower part of the winding cooling flow path, the cooling device → lower oil pipe → lower part of the winding cooling flow path → winding cooling flow path → upper part in the case → upper part Oil pipe → cooling device circulation path,
Insulating oil passes through the cooling device → lower oil pipe → lower part of the winding cooling flow path → oil passage → lower part of the core cooling flow path → core cooling flow path → upper part of the case → upper oil pipe → the circulation path of the cooling device. flows.

In addition, in the above configuration, when the lower oil pipe is communicated with the lower part of the core cooling flow path, cooling device → lower oil pipe → lower part of the core cooling flow path → core cooling flow path →
Upper part inside the case → Upper oil pipe → Cooling device circulation path, Cooling device → Lower oil pipe → Lower part of core cooling flow path → Oil passage → Lower part of winding cooling flow path → Winding cooling flow path →
Insulating oil flows through the upper part of the case → the upper oil pipe → the circulation path of the cooling device.

In any of these cases, by adjusting the flow rate of the insulating oil flowing in the oil passage with a flow rate adjustment means inserted in the middle of the oil passage, the flow rate of the insulating oil in the cooling device can be adjusted without changing the flow rate. The flow rate of the insulating oil in the wire cooling channel can be adjusted to a level that does not cause the flow charging phenomenon. With this adjustment, if the flow rate of the insulating oil in the winding cooling channel is slowed down, the cooling effect on the winding will be reduced, but at this time, the flow rate of the insulating oil in the core cooling channel will conversely increase, so the cooling effect on the core will be reduced. By increasing the cooling effect, it is possible to compensate for the decline in the cooling effect on the windings, contributing to suppressing the temperature rise in the transformer body.

Furthermore, with the above configuration, the cooling device and the oil supply means can be provided in common for the winding cooling channel and the core cooling channel, so that The configuration can be simplified compared to the case where a cooling device and an oil feeding means are provided separately.

In the above configuration, the winding cooling flow path is provided "almost independently" from the core cooling flow path, but this does not mean that the winding cooling flow path is substantially independent from the core cooling flow path to the extent that the two cooling flow paths can have a difference in the flow velocity of the insulating oil. The idea is that the flow rate in the winding cooling passage can be kept lower than the flow velocity in the core cooling passage by adjusting the flow rate in the oil passage with the flow rate adjustment means. As long as it is within this range, there is no problem even if there is some communication path between the two cooling channels.

The transformer of the present invention will be explained in detail below with reference to the illustrated embodiments.

In FIGS. 1 and 2, 1 is a transformer case, which includes a bottom-shaped lower case 2 consisting of a horizontal plate part 2a and a recessed part 2b, and a horizontal plate part 2a.
It consists of a box-shaped upper case 3 which is disposed face down and whose lower end flange part 3a is oil-tightly joined to the peripheral part of the horizontal plate part 2a by welding or the like. On both sides of the recessed part 2b of the lower case 2,
Inclined plates 4, 4 whose ends are joined to the outer surface of the side wall of the concave portion 2b and the lower surface of the horizontal plate portion 2a are provided, and these inclined plates 4, 4, the horizontal plate portion 2a, and the side wall of the concave portion 2b form the concave portion. Common oil passages 5, 5 are formed extending in parallel on both outer sides of the portion 2b. Both ends of these common oil passages 5, 5 (both ends in a direction perpendicular to the paper plane of FIG. 1) are closed off by end plates (not shown). The common oil passages 5, 5 are formed by a plurality of (four in the illustrated example) through holes provided in the horizontal plate portion 2a so as to be located below the windings of a transformer body, which will be described later, housed in the case 1. The hole 6 communicates with the inside of the case 1 . A transformer main body 8 is housed in the case 1 along with an insulating oil 7. Iron core 9 of transformer body 8
is arranged so that its lower yoke portion 9a falls into the recessed portion 2b, and between the lower end surface of the iron core 9 and the bottom surface of the recessed portion 2b is a band-shaped support plate 10,
10 are arranged at predetermined intervals in the longitudinal direction of the concave portion 2b (direction perpendicular to the plane of the paper in FIG. 1). Lower yoke portion 9a inserted into concave portion 2b
is tightened in the lamination direction of the steel plates by core tightening jacks 11, 11 disposed between the side wall of the recessed portion 2b and the lower yoke portion 9a. Further, the upper yoke part 9b of the iron core 9 is connected to the iron core tightening member 1 having a rectangular cross section.
2 and 12, and a connecting member 13 that connects these core tightening members by urging them toward each other in the stacking direction of the cores.

The winding 15 fitted to the iron core 9 is a low voltage winding 1 fitted externally to the leg 9c of the iron core 9 via an insulating cylinder 16.
7 and a high-voltage winding 19 that is externally fitted onto the low-voltage winding 17 via an insulating tube 18 , and an insulating tube 20 is further fitted and inserted on the outside of the high-voltage winding 19 . Winding 1
The lower end of 5 is placed on a winding support plate 21 made of a ring-shaped insulator that is fitted onto the leg part 9c of the iron core 9 and placed on the horizontal plate part 2a of the lower case. At the upper end of the wire 15, a winding holding plate 2 made of a ring-shaped insulator is fitted around the legs 9c of the iron core 9.
2 is placed. A winding tightening jack 23 attached to the core tightening device 14 presses the winding 15 downward via the winding press plate 22, thereby tightening the winding 15 in the axial direction.

Insulating tube 1 placed inside of the above insulating tube
6 is formed so that its lower end surface and upper end surface are in close contact with the upper surface of the winding support plate 21 and the lower surface of the winding press plate 22, respectively, and the insulating cylinder 18 located in the middle
A large number of spacers (not shown) are provided at predetermined intervals in the circumferential direction between the upper end and the winding support plate 21 and between the lower end and the winding holding plate 22, respectively, to form oil channel gaps. . Also, the outermost insulating tube 20
is formed so that its lower end surface is in close contact with the upper surface of the winding support plate 21, and there are also a number of illustrated holes spaced at predetermined intervals in the circumferential direction between the upper end of the insulating cylinder 20 and the winding holding plate 22. A spacer is provided to form an oil passage gap. Spacers (not shown) are arranged at intervals in the circumferential direction between the upper and lower ends of the low voltage winding 17 and the winding press plate 22 and the winding support plate 21, respectively. A predetermined oil passage gap is formed in the oil passage. Similarly, predetermined oil passage gaps are formed between the upper and lower ends of the high-voltage winding 19 and the winding presser plate 22 and the winding support plate 21 by spacers (not shown), respectively. Of course, radial oil passage gaps are also formed within the high and low voltage windings. Furthermore, spacers (not shown) are provided between the low voltage winding 17 and the insulating cylinders 16, 18 and between the high voltage winding 19 and the insulating cylinders 18, 20, parallel to the axial direction of the windings and spaced at predetermined intervals in the circumferential direction. A predetermined oil passage gap is formed. The winding support plate 21 is formed with a through hole 24 that matches the through hole 6 provided in the horizontal plate portion 2a, and the common oil passages 5, 5 are connected to the through hole 6.
and 24 to communicate with the oil passage gap in the winding 15. In this embodiment, the winding support plate 2
1 through hole 24 is provided so as to open into the oil passage gap between the lower end of the central insulating cylinder 18 and the winding support plate 21, and oil is fed into the common oil passage 5 by an oil feed pump to be described later. The insulating oil is poured into the through holes 6 and 24.
The flow is divided into the inside and outside of the insulating cylinder 18 through the passageway, rises through the oil passage gap between the inner and outer peripheries of the low-voltage winding 17 and the high-voltage winding 19, collides with the winding press plate 22, and then merges with the insulating cylinder 20. The oil flows out from inside the winding 15 through the oil passage gap between the upper end and the winding holding plate 22.

Also, between the inner circumferential surfaces of the winding support plate 21 and the winding presser plate 22 and the outer surface of the leg portions 9c of the iron core 9 and the insulating tube 1
6 and the outer surface of the leg portion 9c, oil passage gaps are formed between the oil passage gaps 6 and the outer surface of the leg portion 9c.
A core surface cooling duct 25 is formed that extends from inside b to the top along the outer surface of the leg portion of the core 9. Furthermore, inside the iron core 9, there is a cooling duct 2 extending vertically.
6, 26, . A core cooling flow path is formed from between the supporting plates 10, 10 to the upper part through the cooling ducts 26, 26, . . . that are in contact with the lower end of the cooling duct 26. These core cooling channels are independent from the winding cooling channel that extends from the common oil pipe 5 through the oil pipe gap in the winding 15 to the upper part,
The insulating oil that has passed through the core cooling channel and the winding cooling channel merges at the upper part of the case.

As shown in FIG. 2, the inside of the concave part 2b and the common oil passages 5, 5 on both sides thereof are connected to a first oil passage pipe 27A communicating with the inside of the concave part 2b and this first oil passage pipe 27.
It is connected by second oil passage pipes 27B, 27B branching from A and communicating with the common oil passages 5, 5, and an oil amount regulating valve Va is provided in the middle of the first oil passage pipe 27A.

Insulating oil cooling devices 28, 28 are provided on both sides of the transformer case 1. These cooling devices are
It consists of radiators 29, 29 and a plurality of blower fans F. Oil feed pumps 30, 30 are provided on the oil outlet side of the cooling device 28.
The oil inlet side of the slanted plate part 3b provided at the upper end corner of the upper case 3 by the upper oil feed pipes 31, 31,
It communicates with the inside of the case at 3b. In addition, the lower oil feed pipe 3 is connected to the outlet side of the oil feed pumps 30, 30.
2 and 32 into the common oil pipes 5 and 5.

A low-voltage bushing 33 and a high-voltage bushing 34 are attached to one and the other of the inclined plate parts 3b, 3b of the upper case 3, respectively, and these bushings are connected to the low-voltage winding 17 and the high-voltage winding 19, respectively, by lead wires (not shown). has been done. Further, a conservator 36 is attached to the upper wall of the upper case via a communication pipe 35.

In the above transformer, as shown in FIG. 3, the winding cooling flow path A runs from the common oil passages 5, 5 at the lower part of the case, through the oil passage gap in the winding 15, to the upper part in the case 1. and a core cooling channel B extending from the inside of the concave portion 2b through the surface and inside of the core to the upper part of the case are connected in parallel to the cooling device 28 and the oil pump 30, which are connected in series. The insulating oil sent by the oil pump 30 through the lower oil pipe 32 is distributed between the winding cooling channel A and the core cooling channel B.
The oil flows into two parts, reaches the upper part of the case, joins together, and returns to the cooling device 28 from the upper oil pipe 31. The flow velocity of the insulating oil in both the cooling channels A and B can be arbitrarily adjusted by adjusting the amount of insulating oil flowing into the core cooling channel B using the oil amount regulating valve Va. That is, when the oil amount control valve Va is throttled, the flow velocity of the insulating oil flowing into the winding cooling channel A increases, and the flow velocity within the core cooling channel B decreases. Conversely, when the oil amount control valve Va is opened, the flow velocity in the winding cooling channel A becomes slower and the flow velocity in the core cooling channel B becomes faster. Therefore, by adjusting the oil amount control valve Va, the flow velocity in the winding cooling channel A can be easily adjusted to a velocity at which no flow charging phenomenon occurs. Moreover, in this case, the cooling device 2
The flow rate within 8 does not decrease at all.

When the flow velocity in the winding cooling channel A is slowed down, the cooling effect on the winding 15 is slightly reduced, but since the flow velocity in the core cooling channel B becomes faster, the cooling effect on the core 9 is increased. Thus, the temperature rise in the transformer body is suppressed as much as possible. When the flow velocity in the core cooling channel B becomes faster, there is a possibility that a fluid charging phenomenon will occur on the inner peripheral surfaces of the insulating tube 16, the winding support plate 21, and the winding press plate 22, but some of the electric charge will pass through the core. There is no real harm as it can be released into the ground. In addition, the insulating cylinder 16 and the winding support plate 21,
In order to more completely protect the winding holding plate 22 from the flow charging phenomenon, as shown in FIG.
7 may be formed and this conductive layer may be grounded. Further, as shown in FIG. 5, a conductive layer 37 may be buried within the insulating cylinder 16 and this conductive layer may be grounded.

As shown in FIG. 4 or 5, the insulation cylinder 16
Of course, it is more desirable to form a conductive layer 38 on the inner peripheral surfaces of the winding support plate 21 and the winding press plate 22 as shown in FIG. 6, in addition to providing the conductive layer 37 thereon.

In the above embodiment, the outlet side of the oil pump is connected to the lower part of the winding cooling channel, but the outlet side of the oil pump may be connected to the lower part of the core cooling channel.

In addition, in the above example, the transformer case has a boat-bottom shape (back type), but even when a normal box-shaped transformer case is used, for example, a common oil pipe can be installed in the lower yoke clamping fitting. The present invention can be carried out by making the winding cooling flow path and the core cooling flow path independent of each other so as to form a winding cooling flow path and a core cooling flow path.

As described above, according to the present invention, the core cooling channel and the winding cooling channel are formed almost independently from each other, and both the cooling channels are communicated through the oil passage at the lower part, and the oil passage is A flow rate adjustment means is provided in the middle of the passage, and the lower oil pipe that supplies insulating oil from the cooling device is communicated with the lower part of the winding cooling passage or the lower part of the core cooling passage, so that the flow rate adjustment means can be adjusted separately for both cooling passages. The flow rate of the insulating oil passing through the winding cooling channel can be adjusted to a flow rate at which no flow charging phenomenon occurs using the flow rate adjusting means without installing a cooling device in the cooling device and without changing the flow rate of the insulating oil flowing inside the cooling device. . Therefore, the flow charging phenomenon can be prevented with a simple configuration without reducing the cooling efficiency of the cooling device.

Furthermore, according to the present invention, when the flow velocity of the insulating oil in the winding cooling channel is slowed down, the cooling effect on the winding decreases, but at this time, the flow velocity of the insulating oil in the core cooling channel conversely increases. , the cooling effect on the iron core can be enhanced to compensate for the decline in the cooling effect on the windings, and the temperature rise in the transformer body can be suppressed.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part taken along the - line in Fig. 1, and Fig. 3 is an insulating oil in the embodiment of Fig. 1. FIGS. 4 and 5 are cross-sectional views showing different examples of insulating tubes that can be used in the present invention, and FIG. 6 is a diagram showing a winding support plate and a winding that can be used in the present invention. It is a perspective view showing a wire holding plate. 1...Transformer case, 5...Common oil pipe, 9...
Iron core, 15... Winding wire, 16, 18, 20... Insulating tube, 17... Low voltage winding, 19... High voltage winding, 21
... Winding support plate, 22 ... Winding holding plate, 27A,
27B...Oil pipe, 28...Cooling device, 29...
Heat radiator, 30...Oil pump, Va...Oil volume adjustment valve, 31...Upper oil feed pipe, 32...Lower oil feed pipe.

Claims (1)

[Claims] 1. A transformer body having an iron core and a winding fitted to the iron core, a case housing the transformer body together with insulating oil, and an upper oil pipe connected to the upper part of the case. a cooling device connected to the lower part of the case via a lower oil pipe, and an insulating oil in the cooling device flowing into the case from the lower oil pipe to cause the insulating oil in the case to flow into the upper part of the case. Oil feeding means for generating an oil flow in an insulating oil circulation system formed by the cooling device, a lower oil feeding pipe, a case, and an upper oil feeding pipe so as to flow into the cooling device from the oil feeding pipe. In the type transformer, a core cooling channel is provided to flow insulating oil along the core from a lower part of the case to an upper part of the case along the core, and an insulating oil is provided through the winding. a winding cooling flow path provided almost independently from the core cooling flow path to flow oil from a lower part of the case through the winding to an upper part of the case; and the core cooling flow path. An oil passage provided to communicate the lower part of the oil passage with the lower part of the winding cooling passage, and a flow rate inserted in the middle of the oil passage to adjust the flow rate of the insulating oil flowing through the oil passage. An oil feed type transformer, comprising: an adjusting means, wherein the lower oil feed pipe communicates with a lower part of the winding cooling channel or a lower part of the core cooling channel.