JPH08167527A - Split transformer - Google Patents

Abstract

PURPOSE: To provide a split transformer in which a strong connecting force is obtained between the tanks of unit transformers, the profile sizes and installing areas of the tanks are small, manufacturing cost, weight and loss can be reduced. CONSTITUTION: A polyphase transformer is formed by connecting unit transformers 3U, 3V and 3W in which transformer interiors 1 made of windings and cores, are separately contained in tanks 2U, 2V and 2W together with insulating cooling media at a site installing place. The tank walls between the phases of the tanks 20 and 2V and between the 2V and 2W of the transformers 3U, 3V and 3W are formed of wall plates 4 of steel plates without reinforcing member. Connecting flanges 5 are provided on the entire periphery of the surfaces between the phases, clamped, hermetically sealed by seals 7 at a space 6 between the plates 4 of the phases, and connected with a vacuum pump via the valve of an exhaust tube 8 for evacuating the space 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a split type transformer,
More specifically, the present invention relates to a tank joining structure of a split type transformer in which a plurality of unit transformers each containing a transformer content are joined to separate tanks to form a single multi-phase transformer.

[0002]

2. Description of the Related Art Conventionally, large-capacity transformers (three-phase transformers) are large in weight and size. Therefore, when installed in underground substations or substations in mountainous areas, restrictions on weight during transportation and increased transportation costs are required. Due to restrictions such as road and bridge reinforcement and pit size restrictions (size restrictions on the entrance of the building), the three-phase integrated type cannot be transferred.
It is called a phase (special 3) transformer or a split transformer.

Therefore, in the case of three phases, three single-phase unit transformers are manufactured, tanks are joined, and transition lead wires between phases and a tap changer during load are installed in a common duct to be integrated. FIG. 6 is a front view showing an example of a conventional split transformer,
In FIG. 6, the tap changer tank 22 that accommodates the load tap changer 21 and the unit transformers 23U, 23V, and 23W are arranged side by side, and are connected via a common duct 24 that is arranged above the tank. There is. The common duct 24 includes the tap changer 21 under load and each unit transformer 23.
A connection lead wire for connecting each phase of U, 23V and 23W is stored. In addition, 25 is a tank reinforcing material.

FIG. 7 is an explanatory view showing the state of the tank of the conventional split type transformer during vacuum lubrication. In FIG. 7, in the conventional split type transformer, when the pressure inside the tank is reduced, the side plate of the tank is inside. Since it bends (dents), it requires mechanical strength to withstand it. In order to increase this strength, it is necessary to thicken the tank side plate and add a tank reinforcing material.

[0005]

In the structure of the conventional split type transformer, three unit transformers are joined to form a three-phase transformer, so that the overall external dimensions are large and the installation area and weight are large. It has a problem that the cost becomes high.

Furthermore, a tap voltage regulator (LT) under load
In the case of the transformer with C), a tank for storing the LTC and a common duct for storing the lead wires for the three-phase connection are required, and there is a problem that the size is further increased.

Since the wall of the tank is made of a magnetic structural material such as a steel plate, loss occurs inside the structural material. Therefore, it is necessary to provide a magnetic shield plate on the wall to prevent this.
There is a problem in that the external dimensions and weight increase, and the cost increases.

The present invention has been made in view of the above problems of the prior art. A strong joining force can be obtained between the tanks of the unit transformer, and the outer dimensions and installation area of the tanks are small. An object of the present invention is to provide a split type transformer with reduced manufacturing cost, weight and loss.

[0009]

In order to achieve the above-mentioned object, the split transformer of the present invention is configured such that the contents of a transformer including a winding wire, an iron core, etc., together with an insulating cooling medium are stored in separate tanks for each phase. In a multi-phase transformer that is constructed by joining the unit transformers housed inside to the tank at the site of installation, a flange for joining is provided on the entire circumference of the interphase portion of the tank, and the wall of the interphase portion is a plate. The structure is such that the flange portion is tightened and the air between the wall plates of the interphase portion is airtightly and decompressed by the seal to join the tanks to each other.

Further, by constructing the above-mentioned wall plate of the interphase portion with a non-magnetic plate (for example, a stainless steel plate), the magnetic shield of the tank becomes unnecessary, and the weight and the loss can be reduced.

[0011]

In the structure of the present invention, the wall of the interphase portion of the unit transformer has a plate structure, the flange portion is tightened, and the space between the wall plates of the interphase portion is hermetically sealed by a seal (packing, gasket, etc.), and By decompressing and joining the tanks to each other, a strong joining force can be obtained by the combined force of the suction force due to the depressurization between the tanks and the compression force due to the internal pressure of both tanks.

Since the wall plates of the interphase portions of the tanks of the adjacent unit transformers are in direct contact with each other, the plate thickness can be reduced,
The material of the tank is small, the weight is light and the manufacturing cost can be reduced. The outer dimensions of the tank in which the multi-phase device (for example, three-phase device) is integrated are small, and the installation area is also small.

By constructing the wall plate of the interphase portion with a non-magnetic plate (for example, a stainless steel plate), the magnetic shield of the tank at the joint is unnecessary, and the weight and the loss can be reduced.

Since the common duct, which is long and comparable to the tank of the main body, is eliminated and it becomes a small duct for passing phases, the cost of the tank can be reduced and the external dimensions and weight can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of a split type transformer of the present invention, FIG. 2 is a front view showing an embodiment of a split type transformer of the present invention, and FIG. 3 is also a split type transformer of the present invention. 1 is a front sectional view showing an AA cross section of FIG. 1 of the embodiment of the transformer, and FIG. 4 is a front sectional view showing a portion C of FIG. 3 of the embodiment of the split transformer of the present invention. In FIGS. 3 and 4, unit transformers 3U, 3V and 3W in which a transformer contents 1 including a winding wire and an iron core and the like are housed in separate tanks 2U, 2V and 2W for each phase together with an insulating cooling medium. In the on-site installation site, the unit transformers 3U, 3V and 3W are connected to the tank 2U.
And 2V and between 2V and 2W phases are made of steel plate without reinforcing member and made of wall plate 4, joint flanges 5 and 5 are provided on the entire circumference of the interphase surface, and the flange 5 is tightened. At the same time, the space 6 between the wall plates 4 in the interphase portion is configured to be hermetically sealed by a seal (packing, gasket) 7. Further, in order to exhaust the space 6 between the wall plates 4 of the interphase portion, a vacuum pump can be connected (not shown) via a valve of an exhaust pipe 8.

In this way, the tank walls between the tanks 2U and 2V and between the phases 2V and 2W are made of steel plate without reinforcing members, and the wall plate 4 is formed, and the joint flange portion 5 is provided on the entire circumference of the interphase portion surface. Provided and tighten this flange part 5,
The space 6 between the wall plates 4 in the interphase portion is hermetically sealed by a seal (packing, gasket) 7 by a seal 6, and a vacuum pump can be connected (not shown) via a valve of an exhaust pipe 8. Then, the space 6 between the wall plates 4 in the interphase portion is evacuated, and the three unit transformers are integrated into one unit, so that the mechanical altitude (vacuum resistance,
Vibration and explosion proof).

The space 6 between the wall plates 4 in the interphase portion
Is exhausted from the exhaust pipe 8 by a vacuum pump to reduce the pressure,
The tanks 2U and 2V and the tanks 2V and 2W are joined together. A load tap switching device 9 is housed on the front side inside the tank 2V of the unit transformer 3V. In addition, an inter-phase crossover duct 10 that accommodates connection lead wires for connecting the 3U, 3V, and 3W phases of each unit transformer is arranged at the upper part of the tank. Unit transformers 3U and 3W tanks 2U and 2W on both sides
Magnetic shield 11 inside the outer surface of the split transformer
However, the tank reinforcing member 12 is provided on the outer surface, and the tank 2U of the unit transformer 3U on both sides and the tank 2V of the split transformer of the tank 2W of the unit transformer 3W and the tank 2V of the central unit transformer 3V. There is no magnetic shield inside both sides.

FIG. 5 is an explanatory view showing the state of the tank at the time of vacuum lubrication of the embodiment of the split transformer of the present invention. In FIG. 5, a vacuum is drawn from the upper part of the tanks 2U, 2V and 2W by the exhaust pipe 8. Oil pipe 1 at the bottom of the tank
At the time of vacuum lubrication in which the insulating oil is lubricated from 3, the inside of the tank is in a vacuum, but the space 6 between the wall plates 4 of each tank is also evacuated to a vacuum, so that the tank wall plate 4 is balanced by the atmospheric pressure. Since the pressure becomes zero on both sides of the, no mechanical stress occurs. Moreover, the positive pressure at the time of injecting the insulating oil is the same pressure from both sides, and the pressure difference between the phases becomes zero. By thus hermetically sealing the space 6 of the interphase wall plate 4, mechanical strength can be obtained with a thin wall plate against the pressure difference between the inside and the outside of the tank during the manufacturing process of the transformer. Therefore, the wall plate 4 on the joint surface of the tank can be thinner than the conventional wall plate, and since there is no pressure difference, no reinforcing member is required, the weight of the tank can be reduced, and the outer shape can be reduced. The dimensions are smaller.

Further, by using a thin non-magnetic steel plate as the wall plate between the phases of the tank, the magnetic shield of the tank becomes unnecessary, the weight of the tank can be reduced, and the external dimensions can be reduced.

[0021]

Since the split type transformer of the present invention is constructed as described above, it has the following effects.

Since the wall of the interphase portion has a plate structure and the flange portion is tightened and the space between the wall plates of the interphase portion is airtightly and decompressed by the seal, the tanks are joined together. A strong joining force can be obtained by the combined force of the suction force by depressurization and the compression force by the internal pressure of the tanks on both sides.

The plate thickness of the wall at the interphase portion can be made thin and the weight can be reduced.

The outer dimensions of a tank in which a multi-phase device (for example, a three-phase device) is integrated are reduced.

Therefore, the installation area is small.

The material of the tank is small and the manufacturing cost of the tank can be reduced.

By constructing the wall plate of the interphase portion with a non-magnetic plate (for example, a stainless steel plate), the magnetic shield of the tank at the joint is unnecessary, and the weight and the loss can be reduced.

Since a long common duct comparable to the tank of the transformer main body is eliminated and the duct becomes a small-sized phase transition duct, the cost of the tank is reduced, and the external dimensions and weight can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a split transformer of the present invention.

FIG. 2 is a front view showing an embodiment of a split transformer of the present invention.

3 is a front cross-sectional view showing a cross section taken along the line AA in FIG.

FIG. 4 is a front sectional view showing details of a C portion of FIG.

FIG. 5 is an explanatory view showing the state of the tank during vacuum lubrication of the embodiment of the split type transformer of the present invention.

FIG. 6 is a front view showing an example of a conventional split transformer.

FIG. 7 is an explanatory view showing the state of the tank of the conventional split type transformer during vacuum lubrication.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transformer contents 2U, 2V, 2W ... Transformer tank 3U, 3V, 3W ... Unit transformer 4 ... Wall plate on interphase side of tank 5 ... Flange part 6 ... Space between wall plates 7 ... Seal 8 ... Exhaust pipe 9 ... Tap switching device under load 10 ... Phase transition duct 11 ... Magnetic shield 12 ... Tank reinforcing material 13 ... Lubrication pipe

Claims (2)

[Claims] 1. A unit transformer in which the contents of a transformer consisting of a winding wire, an iron core, etc. are housed together with an insulating cooling medium in separate tanks for each phase, and the unit transformers are constructed by joining the tanks at the site of installation. In the phase transformer, the wall of the interphase portion of the tank of the single-phase transformer has a plate structure, a flange portion for joining is provided on the entire circumference of the interphase portion surface, and the flange portion is tightened and the wall of the interphase portion is sealed by a seal. A split type transformer characterized in that the space between the plates is hermetically sealed, and the tanks are joined together by reducing the pressure. 2. The split transformer according to claim 1, wherein the wall of the interphase portion is a non-magnetic steel plate.