JPS5829611B2 - three phase transformer - Google Patents

Description

[Detailed description of the invention] The present invention relates to a three-phase transformer.

In general, for low-voltage, high-current windings, one to four winding layers in which conductors are arranged in parallel to the windings are arranged in the axial direction, and while winding in the axial direction, A so-called multiple helical winding is used in which conductors are appropriately transposed.

This kind of winding. Generally, a triangular connection is used with a voltage corresponding to the generator voltage of about 11 to 30 kV, and the current reaches 5 to 20 kA.

In a helical winding like the one above, the ends of the winding are above and below the winding, so the high current lead from the bottom of the winding should be raised above the tank so that it can be connected to other phases. We have to go.

Further, since a large current flows through the lead wire extraction portion of the winding, eddy current loss due to leakage magnetic flux is caused in the backing plate of the iron core, the fastening fittings, etc.

Therefore, as a new winding method, a two-stage cylindrical winding, as shown in FIG. 1, has been used.

This winding is made by combining rectangular wires 1 insulated with polyvinyl formal or the like by transposing them as shown in the figure, and using a plurality of transposed wires 3 on which paper-wrapped insulation 2 is applied. A spacer 5 or the like is placed on top of the magnet, and multiple magnolias are wound in the axial direction.

In the case of FIG. 1, an example is shown in which four conductors 11, 12, 13, and 14 are wound in parallel.

In this way, when the first winding layer 6 is wound, at the end of the winding, the conductor 11, which is wound first, passes to the conductors 12, 13, 14 and the second winding layer 7 in order.

In this state, the second winding layer 7 is wound onto the second winding layer 6 with spacers 8 and the like interposed therebetween.

The upper end side of the second winding layer 1 faces the winding start at the upper end of the second winding layer 6, and since the maximum voltage is generated, an insulating tube 9 or the like is inserted as necessary.

This insulation 19'I''i may extend over the entire length inside the second winding layer 7, and another spacer 1 may be provided outside the insulation tube 9.
It is also possible to set it to 0.

In this way, by stacking the cylindrical windings in two stages, the winding leads are the beginning of the first winding layer 6 and the end of the second winding layer 7, and the lead wire from the bottom of the winding. Withdrawals are no longer necessary.

Since the lead wire 15 of the first winding layer 6 and the lead wire 16 of the second winding layer 7 are drawn out from the upper part of the winding, their current directions are opposite, and the magnetic fluxes due to the lead leads are mutually As a result, the eddy current due to the magnetic flux to the iron core abutment and fastening fittings is reduced.

However, according to the conventional structure, the lead wire pulled out in this way is pulled out upward into the tank,
At this point, the connections between each phase were made by crossing each other, or by pulling them out to the bottom of the bushing.

Alternatively, each phase was connected to a triangular connection outside the drawer using two bushings.

Therefore, with this configuration, a large space is required on the top surface of the core, and if there are restrictions on transportation height due to railway transportation, etc., the lead wires and their support plates can be removed at the factory.
There were drawbacks such as the need to replace the cover with a transport cover, assemble and re-insulate the replacement upstream wire with the main cover at the site.

The object of the present invention is to provide a three-phase transformer that eliminates the above-mentioned drawbacks, does not require a large space above the core, does not require the installation of a transport cover during railway transport, shortens the exposure time of the transformer contents to the air, and reduces the number of work steps. Our goal is to provide the following.

The three-phase transformer of the present invention has a low voltage cylindrical winding.
The winding start and the winding end of the second winding layer are respectively disposed at the upper end, and are connected in series at the lower end, and the output leads of the first winding layer and the second winding layer are respectively arranged upwardly. drawer,
One of the above-mentioned lead leads of each phase extends the inner space of the bushing pocket on the upper surface of the cover toward the other phase, and is connected to the bushing in line with a predetermined lead lead of the other phase to form a predetermined triangular connection.

An embodiment of the three-phase transformer of the present invention will be described below with reference to FIGS. 2 and 3.

The iron core 21 is fixed by a dowel 22, a fastener 23, a pin 24, and a connecting fitting 25. An insulating tube 26 is disposed on the outside of the leg of the iron core 21, and a second winding layer 6 is provided on the outside of the insulating tube 26. , a low voltage winding 27 consisting of a second winding layer 7, a main insulation 28, and a high voltage winding 29.

The ends of the low voltage winding 27 and the high voltage winding 29 are provided with an end insulator 30,
It is fixed by a clamping fitting 23 with a clamp pin 31 interposed therebetween.

The contents of these transformers are housed in a transformer tank consisting of a tank 32 and a cover 33, and a bushing pocket 34 in which a low-pressure bushing 37 is attached is attached to the upper surface of the cover 33.

This bushing pocket 34 is configured to form a common oil passage for the three-phase winding portions.

38 is the transport limit.

The protruding leads 15 and 16 of the low-voltage winding 27 are pulled upward from the notches of the end insulator 30 and the fastener 23 and introduced into the bushing pocket 34.

In the bushing pocket 34, the low pressure bushing 3
7 is arranged for three phases according to the phase-to-phase dimensions of the phase separation bus (not shown), but depending on the amount of current, two of these may be provided for each lead of the winding. A triangular connection may be formed on the air side of the low pressure bushing 37 by connecting to this.

Each lead wire in the bushing pocket 34 is guided to the upper bushing part parallel to the plane of the paper of FIG. 2, or is guided in a direction perpendicular to the plane of the paper to form a triangular connection.

This state is as shown in FIG. That is, the leads 43, 44, 4546, 47, 48 corresponding to the lead wires 15, 16 of the low voltage winding 27 pulled out from the end insulator 41 of each phase and the notch of the fastener 42 are connected to the cover surface. 49, is bent toward the low-pressure bushing 37 at this portion, and is drawn around inside the bushing pocket 34.

Among the leads of each phase, one lead each 43, 44, 45
However, each of the other leads 46, 4748 is routed in the direction of the other phase and connected to the low pressure bushing 3 in parallel with the lead 43°44.45.
You will be pulled up in 7 directions.

This extraction method is also possible when each phase has one bushing or two parallel bushings, but in addition to this, if there is dimensional space on the cover, it is possible to pull out the lead of each phase. It is also possible to pull it out onto the bushing pocket using a low-pressure bushing, create another pocket part on the air side, make a triangular connection, and then form a connection terminal to the phase separation bus bar.

In addition, if a lead connection part is made on the rising part of the top surface of the cover and is separated at this point during transportation, the transformer can be transported with the main body cover within the transport limit.

In this case, the lead wire can be transported together with the bushing pocket, low pressure bushing, etc.

With this configuration, there is an advantage that there is no need to pull out the lead wire onto the cover, and the lead connection can be made in advance within the bushing pocket.

Furthermore, by separating the bushing pocket, the transformer can be transported by rail with the main body cover removed, eliminating the need for cover conversion, lead connections, and reassembly, and greatly reducing air exposure time during on-site work. Economic efficiency and reliability can be improved.

As described above, the three-phase transformer of the present invention does not require a large space above the core, does not require the installation of a transport cover during railway transportation, has the effect of shortening the exposure time of the transformer contents to the air, and reducing the number of work steps. It is something.

[Brief explanation of the drawing]

Fig. 1 shows a normal two-stage cylindrical winding for large currents, A is a partial vertical sectional view, the opening is a front view, C is a perspective view of a dislocation section at the bottom of the winding, and Fig. 2 is a three-stage cylindrical winding of the present invention. FIG. 3 is a cross-sectional view of a lead connecting portion of one embodiment of a phase transformer, and FIG. 3 is a perspective view of a lead routing portion in the bushing pocket of FIG. 2. 6...Second winding layer, 7...Second winding layer, 15°16...Output lead, 21...
...Iron core, 27...Low voltage winding, 29...
・High voltage winding, 32...Tank, 33...
・Cover, 34...Bushing pocket, 37
・・・・・・Low pressure bushing, 43, 44, 45°46
．． 47,4B...Lead.

Claims (1)

[Claims] 1. A low-voltage cylindrical winding formed by connecting in series two winding layers formed by winding a plurality of parallel conductors arranged in the axial direction around a three-phase iron core placed in a tank; A high-voltage winding and a high-voltage winding are arranged concentrically for each phase, and a bushing pocket for attaching a bushing to a cover connected to a tank is removably provided, and the low-voltage cylindrical winding of each phase is The winding start and winding end of the - and second winding layers are respectively disposed at the upper end, and are connected in series at the lower end, and the output leads of the - and second winding layers are arranged upwardly. One of the above-mentioned double outlet leads of each phase is extended in the direction of the other phase through the space inside the bushing pocket on the top surface of the cover, and connected to one bushing of each corresponding phase in line with the predetermined outlet lead of the other phase. A three-phase transformer characterized by having a predetermined triangular connection. 2. The three-phase transformer according to claim 1, wherein the lead leads of the first winding layer and the second winding layer are formed to be separable at the portions led out from the windings.