JPS59175111A - Three-phase on-load tap changing transformer - Google Patents

Abstract

PURPOSE:To enable to transport the titled transformer in the state wherein three phases are formed in one body as well as to clear the transportation limit by obtaining a small sized and lightweight transformer by a method wherein the transformer is composed of the main transformer part consisting of a low voltage winding, a medium voltage winding and a high voltage winding, and an on- load voltage control device part. CONSTITUTION:The main transformer part 20A is composed of a low voltage winding 21, a medium voltage winding 31 and a high voltage winding 41. Also, the on-load voltage adjusting device part 30A is composed of an excitation winding 22, a medium part winding 32, a tap winding 51 and an on-load tap changing device 6. The medium part winding 32 is connected in series to the neutral point side of the medium voltage main winding 31, and the medium winding is composed of windings 31 and 32. To be more precise, the medium voltage part winding where a part of conventional medium voltage winding is removed, and the part corresponding to the medium voltage part winding 32 of the medium voltage winding after removal, which is the medium main winding 31, can be reduced both in measurements and weight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a three-phase transformer equipped with an on-load tap changer, and particularly to a three-phase on-load tap changer suitable for large capacity transformers.

[Background of the invention]

FIG. 1 is a block diagram of a conventional three-phase on-load tap-changing transformer. In the figure, 1 is a three-phase three-legged iron core or a three-phase five-legged iron core, 2 is a low-voltage winding wound around the iron core 1, 3 is a medium-voltage winding wound outside the low-voltage winding 2, and 4 is a medium-voltage winding. A high-voltage winding is wound on the outside of the high-voltage winding 3, and 5 is a tap winding wound on the outside of the high-voltage winding 4.

A terminal a%b%C is drawn out from each low-voltage winding 2, a terminal U%V%W%Q is drawn out from each medium-voltage winding 3, and a terminal U, V%W is drawn out from each high-voltage winding 4. be drawn out. Reference numeral 6 denotes an on-load tap changer for changing the tap of the tap winding 5, and voltage adjustment is performed by this switching. Each of these windings 2
, 3.4.5 and the on-load tap changer 6 are housed in the main body tank to form the main transformer 10.

However, in recent years, there has been a trend toward ultra-high voltage and large capacity transformers, which inevitably increases the overall size of the main transformer 10. As a result, the transport weight and transport dimensions of the transformer have increased, and depending on transport conditions such as the transport vehicle and the transport environment including the transport route, it has become impossible to transport the transformer.

In order to avoid such a situation, there is currently a plan to remove the tap winding and on-load tap changer from the main transformer 10 and configure them as a load voltage regulator separately from the main transformer. It is being considered.

FIG. 2 is a block diagram of a three-phase on-load tap-changing transformer as shown in FIG. In the figure, the same parts as those shown in FIG. 1 are given the same reference numerals. The iron core 1 is equipped with a normal pressure low voltage winding 2 from the inside.
1, a medium voltage winding 3, and a high voltage winding 41 are wound, and each of these windings 21 is housed in a 3.41f tank to form the main transformer section 20. On the other hand, a load voltage regulator section 30 is configured separately from the main transformer section 20. That is, the low voltage winding 2 of the 7-core main leg and the 22-core main transformer section 20
1, an excitation winding drawn out in parallel with this and wound around the iron core 7, and a tap winding connected to the high voltage winding 41 of the 51-digit main transformer section 20 and wound outside the excitation winding 22. It is a line. The excitation winding 22 and the tap winding 51 wound around the iron core 7 and the on-load tap changer 6 are connected to the main transformer section 2.
It is accommodated in a tank different from the tank of 0, and constitutes a load voltage regulator section 30. Main transformer part 20
and the on-load voltage regulator section 30 are placed side by side after being transported to the installation site, and a connection is made between them through a duct to form a completed three-phase on-load tap-changing transformer.

As described above, by removing the tap winding 2 and the on-load tap changer 6 from the conventional main transformer 10, the size and weight of the main transformer section 20 are considerably reduced, allowing it to be transported to locations that were previously impossible. can also be transported.

However, in recent years, transformers are being required to have even larger capacities, and this demand has led to the size and weight of transformers increasing, so even with the configuration under consideration above, the main transformer portion becomes larger. However, depending on the transportation conditions, it may be impossible to transport the main transformer.

[Purpose of the invention]

The present invention was made in view of these circumstances, and
Its purpose is to be able to be transported in a three-phase integral form, and
The object of the present invention is to provide a three-phase on-load tap change transformer that is smaller and lighter and can expand the transport limit.

[Summary of the invention]

In order to achieve this object, the present invention configures a main transformer part with a low voltage winding, a medium voltage main winding, and a high voltage winding, and also includes an excitation winding connected to the low voltage winding, and the medium voltage main winding. The on-load voltage regulator section is composed of the medium-voltage partial winding connected to the line, the tap winding connected to the high-voltage winding, and the on-load tap changer.

The main transformer section and the on-load voltage regulator section constitute a three-phase on-load tap change transformer.
1. ,.

[Embodiments of the invention]

The present invention will be explained below based on the embodiment shown in FIG.

FIG. 3 is a configuration diagram of a three-phase on-load tap change transformer according to an embodiment of the present invention. In the figure, the same parts as those shown in FIG. 2 are given the same reference numerals. 31 is a medium voltage main winding wound around the iron core 1. low voltage winding 21, medium voltage main winding 31,
The high voltage winding 41 constitutes the main transformer portion 2OA.

32 is a medium voltage partial winding wound around the iron core 7. Each winding of the excitation winding 22, the intermediate voltage partial winding 32, and the tap winding 51,
The on-load tap changer 6 constitutes an on-load voltage regulator section 30A. The intermediate voltage partial winding 32 is connected in series to the neutral point side of the intermediate voltage main winding 31, and both windings 31, 3
2 constitutes a normal medium voltage winding 3 shown in FIGS. 1 and 2. In other words, the intermediate voltage partial winding 32 can be said to be a portion of a conventional intermediate voltage winding with a part removed.
After removal, the intermediate voltage winding, ie, the intermediate voltage main winding 31, is reduced in size and weight by an amount corresponding to the intermediate voltage partial winding 32. Therefore, the main transformer section 20A is not only smaller and lighter than the conventional main transformer 10, but also larger in size and weight than the main transformer section 20 under consideration. will be reduced.

In this way, in this embodiment, the tap winding and the on-load tap changer are separated from the main transformer to constitute the on-load voltage regulator part, and furthermore, a considerable part of the medium voltage winding is also separated from the main transformer. Since the winding is incorporated into the on-load voltage regulator, the main transformer is small and lightweight, and can be transported as a three-phase integrated structure to locations with poor transportation conditions without any problems. Further, by adjusting the number of turns of the medium voltage main winding and the medium voltage partial winding, the impedance between the medium voltage winding and the low voltage winding and the impedance between the medium voltage winding and the high voltage winding can be adjusted.

Although the above embodiment has been explained using an example of a three-winding transformer, the present invention can also be applied to an auto-transformer having a series winding and a shunt winding. It can be applied by moving from the transformer section to the on-load voltage regulator section.

〔Effect of the invention〕

As described above, the present invention provides a low voltage winding, a medium voltage main winding,
A three-phase on-load tap-changing transformer with a main transformer section with a high-voltage winding and an on-load voltage regulator section with an excitation winding, a medium-voltage section winding, a tap winding, and an on-load tap changer. As a result, the main transformer part is small and lightweight, and it can be transported as a three-phase integrated type without any problems even to places with poor transportation conditions. Further, by adjusting the number of turns of the medium voltage main winding and the medium voltage partial winding, it is also possible to adjust the impedance between the medium voltage winding and the low voltage winding, and between the medium voltage winding and the high voltage winding.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional three-phase on-load tap-changing transformer.
FIG. 2 is a block diagram of a three-phase on-load tap-changing transformer having a divided structure, and FIG. 3 is a block diagram of a three-phase on-load tap-changing transformer according to an embodiment of the present invention. 1...Iron core, 6...On-load tap changer, 20A...Main transformer part, 21...
・Low voltage winding, 22...Excitation winding, 30A...
...Load voltage adjustment component, 31...Medium voltage main winding, 32...Medium voltage partial winding, 41...
...High voltage winding, 51...Tap winding.

Claims (1)

[Claims] 1. A main transformer portion including a low voltage winding, a medium voltage main winding, and a high voltage winding wound around an iron core; excitation winding connected to the low voltage winding,
Each winding of an intermediate-voltage partial winding connected to the intermediate-voltage main winding, a tap winding connected to the high-voltage winding, and an on-load tap changer for switching the taps of the tap winding. A three-phase on-load tap-changing transformer, comprising a regulator section. 2. In claim 1, the excitation winding is
A three-phase on-load tap-changing transformer, characterized in that the transformer is connected in parallel to the low-voltage winding. 3. The three-phase on-load tap change transformer according to claim 1, wherein the medium voltage partial winding is connected in series to the neutral point side of the medium voltage main winding. vessel.