CN117524670A - Layer-type winding voltage regulating structure of on-load linear voltage regulating distribution transformer - Google Patents

Abstract

The application discloses on-load linear voltage regulation distribution transformer layer-type winding voltage regulation structure, high-voltage layer formula winding composition is 4 sections, sets up tapping section winding at 2, 3 sections, and every level of tapping section winding meets full layer winding height, sets up first winding section simultaneously around to the opposite to the winding of other windings to distribute the voltage difference between K end break point and the adjacent tapping tap, first winding section includes one set or two sets of, confirms in 3 rd section tapping section windings, and winding break point and tapping tap have independent oil duct. The first winding section is determined to be arranged in the 3 rd winding section for reverse winding direction setting, so that voltage difference between a break point of a K end and different tapping taps is distributed, when the minimum tapping position of the on-load voltage-regulating distribution transformer operates, the high voltage difference between the break point and the adjacent tapping taps can increase the insulation distance of the oil duct, the break point induction voltage difference is born through an oil gap, the field intensity is reduced, partial discharge gas production is avoided, and meanwhile, the heat dissipation of the oil duct is improved.

Description

Layer-type winding voltage regulating structure of on-load linear voltage regulating distribution transformer

Technical Field

The application relates to the technical field of design and manufacture of distribution transformers, in particular to a layer-type winding voltage regulating structure of an on-load linear voltage regulating distribution transformer.

Background

For an oil-immersed on-load voltage-regulating power distribution (or station) transformer, a 66kV transformer on-load voltage-regulating can be provided with a V-shaped switch, and a 35kV transformer on-load voltage-regulating can be provided with a V-shaped switch, in particular to a transformer for a high-altitude 35kV on-load voltage-regulating station. The high-voltage side of the transformer is a 4-section layer winding, and the V-shaped switch only selects a linear voltage regulating mode.

In the prior art, in a layered winding of a common linear voltage regulating structure of a 35kV and 66kV transformer, as shown in fig. 1, 9 tapping points are respectively and electrically connected with an 8-level linear voltage regulating switch in fig. 2, the total number of turns of the winding of the distribution transformer is N turns, the winding is divided into 4 sections, the number of turns N1 in the 1 st section and the number of turns N2 in the 3 rd section are about equal to the number of turns N2+4 delta N in the 3 rd section, a break point K is insulated with a tapping point 1 in the 3 rd section by an insulating paperboard, when the transformer operates at a position of a low voltage tapping 7-9, the switch K is connected with 7-9, a larger voltage difference of 7.5-10% times of rated voltage occurs between the winding break point K and the 1 tapping point, the increase of the insulating paperboard overcomes creepage, the insulating thickness of the layer is not feasible to avoid breakdown, at this moment, the winding voltage regulating structure needs to be consistent with the operating tapping position of the transformer, if the break point K is close to the tapping point 1 tapping point in fig. 2, the transformer only meets the operating range of 1-5 tapping, and if the transformer operates in the range of 5-9K needs to be close to the break point 9 tapping point. Therefore, the common linear voltage regulating structure in fig. 2 can not meet the voltage regulation in the whole range of 1-9, and only the offset design tapping and the offset tapping can be operated. Referring to fig. 1, which is a winding diagram of a layered winding linear voltage regulating structure, the voltage difference between the break point of the K end and the tap 1 is minimum 0 and maximum 8 times delta n turns induction voltage, and it can be seen that the common linear voltage regulating structure cannot bear the voltage difference of the head and the tail contacts of the switch.

Therefore, when the transformer is operated in reverse bias voltage regulation, the voltage difference between the break points and the layers is larger, the partial weak partial discharge of the layer insulation produces gas, if the insulation is thickened, heat dissipation is hindered, and meanwhile, the leakage magnetic field ampere-turn is asymmetric in rated split operation, so that the short circuit resistance of the winding is affected.

Disclosure of Invention

In order to solve the technical problems, the application provides the following technical scheme:

in a first aspect, an embodiment of the present application provides an on-load linear voltage-regulating distribution transformer layer winding voltage-regulating structure, a high-voltage layer winding component is divided into 4 sections, the 4-section high-voltage winding is provided with a tapping section winding in 2 and 3 sections, each section of tapping section winding occupies the whole layer of winding height, and meanwhile, a first winding section is provided with a winding direction opposite to that of other windings, so that a voltage difference between a K-end break point and an adjacent tapping tap is distributed, the first winding section comprises one or two groups, and is determined in the 3 rd section tapping section winding, and the winding break point and the tapping tap have separate oil channels.

In one possible implementation, the 2 nd winding is connected with the tapping tap 9, the 3 rd normal winding break point K is close to the tapping tap 7 or 5, and the break point K is shorter than the normal layer end position by 5-10 mm or 3-5 turns, so as to improve the creepage distance between K and the adjacent tapping section or tapping tap.

In one possible implementation manner, when the break point K of the 3 rd-segment normal winding is close to the tap 7, the winding direction of the 2 nd-segment tap winding is forward, and two groups of winding directions of the first winding segment in the 3 rd-segment tap winding are reverse.

In one possible implementation, the 3 rd stage tap arrangement is 7, 6, 5 and 3, 2, 1, the oil passage is set to withstand the voltage difference between the normal winding break point K and tap 7.

In one possible implementation manner, if the break point K of the 3 rd-segment normal winding is close to the tap 5, the winding direction of the 2 nd-segment tap winding is positive, a group of winding directions of the first winding segment in the 3 rd-segment tap winding are reverse, and the winding direction of the winding segment of the 3 rd-segment tap winding adjacent to the break point K tap is positive.

In one possible implementation, the 3 rd-stage tapping points are arranged as 5, 6, 7 and 3, 2 and 1, the oil duct is arranged to bear the voltage difference between the normal winding break point K and the tapping point 5, and the insulation between the tapping points 7 and 3 is doubled.

In one possible implementation, the tapping area has a high winding length, a large number of turns, a short winding length at the first and last sections, and a small number of turns, wherein: the number of turns of each layer of the 1 st section and the 4 th section is larger than or equal to 60% of the number of turns of each layer of the 1 st section and the 3 rd section, and is smaller than 100% of the number of turns of each layer of the 1 st section and the 4 th section.

In one possible implementation, when the 3 rd-segment normal winding break point K is close to the tap 5, the oil channel width between the normal winding break point K and the tap 5 is smaller than when the 3 rd-segment normal winding break point K is close to the tap 7, the oil channel width between the normal winding break point K and the tap 7.

In one possible implementation, the 1 st and 4 th windings are provided with the same width oil channels at the break point oil channel positions of the 2 nd and 3 rd windings.

In this application embodiment, confirm to set up the first winding section and carry out the rewind to setting up through in 3 rd section tapping section windings to the voltage between K end break point and the adjacent tapping point has been allocated, and when on-load voltage regulating distribution transformer minimum tapping position was operated, high voltage difference between break point and the adjacent tapping point can increase the oil duct and increase insulating distance, and the gap of crossing oil bears break point induced voltage difference, and the field strength reduces, avoids partial discharge gas production, and the oil duct improves the heat dissipation simultaneously.

Drawings

FIG. 1 is a schematic diagram of a winding of a conventional layered winding linear voltage regulating structure;

FIG. 2 is a schematic diagram of the 8-stage linear voltage regulating switch wiring;

FIG. 3 is a simplified diagram of a layered winding linear voltage regulation structure winding;

fig. 4 is a schematic diagram of a layer winding voltage regulating structure of an on-load linear voltage regulating distribution transformer according to an embodiment of the present application;

FIG. 5 is a simplified schematic diagram of the layered winding voltage regulation structure of the on-load linear voltage regulation distribution transformer of FIG. 4;

fig. 6 is a schematic diagram of another voltage regulation structure of a layer winding of an on-load linear voltage regulation distribution transformer according to an embodiment of the present application;

fig. 7 is a simplified diagram of the layer winding voltage regulation structure of the on-load linear voltage regulation distribution transformer of fig. 6.

Detailed Description

The present invention is described below with reference to the drawings and the detailed description.

Referring to fig. 4 and 5, for the layer winding voltage regulating structure of the on-load linear voltage regulating distribution transformer provided in the embodiments of the present application, the total number of winding turns is N, and the winding is divided into four sections, each section is divided into m layers, and the number of turns N1 in the 1 st section and the number of turns N2 in the 4 th section and the number of turns N2+4 delta N in the 3 rd section may be unequal.

The method comprises the steps of firstly designing the number of turns of the 2 nd section and the 3 rd section, designing the height of each layer from the number of tapping turns, selecting two-stage tapping turns 2 delta N to be distributed outside a winding according to 2-4 layers of full turns, wherein a break point K is not arranged on the same layer as the tapping tap 1, the break point K is arranged at the upper end of the 3 rd section, controlling the height of a normal winding, enabling the number of turns (N2+4 delta N)/m of each layer in the 2 nd section and the 3 rd section to be basically equal to the number of turns of a coil designed by the two-stage tapping turns, arranging an oil duct on an insulating layer between the break point K and the tapping tap 7 or 5, and enabling the width of the oil duct to meet the requirement that the working field intensity required by a voltage difference is lower than 2kV/mm, and enabling a heat dissipation oil duct to exist between the tapping region and the normal winding.

Furthermore, the height of the layer winding where the K is located is 5-10 mm shorter than the height of the 3 rd section normal layer, or 3-5 turns of wires are short, so that the insulation leading-out position of the K coil is lower than the end part of the wire section, and the creepage distance between the K and the adjacent tapping section or tapping tap is improved.

According to the total turns without the 2 nd and 3 rd section total turns, the 1 st and 4 th section turns are designed, the number of winding layers is the same as that of the 2 nd and 3 rd sections, the oil channels with the same width are arranged at the same radial positions of the 2 nd and 3 rd sections, the number of turns of each layer of the 1 st and 4 th sections is less than or equal to that of each layer of the 2 nd and 3 rd sections, and the number of turns of each layer of the 1 st and 4 th sections is controlled to be more than or equal to 60% of the number of turns of each layer of the 2 nd and 3 rd sections.

Furthermore, according to different wire gauges of the tapping area and the 1 st to 4 th normal windings, the wire gauge density of the tapping area can be 20% higher, the number of turns of each layer of the 2 nd and 3 rd normal windings can be reduced by 0 to 15%, and the number of turns ratio of each layer of the 1 st and 4 th sections is increased compared with that of each layer of the 2 nd and 3 rd sections.

In fig. 4, each tapping position is further designed, the tapping taps 9, 8, 7 'and 5, 4 and 3' are in the 2 nd section, the tapping tap 9 is connected with a normal winding, the tapping taps 7, 6, 5 'and 3, 2 and 1 are in the 3 rd section, the tapping tap 7 is adjacent to the breaking point K, the tapping tap 7 is connected with the tapping tap 7', the tapping tap 5 is connected with the tapping tap 5', the tapping tap 3 is connected with the tapping tap 3', and thus, the linear voltage regulating structure is arranged, no matter which tapping operation the breaking point K is connected with, the breaking point K is separated from the tapping tap 7 by oil duct insulation, the oil gap distance meets the insulation requirement of a high voltage difference, the insulation breakdown problem when the high voltage difference existing in the common structure of fig. 1 is avoided, and the voltage difference of the tapping tap at the beginning and the end of the switch is born by the breaking point oil gap.

In fig. 5, the winding direction of each tapping line segment of the winding voltage regulating structure of fig. 4 is marked, and the tapping sections of the 3 rd section are all in the reverse winding direction. With the structure in this embodiment, when the transformer operates in different taps, the minimum potential difference between the break point K and the tap 7 is 0, and when the transformer operates in 7 th gear, the voltage difference between the break point K and the tap 7 is the maximum and is 6 times Δn corresponding to the induced voltage difference. Compared to the structure in fig. 1, 6 Δn is smaller than 8 Δn, so that the voltage difference between the K-terminal break point and the different tap is distributed.

Corresponding to the layer-type winding voltage regulating structure of the on-load linear voltage regulating distribution transformer provided by the embodiment, the application also provides another layer-type winding voltage regulating structure of the on-load linear voltage regulating distribution transformer.

Referring to fig. 6 and 7, in the on-load voltage-regulating distribution transformer linear voltage-regulating structures shown in fig. 6 and 7, the same as the voltage-regulating structures shown in fig. 4 and 5 have the characteristics of balanced ampere turns of a tapping area when the tapping area is in maximum, rated and minimum tapping operation, and the short-circuit force is not increased and the short-circuit resistance is not reduced when the distribution transformer is in short-circuit.

In fig. 6, fig. 7, fig. 4 and fig. 5, in fig. 4, 7 in tapping taps 7, 6 and 5 'is close to the break point K, and in fig. 6, 5' in tapping taps 5', 6 and 7 is changed to be close to the break point K, so that the break point K is adjacent to 5' and the voltage difference is reduced, and the break point oil duct of fig. 6 can be reduced to the 2/3 level of fig. 4; the adjacent voltage difference between the tapping 7 and the tapping 3 in the corresponding map 6 is increased to twice the adjacent voltage difference between the tapping 5 and the tapping 3 in the map 4, and the layer insulation between the tapping 7 and the tapping 3 in the map 6 needs to be thickened by one time; the winding direction of each tapping line segment shown in fig. 7 is changed into the positive winding direction of the layer where tapping 5', 6 and 7 are located.

The layered winding linear voltage regulating structure shown in fig. 4, 5 or fig. 6 and 7 can be used for normal tap operation of the transformer.

In this embodiment, when the tapping range of the linear voltage regulating distribution transformer is +3 to-5×2.5%, +2 to-6×2.5%, +6 to-2×2.5%, +5 to-3×2.5%, etc., the design method adopted by the layer winding linear voltage regulating structure is the same as +4×2.5%, and the corresponding linear voltage regulating structure arrangement is also within the protection range of the application.

When the positions of the tapping taps 3 and 3', 5 and 5', 7 and 7' in the winding structure diagram and the electric wiring schematic diagram of the linear voltage-regulating distribution transformer are replaced, the principle is the same, the voltage-regulating structure is unchanged, and the changed structure still belongs to the protection scope of the application.

The layered winding linear on-load voltage regulating structure is suitable for a high-altitude 35KV distribution transformer or a 66KV distribution transformer of a V-shaped linear voltage regulating switch, and the voltage difference of the tap of the switch at the head and the tail is born through an oil gap at a break point.

In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relation of association objects, and indicates that there may be three kinds of relations, for example, a and/or B, and may indicate that a alone exists, a and B together, and B alone exists. Wherein A, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of the following" and the like means any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or plural.

The foregoing is merely specific embodiments of the present application, and any person skilled in the art may easily conceive of changes or substitutions within the technical scope of the present application, which should be covered by the protection scope of the present application. The protection scope of the present application shall be subject to the protection scope of the claims.

Claims (9)

1. The utility model provides a load linear voltage regulation distribution transformer laminar winding voltage regulation structure, its characterized in that, the laminar winding group of high tension is 4 sections, and 4 sections high tension winding sets up tapping section windings in 2, 3 sections, and every level in tapping section winding meets full layer winding height, sets up first winding section winding direction in contrast with the winding direction of other windings simultaneously to distribute the voltage difference between K end break point and the adjacent tapping tap, first winding section includes one set or two sets of, confirms in 3 rd section tapping section windings, and winding break point and tapping tap have independent oil duct.

2. The on-load linear voltage regulating distribution transformer layer type winding voltage regulating structure according to claim 1, wherein the normal section of the 2 nd section winding is connected with the tapping section tapping tap 9, the break point K of the 3 rd section normal winding is close to the tapping section winding tapping tap 7 or 5, and the break point K is shorter than the end position of the normal layer by 5-10 mm or 3-5 turns, so as to increase the creepage distance between K and the adjacent tapping section or tapping tap.

3. The voltage regulating structure of on-load linear voltage regulating distribution transformer layer winding according to claim 2, wherein the 3 rd normal winding break point K is close to the tapping point 7 of the tapping section, the winding direction of the 2 nd tapping section winding is positive, and the winding direction of the 3 rd tapping section winding is reverse.

4. The on-load linear voltage regulating distribution transformer layer winding voltage regulating structure according to claim 3, wherein the 3 rd stage tapping tap arrangement is 7, 6, 5 and 3, 2, 1, and the oil duct is arranged to bear the voltage difference between the normal winding break point K and the tapping tap 7.

5. The voltage regulating structure of on-load linear voltage regulating distribution transformer layer winding according to claim 2, wherein the 3 rd normal winding break point K is close to the tap 5, the winding direction of the 2 nd tap winding is positive, the winding direction of the first winding segment in the 3 rd tap winding is reverse, and the winding direction of the winding segment of the 3 rd tap winding close to the break point K is positive.

6. The on-load linear voltage regulating distribution transformer layer-type winding voltage regulating structure according to claim 5, wherein the 3 rd-stage tapping tap arrangement is 5, 6, 7 and 3, 2, 1, the oil duct is arranged to bear the voltage difference between the normal winding break point K and the tapping tap 5, and the layer insulation between the tapping 7 and 3 is doubled.

7. The on-load linear voltage regulating distribution transformer layer winding voltage regulating structure according to claim 4 or 6, wherein the section winding of the tapping area is high, the number of turns is large, the first and last section windings are short, the number of turns is small, wherein: the number of turns of each layer of the 1 st section and the 4 th section is larger than or equal to 60% of the number of turns of each layer of the 2 nd section and the 3 rd section, and is smaller than 100% of the number of turns of each layer of the 2 nd section and the 3 rd section.

8. The on-load linear voltage regulating distribution transformer layer-type winding voltage regulating structure according to claim 7, wherein when the 3 rd segment normal winding break point K is close to the tap 5, the width of the oil channel between the normal winding break point K and the tap 5 is smaller than when the 3 rd segment normal winding break point K is close to the tap 7, the width of the oil channel between the normal winding break point K and the tap 7.

9. The on-load linear voltage regulating distribution transformer layer-type winding voltage regulating structure according to claim 1, wherein the 1 st and 4 th windings are provided with the same width oil duct at the break point oil duct position of the 2 nd and 3 rd windings.