WO2023044964A1

WO2023044964A1 - Single-column sleeved single-phase autotransformer

Info

Publication number: WO2023044964A1
Application number: PCT/CN2021/122545
Authority: WO
Inventors: 王炳光; 冯弼乾; 安振; 冯春玲; 高辉; 李国旗; 李杨
Original assignee: 吴江变压器有限公司
Priority date: 2021-09-26
Filing date: 2021-10-08
Publication date: 2023-03-30
Also published as: CN113871158A

Abstract

Disclosed in the present invention is a single-column sleeved single-phase autotransformer, comprising: two side columns, a core column arranged between the two side columns, and a low-voltage coil, a common coil, a series coil and a voltage regulating coil, which are sequentially wound around an outer side of the core column from inside to outside, wherein the side columns are not provided with coils; and the common coil, the voltage regulating coil, and the series coil are sequentially connected in series. In the present invention, the voltage regulating coil is arranged on the outer side of the core column, and an excitation coil is omitted, such that a large amount of manufacturing costs are saved; moreover, no coil is wound around the side columns on two sides of the core column, the side columns are only configured to connect a magnetic circuit, and the side columns on the two sides are symmetrically arranged, such that the center of gravity is stable, and the autotransformer body is stable. In this way, the side columns are only configured to connect a magnetic circuit, and therefore are not subjected to interference from other coils. Moreover, the center distances between the core column and the two side columns are equal, and the length of the whole iron core is greatly reduced, so that the number of silicon steel sheets of the iron core is reduced while the excitation coil is omitted, and the no-load loss of a product is decreased.

Description

A Single-Phase Autotransformer with Single-column Package

Application field

The invention relates to the field of transformer design, in particular to a single-phase autotransformer with a single-column package.

Background technique

The 500kV single-phase autotransformer mainly adopts a single-phase three-column core. The single-phase three-column core includes a low-voltage coil, a common coil, and a series coil that are sequentially set on the middle core column from the inside to the outside, and side columns arranged on both sides of the core. . In order to make the deviation between the most positive and most negative tapped impedance of the transformer less than the rated tapped impedance, a voltage regulating coil is usually installed on the side column. The voltage regulating coil arranged on the side column is arranged on the side column and an excitation coil is added on its periphery to enhance the induced electromotive force at both ends of the click, so as to play a corresponding role.

There are many problems in this method. One is that the distance from the central center column to the side columns on both sides is not equal, and the center of gravity is easy to shift; The addition of the excitation coil which is only used to cooperate with the voltage regulating coil increases the amount of copper used, resulting in an increase in cost and low cost performance.

Therefore, the inventor considers transferring the voltage regulating coil from the side column to the core column, so that not only the magnetic flux on the side column will not be disturbed, but also the excitation coil can be omitted, but this needs to solve the problem of the relationship between the voltage regulating coil and the low voltage after the transfer. Coils, common coils, setting positions of series coils, insulation methods and outlet methods, etc.

Contents of the invention

The present invention overcomes the shortcomings of high cost and unstable center of gravity of the single-phase autotransformer in the prior art, and provides a single-phase autotransformer with a single-column package. In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is : A single-phase autotransformer with a single-column package, which includes: two side columns, a core column arranged between the two side columns, and a low-voltage coil wound on the outside of the core column sequentially from the inside to the outside, The common coil, the series coil and the voltage regulation coil, no coil is arranged on the side column; the common coil, the voltage regulation coil and the series coil are serially connected in sequence.

In a preferred embodiment of the present invention, an upper iron yoke is fixedly arranged on the top of the stem, and the upper iron yoke is electrically connected to the stem; a lower iron yoke is arranged on the bottom of the stem, and the center The column is electrically connected with the lower iron yoke; the top of the voltage regulating coil is provided with an upper magnetic screen, and the upper magnetic screen is electrically connected with the upper iron yoke; the bottom of the coil is provided with a lower magnetic screen , the lower magnetic shield plate is electrically connected to the lower iron yoke.

In a preferred embodiment of the present invention, the top of the series coil is provided with a series electrostatic plate, a number of series split angle rings and a series end insulation structure, and the series end insulation structure is laminated with the series series split angle rings .

In a preferred embodiment of the present invention, the top of the voltage regulation coil is provided with a first electrostatic plate, a first split angle ring and a first end insulation structure, and the first split angle ring is connected to the first The end insulation structure is stacked;

The bottom of the voltage regulating coil is provided with a second electrostatic plate, a second split angle ring and a second end insulation structure; the end insulation structure is stacked with the split angle ring.

In a preferred embodiment of the present invention, an insulating cylinder is provided on the outside of the voltage regulation coil, and a first support plate is provided between the top of the insulation cylinder and the first electrostatic plate, and the first support plate includes A number of insulating rods arranged side by side, and a connecting rod used to fix the insulating rods and arranged perpendicularly to the insulating rods, the center position of the first support plate is preset with a first connecting hole, and the first connecting hole One side of the first connecting hole is the first electrostatic plate, and one side of the first connecting hole is the insulating cylinder;

A second support plate is provided between the bottom of the insulating cylinder and the second electrostatic plate, the second support plate includes several insulating rods arranged side by side, and is used to fix the insulating rods and connect with the insulating rods. A vertically arranged connecting rod, a second connecting hole is preset at the center of the second support plate, one side of the second connecting hole is the second electrostatic plate, and one side of the second connecting hole is The insulating cylinder.

In a preferred embodiment of the present invention, a copper tube is arranged outside the terminal outlet of the series coil.

In a preferred embodiment of the present invention, the voltage regulating coil includes a first voltage regulating coil wound on the upper half of the series coil and a second voltage regulating coil wound on the lower half of the series coil, so The first voltage regulating coil and the second voltage regulating coil are connected in parallel through copper rods; the two ends of the first voltage regulating coil are provided with first insulators, and the first voltage regulating coil and the second voltage regulating coil are connected in parallel. Angle ring insulating components are arranged between the pressure coils, and second insulators are arranged at both ends of the second voltage regulating coil.

In a preferred embodiment of the present invention, the angle ring insulation assembly includes an inner angle ring, an outer angle ring, a separation cylinder, and a tensioning cylinder, and the outer angle ring includes an outer flat ring fixed inside the series coil and an outer flat ring from the series coil. The coil extends outwards to the outer cylinder outside the pressure regulating coil; the inner corner ring includes an inner flat ring located between the outer flat ring and the series coil and an inner cylinder located inside the outer cylinder , the outer angle ring is composed of several split angle rings, the inner angle ring is surrounded by a number of split angle rings, and the inner angle ring is set on the inner cylinder body by a tensioning tube and a hoop that are clamped inside the inner cylinder body The outer corner ring of the outer wall is fixed into a ring, and a partition cylinder is arranged between the outer cylinder body and the inner cylinder body.

In a preferred embodiment of the present invention, the series coil includes a first series coil wound on the upper half of the common coil and a second series coil wound on the lower half of the common coil, the The first series coil is connected in parallel with the second series coil, the first outlet end of the first series coil is drawn out through the inner cylinder body, and the end outlet end of the first series coil is set at the first adjustable The top of the pressure coil; the first outlet end of the second series coil is drawn out through the inner barrel, and the end outlet end of the second series coil is arranged at the bottom of the second voltage regulating coil.

In a preferred embodiment of the present invention, an arc-shaped enclosure is provided between the voltage regulation coil and the side column, and the enclosure is attached to the outside of the voltage regulation coil.

The present invention solves the defect existing in the background technology, and the present invention has the following beneficial effects:

(1) In the present invention, the voltage regulating coil is arranged on the outside of the stem, and the excitation coil is canceled, which saves a lot of production costs. At the same time, no coils are wound on the side columns on both sides of the stem, and the side columns on both Symmetrical setting, stable center of gravity and stable body. In addition, the side column is only used for the magnetic circuit and will not be interfered by other coils.

(2) The center distance between the central column and the two side columns is equal, and the length of the entire iron core is greatly reduced. When the excitation coil is eliminated, the consumption of the core silicon steel sheet is also reduced, and the no-load loss of the product is reduced.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain the drawings of other embodiments according to these drawings without creative work.

Fig. 1 is a schematic diagram of a coil package of a single-column packaged single-phase autotransformer described in an embodiment of the present invention;

Fig. 2 is a coil connection schematic diagram of a single-column packaged single-phase autotransformer described in an embodiment of the present invention;

3 is a schematic diagram of a magnetic shielding structure of a single-column packaged single-phase autotransformer described in an embodiment of the present invention;

Fig. 4 is a schematic diagram of the insulation structure of a single-column packaged single-phase autotransformer described in an embodiment of the present invention;

Fig. 5 is a schematic diagram of cooperation between a supporting plate and an insulating cylinder of a single-column packaged single-phase autotransformer described in an embodiment of the present invention;

Fig. 6 is a schematic diagram of coil distribution of a single-column packaged single-phase autotransformer described in an embodiment of the present invention;

Fig. 7 is a schematic diagram of a support plate of a single-column packaged single-phase autotransformer described in an embodiment of the present invention.

Reference signs are as follows: 101, side column; 102, core column; 103, low-voltage coil (LV); 104, public coil (MV); 105, series coil (HV); 1051, first series coil; Two series coils; 106, voltage regulating coil (TV); 1061, first voltage regulating coil; 1062, second voltage regulating coil; 107, copper pipe; 108, upper iron yoke; 109, upper magnetic screen plate; 110, surrounding screen ;2011, the first electrostatic plate; 2012, the first split angle ring; 2013, the first end insulation structure; 2014, the insulation cylinder; 202, the angle ring insulation assembly; 2021, the inner angle ring; 20211, the inner cylinder body; , outer angle ring; 2023, separation tube; 2024, tensioning tube; 2031, second electrostatic plate; 2032, second split corner ring; 2041, series electrostatic plate; 2042, series end insulation structure; 2043, series split Angle ring; 205, bracing plate; 2051, insulating rod; 2052, connecting rod.

Detailed ways

In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. structure, so it only shows the configuration related to the present invention, and it should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the associated drawings. Preferred embodiments of the invention are shown in the accompanying drawings. However, the present invention can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

As shown in Figure 1, a single-phase autotransformer set in a single column, including: two side columns 101, a core column 102 arranged between the two side columns 101, and a core column 102 arranged in sequence from the inside to the outside 102 outside the low-voltage coil 103, common coil 104, series coil 105 and voltage regulation coil 106, side column 101 is not provided with coils; as shown in Figure 2, the common coil 104, voltage regulation coil 106 and series coil 105 are connected in series.

In the present invention, referring to FIG. 1 , the voltage regulating coil 106 is arranged on the outside of the stem 102, the excitation coil is eliminated, and a large amount of manufacturing cost is saved. At the same time, no coils are wound on the side pillars 101 on both sides of the stem 102. Only used for the magnetic circuit, the side columns 101 on both sides are symmetrically arranged, the center of gravity is stable, and the body is stable. In this way, the side column 101 is only used for the magnetic circuit, so it is not interfered by other coils. In addition, the center-to-center distance between the core column 102 and the two side columns 101 is equal, and the length of the entire iron core is greatly reduced. While the excitation coil is eliminated, the consumption of core silicon steel sheets is also reduced, and the no-load loss of the product is reduced.

Continuing to refer to FIG. 1 , in one embodiment of the present invention, a copper tube 107 is provided outside the terminal outlet of the series coil 105 . The copper tube 107 here is only used for wire shielding. It should be noted that, if the series coil 105 is composed of multiple coils, a copper tube 107 is provided outside the terminal outlet of each coil.

As shown in Figure 3, the top of the stem 102 is fixedly provided with an upper iron yoke 108, and the upper iron yoke 108 is electrically connected with the stem 102; not shown in the figure), the core 102 is electrically connected with the lower iron yoke; the top of the voltage regulating coil 106 is provided with an upper magnetic shield plate 109, and the upper magnetic shield plate 109 is electrically connected with the upper iron yoke 108; the bottom of the coil is provided with a lower The magnetic shield plate (set up and down as a mirror image with the upper magnetic shield plate 109, not shown in the figure), and the lower magnetic shield plate is electrically connected with the lower iron yoke. Here, the upper magnetic shield plate 109 and the lower magnetic shield plate are provided mainly to shield magnetic flux leakage, and both the upper magnetic shield plate 109 and the lower magnetic shield plate are electrically connected to the stem 102 through the iron yoke, so the magnetic flux leakage can be introduced into the stem 102 , avoiding loss caused by magnetic flux leakage, and at the same time strengthening the magnetic flux of the stem 102 . The vertical section of the upper iron yoke 108 and the lower iron yoke are both T-shaped sections, which can ensure that the leakage flux of the coil is transmitted to the iron core through the magnetic shield of the body as much as possible, and further reduce the stray loss of the product due to the leakage flux . As shown in Figure 1, an arc-shaped enclosure 110 is provided between the voltage regulation coil 106 and the side column 101, and the enclosure 110 is attached to the outside of the voltage regulation coil 106 to increase the electrical strength of the voltage regulation coil 106 to the side yoke.

Generally speaking, the low-voltage coil 103 , the common coil 104 and the series coil 105 are sequentially placed on the middle stem 102 from inside to outside. The common coil 104 is equivalent to a medium-voltage coil, and the common coil 104 and the series coil 105 are connected in series to form a high-voltage coil. Therefore, placing the series coil 105 on the outermost layer can make the insulation structure relatively simple and easy to operate. However, in the present invention, a voltage regulating coil 106 is wound outside the series coil 105, and a new insulating structure is provided when the original insulating structure is inconvenient to use.

As shown in Figure 4, the top of the series coil 105 is provided with a series electrostatic plate 2041, a number of series split angle rings 2043 and a series end insulation structure 2042, the series end insulation structure 2042 is stacked with the series series split angle ring 2043, and the series coil The bottom of 105 is also provided with a series electrostatic plate 2041, a number of series split angle rings 2043 and a series end insulation structure 2042, the series end insulation structure 2042 is stacked with the series series split angle ring 2043, the insulation between the top and bottom of the series coil 105 The components are arranged mirror-symmetrically.

Continuing to refer to FIG. 4, the top of the voltage regulating coil 106 is provided with a first electrostatic plate 2011, a first split angle ring 2012 and a first end insulation structure 2013, and the first split angle ring 2012 is insulated from the first end. The structure 2013 is stacked; the bottom of the voltage regulating coil 106 is provided with a second electrostatic plate 2031 , a second split angle ring 2032 and a second end insulation structure; the end insulation structure and the split angle ring are stacked. Setting the electrostatic plate here can improve the electric field at the end of the coil and enhance the electric strength.

As shown in Figures 4-6, an insulating cylinder 2014 is provided on the outside of the voltage regulating coil 106, and a first strut 205 is disposed between the top of the insulating cylinder 2014 and the first electrostatic plate 2011. The first strut 205 includes several parallel arrangements. The insulating rod 2051 of the insulating rod 2051, and the connecting rod 2052 which is used to fix the insulating rod 2051 and is perpendicular to the insulating rod 2051, the center position of the first support plate 205 is preset with a first connecting hole, and one side of the first connecting hole is the first Electrostatic plate 2011, one side of the first connection hole is an insulating cylinder 2014; a second support plate 205 is provided between the bottom of the insulating cylinder 2014 and the second electrostatic plate 2031, and the second support plate 205 includes several insulating rods 2051 arranged side by side , and a connecting rod 2052 for fixing the insulating rod 2051 and perpendicular to the insulating rod 2051, a second connecting hole is preset at the center of the second support plate 205, and one side of the second connecting hole is a second electrostatic plate 2031, One side of the second connection hole is an insulating cylinder 2014 . Here, the insulating cylinder 2014, the first support plate 205 and the first split angle ring 2012 can support the voltage regulating coil 106 in addition to their own insulation function, so as to ensure the stability of the device. Because the insulating cylinder 2014 supports the voltage regulating coil 106, and at the same time leaves a position for the series outlet, it must have a certain strength. In the present invention, the insulating cylinder 2014 adopts three layers of 5mm thick extra-hard paper cylinders and the corresponding first A support plate 205 is made by riveting.

As shown in Figure 7, in order to facilitate the connection of the series coil 105, the voltage regulating coil 106 of the present invention includes a first voltage regulating coil 1061 wound on the upper half of the series coil 105 and a second voltage regulating coil 1061 wound on the lower half of the series coil 105. The voltage regulating coil 1062, the first voltage regulating coil 1061 and the second voltage regulating coil 1062 are connected in parallel through copper rods; An angle ring insulating assembly 202 is provided between the voltage regulating coils 1062, and the above-mentioned insulating assembly is provided at the bottom of the second voltage regulating coil 1062. One thing that needs to be explained is that the insulating assembly of the first voltage regulating coil 1061 is connected with the second voltage regulating coil 1062. The insulating components of the two voltage regulating coils 1062 are mirror-symmetrically arranged.

Specifically, the angle ring insulation assembly 202 includes an inner angle ring 2021, an outer angle ring 2022, a separation cylinder 2023, and a tensioning cylinder 2024. The outer angle ring 2022 includes an outer flat ring fixed inside the series coil 105 and extends outward from the series coil 105 to The outer cylinder body outside the pressure regulating coil 106; the inner angle ring 2021 includes an inner flat ring located between the outer flat ring and the series coil 105 and an inner cylinder body 20211 located inside the outer cylinder body, and the outer angle ring 2022 is surrounded by several split angle rings Composition, the inner angle ring 2021 is surrounded by several split angle rings, the inner angle ring 2021 is fixed into a ring by the tensioning tube 2024 clamped inside the inner cylinder body 20211 and the outer angle ring 2022 hooped on the outer wall of the inner cylinder body 20211, and the outer cylinder A separation cylinder 2023 is arranged between the body and the inner cylinder body 20211, and the outside of the outer cylinder body is insulated and tightened by crepe paper.

7, the series coil 105 includes a first series coil 1051 wound on the upper half of the common coil 104 and a second series coil 1052 wound on the lower half of the common coil 104. The first series coil 1051 Connected in parallel with the second series coil 1052, the first outlet of the first series coil 1051 is drawn out through the inner barrel 20211, and the end outlet of the first series coil 1051 is set on the top of the first voltage regulating coil 1061; the first outlet Leading out from the top of the first voltage regulating coil 1061 can increase the creepage distance from the head to the low potential while improving the electric field of the lead at the lead end. The first outlet of the second series coil 1052 is drawn out through the inner barrel 20211 , and the end outlet of the second series coil 1052 is set at the bottom of the second voltage regulating coil 1062 . That is to say, the lead-out end of the first series coil 1051 and the lead-out end of the second series coil 1052 are drawn from the inside of the inner angle ring 2021, and the first voltage regulating coil 1061 and the second voltage regulating coil 1062 The insulation is achieved through the angle ring insulation component 202.

Referring to Fig. 7, the second insulating member at the bottom of the second voltage regulating coil 1062 is arranged symmetrically with the first insulating assembly, and the arrangement structure here is symmetrical with that of the first voltage regulating coil 1061, and the functions of the corresponding elements are also same.

The invention mainly aims to reduce the cost of the transformer as much as possible on the basis of ensuring the performance parameters of the transformer. Compared with the prior art, the invention not only saves the consumption of copper, silicon steel sheets, transformer oil and insulating parts, but also properly reduces the loss of the transformer.

Since the voltage regulating coil 106 has fewer turns and its own weight is lighter, the upper and lower parts of the voltage regulating coil 106 need to be uniformly wound on the insulating cylinder 2014 for the convenience of assembly, and a vertical winding machine must be used for winding. At the same time, when the voltage regulating coil 106 is wound, due to the large number of insulating parts, attention should be paid to the problem of excessive winding height of the coil. If necessary, the insulating parts should be dried in the oven in advance.

The above examples only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as limiting the scope of the patent for the invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims

A single-phase autotransformer set in a single column, characterized in that it includes: two side columns, a core column arranged between the two side columns, and a low-voltage coil wound on the outside of the core column sequentially from inside to outside , a common coil, a series coil and a voltage regulating coil, and no coil is provided on the side column; the common coil, the voltage regulating coil and the series coil are connected in series in sequence.
A single-phase autotransformer set in a single column according to claim 1, wherein an upper iron yoke is fixedly arranged on the top of the core column, and the upper iron yoke is electrically connected to the core column; The bottom of the core column is provided with a lower iron yoke, and the core column is electrically connected with the lower iron yoke; the top of the voltage regulating coil is provided with an upper magnetic screen plate, and the upper magnetic screen plate is connected with the upper iron yoke Electrical connection; the bottom of the coil is provided with a lower magnetic shield plate, and the lower magnetic shield plate is electrically connected with the lower iron yoke.
A single-phase autotransformer set in a single column according to claim 1, characterized in that: the top of the series coil is provided with a series electrostatic plate, a number of series split angle rings and an insulating structure at the end of the series, the A series end insulation structure is laminated to the series split angle rings.
The single-phase autotransformer set in a single column according to claim 1, characterized in that: the top of the voltage regulating coil is provided with a first electrostatic plate, a first split angle ring and a first end insulation structure , the first split angle ring is stacked with the first end insulation structure;

The bottom of the voltage regulating coil is provided with a second electrostatic plate, a second split angle ring and a second end insulation structure; the end insulation structure is stacked with the split angle ring.
The single-phase autotransformer set in a single column according to claim 4, characterized in that: an insulating cylinder is arranged on the outside of the voltage regulating coil, and the top of the insulating cylinder and the first electrostatic plate A first brace is provided, and the first brace includes several insulating rods arranged side by side, and a connecting rod for fixing the insulating rods and perpendicular to the insulating rods. The center position of the first brace is A first connection hole is preset, one side of the first connection hole is the first electrostatic plate, and one side of the first connection hole is the insulating cylinder;

A second support plate is provided between the bottom of the insulating cylinder and the second electrostatic plate, the second support plate includes several insulating rods arranged side by side, and is used to fix the insulating rods and connect with the insulating rods. A vertically arranged connecting rod, a second connecting hole is preset at the center of the second support plate, one side of the second connecting hole is the second electrostatic plate, and one side of the second connecting hole is The insulating cylinder.
The single-phase autotransformer with a single-column package according to claim 1, wherein a copper tube is arranged outside the terminal outlet of the series coil.
The single-phase autotransformer set in a single column according to claim 1, wherein the voltage regulating coil includes a first voltage regulating coil wound on the upper half of the series coil and a first voltage regulating coil wound on the upper half of the series coil. The second voltage regulating coil in the lower half of the series coil, the first voltage regulating coil and the second voltage regulating coil are connected in parallel through copper rods; the two ends of the first voltage regulating coil are provided with first insulators , An angle ring insulation assembly is arranged between the first voltage regulation coil and the second voltage regulation coil, and a second insulator is arranged at both ends of the second voltage regulation coil.
A single-phase autotransformer set in a single column according to claim 7, characterized in that: the angle ring insulation assembly includes an inner angle ring, an outer angle ring, a separation cylinder and a tensioning cylinder, and the outer angle ring includes a The outer flat ring inside the series coil and the outer cylinder body extending outward from the series coil to the outside of the voltage regulating coil; the inner angle ring includes an inner ring between the outer flat ring and the series coil A flat ring and an inner cylinder body located inside the outer cylinder body, the outer angle ring is surrounded by several split angle rings, the inner angle ring is surrounded by several split angle rings, and the inner angle ring is formed by clamping inside The tensioning tube inside the cylinder body and the hoop are arranged on the outer corner ring on the outer wall of the inner cylinder body to form a ring, and a separation cylinder is arranged between the outer cylinder body and the inner cylinder body.
The single-phase autotransformer set in a single column according to claim 8, wherein the series coil includes a first series coil wound on the upper half of the common coil and a first series coil wound on the upper half of the common coil. The second series coil in the lower half of the common coil, the first series coil is connected in parallel with the second series coil, the first outlet end of the first series coil is drawn out through the inner barrel, and the first series coil The terminal outlet of the series coil is set on the top of the first voltage regulating coil; the first outlet of the second series coil is drawn out through the inner barrel, and the terminal outlet of the second series coil is set at the bottom of the second voltage regulating coil.
The single-phase autotransformer set in a single column according to claim 1, wherein an arc-shaped enclosure is arranged between the voltage regulating coil and the side column, and the enclosure is attached to the regulating coil. Press the outside of the coil.