WO2024108685A1 - Single-phase self-coupling excitation-free medium-voltage multi-tap voltage-regulating transformer and voltage regulation method therefor - Google Patents

Abstract

The present invention belongs to the field of transformer tap regulation. Particularly disclosed is a single-phase self-coupling excitation-free medium-voltage multi-tap voltage-regulating transformer. A voltage-regulating coil is wound on a side column, the voltage-regulating coil comprises a plurality of longitudinally arranged wire turns, and tap points are arranged on the wire turns; and a tap switch is of a dual-layer disk structure, a disk a has the same structure as a disk b, and each disk is provided with a first contact, a second contact, a fixed contact point, which is connected to the first contact, and a rated contact point and several regulating contact points, which can be connected to the second contact, wherein the regulating contact points are correspondingly connected to the tap points on the wire turns on a one-to-one basis, and the second contact on the disk a is electrically connected to the second contact on the disk b. In the present invention, a dual-layer tap switch is utilized, such that the voltage tap level of a transformer can be regulated more conveniently; and by means of regulating the voltage tap level, the voltage regulation manner of the transformer is simple and convenient, such that one transformer can serve as a standby-phase transformer of a plurality of transformers, thereby not only saving on the cost, but also avoiding a loss caused by the outage of a transformer fault system.

Description

Single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer and voltage regulating method thereof Technical Field

The invention belongs to the technical field of transformer tapping regulation, and in particular relates to a single-phase auto-coupling non-excitation medium-voltage multi-tap voltage regulating transformer.

Background technique

At present, most of the 500kV substations of the State Grid in my country are operated by a group of three-phase transformers composed of single-phase transformers. Each single-phase transformer will have a corresponding type of spare phase transformer, but due to cost constraints, spare phase transformers are generally not ordered when ordering. If each substation is equipped with a spare phase transformer, the investment cost of the substation will be greatly increased. If spare phase transformers are not ordered additionally, when a single-phase transformer in the transformer group of the substation fails, the entire transformer group needs to be withdrawn. If there is a suitable spare phase transformer that can quickly replace the faulty phase transformer, the power supply can be restored quickly, minimizing the losses caused by power outages.

Ordinary transformers can only be used as backup phases for transformers of the same model and parameters. If the parameters are different, forcibly putting them into the transformer group of the substation may cause certain safety hazards and thus cause higher losses. In order to enable the transformer to be used as a backup phase for transformers of different models and parameters, the development of a transformer that can flexibly adjust the voltage tapping level has become an urgent problem to be solved.

Summary of the invention

The present invention provides a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer and a voltage regulating method thereof, which are used to solve the problem that when a transformer group in a current substation fails, there is no suitable spare phase to replace it, which will cause great losses.

In order to solve the above technical problems, the technical solution of the present invention is: the single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer, wherein, comprises: an oil tank, an iron core column arranged in the oil tank, a side column fixed to one side of the iron core column, and a tap switch fixed to the oil tank;

The side column is wound with an excitation coil and a voltage regulating coil in sequence from the inside to the outside; the voltage regulating coil is a multi-spiral coil, including a plurality of turns arranged longitudinally, and a tapping point is arranged on the turns;

The tap changer is a double-layer disk structure, including a disk and a disk. The structure of the a disk is the same as that of the b disk. The disk is provided with a first contact, a second contact, a fixed contact connected to the first contact, and a rated contact and a plurality of adjustment contacts that can be connected to the second contact. The second contact is electrically connected to one of the rated contact and the plurality of adjustment contacts to achieve the adjustment of the transformer voltage tap level. The adjustment contact is connected to the tap points on the turns in a one-to-one correspondence. The second contact on the a disk is electrically connected to the second contact on the b disk.

In a preferred embodiment of the present invention, a low-voltage coil, a medium-voltage coil and a high-voltage coil are wound on the core column from the inside to the outside in sequence, the low-voltage coil is an end spiral wire feeder, the medium-voltage coil is a continuous end wire feeder, and the high-voltage coil is an inner-screen continuous middle wire feeder.

In a preferred embodiment of the present invention, the low voltage coil is made of a self-adhesive transposed mesh-wrapped conductor, the medium voltage coil, high voltage coil and excitation coil are made of a self-adhesive transposed paper-wrapped conductor, and the voltage regulating coil is made of a combined paper-wrapped conductor.

In a preferred embodiment of the present invention, an electrostatic plate is provided at the end of the outlet terminal of the medium voltage coil, and an electrostatic plate is provided at the end of the outlet terminal of the high voltage coil.

In a preferred embodiment of the present invention, an upper iron yoke is fixedly provided on the top of the iron core column, a lower iron yoke is fixedly provided on the bottom of the iron core column, and the upper and lower parts of the high-voltage coil and the medium-voltage coil are provided with lung-type magnetic shielding plates; the inner wall of the high-pressure side of the oil tank is provided with a plurality of rolled strip-shaped magnetic shielding parts, and the inner wall of the low-pressure side is provided with a plurality of rolled strip-shaped magnetic shielding parts.

In a preferred embodiment of the present invention, the medium voltage coil is connected in parallel with the excitation coil, and the high voltage coil includes an upper high voltage coil and a lower high voltage coil arranged in parallel, and the terminal outlet of the upper high voltage coil and the terminal outlet of the lower high voltage coil are electrically connected to the first terminal outlet of the medium voltage coil.

In a preferred embodiment of the present invention, the voltage regulating coil includes a plurality of wire turns arranged longitudinally and connected in series in sequence, the end outlet of the wire turns is a regulating tapping point, the first outlet of the voltage regulating coil is a rated tapping point, the rated tapping point is electrically connected to the rated contact, and the regulating tapping point is connected to the regulating contact in a one-to-one correspondence.

In a preferred embodiment of the present invention, two adjacent turns are connected via a copper rod, and the copper rod is electrically connected to a corresponding contact.

In a preferred embodiment of the present invention, the fixed contact of the a disk is electrically connected to the medium voltage bushing, and the fixed contact of the b disk is electrically connected to the first outlet terminal of the medium voltage coil.

The present invention also discloses a voltage regulation method for a single-phase auto-coupling non-excitation medium-voltage multi-tap voltage regulating transformer, which comprises the following steps:

When the target voltage is positive tap, the second contact of disk a is connected to the rated contact of disk a, and the positive tap adjustment is achieved by changing the adjustment contact of disk b connected to the second contact of disk b;

When the target voltage is negative tap, the second contact of disk b is connected to the rated contact of disk b, and the negative tap adjustment is achieved by changing the adjustment contact of disk a connected to the second contact of disk a;

When the target voltage is the rated tap, the second contact of disk a is electrically connected to the rated contact of disk a, and the second contact of disk b is electrically connected to the rated contact of disk b.

In a preferred embodiment of the present invention, when the target voltage is positive tap, taking the rated contact of disk b as the starting point, the second contact of disk b is sequentially connected to each adjustment contact arranged clockwise or counterclockwise on disk b, and the rated tap level decreases sequentially.

In a preferred embodiment of the present invention, when the target voltage is negative tap, taking the rated contact of disk a as the starting point, the second contact of disk a is sequentially connected to each adjustment contact arranged clockwise or counterclockwise on a, and the rated tap level increases sequentially.

The technical solution provided by the present invention has the following advantages compared with the prior art:

The present invention provides a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer and a voltage regulating method thereof. A double-layer tap switch is adopted, so that the voltage tapping level of the transformer can be adjusted more conveniently. By adjusting the voltage tapping level, the voltage regulating method of the transformer is simple and convenient, so that one transformer can become a backup phase transformer for multiple transformers, which not only saves costs but also avoids losses caused by system shutdown due to transformer failure.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without paying creative work.

FIG1 is a top view of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer according to an embodiment of the present invention;

2 is a schematic diagram of lead connection of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer according to an embodiment of the present invention;

3 is a schematic diagram of the magnetic shielding structure of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer according to an embodiment of the present invention;

4 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is +1% according to an embodiment of the present invention;

5 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is +2% according to an embodiment of the present invention;

6 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is +3% according to an embodiment of the present invention;

7 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is +4% according to an embodiment of the present invention;

8 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is +5% according to an embodiment of the present invention;

9 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is -1% according to an embodiment of the present invention;

10 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is -2% according to an embodiment of the present invention;

11 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is -3% according to an embodiment of the present invention;

12 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is -4% according to an embodiment of the present invention;

13 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer when the tapping level is -5% according to an embodiment of the present invention;

14 is a wiring schematic diagram of a single-phase auto-coupling non-excitation medium-voltage multi-tap voltage regulating transformer described in one embodiment of the present invention when the tapping level is the rated tapping.

As shown in the figure: 101-side column; 102-iron core column; 103-side yoke; 104-upper iron yoke; 105-lower iron yoke; 201-low voltage coil; 202-medium voltage coil; 203-high voltage coil; 204-excitation coil; 205-voltage regulating coil; 2051-copper rod; 206-static plate; 301-magnetic shielding plate; 302-magnetic shielding member; 401-tap changer.

Detailed ways

For ease of understanding, a single-phase auto-coupled non-excitation medium voltage multi-tap voltage regulating transformer and its voltage regulating method are described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left",

The directions or positional relationships indicated by "right", "vertical", "horizontal", "inside", "outside", etc. are based on the directions and positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented 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 thoroughly understood.

The present invention discloses a single-phase auto-coupling non-excitation medium-voltage multi-tap voltage-regulating transformer, as shown in FIG1, which includes: an oil tank, an iron core column 102 arranged in the oil tank, a low-voltage coil 201, a medium-voltage coil 202 and a high-voltage coil 203 wound on the iron core column 102 from the inside to the outside, a side column 101 fixed on one side of the iron core column 102, an excitation coil 204 and a voltage-regulating coil 205 wound on the side column 101 from the inside to the outside, a tap switch 401 fixed on the oil tank, and a side yoke 103 fixed on the other side of the iron core column 102. The present invention adopts a single-phase three-column iron core structure, which can well reduce coil leakage while meeting product technical parameters, thereby reducing transformer stray losses.

The low voltage coil 201 is made of a self-adhesive transposed mesh-wrapped conductor, and the end is a spiral-type wire feeder.

The medium voltage coil 202 is made of self-adhesive transposed paper-wrapped conductor and is a continuous end-inlet wire. An electrostatic plate 206 is provided at the end of the outlet end of the medium voltage coil 202.

The high-voltage coil 203 is made of self-adhesive transposed paper-wrapped conductor. The high-voltage coil 203 is an inner-screen continuous middle-inlet wire. The end of the high-voltage coil 203 outlet is provided with an electrostatic plate 206. The high-voltage coil 203 includes an upper high-voltage coil 203 and a lower high-voltage coil 203 arranged in parallel. The terminal outlet of the upper high-voltage coil 203 and the terminal outlet of the lower high-voltage coil 203 are electrically connected to the first outlet of the medium-voltage coil 202.

As shown in Figure 2-3, an upper iron yoke 104 is fixedly installed on the top of the iron core column 102, a lower iron yoke 105 is fixedly installed on the bottom of the iron core column 102, and lung-type magnetic shielding plates 301 are provided on the upper and lower parts of the high-voltage coil 203 and the medium-voltage coil 202; the inner wall of the high-pressure side of the oil tank is provided with longitudinally arranged parallel rolled strip magnetic shielding parts 302, and the inner wall of the low-pressure side is also provided with longitudinally arranged parallel rolled strip magnetic shielding parts 302.

The magnetic leakage of the transformer coil increases with the increase of the transformer capacity. An upper magnetic shield plate and a lower magnetic shield plate are set at the upper and lower ends of the coil, and a magnetic leakage control system with a vertical magnetic shield plate is added to provide two paths for the magnetic leakage of the coil. One is a leakage magnetic circuit formed by the upper iron yoke 104, the lower iron yoke 105, a side column 101, and a side yoke 103 through the upper magnetic shield plate and the lower magnetic shield plate, and the other is a circuit formed by the magnetic shielding of the upper and lower ends of the body and the vertical oil tank magnetic shielding, which solves the problem of overheating of the core structure and the oil tank structure caused by the magnetic leakage of the coil.

The exciting coil 204 is made of self-adhesive transposed paper-wrapped conductor, and the exciting coil 204 is connected in parallel with the medium voltage coil 202.

The voltage regulating coil 205 is made of a combined paper-wrapped conductor and is a multi-spiral coil, including a plurality of turns arranged longitudinally, and tapping points are provided on the turns. The voltage regulating coil 205 includes a plurality of turns arranged longitudinally and connected in series in sequence, the end outlet of the turns is the regulating tapping point, the first outlet of the voltage regulating coil 205 is the rated tapping point, the rated tapping point is electrically connected to the rated contact, and the regulating tapping point is connected to the regulating contact in a one-to-one correspondence. Two adjacent turns are connected by a copper rod 2051, and the copper rod 2051 is electrically connected to the corresponding contact. The fixed contact of the a disk is electrically connected to the medium voltage casing, and the fixed contact of the b disk is electrically connected to the first outlet of the medium voltage coil 202.

The tap changer 401 is a double-layer disk structure, including a disk and b disk. The a disk has the same structure as the b disk. The disk is provided with a first contact, a second contact, a fixed contact connected to the first contact, and a rated contact and a plurality of adjustment contacts that can be connected to the second contact. The adjustment contacts are connected to the tap points on the turns one by one. The second contact on the a disk is electrically connected to the second contact on the b disk. The fixed contact of the a disk is electrically connected to the medium voltage bushing, and the fixed contact of the b disk is electrically connected to the first outlet terminal of the medium voltage coil 202.

In one embodiment of the present invention, the voltage between the voltage regulating coil 205 and the tap switch 401 is 220 kV. In order to achieve a voltage regulation mode of ±5×1%, the voltage regulating coil 205 includes five turns, namely a first turn, a second turn, a third turn, a fourth turn and a fifth turn. The end outlet of the first turn is a first tap point, the end outlet of the second turn is a second tap point, the end outlet of the third turn is a third tap point, the end outlet of the fourth turn is a fourth tap point, the end outlet of the fifth turn is a fifth tap point, and the beginning outlet of the fifth turn is a sixth tap point.

The adjacent turns are connected by the copper rod 2051, and the tapping point is electrically connected to the corresponding contact through the copper rod 2051. The upper and lower taps of the voltage regulating coil 205 are first connected to the upper and lower ends of the longitudinally arranged copper rods 2051 in sequence, and then the cables are connected to the corresponding contacts of the a and b disks of the tap switch 401 through the two sets of terminal connections at the upper and lower parts of the copper rod 2051, and the voltage regulation mode of ±5×1% is realized through the transformation of the tap switch 401.

Specifically, the a-disk includes a K contact, a first contact, a second contact, a third contact, a fourth contact, a fifth contact, and six sixth contacts connected in series, wherein the K contact is a fixed contact, the first contact, the second contact, the third contact, the fourth contact, and the fifth contact are adjustment contacts, and the sixth contact is a rated contact. The K contact is electrically connected to the medium voltage bushing, the first contact is electrically connected to the first tap point, the second contact is electrically connected to the second tap point, the third contact is electrically connected to the third tap point, the fourth contact is electrically connected to the fourth tap point, the fifth contact is electrically connected to the fifth tap point, and the sixth contact is electrically connected to the sixth tap point.

The b-disk includes an O contact, a first contact, a second contact, a third contact, a fourth contact, a fifth contact, and six sixth contacts connected in series. Among them, the O contact is a fixed contact, the first contact, the second contact, the third contact, the fourth contact, and the fifth contact are adjustment contacts, and the sixth contact is a rated contact. The O contact is electrically connected to the first outlet terminal of the medium voltage coil 202, the first contact is electrically connected to the first tap, the second contact is electrically connected to the second tap, the third contact is electrically connected to the third tap, the fourth contact is electrically connected to the fourth tap, the fifth contact is electrically connected to the fifth tap, and the sixth contact is electrically connected to the sixth tap.

A single-phase auto-coupling non-excitation medium-voltage multi-tap voltage-regulating transformer in the present invention has a voltage regulation method as follows.

When the target voltage is positive tap, the second contact of disk a is connected to the rated contact of disk a, and the positive tap adjustment is achieved by changing the adjustment contact of disk b connected to the second contact of disk b. Starting from the rated contact of disk b, the second contact of disk b is connected to the adjustment contacts arranged clockwise or counterclockwise on disk b in sequence, and the rated tap level decreases in sequence.

As shown in FIG4 , specifically, when the target voltage is +1% tapping, the first contact of disk a is connected to the K contact, the second contact is connected to the sixth contact, the first contact of disk b is connected to the O contact, and the second contact is connected to the fifth contact;

As shown in FIG5 , when the target voltage is +2% tapping, the first contact of disk a is connected to the K contact, the second contact is connected to the sixth contact, the first contact of disk b is connected to the O contact, and the second contact is connected to the fourth contact;

As shown in FIG6 , when the target voltage is +3% tapping, the first contact of disk a is connected to the K contact, the second contact is connected to the sixth contact, the first contact of disk b is connected to the O contact, and the second contact is connected to the third contact;

As shown in FIG7 , when the target voltage is +4% tapping, the first contact of disk a is connected to the K contact, the second contact is connected to the sixth contact, the first contact of disk b is connected to the O contact, and the second contact is connected to the second contact;

As shown in FIG8 , when the target voltage is +5% tap, the first contact of disk a is connected to the K contact, the second contact is connected to the sixth contact, and the first contact of disk b is connected to the O contact, the second contact is connected to the first contact.

When the target voltage is negative tap, the second contact of disk b is connected to the rated contact of disk b, and the negative tap adjustment is achieved by changing the adjustment contact of disk a connected to the second contact of disk a. Starting from the rated contact of disk a, the second contact of disk a is connected to the adjustment contacts arranged clockwise or counterclockwise on disk a in sequence, and the rated tap level increases in sequence.

Specifically, as shown in FIG9 , when the target voltage is -1% tapped, the first contact of disk a is connected to the K contact, and the second contact is connected to the fifth contact; the first contact of disk b is connected to the O contact, and the second contact is connected to the sixth contact;

As shown in FIG10 , when the target voltage is -2% tapped, the first contact of disk a is connected to the K contact, and the second contact is connected to the fourth contact; the first contact of disk b is connected to the O contact, and the second contact is connected to the sixth contact;

As shown in FIG11 , when the target voltage is -3% tapped, the first contact of disk a is connected to the K contact, and the second contact is connected to the third contact; the first contact of disk b is connected to the O contact, and the second contact is connected to the sixth contact;

As shown in FIG12 , when the target voltage is -4% tapped, the first contact of disk a is connected to the K contact, and the second contact is connected to the second contact; the first contact of disk b is connected to the O contact, and the second contact is connected to the sixth contact;

As shown in FIG. 13 , when the target voltage is -5% tap, the first contact of disk a is electrically connected to contact K, and the second contact is electrically connected to the first contact; the first contact of disk b is connected to contact O, and the second contact is connected to contact No. 6.

As shown in FIG14 , when the target voltage is the rated tap, the first contact of disk a is connected to the K contact, and the second contact is connected to the sixth contact; the first contact of disk b is connected to the O contact, and the second contact is connected to the sixth contact.

The present invention provides a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer and a voltage regulating method thereof. A double-layer tap switch is adopted, so that the voltage tapping level of the transformer can be adjusted more conveniently. By adjusting the voltage tapping level, the voltage regulating method of the transformer is simple and convenient, so that one transformer can become a backup phase transformer for multiple transformers, which not only saves costs but also avoids losses caused by system shutdown due to transformer failure.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims (12)

A single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer, characterized in that it comprises: an oil tank, an iron core column arranged in the oil tank, a side column located on one side of the iron core column, and a tap switch fixed on the oil tank; The side column is wound with an excitation coil and a voltage regulating coil in sequence from the inside to the outside; the voltage regulating coil is a multi-spiral coil, including a plurality of turns arranged longitudinally, and a tapping point is arranged on the turns; The tap changer is a double-layer disk structure, including a disk and a disk. The structure of the a disk is the same as that of the b disk. The disk is provided with a first contact, a second contact, a fixed contact connected to the first contact, and a rated contact and a plurality of adjustment contacts that can be connected to the second contact. The second contact is electrically connected to one of the rated contact and the plurality of adjustment contacts to achieve the adjustment of the transformer voltage tap level. The adjustment contact is connected to the tap points on the turns in a one-to-one correspondence. The second contact on the a disk is electrically connected to the second contact on the b disk. According to claim 1, a single-phase auto-coupling non-excitation medium-voltage multi-tap voltage regulating transformer is characterized in that: a low-voltage coil, a medium-voltage coil and a high-voltage coil are wound on the core column from the inside to the outside in sequence, the low-voltage coil is an end spiral wire feeder, the medium-voltage coil is a continuous end wire feeder, and the high-voltage coil is an inner-screen continuous middle wire feeder. According to claim 2, a single-phase auto-coupling non-excitation medium-voltage multi-tap voltage-regulating transformer is characterized in that: the low-voltage coil is made of a self-adhesive transposed mesh-wrapped conductor, the medium-voltage coil, high-voltage coil, and excitation coil are made of a self-adhesive transposed paper-wrapped conductor, and the voltage regulating coil is made of a combined paper-wrapped conductor. According to the single-phase auto-coupling non-excitation medium-voltage multi-tap voltage regulating transformer described in claim 2, it is characterized in that an electrostatic plate is provided at the end of the outlet terminal of the medium-voltage coil, and an electrostatic plate is provided at the end of the outlet terminal of the high-voltage coil. According to claim 2, a single-phase auto-coupling non-excitation medium-voltage multi-tap regulating transformer is characterized in that: an upper iron yoke is fixedly provided on the top of the iron core column, a lower iron yoke is fixedly provided on the bottom of the iron core column, and lung-lobe type magnetic shielding plates are provided on the upper and lower parts of the high-voltage coil and the medium-voltage coil; a plurality of rolled strip-shaped magnetic shielding parts are provided on the inner wall of the high-voltage side of the oil tank, and a plurality of rolled strip-shaped magnetic shielding parts are provided on the inner wall of the low-voltage side. According to the single-phase auto-coupling non-excitation medium-voltage multi-tap voltage regulating transformer described in claim 2, it is characterized in that: the medium-voltage coil is connected in parallel with the excitation coil, the high-voltage coil includes an upper high-voltage coil and a lower high-voltage coil arranged in parallel, and the terminal outlet of the upper high-voltage coil and the terminal outlet of the lower high-voltage coil are electrically connected to the first outlet of the medium-voltage coil. A single-phase auto-coupling non-excited medium-voltage multi-tap voltage regulating transformer according to claim 1, characterized in that: the voltage regulating coil comprises a plurality of turns arranged longitudinally and connected in series in sequence, the end outlet of the turns is the regulating tap point, the first outlet of the voltage regulating coil is the rated tap point, the rated tap point is electrically connected to the rated contact, and the regulating tap point is connected to the regulating contact in a one-to-one correspondence. The single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer according to claim 7 is characterized in that two adjacent turns are connected by a copper rod, and the copper rod is electrically connected to the corresponding contact. According to the single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer described in claim 1, it is characterized in that: the fixed contact of the a disk is electrically connected to the medium voltage bushing, and the fixed contact of the b disk is electrically connected to the first outlet terminal of the medium voltage coil. A voltage regulation method for a single-phase auto-coupling non-excitation medium voltage multi-tap voltage regulating transformer as claimed in any one of claims 1 to 9, characterized in that it comprises the following steps: When the target voltage is positive tap, the second contact of disk a is connected to the rated contact of disk a, and the positive tap adjustment is achieved by changing the adjustment contact of disk b connected to the second contact of disk b; When the target voltage is negative tap, the second contact of disk b is connected to the rated contact of disk b, and the negative tap adjustment is achieved by changing the adjustment contact of disk a connected to the second contact of disk a; When the target voltage is the rated tap, the second contact of disk a is electrically connected to the rated contact of disk a, and the second contact of disk b is electrically connected to the rated contact of disk b. The voltage regulation method of a single-phase auto-coupling non-excitation medium voltage multi-tap regulating transformer according to claim 10 is characterized in that: when the target voltage is a positive tap, taking the rated contact of disk b as the starting point, the second contact of disk b is sequentially connected to each regulating contact arranged clockwise or counterclockwise on disk b, and the rated tap level decreases sequentially. The voltage regulation method of a single-phase auto-coupling non-excitation medium voltage multi-tap regulating transformer according to claim 10 is characterized in that: when the target voltage is a negative tap, taking the rated contact of disk a as the starting point, the second contact of disk a is sequentially connected to each regulating contact arranged clockwise or counterclockwise on a, and the rated tap level increases sequentially.

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