Special connection group high-impedance transformer

Abstract

The high-impedance transformer comprises a first central column, a second central column and a third central column which are arranged in sequence, a first side column is arranged on the side, away from the second central column, of the first central column, and a second side column is arranged on the side, away from the second central column, of the third central column. A first high-medium-low voltage winding structure is arranged in the first center column, a second high-medium-low voltage winding structure is arranged in the second center column, a third high-medium-low voltage winding structure is arranged in the third center column, and the first high-medium-low voltage winding structure, the second high-medium-low voltage winding structure and the third high-medium-low voltage winding structure are in star connection. A balance winding structure is arranged in the first center column, the second center column and the third center column jointly, and the balance winding structure is in triangular connection. The arrangement of the concentric windings is adjusted to achieve a specified connection group label, the built-in series reactor is added to meet the high-impedance requirement, and the balance winding is configured to improve the phase electromotive force and shield the zero-sequence current.

Description

Technical Field

[0001] The utility model belongs to the technical field of transformers, and in particular relates to a special connection group high impedance transformer. Background Art

[0002] The interconnection characteristics of high-voltage power systems determine that the phase angle difference of the no-load voltage on both sides of the transformer varies very little. However, due to regional differences, when the line voltage at both ends of the interconnection power grid is required to meet a special phase angle relationship, conventional structure transformers can no longer achieve this, and a specific connection group transformer is required to match the phase angle relationship on both sides of the grid. At the same time, as the capacity of the high-voltage power grid increases, the requirements for the transformer's short-circuit resistance become more stringent, and the transformer impedance increases accordingly.

[0003] Therefore, it is necessary to design a special connection group high impedance transformer to solve the above problems. Utility Model Content

[0004] The utility model aims to provide a special connection group high impedance transformer, which realizes the designated connection group number by adjusting the concentric winding arrangement, adds a built-in series inductor to meet the high impedance requirement, and configures a balanced winding to improve the phase electromotive force and shield the zero sequence current.

[0005] To achieve the above-mentioned purpose, the utility model provides the following scheme: a special connection group high-impedance transformer, comprising a first central column, a second central column, and a third central column arranged in sequence, a first side column is arranged on the side of the first central column away from the second central column, a second side column is arranged on the side of the third central column away from the second central column, a first high school low voltage winding structure is arranged in the first central column, a second high school low voltage winding structure is arranged in the second central column, a third high school low voltage winding structure is arranged in the third central column, the first high school low voltage winding structure, the second high school low voltage winding structure and the third high school low voltage winding structure are star-connected, a balanced winding structure is commonly arranged in the first central column, the second central column and the third central column, the balanced winding structure is triangularly connected, and a reactor winding structure is arranged in the first high school low voltage winding structure, the second high school low voltage winding structure and the third high school low voltage winding structure.

[0006] Preferably, the first high, medium and low voltage winding structure includes a first high voltage winding, a first medium voltage winding, and a third low voltage winding. The first high voltage winding and the first medium voltage winding are left-wound, and the third low voltage winding is right-wound. The first high voltage winding, the first medium voltage winding, the third low voltage winding, the second high, medium and low voltage winding structure, and the third high, medium and low voltage winding structure are star-connected, and the reactor winding structure is connected in series with the third low voltage winding.

[0007] Preferably, the second high, medium and low voltage winding structure includes a second high voltage winding, a second medium voltage winding, and a first low voltage winding. The second high voltage winding and the second medium voltage winding are left-wound, and the first low voltage winding is right-wound. The second high voltage winding, the first high voltage winding and the third high, medium and low voltage winding structure are star-connected. The second medium voltage winding, the first medium voltage winding and the third high, medium and low voltage winding structure are star-connected. The first low voltage winding, the third low voltage winding and the third high, medium and low voltage winding structure are star-connected. The reactor winding structure is connected in series with the first low voltage winding.

[0008] Preferably, the third high, medium and low voltage winding structure includes a third high voltage winding, a third medium voltage winding and a second low voltage winding. The third high voltage winding and the third medium voltage winding are left-wound, and the second low voltage winding is right-wound. The third high voltage winding is star-connected with the first high voltage winding and the second high voltage winding. The third medium voltage winding is star-connected with the first medium voltage winding and the second medium voltage winding. The second low voltage winding is star-connected with the third low voltage winding and the first low voltage winding. The reactor winding structure is connected in series with the second low voltage winding.

[0009] Preferably, the connecting ends of the first high-voltage winding, the second high-voltage winding and the third high-voltage winding are connected to a high-voltage neutral point terminal.

[0010] Preferably, a medium voltage neutral point terminal is connected to the connecting ends of the first medium voltage winding, the second medium voltage winding and the third medium voltage winding.

[0011] Preferably, the connecting ends of the first low-voltage winding, the second low-voltage winding and the third low-voltage winding are connected to a low-voltage neutral point terminal.

[0012] Preferably, the balanced winding structure includes a first balanced winding, a second balanced winding, and a third balanced winding, the first balanced winding is arranged in the first center column, the second balanced winding is arranged in the second center column, and the third balanced winding is arranged in the third center column, and the first balanced winding, the second balanced winding and the third balanced winding are connected in a triangle.

[0013] Preferably, the first high-voltage winding is connected in series with a first voltage regulating winding, the second high-voltage winding is connected in series with a second voltage regulating winding, and the third high-voltage winding is connected in series with a third voltage regulating winding.

[0014] Preferably, the reactor winding structure includes a first reactor winding, a second reactor winding, and a third reactor winding, the first reactor winding is connected in series with the first low-voltage winding, the second reactor winding is connected in series with the second low-voltage winding, and the third reactor winding is connected in series with the third low-voltage winding.

[0015] Compared with the prior art, the utility model has the following advantages and technical effects:

[0016] The utility model adjusts the high and low voltage phase sequence of the concentric windings and changes the winding direction to adjust the winding voltage vector to meet the phase difference requirements of the high and low voltage no-load voltage vectors. The high and low and medium and low impedances are increased by connecting the low voltage winding in series with the reactor to limit the short-circuit current and improve the transformer's short-circuit resistance. A triangular connection balance coil is added to eliminate odd harmonic components and provide a path for zero-sequence current. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor:

[0018] Figure 1 This is the structural layout diagram of the utility model;

[0019] Figure 2 It is the voltage vector diagram of the utility model;

[0020] Figure 3 This is a schematic diagram of the high voltage winding of the utility model;

[0021] Figure 4 This is a schematic diagram of the medium voltage winding of the utility model;

[0022] Figure 5 This is a schematic diagram of the low voltage winding of the utility model;

[0023] Figure 6 This is a schematic diagram of the balanced winding of the utility model.

[0024] Among them, 1. the first central column; 2. the second central column; 3. the third central column; 4. the first side column; 5. the second side column; 6. the first high-voltage winding; 7. the second high-voltage winding; 8. the third high-voltage winding; 9. the first medium-voltage winding; 10. the second medium-voltage winding; 11. the third medium-voltage winding; 12. the first low-voltage winding; 13. the second low-voltage winding; 14. the third low-voltage winding; 15. the first voltage-regulating winding; 16. the second voltage-regulating winding; 17. the third voltage-regulating winding; 18. the first balancing winding; 19. the second balancing winding; 20. the third balancing winding; 21. the high-voltage neutral point terminal; 22. the medium-voltage neutral point terminal; 23. the low-voltage neutral point terminal; 24. the first reactor winding; 25. the second reactor winding; 26. the third reactor winding. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0027] Reference Figure 1-Figure 6 The utility model provides a special connection group high impedance transformer, comprising a first central column 1, a second central column 2, and a third central column 3 arranged in sequence, a first side column 4 is arranged on the side of the first central column 1 away from the second central column 2, a second side column 5 is arranged on the side of the third central column 3 away from the second central column 2, a first high school low voltage winding structure is arranged in the first central column 1, a second high school low voltage winding structure is arranged in the second central column 2, a third high school low voltage winding structure is arranged in the third central column 3, the first high school low voltage winding structure, the second high school low voltage winding structure and the third high school low voltage winding structure are star-connected, a balanced winding structure is commonly arranged in the first central column 1, the second central column 2 and the third central column 3, the balanced winding structure is triangularly connected, and a reactor winding structure is arranged in the first high school low voltage winding structure, the second high school low voltage winding structure and the third high school low voltage winding structure.

[0028] Further optimization scheme, the first high, medium and low voltage winding structure includes a first high voltage winding 6, a first medium voltage winding 9, and a third low voltage winding 14. The first high voltage winding 6 and the first medium voltage winding 9 are left-winding, and the third low voltage winding 14 is right-winding. The first high voltage winding 6, the first medium voltage winding 9, the third low voltage winding 14 and the second high, medium and low voltage winding structure and the third high, medium and low voltage winding structure are star-connected, and the reactor winding structure is connected in series with the third low voltage winding 14.

[0029] Further optimization scheme, the second high, medium and low voltage winding structure includes a second high voltage winding 7, a second medium voltage winding 10, and a first low voltage winding 12. The second high voltage winding 7 and the second medium voltage winding 10 are left-winding, and the first low voltage winding 12 is right-winding. The second high voltage winding 7 and the first high voltage winding 6 and the third high, medium and low voltage winding structure are star-connected. The second medium voltage winding 10 and the first medium voltage winding 9 and the third high, medium and low voltage winding structure are star-connected. The first low voltage winding 12 and the third low voltage winding 14 and the third high, medium and low voltage winding structure are star-connected. The reactor winding structure is connected in series with the first low voltage winding 12.

[0030] Further optimization scheme, the third high, medium and low voltage winding structure includes a third high voltage winding 8, a third medium voltage winding 11, and a second low voltage winding 13. The third high voltage winding 8 and the third medium voltage winding 11 are left-winding, and the second low voltage winding 13 is right-winding. The third high voltage winding 8 is star-connected with the first high voltage winding 6 and the second high voltage winding 7. The third medium voltage winding 11 is star-connected with the first medium voltage winding 9 and the second medium voltage winding 10. The second low voltage winding 13 is star-connected with the third low voltage winding 14 and the first low voltage winding 12. The reactor winding structure is connected in series with the second low voltage winding 13.

[0031] According to a further optimized solution, a high voltage neutral point terminal 21 is led out from the connecting end of the first high voltage winding 6 , the second high voltage winding 7 and the third high voltage winding 8 .

[0032] According to a further optimization scheme, a medium voltage neutral point terminal 22 is led out from the connecting end of the first medium voltage winding 9 , the second medium voltage winding 10 and the third medium voltage winding 11 .

[0033] According to a further optimization scheme, the connection ends of the first low-voltage winding 12 , the second low-voltage winding 13 , and the third low-voltage winding 14 lead out to a low-voltage neutral point terminal 23 .

[0034] According to a further optimization scheme, the balanced winding structure includes a first balanced winding 18, a second balanced winding 19, and a third balanced winding 20. The first balanced winding 18 is arranged in the first center column 1, the second balanced winding 19 is arranged in the second center column 2, and the third balanced winding 20 is arranged in the third center column 3. The first balanced winding 18, the second balanced winding 19 and the third balanced winding 20 are connected in a triangle.

[0035] The Px end of the first balanced winding 18 is connected to the Pc end of the third balanced winding 20, the Pa end of the first balanced winding 18 is connected to the Py end of the second balanced winding 19, and the Pb end of the second balanced winding 19 and the Pz end of the third balanced winding 20 are connected to the neutral line.

[0036] According to a further optimized solution, the first high-voltage winding 6 is connected in series with a first voltage regulating winding 15 , the second high-voltage winding 7 is connected in series with a second voltage regulating winding 16 , and the third high-voltage winding 8 is connected in series with a third voltage regulating winding 17 .

[0037] According to a further optimization scheme, the reactor winding structure includes a first reactor winding 24, a second reactor winding 25, and a third reactor winding 26. The first reactor winding 24 is connected in series with the first low-voltage winding 12, the second reactor winding 25 is connected in series with the second low-voltage winding 13, and the third reactor winding 26 is connected in series with the third low-voltage winding 14.

[0038] in Figure 2 The voltage vector diagram shown ignores the voltages of the first balanced winding 18 , the second balanced winding 19 and the third balanced winding 20 .

[0039] The first low-voltage winding 12, the second low-voltage winding 13, and the third low-voltage winding 14 are connected in series with the first reactor winding 24, the second reactor winding 25, and the third reactor winding 26 through low-voltage copper bars, and then a low-voltage neutral point is led out.

[0040] The large current lead accessory structures such as the intersection of single-phase and two-phase leads corresponding to the oil tank and the inner web of the reactor are made of low-magnetic steel material to reduce losses, and equipotential connections are added along the tank to prevent overheating of the oil tank.

[0041] The utility model is a high impedance transformer with a special connection group (YN yn0 yn10+d11). By adjusting the high and low voltage phase sequence of the concentric windings and changing the winding direction, the winding voltage vector is adjusted to meet the phase difference requirements of the high and low voltage no-load voltage vectors. The high and low and medium and low impedances are increased by connecting the low voltage winding in series with the reactor to limit the short-circuit current and improve the transformer's short-circuit resistance. A triangular connection balance coil is added to eliminate odd harmonic components and provide a path for zero-sequence current.

[0042] The utility model determines the winding arrangement according to the voltage level and the lead arrangement to determine the main insulation, uses magnetic field software to optimize the structural parts near the large current lead to reduce loss and temperature rise, and uses wave process software to determine the best arrangement plan for the first and last ends of the winding, thereby improving the reliability of equipment operation.

[0043] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] The embodiments described above are only descriptions of the preferred methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A special connection group high impedance transformer, characterized in that: The invention comprises a first central column (1), a second central column (2) and a third central column (3) arranged in sequence, wherein a first side column (4) is arranged on a side of the first central column (1) away from the second central column (2), and a second side column (5) is arranged on a side of the third central column (3) away from the second central column (2); a first high, medium and low voltage winding structure is arranged in the first central column (1), a second high, medium and low voltage winding structure is arranged in the second central column (2), and a third high, medium and low voltage winding structure is arranged in the third central column (3); the first high, medium and low voltage winding structure, the second high, medium and low voltage winding structure and the third high, medium and low voltage winding structure are star-connected; a balanced winding structure is arranged in the first central column (1), the second central column (2) and the third central column (3); and a reactor winding structure is arranged in the first high, medium and low voltage winding structure, the second high, medium and low voltage winding structure and the third high, medium and low voltage winding structure.

2. A special connection group high impedance transformer according to claim 1, characterized in that: The first high-, medium- and low-voltage winding structure comprises a first high-voltage winding (6), a first medium-voltage winding (9) and a third low-voltage winding (14); the first high-voltage winding (6) and the first medium-voltage winding (9) are left-winding, the third low-voltage winding (14) is right-winding, the first high-voltage winding (6), the first medium-voltage winding (9), the third low-voltage winding (14) and the second high-, medium- and low-voltage winding structure and the third high-, medium- and low-voltage winding structure are star-connected, and the reactor winding structure is connected in series with the third low-voltage winding (14).

3. A special connection group high impedance transformer according to claim 2, characterized in that: The second high, medium and low voltage winding structure comprises a second high voltage winding (7), a second medium voltage winding (10) and a first low voltage winding (12); the second high voltage winding (7) and the second medium voltage winding (10) are left-winding, the first low voltage winding (12) is right-winding, the second high voltage winding (7) and the first high voltage winding (6) and the third high, medium and low voltage winding structure are star-connected, the second medium voltage winding (10) and the first medium voltage winding (9) and the third high, medium and low voltage winding structure are star-connected, the first low voltage winding (12) and the third low voltage winding (14) and the third high, medium and low voltage winding structure are star-connected, and the reactor winding structure is connected in series with the first low voltage winding (12).

4. A special connection group high impedance transformer according to claim 3, characterized in that: The third high, medium and low voltage winding structure comprises a third high voltage winding (8), a third medium voltage winding (11) and a second low voltage winding (13); the third high voltage winding (8) and the third medium voltage winding (11) are left-winding, the second low voltage winding (13) is right-winding, the third high voltage winding (8) and the first high voltage winding (6) and the second high voltage winding (7) are star-connected, the third medium voltage winding (11) and the first medium voltage winding (9) and the second medium voltage winding (10) are star-connected, the second low voltage winding (13) and the third low voltage winding (14) and the first low voltage winding (12) are star-connected, and the reactor winding structure is connected in series with the second low voltage winding (13).

5. A special connection group high impedance transformer according to claim 4, characterized in that: The connecting ends of the first high-voltage winding (6), the second high-voltage winding (7) and the third high-voltage winding (8) are connected to a high-voltage neutral point terminal (21).

6. A special connection group high impedance transformer according to claim 4, characterized in that: The connecting ends of the first medium voltage winding (9), the second medium voltage winding (10) and the third medium voltage winding (11) are connected to a medium voltage neutral point terminal (22).

7. A special connection group high impedance transformer according to claim 4, characterized in that: The connecting ends of the first low-voltage winding (12), the second low-voltage winding (13), and the third low-voltage winding (14) are connected to a low-voltage neutral point terminal (23).

8. A special connection group high impedance transformer according to claim 1, characterized in that: The balanced winding structure comprises a first balanced winding (18), a second balanced winding (19), and a third balanced winding (20); the first balanced winding (18) is arranged in the first center column (1), the second balanced winding (19) is arranged in the second center column (2), and the third balanced winding (20) is arranged in the third center column (3); the first balanced winding (18), the second balanced winding (19) and the third balanced winding (20) are connected in a triangle.

9. A special connection group high impedance transformer according to claim 5, characterized in that: The first high-voltage winding (6) is connected in series with a first voltage regulating winding (15), the second high-voltage winding (7) is connected in series with a second voltage regulating winding (16), and the third high-voltage winding (8) is connected in series with a third voltage regulating winding (17).

10. A special connection group high impedance transformer according to claim 7, characterized in that: The reactor winding structure comprises a first reactor winding (24), a second reactor winding (25), and a third reactor winding (26); the first reactor winding (24) is connected in series with the first low-voltage winding (12); the second reactor winding (25) is connected in series with the second low-voltage winding (13); and the third reactor winding (26) is connected in series with the third low-voltage winding (14).

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