transformer

Abstract

The present invention relates to a transformer, which includes: an iron core, which includes a main column and a side column; a first winding, which is arranged on the main column; a second winding, which is arranged on the side column, wherein the second winding is connected in parallel with the first winding and is provided with an excitation current; and an inductor, which is arranged to form a series connection with the first winding, wherein the second winding and the first winding are connected so that a circulating current generated between the first winding and the second winding flows only through the first winding when entering the series connection formed by the inductor and the first winding.

Description

Technical Field

[0001] The invention relates to a transformer. Background Art

[0002] Due to the limitations of transportation dimensions and impedance requirements for extreme tapping, it is usually necessary to use a side-column excitation solution to meet user requirements. When the above requirements are superimposed on the large impedance requirements, it is necessary to connect a built-in reactor in series in this type of transformer. In order to increase the flexibility of the placement of the low-voltage bushing of this type of transformer, facilitate the direct lead-out of the reactor and the low-voltage lead on the excitation side to obtain a larger lead-out space, and to simplify the processing of copper parts, the low-voltage side outgoing wires of the transformer side column and the main column reactor side outgoing wires are usually connected to the low-voltage bushing, and the side-column excitation winding is connected across the two sides of the main column. For the side-column excitation transformer, when it operates at non-rated speed, a circulating current will be generated between the excitation winding of the main column and the excitation winding of the side column. This circulating current will increase the circulating current loss of the transformer, and the increased loss will bring about temperature rise problems. Summary of the invention

[0003] In view of this, an embodiment of the present invention proposes a new type of transformer. The improvement of the transformer does not occupy more lead space in order to solve the above problems, and the optimized lead design and overall layout can ensure the flexible placement of the low-voltage bushing and the reactor. At the same time, by means of the lead connection provided by the transformer provided by the present invention, the voltage regulating lead of the side column of the transformer can be axially led out, which avoids a large amount of electric field calculation and angle ring arrangement.

[0004] According to a preferred embodiment of the present invention, a transformer is provided, which includes: an iron core, including a main column and a side column; a first winding, arranged on the main column; a second winding, arranged on the side column, wherein the second winding is connected in parallel with the first winding and is provided with an excitation current; and a reactor, which is arranged to form a series connection with the first winding, wherein the second winding and the first winding are connected so that the circulating current generated between the first winding and the second winding only flows through the first winding when entering the series connection formed by the reactor and the first winding. Thus, by adopting the transformer of the present invention, when the transformer is operating at a non-rated gear, such as the non-rated gear when the high voltage and medium voltage are operating and the non-rated gear when the medium voltage and low voltage are operating, the circulating current between the side column excitation winding and the main column excitation winding will no longer flow into the built-in series reactor. The loss caused by the circulating current in the reactor is reduced to zero.

[0005] According to an exemplary embodiment of the present invention, the transformer further includes a third winding as a voltage regulating winding, wherein the third winding is arranged outside the second winding in the radial direction of the side pole. The voltage regulating winding on the side pole realizes the voltage output from the side pole, and even if a circulating current between the excitation winding of the side pole and the excitation winding of the main pole is caused by the voltage regulating winding of the side pole, the current cannot enter the built-in inductor of the transformer.

[0006] According to an exemplary embodiment of the present invention, the transformer further includes a fourth winding as a common winding and a fifth winding as a series winding, wherein the fourth winding and the fifth winding are both arranged on the main column, and in the radial direction of the main column, the fourth winding is arranged outside the first winding, and the fifth winding is arranged outside the fourth winding. Thus, the transformer can not only provide low-voltage output, but also effectively provide high-voltage output, especially high-voltage output after voltage regulation.

[0007] According to an exemplary embodiment of the present invention, the transformer further includes a low voltage outlet terminal, a medium voltage outlet terminal, a high voltage outlet terminal and a neutral point, wherein the low voltage outlet terminal is arranged on the terminal of the reactor, the medium voltage outlet terminal is arranged on the terminal of the third winding, the high voltage outlet terminal is arranged on the terminal of the fifth winding, and the neutral point is arranged on the terminal of the fourth winding. The transformer can convert and output three voltages: low, medium and high, and the lead wires of the main column excitation winding and the lead wires of the side column excitation winding are not directly connected to the low voltage outlet terminal, but are connected between the reactor and the main column excitation winding, thereby avoiding the extra loss of the transformer caused by the circulating current.

[0008] According to an exemplary embodiment of the present invention, the first winding includes a first head end and a first tail end, and the second winding includes a second head end and a second tail end, the second head end is electrically connected to a first node between the first head end of the first winding and the reactor, and the second tail end is electrically connected to a second node between the first tail end of the first winding and the reactor. This simplifies the lead connection between the main column excitation winding and the side column excitation winding in the transformer used to solve the above problem, avoids the use of additional copper materials and insulating supports, and makes the lead connection inside the transformer simple and compact.

[0009] According to an exemplary embodiment of the present invention, the reactor includes a first coil and a second coil connected in series and a third coil and a fourth coil connected in series, wherein the first node and the node between the first coil and the second coil are at the same potential, and the second node and the node between the third coil and the fourth coil are at the same potential. The multiple coils of the reactor are respectively connected in series at the head end and the tail end of the main column excitation winding, which enables the isolation and protection of the transformer by the reactor to be fully and effectively realized.

[0010] According to an exemplary embodiment of the present invention, the transformer further comprises a switch terminal for the third winding, wherein the switch terminal is arranged between the first winding and the second winding. This makes the overall design of the transformer compact and reduces the overall volume of the transformer body.

[0011] According to an exemplary embodiment of the present invention, the lead wire of the third winding is led out in the axial direction of the side column. Thus, the overall structure of the transformer improved thereby becomes compact, avoiding a large amount of electric field calculation and corner ring arrangement.

[0012] According to an exemplary embodiment of the present invention, the transformer is a single-phase transformer. Therefore, the single-phase transformer according to the present invention can have a compact structure and body, avoid the loss caused by circulating current in the reactor, and reduce the use of copper materials and insulating materials.

[0013] According to an exemplary embodiment of the present invention, the transformer further includes an oil tank, wherein the iron core and the reactor are both arranged inside the oil tank. Thus, the transformer has a built-in reactor, and since the loss of the reactor is reduced, the cooling oil passage of the transformer body is reduced, and the reactor itself can be made more compact, for example, the reactor is placed under the switch, which is conducive to the compact design of the transformer as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the above and other features and advantages of the present invention will be more apparent to those skilled in the art. In the accompanying drawings:

[0015] Figure 1 A front view schematically shows the structure of a transformer according to an embodiment of the present invention.

[0016] Figure 2 A schematic side view of the structure of a transformer according to an embodiment of the present invention is shown.

[0017] Figure 3 A circuit diagram of a transformer according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other solutions obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0019] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a product or device comprising a series of units is not necessarily limited to those units explicitly listed, but may include other units that are not listed or inherent to these products or devices.

[0020] Figure 1 A front view schematic diagram of the structure of a transformer according to an embodiment of the present invention is shown. Figure 1In the illustrated embodiment, the transformer includes an iron core 10, a first winding 20, a second winding 30, and a reactor 40. The iron core 10 includes a main column 11 and a side column 12. The first winding 20 is provided on the main column 11, the second winding 30 is provided on the side column 12, and the second winding 30 is connected in parallel with the first winding 20 and is provided with an excitation current. The reactor 40 is provided to form a series connection with the first winding 20. In this embodiment, the second winding 30 and the first winding 20 are connected so that the circulating current generated between the first winding 20 and the second winding 30 flows only through the first winding 20 when entering the series connection formed by the reactor 40 and the first winding 20. This prevents the circulating current generated between the first winding 20 as an excitation winding on the main column 11 and the second winding 30 as an excitation winding on the side column 12 from flowing into the reactor 40, thereby avoiding the loss caused by the circulating current flowing into the reactor 40.

[0021] at the same time, Figure 1 It is also shown that the first winding 20 includes a first head end 22 and a first tail end 23, and the second winding 30 includes a second head end 32 and a second tail end 33. The second head end 32 of the second winding 30 is electrically connected to a first node between the first head end 22 of the first winding 20 and the reactor 40, and the second tail end 33 of the second winding 30 is electrically connected to a second node between the first tail end 23 of the first winding 20 and the reactor 40. Figure 1 In the illustrated embodiment, the transformer is implemented as a single-phase transformer, such as a side pole 12 excitation single-phase transformer with large impedance. In an embodiment not shown, the transformer further includes an oil tank, and the iron core 10 and the reactor 40 of the transformer are both arranged inside the oil tank and immersed in the oil of the transformer oil tank.

[0022] Figure 2 FIG. 1 is a side view schematic diagram showing the structure of a transformer according to an embodiment of the present invention. Figure 2 , which shows a main column 11 and a first winding 20 arranged on the main column 11, and the inductor 40 includes a first coil 41 and a second coil 42 connected in series and a third coil 43 and a fourth coil 44 connected in series. In this embodiment, the first node between the inductor 40 and the first head end of the first winding 20 and the node between the first coil 41 and the second coil 42 are of equipotential. The second node between the inductor 40 and the first tail end of the first winding 20 and the node between the third coil 43 and the fourth coil 44 are of equipotential. In one embodiment, in order to realize the lead connection of the first winding and the second winding to the inductor 40, the lead of the first winding 20 arranged on the main column 11 and the lead of the second winding arranged on the side column are first connected together by crimping a copper rod, and then connected to the lead of the inductor 40. As shown Figure 2As shown, the head end 411 of the first coil 41 is connected to the low-voltage outlet terminal 21, the tail end 412 of the first coil 41 is crimped together with the tail end 422 of the second coil 42, and the head end 421 of the second coil 42 is connected to the head end 411 of the first coil 41. At the same time, the head end 431 of the third coil 43 is crimped together with the head end 441 of the fourth coil 44, and the tail end 432 of the third coil 43 is connected to the tail end 442 of the fourth coil 44. On this basis, one end of the first winding 20 is connected to the crimped tail end 412 of the first coil 41 and the tail end 422 of the second coil 42, and the other end is connected to the crimped head end 431 of the third coil 43 and the head end 441 of the fourth coil 44.

[0023] Figure 3 FIG. 1 shows a circuit diagram of a transformer according to an embodiment of the present invention. In this embodiment, the transformer according to the present invention includes not only a first winding 20 and a second winding 30 and a reactor 40 including a first coil 41, a second coil 42, a third coil 43 and a fourth coil 44, but also includes a third winding 50 as a voltage regulating winding. In the radial direction of the side column, the third winding 50 is arranged outside the second winding 30. At the same time, as shown in FIG. Figure 3 The circuit of the transformer shown also includes a fourth winding 60 as a common winding and a fifth winding 70 as a series winding. Both the fourth winding 60 and the fifth winding 70 are arranged on the main column, and in the radial direction of the main column, the fourth winding 60 is arranged outside the first winding 20, and the fifth winding 70 is arranged outside the fourth winding 60. Moreover, the transformer also includes a low-voltage outlet terminal 21, a medium-voltage outlet terminal 51, a high-voltage outlet terminal 71 and a neutral point O. The low-voltage outlet terminal 21 is arranged on the terminal of the reactor 40, the medium-voltage outlet terminal 51 is arranged on the terminal of the third winding 50, the high-voltage outlet terminal 71 is arranged on the terminal of the fifth winding 70, and the neutral point O is arranged on the terminal of the fourth winding 60. Corresponding bushings are respectively arranged on each outlet terminal. In addition, the transformer also includes a switch terminal 80 for the third winding 50, wherein the switch terminal 80 is spatially arranged between the first winding 20 and the second winding 30 or arranged near the side column. The lead wires of the third winding 50 are led out in the axial direction of the side pole.

[0024] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A transformer, characterized in that: The transformer comprises: The iron core (10) comprises a main column (11) and a side column (12); A first winding (20) is arranged on the main column (11); a second winding (30) disposed on the side pole (12), wherein the second winding (30) is connected in parallel with the first winding (20) and is provided with an excitation current; and A reactor (40) is arranged to be connected in series with the first winding (20), wherein the second winding (30) and the first winding (20) are connected so that a circulating current generated between the first winding (20) and the second winding (30) flows only through the first winding (20) when entering the series connection formed by the reactor and the first winding, The first winding (20) comprises a first head end (22) and a first tail end (23), and the reactor (40) comprises a first coil (41) and a second coil (42) connected in series and a third coil (43) and a fourth coil (44) connected in series, wherein a node between the reactor (40) and the first head end (22) and a node between the first coil (41) and the second coil (42) are of equal potential, and a node between the reactor (40) and the first tail end (23) and a node between the third coil (43) and the fourth coil (44) are of equal potential.

2. The transformer according to claim 1, characterized in that: The transformer further comprises a third winding (50) as a voltage regulating winding, wherein in the radial direction of the side column (12), the third winding (50) is arranged outside the second winding (30).

3. The transformer according to claim 2, characterized in that: The transformer further comprises a fourth winding (60) as a common winding and a fifth winding (70) as a series winding, wherein both the fourth winding (60) and the fifth winding (70) are arranged on the main column (11), and in the radial direction of the main column (11), the fourth winding (60) is arranged outside the first winding (20), and the fifth winding (70) is arranged outside the fourth winding (60).

4. The transformer according to claim 3, characterized in that: The transformer further comprises a low voltage outlet terminal (21), a medium voltage outlet terminal (51), a high voltage outlet terminal (71) and a neutral point (O), wherein the low voltage outlet terminal (21) is arranged on a terminal of the reactor (40), the medium voltage outlet terminal (51) is arranged on a terminal of the third winding (50), the high voltage outlet terminal (71) is arranged on a terminal of the fifth winding (70), and the neutral point (O) is arranged on a terminal of the fourth winding (60).

5. The transformer according to claim 1, characterized in that The second winding (30) comprises a second head end (32) and a second tail end (33), wherein the second head end (32) is electrically connected to a first node between the first head end (22) of the first winding (20) and the reactor (40), and the second tail end (33) is electrically connected to a second node between the first tail end (23) of the first winding (20) and the reactor (40).

6. The transformer according to claim 2, characterized in that: The transformer further comprises a switch terminal (80) for the third winding (50), wherein the switch terminal (80) is arranged between the first winding (20) and the second winding (30).

7. The transformer according to claim 2, characterized in that: Lead wires of the third winding (50) are led out in the axial direction of the side column (12).

8. The transformer according to claim 1, characterized in that: The transformer is a single-phase transformer.

9. The transformer according to claim 1, characterized in that: The transformer further comprises an oil tank, wherein the iron core (10) and the reactor (40) are both arranged inside the oil tank.

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