Full-foil coil winding dry type converter transformer

Abstract

The utility model relates to the field of transformers, in particular to an all-foil winding coil dry type converter transformer. Which comprises an iron core and a winding arranged on the iron core, and is characterized in that the winding comprises a first coil and a second coil, the second coil is axially wound on the outer side of the iron core, the first coil is radially and concentrically wound on the outer side of the second coil, and the first coil comprises a first sub-coil and a second sub-coil which are arranged in series up and down in the axial direction. The first coil and the second coil are formed by winding the whole foil, the first coil is composed of the first sub-coil and the second sub-coil which are arranged at the upper section and the lower section, the overall structure is simple, use is convenient, the installation space is saved, and cost is reduced; the first coil can provide 7-level voltage output of + 4 / -2%, the problems of unstable inter-turn field intensity, high partial discharge and the like in the prior art are solved, and stable operation of a commutation system is ensured.

Description

Technical Field

[0001] The utility model relates to the field of transformers, in particular to a full-foil winding dry-type converter transformer. Background Art

[0002] With the needs of my country's national economic construction and the development of power construction, the research and application of high-voltage direct current transmission technology in my country has been very in-depth and mature. This dry-type converter transformer is suitable for the development of a new LCC converter valve with the ability to suppress commutation failure. It can insulate the DC part of the system from the AC system and limit the fault current. However, this dry-type converter transformer is usually made by wire winding, so the dry-type converter transformer has the disadvantages of large size, unstable inter-turn field strength, and high partial discharge. Utility Model Content

[0003] In view of the problems mentioned in the prior art, the utility model proposes a full-foil winding dry-type converter transformer to solve the problems in the background technology.

[0004] The utility model discloses a full foil wound coil dry-type converter transformer, comprising an iron core and a winding arranged on the iron core, wherein the winding comprises a first coil and a second coil, the secondary coil is axially wound on the outside of the iron core, the first coil is radially concentrically wound on the outside of the second coil, wherein the first coil comprises a first sub-coil and a second sub-coil which are axially arranged in series up and down.

[0005] Preferably, the first sub-coil and the second sub-coil adopt a D-connected lead structure, and the first sub-coil lead-out copper bar start end and the second sub-coil lead-out copper bar end are softly connected.

[0006] Preferably, the lead-out copper bar start end and the lead-out copper bar end are connected via a connecting copper bar, and the connecting copper bar is clamped and fixed by a lead support.

[0007] Preferably, the second coil adopts a Y-connected lead structure.

[0008] Preferably, it also includes load-bearing long wheel frames arranged at the top and bottom of the iron core.

[0009] Preferably, a short load-bearing wheel frame is further provided between the long load-bearing wheel frames.

[0010] Preferably, both the upper iron yoke and the lower iron yoke of the iron core are sleeved with iron yoke straps.

[0011] Preferably, the cross section of the core is circular or elliptical.

[0012] Compared with the prior art, the utility model has achieved the following technical effects:

[0013] The first coil and the second coil of the device are wound with a whole piece of foil. The first coil is composed of the first sub-coil and the second sub-coil in series of the upper and lower sections. The overall structure is simple, easy to use, saves installation space, and reduces costs. The first coil can provide +4 / -2%, a total of 7 levels of voltage output, which solves the problems of unstable inter-turn field strength and high partial discharge in the prior art, and ensures the stable operation of the commutation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a high-pressure view of the utility model;

[0015] Figure 2 It is a side view of the utility model;

[0016] Figure 3 This is a low-pressure view of the utility model;

[0017] Figure 4 This is a schematic diagram of the connection of the first sub-coil of the utility model;

[0018] Figure 5 This is a schematic diagram of the connection of the second sub-coil of the utility model;

[0019] Figure 6 This is a schematic diagram of the first coil and the second coil of the utility model.

[0020] Figure numerals: 1. iron core; 2. iron yoke pull strap; 3. three-phase coil; 4. lead-out copper busbar start; 5. lead-out copper busbar end; 6. flexible connection; 7. lead support; 8. load-bearing long wheel frame; 9. load-bearing short wheel frame; 10. second coil; 11. first coil; 111. first sub-coil; 112. second sub-coil. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0022] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0024] like Figure 1 , Figure 2 , Figure 3 As shown, the utility model is a fully foil wound coil dry-type converter transformer with three-phase coil 3, and a group of windings is provided on the iron core 1 of each phase coil, and the windings include a first coil 11 and a second coil 10, and the secondary coil is axially wound on the outside of the iron core 1, and the first coil 11 is radially and concentrically wound on the outside of the second coil 10, wherein the first coil 11 includes a first sub-coil 111 and a second sub-coil 112 arranged in series up and down along the axial direction. In this embodiment, the windings are sequentially provided with the first coil 11 and the second coil 10 from the outside to the inside, and the first coil 11 and the second coil 10 are both continuously wound with a whole copper foil strip. In this embodiment, the first coil 11 and the second coil 10 correspond to the 10kV level, and the device controls the inter-turn field strength, strengthens the inter-layer insulation thickness, and controls the local discharge amount of the three-phase coil 3.

[0025] like Figure 6 The figure shows a schematic diagram of the structure 10 of the first coil 11 and the second coil of the device. Different from the prior art, the first coil 11 of the device is connected in series with the first sub-coil 111 and the second sub-coil 112 in the axial direction. Most of the existing structures adopt a double-split structure, specifically, the upper and lower coils are connected in parallel, while the device is connected in series, which can provide +4%, +3%, +2%...-2%, a total of 7 levels of voltage output. Different levels of voltage output correspond to different scenarios, which solves the problems of unstable inter-turn field strength and high local discharge in the prior art, thereby ensuring the stable operation of the commutation system.

[0026] like Figure 4 and Figure 5 As shown, the first sub-coil 111 and the second sub-coil 112 both adopt a D-connected lead structure, which is slightly different from the prior art. The copper bar head 4 of the first sub-coil 111 and the copper bar end 5 of the second sub-coil 112 are connected by a flexible connection 6. The 4 branched outgoing wires of the first sub-coil 111 are staggered in the circumferential direction. Figure 4 As shown, they are A1, A2, A3, and A4, connected to the primary lead copper bar head 4 through the soft connection 6, and the second sub-coil 112 is connected to the lead wire bar in a staggered distribution in the circumferential direction. Figure 5As shown, they are X1, X2, X3, and X4 respectively, which are connected to the end of the primary lead-out copper bar 5 through a soft connection 6, and the primary lead-out copper bar starting head 4 between two phases is connected with the primary lead-out copper bar starting head 4 to realize D connection. This arrangement method of the present embodiment can reduce the space occupied by the primary coil copper bar. In order to facilitate the connection of the upper and lower connecting copper bars, the lead-out copper bar starting head 4 is respectively arranged on the upper part of the device, and the fixed lead-out copper bar starting head is arranged on the lower part. In addition, considering the manufacturing deviation of the outgoing line bar, the connecting copper bar and the lead-out copper bar starting head are tapped and voltage-regulated by means of a soft connection 6.

[0027] The lead-out copper bar head 4 is connected to the lead-out copper bar tail 5 through a connecting copper bar, and the connecting copper bar is clamped and fixed by a lead support 7. Figure 2 As shown in the primary coil lead, the connecting copper bars between each two phases are clamped by the lead support 7. Through the clamping of the lead support 7, the accurate connection between the lead copper bar start 4 and the lead copper bar end 5 is ensured, further enhancing the stability of the lead structure.

[0028] The second coil 10 adopts a Y-connected lead wire structure, and the lead wire row extends from the upper and lower sides of the second coil 10, and the three phases are connected with a copper plate. The Y-connected lead wire structure is a commonly used technology in this field. The Y-connected lead wire structure adopted in this device is the same as the existing technology, so it will not be elaborated here.

[0029] It also includes a load-bearing long wheel frame 8 arranged at the top and bottom of the iron core 1. A load-bearing short wheel frame 9 is also arranged between the load-bearing long wheel frames 8. In this embodiment, the load-bearing long wheel frames 8 are arranged in pairs, and the load-bearing long wheel frames 8 mainly play a supporting role for the device, such as Figure 3 As shown, a pair of load-bearing long wheel frames 8 are respectively arranged at both ends of the iron core, and a pair of load-bearing short wheel frames 9 are also arranged between the pair of load-bearing long wheel frames 8. The load-bearing short wheel frames 9 can enhance the structural stability of the entire device.

[0030] The upper iron yoke and the lower iron yoke of the iron core 1 are both sleeved with iron yoke straps 2 for further strengthening and fastening. Figure 2 As shown, the upper yoke and the lower yoke of the iron core 1 are provided with yoke tie straps 2, and the yoke tie straps 2 can tighten the upper yoke and the lower yoke to further strengthen the fastening.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, 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 utility model.

Claims

1. A full foil wound coil dry-type converter transformer, comprising an iron core and a winding arranged on the iron core, characterized in that: The winding comprises a first coil and a second coil, wherein the second coil is axially wound on the outside of the iron core, and the first coil is radially and concentrically wound on the outside of the second coil, wherein the first coil comprises a first sub-coil and a second sub-coil which are axially arranged in series up and down.

2. According to claim 1, a full foil wound dry-type converter transformer is characterized in that: The first sub-coil and the second sub-coil adopt a D-connected lead structure, and the first sub-coil lead-out copper bar start end and the second sub-coil lead-out copper bar end are softly connected.

3. The full foil wound dry-type converter transformer according to claim 2, characterized in that: The lead-out copper bar start end and the lead-out copper bar end are connected via a connecting copper bar, and the connecting copper bar is clamped and fixed by a lead support member.

4. The full foil wound dry-type converter transformer according to claim 1, characterized in that: The second coil adopts a Y-connected lead structure.

5. The full foil wound dry-type converter transformer according to claim 1, characterized in that: The utility model also comprises load-bearing long wheel frames arranged at the top and the bottom of the iron core.

6. The full foil wound dry-type converter transformer according to claim 5, characterized in that: A short load-bearing wheel frame is also provided between the long load-bearing wheel frames.

7. The full foil wound dry-type converter transformer according to claim 1, characterized in that: The upper iron yoke and the lower iron yoke of the iron core are both sleeved with iron yoke drawstrings.

8. The full foil wound dry-type converter transformer according to claim 1, characterized in that: The cross section of the iron core is circular or elliptical.

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