Shielding structure of K-factor transformer applied to high-harmonic occasion

Abstract

The utility model discloses a shielding structure of a K factor transformer applied to a high harmonic occasion, which comprises an iron core iron column, an inner winding coil and an outer winding coil are sequentially arranged on the outer side of the iron core iron column, and a first insulation paper layer, a first shielding layer and an inner cylinder are sequentially arranged on the inner side of the inner winding coil. A second insulation paper layer, a second shielding layer and a third insulation paper layer are sequentially arranged on the outer side of the inner winding coil, an inter-group air channel is arranged between the inner winding coil and the outer winding coil, and a fifth insulation paper layer, a third shielding layer and a fourth insulation paper layer are sequentially arranged on the inner side of the outer winding coil. And shielding insulating layers are arranged on the outer sides of the roots of the inner outgoing line and the outer outgoing line of the inner winding coil. Due to the design of the multiple shielding layers, the electromagnetic shielding effect is more remarkable, electromagnetic interference can be more effectively isolated and reduced, the shielding effect is good, and the performance and the stability of equipment are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to dry -type transformer technical field, concretely is a shielding structure of K factor transformer for high harmonic occasion. BACKGROUND

[0002] In recent years, with the wide application of power electronic technology in power load, a large number of nonlinear loads appear in power system, including arc furnace, frequency conversion equipment, inverter cabinet, UPS system and other electronic power supply and other equipment. Nonlinear load generates harmonic current, these currents flow from the load to the power system along the path of minimum impedance. Harmonic current has adverse effects on almost every component in the power system, producing additional heat, mechanical force and insulation loss.

[0003] Under normal circumstances, the coil loss of transformer under linear load is direct current resistance loss and additional loss. But when the transformer runs in the harmonic environment of nonlinear load, the additional loss in coil loss will increase significantly, which may cause abnormal heating of the coil and lead to coil burnout.

[0004] K factor transformer is a dry-type transformer designed considering the increase of coil loss under harmonic operation. K factor transformer, also known as K coefficient transformer or fireproof transformer, is a dry-type transformer with special structure and design, aiming to withstand the influence of highly nonlinear load and effectively suppress harmonic current and voltage.

[0005] The shielding design of K factor transformer is one of the key factors of its performance, which is directly related to the stable operation of the transformer in the harmonic environment and the degree of electromagnetic interference to the surrounding electronic equipment. At present, K factor transformer generally sets shielding structure between inner winding and outer winding, which can reduce electromagnetic interference to a certain extent, but the traditional shielding structure has limited effect on reducing eddy current loss, in addition, the shielding measures of the lead-out wire of inner winding are not in place, which also causes certain influence on the surrounding electronic equipment. UTILITY MODEL CONTENTS

[0006] The utility model aims at improving and innovating the shortcomings and problems in the background art, to better adapt to K factor transformer, reduce the interference of transformer operation to the surrounding electronic equipment, and provide a shielding structure of K factor transformer for high harmonic occasion.

[0007] The application discloses a shielding structure of a K-factor transformer applied to a high harmonic occasion, which comprises a core iron column, an inner winding coil and an outer winding coil are sequentially arranged outside the core iron column, a first insulation paper layer, a first shielding layer and an inner cylinder are sequentially arranged inside the inner winding coil, a second insulation paper layer, a second shielding layer and a third insulation paper layer are sequentially arranged outside the inner winding coil, an inter-group air channel is arranged between the inner winding coil and the outer winding coil, a fifth insulation paper layer, a third shielding layer and a fourth insulation paper layer are sequentially arranged inside the outer winding coil, and a shielding insulation layer is arranged outside the root of inner and outer lead-out wires of the inner winding coil.

[0008] Further, the first shielding layer, the second shielding layer and the third shielding layer are mutually overlapped by 20mm at both ends, and the overlapped parts are separated by insulation paper, and the first shielding layer, the second shielding layer and the third shielding layer are folded and edged by insulation paper at both ends.

[0009] Further, the inner side of the shielding insulation layer is insulation paper which is overlapped along the length direction of the lead-out wire, the middle layer of the shielding insulation layer is shielding, the shielding is overlapped by 5-10mm at both ends, the overlapped parts are separated by insulation paper, and the outer side of the shielding insulation layer comprises insulation paper which is overlapped along the length direction of the lead-out wire and glass silk tape which is overlapped along the length direction of the lead-out wire.

[0010] Further, the corresponding insulation paper of the inner side of the shielding insulation layer is overlapped by two layers, the corresponding insulation paper of the outer side of the shielding insulation layer is overlapped by one layer, and the corresponding glass silk tape of the outer side of the shielding insulation layer is overlapped by one layer.

[0011] Further, the corresponding insulation paper of the inner side and the outer side of the shielding insulation layer is overlapped by half of the width of the insulation paper when overlapped, and the corresponding glass silk tape of the outer side of the shielding insulation layer is overlapped by half of the width of the glass silk tape when overlapped.

[0012] Further, the shielding of the first shielding layer, the second shielding layer and the third shielding layer is cut by narrow slits, and the narrow slits are cut at the upper end and the lower end of the shielding.

[0013] Further, the width of the narrow slit is 0.5mm.

[0014] Further, the shielding comprises a copper belt and a cable, and the cable is arranged on the copper belt.

[0015] Compared with the prior art, the utility model discloses the beneficial effect is: (1) the utility model discloses the inside winding coil inside, the inside winding coil outside and the outside winding coil inside are provided with first shielding layer, second shielding layer and third shielding layer respectively, and the design of multilayer shielding layer makes electromagnetic shielding effect more remarkable, can more effectively isolate and reduce electromagnetic interference, has the advantage that the shielding effect is good, improves the performance and stability of equipment.

[0016] (2) The utility model discloses the two lead-out wires of inside winding coil are provided with shielding insulation layer respectively, can effectively isolate and reduce the leakage of electromagnetic field, thereby can reduce the interference of transformer operation to surrounding electronic equipment.

[0017] (3) The utility model discloses the first shielding layer, second shielding layer and third shielding layer of the utility model discloses the narrow slit of corresponding shielding is tailor, the narrow slit is tailor in the upper end and lower end of shielding, can limit the flow path of eddy current, to reduce eddy current loss, thereby reducing the additional loss in shielding, guaranteeing the normal work of transformer and the stable operation of surrounding equipment. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will be briefly introduced the drawing needed to be used in the embodiment, and obviously, the drawing in the following description is only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creating labor.

[0019] Figure 1 The sectional structure schematic diagram of the shielding structure of the K factor transformer applied to high harmonic occasions provided by the utility model embodiment;

[0020] Figure 2 The structure schematic diagram of the shielding on the inside winding coil provided by the utility model embodiment;

[0021] Figure 3 The structure schematic diagram of the shielding on the outside winding coil provided by the utility model embodiment;

[0022] Figure 4 The structure schematic diagram of the lead-out wire on the inside winding coil provided by the utility model embodiment;

[0023] Figure 5 The structure schematic diagram of the shielding corresponding to the first shielding layer, second shielding layer and third shielding layer provided by the utility model embodiment;

[0024] Figure 6 The structure schematic diagram of the shielding corresponding to the shielding insulation layer provided by the utility model embodiment.

[0025] Core iron column 1, inner cylinder 2, first shielding layer 3, first insulation paper layer 4, inner winding coil 5, second insulation paper layer 6, second shielding layer 7, third insulation paper layer 8, group air channel 9, fourth insulation paper layer 10, third shielding layer 11, fifth insulation paper layer 12, outer winding coil 13, copper belt 14, cable 15, narrow slot 16, shielding insulation layer 17. DETAILED DESCRIPTION

[0026] To make the purpose, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0027] It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can be present.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0029] Referring to Figures 1-6 The present application provides a shielding structure of a K-factor transformer applied to a high harmonic occasion, comprising a core iron column 1, wherein the outer side of the core iron column 1 is sequentially provided with an inner winding coil 5 and an outer winding coil 13. The outer winding coil 13 is an input winding, and the inner winding coil 5 is an output winding. The inner side of the inner winding coil 5 is sequentially provided with a first insulation paper layer 4, a first shielding layer 3 and an inner cylinder 2, wherein the inner cylinder 2 is made of an insulating material and plays a supporting role. The outer side of the inner winding coil 5 is sequentially provided with a second insulation paper layer 6, a second shielding layer 7 and a third insulation paper layer 8. A group air channel 9 is arranged between the inner winding coil 5 and the outer winding coil 13, and the inner side of the outer winding coil 13 is sequentially provided with a fifth insulation paper layer 12, a third shielding layer 11 and a fourth insulation paper layer 10.

[0030] It should be noted that the first shielding layer 3, the second shielding layer 7 and the third shielding layer 11 are all overlapped by 20mm at the two ends, and the overlapping part is separated by insulating paper. The upper and lower ends of the first shielding layer 3, the second shielding layer 7 and the third shielding layer 11 are folded and wrapped by insulating paper, and are fixed by double-sided adhesive. Among them, the upper and lower ends of the first shielding layer 3, the second shielding layer 7 and the third shielding layer 11 are folded and wrapped by 2 pieces of 0.08mmX40mm NOMEX insulating paper, 0.08mm is the thickness of the NOMEX insulating paper, and 40mm is the width of the NOMEX insulating paper. The first and last ends of the shielding are overlapped by 20mm, and the overlapping part is separated by 2 pieces of 0.13mm NOMEX insulating paper to ensure that the shielding is not short-circuited.

[0031] Please refer to Figure 4 The inner and outer lead wires of the inner winding coil 5 are provided with shielding insulation layers 17 outside the roots. The shielding insulation layer 17 can effectively isolate and reduce the leakage of electromagnetic field, thereby reducing the interference of the transformer operation on the surrounding electronic equipment. The inner side of the shielding insulation layer 17 is insulating paper stacked along the length direction of the lead wire, the middle layer of the shielding insulation layer 17 is shielding, the shielding is overlapped by 5-10mm at the two ends, and the overlapping part is separated by insulating paper. The outer side of the shielding insulation layer 17 includes insulating paper stacked along the length direction of the lead wire and glass tape stacked along the length direction of the lead wire. The glass tape plays a protective role to prevent the insulating paper from being worn. Among them, the inner and outer lead wires of the inner winding coil 5 are first stacked by 2 layers of 0.08mmX20mm NOMEX insulating paper, 0.08mm is the thickness of the NOMEX insulating paper, and 20mm is the width of the NOMEX insulating paper; then wrap the shielding, the shielding is overlapped by 5-10mm at the two ends, and the overlapping part is separated by 2 pieces of 0.13mm NOMEX paper. Then stack 1 layer of 0.08mmX20mm NOMEX insulating paper, and finally stack 1 layer of 0.18mmX40mm glass tape.

[0032] Further, the inner and outer sides of the shielding insulation layer 17 are overlapped by half of the width of the insulating paper when the corresponding insulating paper is stacked, and the glass tape corresponding to the outer side of the shielding insulation layer 17 is overlapped by half of the width of the glass tape when the glass tape is stacked. For example, the inner and outer lead wires of the inner winding coil 5 are first stacked by 0.08mmX20mm NOMEX insulating paper along the length direction of the lead wire, and the insulating paper is stacked by half of the width of the insulating paper when the insulating paper is stacked, that is, the adjacent insulating paper is overlapped by 10mm.

[0033] It should be noted that, since the first shielding layer 3, the second shielding layer 7 and the third shielding layer 11 have a relatively large area and are in a high harmonic and coil leakage magnetic field, in order to reduce the additional loss in the shielding, the present application cuts a narrow slit 16 on the shielding corresponding to the first shielding layer 3, the second shielding layer 7 and the third shielding layer 11, as shown in Figure 5 The narrow slit 16 is cut at the upper end and the lower end of the shielding. The width of the narrow slit 16 is 0.5mm. The narrow slit 16 can limit the flow path of the eddy current to reduce the eddy current loss, thereby reducing the additional loss in the shielding, ensuring the normal operation of the transformer and the stable operation of the surrounding equipment. Here, the two shields arranged at the root of the inner lead-out wire and the outer lead-out wire of the inner winding coil 5 are not cut with a slit on the shield, as shown in Figure 6 due to the small shielding area and for the convenience of wrapping the lead-out wire.

[0034] Specifically, the shielding includes a copper strip 14 and a cable 15, and the cable 15 is arranged on the copper strip 14, and the cable 15 is used for grounding.

[0035] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the different embodiments or examples described in the present application and the features of the different embodiments or examples can be combined and modified by those skilled in the art without contradiction.

[0036] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A shielding structure for a K-factor transformer used in high harmonic applications, comprising an iron core and an iron column (1), wherein an inner winding coil (5) and an outer winding coil (13) are sequentially arranged on the outer side of the iron core and the iron column (1), characterized in that: The inner side of the inner winding coil (5) is provided with a first insulating paper layer (4), a first shielding layer (3) and an inner cylinder (2) in sequence, and the outer side of the inner winding coil (5) is provided with a second insulating paper layer (6), a second shielding layer (7) and a third insulating paper layer (8) in sequence. An inter-group air passage (9) is provided between the inner winding coil (5) and the outer winding coil (13). The inner side of the outer winding coil (13) is provided with a fifth insulating paper layer (12), a third shielding layer (11) and a fourth insulating paper layer (10) in sequence. The outer side of the inner lead wire and the outer lead wire root of the inner winding coil (5) are both provided with a shielding insulating layer (17).

2. The shielding structure of a K-factor transformer for high harmonic applications according to claim 1, characterized in that: The first shielding layer (3), the second shielding layer (7) and the third shielding layer (11) are overlapped by 20 mm at both ends, and the overlapped portions are separated by insulating paper. The upper and lower ends of the first shielding layer (3), the second shielding layer (7) and the third shielding layer (11) are folded with insulating paper for wrapping.

3. The shielding structure of a K-factor transformer for high harmonic applications according to claim 1, characterized in that: The inner side of the shielding insulation layer (17) is insulating paper that is mutually wrapped along the length direction of the lead wire, the middle layer of the shielding insulation layer (17) is a shield, the shield is overlapped 5 to 10 mm at the beginning and end, and the overlap is separated by insulating paper, and the outer side of the shielding insulation layer (17) includes insulating paper that is mutually wrapped along the length direction of the lead wire and glass ribbons that are mutually wrapped along the length direction of the lead wire.

4. The shielding structure of a K-factor transformer for high harmonic applications according to claim 3, characterized in that: The inner side of the shielding insulation layer (17) corresponds to two layers of insulation paper, the outer side of the shielding insulation layer (17) corresponds to one layer of insulation paper, and the outer side of the shielding insulation layer (17) corresponds to one layer of glass ribbon.

5. The shielding structure of a K-factor transformer for high harmonic applications according to claim 3, characterized in that: The overlapping dimensions of the insulating papers corresponding to the inner and outer sides of the shielding insulation layer (17) when they are stacked are both half the width of the insulating papers, and the overlapping dimensions of the glass ribbons corresponding to the outer side of the shielding insulation layer (17) when they are stacked are both half the width of the glass ribbons.

6. The shielding structure of a K-factor transformer for high harmonic applications according to claim 1, characterized in that: Narrow slits (16) are cut on the shields corresponding to the first shielding layer (3), the second shielding layer (7) and the third shielding layer (11), and the narrow slits (16) are cut at intervals at the upper end and the lower end of the shields.

7. The shielding structure of a K-factor transformer for high harmonic applications according to claim 6, characterized in that: The width of the narrow slit (16) is 0.5 mm.

8. A shielding structure for a K-factor transformer used in high harmonic applications according to any one of claims 1 to 7, characterized in that: The shielding comprises a copper tape (14) and a cable (15), wherein the cable (15) is arranged on the copper tape (14).

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