Transformer free of local overheating and capable of operating safely

Abstract

The utility model relates to a safe operation transformer or reactor without local overheating, which comprises a coil, an iron core, a clamping piece and the like, the coil is sleeved on the iron core, and the clamping piece is used for clamping the iron core. After the coil passes through the current, excitation is carried out in the iron core, and main magnetic flux passes through the interior of the iron core to be closed to form a closed loop; leakage flux is closed outside an iron core, eddy current loss and heating are generated in a clamp closest to a coil, surrounding insulating media are aged, and the operation safety and the service life of a product are affected. Holes are formed in the most concentrated position of the leakage magnetic field on the upper portion of the coil in the direction that the vertical component of the leakage magnetic field enters the plane of the clamping piece, eddy-current loss caused by the leakage magnetic field is reduced, holes are formed in the thickness direction of the clamping piece, the two holes are communicated, convection heat dissipation of air or transformer oil can be enhanced, heating caused by the leakage magnetic field is reduced, and the service life of the transformer is prolonged. Heat dissipation of a magnetic field concentration area is improved, product insulation accelerated aging and transformer oil chromatography standard exceeding are avoided, product operation safety is improved, and the service life of the product is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of power transmission and distribution, and in particular to a transformer and a reactor that can operate safely without local overheating, including coil products such as dry-type and oil-immersed transformers and reactors. Background Art

[0002] In the power industry, the leakage magnetic field of coil products such as transformers and reactors produces large eddy current losses in the metal structural parts inside the product body, causing local overheating of the metal parts, accelerated aging of the insulating materials close to the metal parts, and accelerated decomposition of the transformer oil. After running for a period of time, not only will the oil chromatography be unqualified, but it will also have a significant impact on the operating safety and life of the product.

[0003] Conventional solutions are: generally based on different parts of the product and leakage magnetic characteristics: transformers, reactors oil body clamps use low magnetic steel, the tank wall uses magnetic shielding, the body lead parts use electric shielding and other traditional solutions. However, in some local areas of the product, due to product structural reasons, the above solutions are difficult to install, the structure is complex and the cost is high. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides a transformer and a reactor that can operate safely without local overheating, which can not only reduce local overheating of the product and avoid affecting the operating safety and life of the product, but also does not increase the material cost of the product, thereby improving the quality and cost competitiveness of the product.

[0005] The utility model is realized through the following technical solutions:

[0006] A transformer that operates safely without local overheating, comprising a transformer body, the transformer body comprising a coil and an iron core arranged in the coil and with a top end extending outside the coil, and heat dissipation structures capable of preventing local overheating of the transformer body are installed on both sides of the top end of the iron core;

[0007] The heat dissipation structure comprises two clamps respectively fitted with the end surfaces of both sides of the iron core, and a plurality of heat dissipation holes penetrating through the wall thickness of the clamps are evenly opened at the positions where the clamps fit with the iron core.

[0008] The utility model also provides a reactor which operates safely without local overheating, and the heat dissipation structure is also installed on the reactor.

[0009] The electrical part of the transformer and reactor of the utility model is mainly the body: the body is composed of a coil and an iron core. The coil generates current after voltage is applied through the power grid and the switch, and the current is excited in the iron core of the transformer and the reactor. The main magnetic flux passes through the iron core to close and form a closed loop. Since the leakage magnetic flux passes through the outside of the iron core and is closed, the leakage magnetic flux passes through the external metal parts such as the transformer and the reactor, and eddy current loss will be generated inside the metal parts. In particular, in the area where the leakage magnetic field is concentrated and the metal parts are close, large eddy currents will be generated, causing local temperature rise, accelerating the decomposition of the surrounding insulating medium and transformer oil, and affecting the operating safety and life of the transformer and the reactor.

[0010] According to the basic physical principle, the eddy current loss generated by the leakage magnetic field in the metal part is proportional to the bisection of the area of ​​the metal part where the magnetic field is perpendicular to the incident magnetic field, proportional to the bisection of the thickness of the metal part, and inversely proportional to the resistivity of the metal part, that is, P (eddy current loss) ∝ S 2 (Metal area)*d 2 (Thickness) / ρ(Resistivity). Due to the limitation and need of mechanical strength, some metal parts made of non-magnetic materials in transformers and reactors have large area and thickness, so eddy current loss is large.

[0011] The utility model is characterized in that a plurality of circular holes or square holes are processed in the plane and thickness directions of the metal parts in the leakage magnetic field concentration area, and the holes in different directions are connected inside the metal. This structure reduces the vertical area of ​​the magnetic field vertically entering the metal parts, increases the resistance of the eddy current of the metal parts in this area, and reduces the eddy current loss. At the same time, the through holes in different directions ensure that the heat dissipation medium air and oil-immersed oil enter the metal parts of the transformer and the reactor to form convection heat dissipation. This utility model can reduce the temperature of the local field strength concentration area by more than 40%, and solves the problem of insulation aging caused by local overheating affecting the operating safety and life of the product.

[0012] In a preferred embodiment of the utility model, the transformer has a plurality of bodies, the plurality of bodies are arranged in a straight line, and the clamp is in contact with both side end surfaces of the iron core of each body.

[0013] In order to ensure the heat dissipation effect, the heat dissipation holes include first heat dissipation holes evenly distributed in the plane direction of the clamp and second heat dissipation holes evenly distributed in the thickness direction of the clamp, and the second heat dissipation holes are connected to the inside of the first heat dissipation holes.

[0014] The iron core is formed by stacking silicon steel sheets in stages, and the iron core is a channel for the main magnetic flux to form a closed loop.

[0015] In order to facilitate disassembly and assembly, the two ends of the two clamps are fixed by locking pieces.

[0016] The beneficial effects of the utility model are as follows: the utility model can reduce and lower local overheating of product structural parts caused by internal leakage magnetic field of the product, avoid accelerated aging of product insulation and excessive color spectrum of transformer oil, enhance product operation safety and life span, and has a simple structure and does not increase product material cost. Compared with conventional transformers and reactors, the utility model further improves product quality and cost competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional structural schematic diagram of a transformer or reactor that operates safely without local overheating according to the utility model;

[0018] Figure 2 It is a front view of a transformer or reactor that operates safely without local overheating according to the utility model;

[0019] Figure 3 It is a schematic diagram of the divorced structure of the heat dissipation structure of the utility model. DETAILED DESCRIPTION

[0020] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more specific definition of the protection scope of the present invention. The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "top", "bottom", etc., are only for reference to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present invention, rather than to limit the present invention.

[0021] Combination Figure 1-3 The transformer or reactor shown in the figure, which operates safely without local overheating, includes a body, which includes a coil 3 and an iron core 1 arranged in the coil 3 and with the top end extending outside the coil 3. Heat dissipation structures capable of preventing local overheating of the transformer body are installed on both sides of the iron core 1.

[0022] Specifically, the transformer or reactor has a plurality of bodies 3, and the plurality of bodies 3 are arranged in a straight line. The iron core 1 is formed by stacking silicon steel sheets in stages, and the iron core 1 is a channel for the main magnetic flux to form a closed loop. The heat dissipation structure includes two clamps 2 respectively fitted with the end faces on both sides of the iron core 1, and a plurality of heat dissipation holes are evenly opened at the fitting positions of the clamps 2 and the iron core 1. The heat dissipation holes include first heat dissipation holes 4 evenly distributed in the plane direction of the clamps 2 and second heat dissipation holes 6 evenly distributed in the thickness direction of the clamps 2. The second heat dissipation holes 6 are connected to the inside of the first heat dissipation holes 4, and the two ends of the two clamps 2 are fixed by locking members 5. The coil 3 is wound by electromagnetic wire and is sleeved on the outside of the iron core 1. After power is applied, the main magnetic flux and leakage magnetic flux are formed in the magnetic field, and the corresponding position of the heat dissipation hole 4 is one of the leakage magnetic field concentration areas.

[0023] In the utility model, the iron core is made of graded stacked silicon steel sheets, the clamp is made of metal materials such as steel plates and channel steels, and the coil is wound by electromagnetic wires. That is, coil products composed of coils, iron cores, clamps, etc., adopting the above structure to reduce eddy currents and improve heat dissipation efficiency are all within the protection scope of the utility model;

[0024] The transformer, reactor and other coil products described in the utility model have several heat dissipation holes processed in the plane direction of the clamp at the local position where the field strength of the upper clamp of the coil is concentrated, and several heat dissipation holes are processed in the thickness direction. The holes in the plane and thickness directions are connected inside the metal part. As long as they are used to reduce the local overheating caused by eddy currents, the size and number of the holes are not specified and are within the protection scope of the utility model;

[0025] The transformer, reactor and other coil products described in the utility model, in addition to opening holes in local positions where the field strength of the upper clamp of the coil is concentrated to reduce local overheating caused by eddy currents, the metal parts in other field strength concentrated areas have holes opened in the plane and thickness directions and in the thickness direction to reduce eddy currents and heat dissipation structures, all of which are within the protection scope of the utility model.

[0026] At the local position where the field strength of the upper clamp of the transformer and reactor coil is concentrated, a number of round holes or square holes are processed from the plane and thickness directions respectively. The holes in different directions are connected inside the metal. This structure not only reduces the vertical area of ​​the magnetic field entering the metal part vertically, but also increases the resistance of the eddy current of the metal part in this area, which not only reduces the eddy current loss generated, but also the through holes in different directions ensure that the heat dissipation medium air and oil-immersed oil enter the metal parts of the transformer and reactor, forming convection heat dissipation, reducing the temperature of the local field strength concentration area by more than 40%, and solving the problem of insulation aging caused by local overheating affecting the operating safety and life of the product.

[0027] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "set", "provided with", etc. 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.

[0028] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model.

Claims

1. A transformer that operates safely without local overheating, comprising a transformer body, wherein the transformer body comprises a coil and an iron core disposed in the coil and having a top end extending outside the coil, wherein: Both sides of the top of the iron core are provided with heat dissipation structures capable of preventing local overheating of the transformer body; The heat dissipation structure comprises two clamps respectively fitted with the end surfaces of both sides of the iron core, and a plurality of heat dissipation holes are evenly provided at the positions where the clamps fit with the iron core.

2. The transformer with safe operation without local overheating according to claim 1 is characterized in that: The transformer has a plurality of bodies, which are arranged in a straight line, and the clamp is fitted to both side end surfaces of the iron core of each body.

3. The transformer with no local overheating and safe operation according to claim 2, characterized in that: The heat dissipation holes include first heat dissipation holes evenly distributed in the plane direction of the clamp and second heat dissipation holes evenly distributed in the thickness direction of the clamp, and the second heat dissipation holes are connected to the inside of the first heat dissipation holes.

4. The transformer with safe operation without local overheating according to claim 2 is characterized in that: The iron core is formed by stacking silicon steel sheets in stages.

5. The transformer with safe operation without local overheating according to claim 2, characterized in that: The two ends of the two clamps are fixed by a locking piece.

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