Oil filled transformer

Abstract

The present invention relates to an oil-filled transformer capable of extending the lifespan of the transformer by improving cooling efficiency through the formation of a plurality of ventilation holes in the longitudinal direction of an iron core, comprising: a tank in which insulating oil is stored; a winding wound on an iron core provided inside the tank; a heat sink disposed on the outside of the tank and forming a flow path through which the insulating oil stored in the tank exchanges heat with the outside air; and a heat dissipation pipe connecting the tank and the heat sink to form a path through which insulating oil circulates between the tank and the heat sink, wherein ventilation holes are formed in the longitudinal direction at regular intervals in the iron core, allowing insulating oil to flow into the interior of the ventilation holes.

Description

Technology Field

[0001] The present invention relates to an oil-filled transformer, and more particularly to an oil-filled transformer that can improve the lifespan of the transformer by configuring a plurality of ventilation holes in the iron core to improve cooling efficiency. Background Technology

[0002] Generally, a transformer refers to a device that changes current or voltage using the phenomenon of electromagnetic induction. Transformers can be classified into oil-filled transformers, dry-type transformers, and molded transformers depending on their insulation method.

[0003] Among these, an oil-immersed transformer refers to a transformer that is submerged in insulating oil to enhance insulation performance and cool and extinguish the arc. To this end, although the actual structure of the oil-immersed transformer varies depending on capacity or voltage, the main parts are the windings and the iron core; the windings and the iron core are placed inside a case and filled with insulating oil.

[0004] The reason for using the aforementioned insulating oil is to prevent moisture or dust from entering the insulation of the windings, which would lower the dielectric strength, and to dissipate the heat generated in the iron core or windings through the convection or radiation of the oil.

[0005] Meanwhile, in large-capacity oil-filled transformers, pipes circulating insulating oil or heat sinks are installed on the outside of the tank to improve heat dissipation capabilities; furthermore, in even larger-capacity oil-filled transformers, fans are installed on the heat sinks to blow air, thereby enhancing the heat dissipation effect.

[0006] At this time, depending on the location where the above-mentioned oil-filled transformer is installed, instead of installing a heat sink, there is a method of drawing out the insulating oil heated inside the oil-filled transformer through a pipe and cooling it with cooling water, or a method of passing water through a water cooling pipe into the transformer and circulating water with a pump, and there are also many cases where a three-phase system is used for medium and large-capacity transformers.

[0007] In an ideal incoming transformer, the output power is equal to the input power, so no loss occurs during transformation; however, in actual transformers, losses occur due to the load, making it difficult to expect 100% transformation efficiency.

[0008] Losses caused by the above load are converted into heat, which shortens the lifespan of the transformer itself or damages components within the transformer, so the temperature inside the transformer is lowered through a heat sink.

[0009] The above-mentioned radiator is equipped with a plurality of heat sinks, and insulating oil circulates through the heat sinks. As the insulating oil circulates through the heat sinks, it can cool the incoming transformer by radiating heat generated from the incoming transformer to the outside.

[0010] Figure 1 is a side view schematically showing the flow of insulating oil inside an incoming transformer according to conventional technology.

[0011] As shown in FIG. 1, an inflow transformer according to conventional technology has an iron core (20) and a winding (30) provided inside a tank (10), a support plate (50) placed outside the winding (30) to support the iron core (20) and the winding (30), and an insulating barrier (40) for insulating the winding (30).

[0012] In addition, this inlet transformer is configured to have a cooler consisting of a circulation pipe (61, 62) and a heat sink (70) on the outside of the tank (10) so that the insulating oil stored inside the tank (10) can circulate to the outlet side circulation pipe (61), the inlet side circulation pipe (62), and the heat sink (70).

[0013] However, in conventional inflow transformers, as shown in FIG. 1, internal flow resistance may occur due to internal components such as a support plate (50) and an insulating barrier (40), and due to this cause, the insulating oil may not circulate well to the winding (30), which may cause overheating of the transformer winding (30).

[0014] That is, in conventional inflow transformers, the insulating oil flowing out of the inflow side circulation pipe (62) into the tank (10) from the cooler is obstructed by the support plate (50), insulating barrier (40), etc., so the amount of flow to the winding (30) side is reduced, and thus the cooling efficiency of the winding (30) through the insulating oil is reduced.

[0015] In addition, to prevent the overheating of the coil (30), the outflow side circulation pipe (61) and the inflow side circulation pipe (62) connected between the cooler and the tank (10) must be installed at appropriate locations, but due to interference issues with various fittings attached to the tank, it is difficult to install the pipes at the desired locations. The problem to be solved

[0016] The present invention was devised to solve the aforementioned conventional problems and aims to provide an oil-filled transformer that can extend the lifespan of the transformer by improving cooling efficiency through the configuration of a plurality of ventilation holes in the longitudinal direction of the iron core. means of solving the problem

[0017] An inflow transformer according to the present invention for achieving the above-mentioned purpose comprises: a tank in which insulating oil is stored; a winding wound around an iron core provided inside the tank; a heat sink disposed on the outside of the tank and forming a flow path through which the insulating oil stored in the tank exchanges heat with the outside air; and a heat dissipation pipe connecting the tank and the heat sink to form a path through which insulating oil circulates between the tank and the heat sink, wherein ventilation holes are formed in the iron core at regular intervals in the longitudinal direction, allowing insulating oil to flow into the ventilation holes. Effects of the invention

[0018] The inflow transformer according to an embodiment of the present invention has the following effects.

[0019] In other words, the lifespan of the transformer can be extended by improving cooling efficiency through the configuration of multiple ventilation holes along the length of the iron core. Brief explanation of the drawing

[0020] FIG. 1 is a side view schematically showing the flow of insulating oil inside an oil-filled transformer according to conventional technology. FIG. 2 is a side view schematically showing the internal configuration of an inflow transformer according to one embodiment of the present invention. FIG. 3 is a plan view showing a silicon steel plate applied to the iron core of an inflow transformer according to an embodiment of the present invention. FIGS. 4 to 6 are perspective views showing an iron core formed by laminating the silicon steel plates of FIG. 3. Specific details for implementing the invention

[0021] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, detailed descriptions of known functions or configurations that may obscure the essence of the present invention in the following description and the accompanying drawings are omitted. Additionally, it should be noted that identical components throughout the drawings are indicated by the same reference numerals whenever possible.

[0022] The terms and words used in the specification and claims described below should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the invention and do not represent all of the technical spirit of the invention; therefore, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0023] FIG. 2 is a side view schematically showing the internal configuration of an inflow transformer according to one embodiment of the present invention.

[0024] An inflow transformer according to one embodiment of the present invention is configured to include a tank (110), an iron core (120), a winding (130), heat dissipation pipes (161, 162) and a heat dissipation plate (170), as shown in FIG. 2.

[0025] The above tank (110) is a structure in the form of a sealed container in which the iron core (120), winding (130), and internal components (not shown) are housed, and insulating oil can be stored inside.

[0026] Meanwhile, although the tank (110) is described as a rectangular shape in the embodiment of the present invention, it is not limited thereto and can be formed in various shapes, such as a cylindrical shape or a polygonal shape.

[0027] In addition, to maximize the absorption of the rising oil temperature of the working fluid within the incoming transformer according to an embodiment of the present invention, an evaporator (not shown) composed of a copper tube and a rolled fin tube into which the copper tube is inserted may be additionally configured.

[0028] The above iron core (120) may be configured by arranging a plurality of thin plates so as to overlap. The above iron core (120) may be formed by arranging a plurality of thin plates so as to overlap in the width direction with a thickness of 0.2 to 0.3 mm.

[0029] The above iron core (120) is configured such that the thin plate located in the middle is the widest and the thin plate placed at the edge is relatively narrow, so it is macroscopically shaped like a cylinder, but when viewed closely, there may be a step difference between adjacent thin plates.

[0030] The above iron core (120) may use a high-permeability directional silicon steel sheet that does not undergo aging.

[0031] A plurality of ventilation holes (200) are formed in the iron core (120) at regular intervals in the longitudinal direction, and insulating oil passes through the ventilation holes (200).

[0032] The above winding (130) may have a form wound on the iron core (120). The above winding (130) may be shown in a form with multiple layers stacked, and insulating paper (not shown) may be placed between the multiple layers. Meanwhile, a plurality of ventilation holes may also be formed in the above winding (130) to allow insulating oil to pass through.

[0033] Additionally, the above winding (130) can be drawn out toward the outside of the inflow transformer through at least some of the plurality of bushings.

[0034] The above windings (130) may be arranged in multiple numbers with spacing in the height or width direction. These windings (130) are not particularly limited and may be composed of various types of low-voltage and high-voltage windings included in known incoming transformers.

[0035] Additionally, the iron core (120) and the winding (130) wound on the iron core (120) are provided inside the tank (110) and can be immersed in insulating oil stored inside the tank (110).

[0036] Additionally, the internal components may be composed of a structure supporting the iron core (120) and the winding (130), an insulating material insulating the winding (130), a support plate (150) supporting the upper and lower portions of the winding (130), and an insulating barrier (140) insulating the outer surface of the winding (130), but are not limited thereto.

[0037] The insulating barrier (140) is a member disposed on both sides of the winding (130) and may be provided in a cylindrical shape on the inner and outer sides, respectively, of the cylindrical winding (130). This insulating barrier (140) can perform the function of insulating the winding (130) from an element disposed adjacent to the winding (130).

[0038] Additionally, the heat sink (170) may be composed of a plate-shaped member having a space through which insulating oil can flow, and the insulating oil flowing inside the heat sink (170) can radiate heat to the outside.

[0039] The heat sink (170) is positioned on the outside of the tank (110) to form a flow path through which the insulating oil stored in the tank (110) exchanges heat with the outside air. That is, the heat sink (170) is configured to allow insulating oil to flow inside, and can act as a medium to release heat from the insulating oil to the outside by exchanging heat between the insulating oil flowing inside and the outside air. In one embodiment, a plurality of the heat sinks (170) may be arranged side by side.

[0040] In addition, the heat dissipation pipes (161, 162) can connect the tank (110) and the heat dissipation plate (170) to form a path for insulating oil to circulate between the tank (110) and the heat dissipation plate (170).

[0041] The above heat dissipation pipes (161, 162) may be composed of an outflow side heat dissipation pipe (161) provided on the outflow side through which insulating oil flows out from the tank (110) toward the heat dissipation plate (170), and an inflow side heat dissipation pipe (162) provided on the inflow side through which insulating oil flows from the heat dissipation plate (170) toward the tank (110).

[0042] Through this configuration, the insulating oil stored in the tank (110) is circulated through the tank (110), the outflow side heat dissipation pipe (161), the heat dissipation plate (170), and the inflow side heat dissipation pipe (162), and heat is radiated to the outside air from the heat dissipation plate (170) to cool it down and then flow into the tank (110) in a lowered state to cool the iron core (120) and the winding (130).

[0043] At least a portion of the insulating oil flowing into the tank (110) from the above heat dissipation pipes (161, 162) can be guided toward the iron core (120) and winding (130).

[0044] The above insulating oil is classified into low temperature, medium-low temperature, and high temperature types, and since the insulating oil of a transformer must maintain an oil temperature of around 55°C, water, alcohol, etc., which are used for medium-low temperature applications, distilled water is used in the embodiments of the present invention.

[0045] In addition, since the insulating oil cooled in the heat dissipation plate (170) is to be guided in a desired direction inside the tank (110), it may be provided at the connection point between the inlet side heat dissipation pipe (162) and the tank (110) among the heat dissipation pipes (161, 162).

[0046] The insulating oil guided to the outer direction of the internal components by the above-mentioned heat dissipation pipes (161, 162) can flow toward the iron core (120) and winding (130) as shown in FIG. 2.

[0047] Through this, a large amount of insulating oil is guided toward the iron core (120) and winding (130), thereby improving the cooling performance of the iron core (120) and winding (130) by the insulating oil.

[0048] In an embodiment of the present invention, the inflow transformer can secure cooling efficiency by forming a plurality of ventilation holes (200) in the iron core (120) together with the heat dissipation pipes (161, 162), so there is an advantage that the freedom of installation of the heat dissipation pipes (161, 162) is improved.

[0049] The above-mentioned heat dissipation pipes (161, 162) can be made in a double-pipe structure, and the heat dissipation plate (170) connected to the heat dissipation pipes (161, 162) can also be manufactured in a double-pipe form. In this case, the insulating oil can be configured to circulate through the inner pipe and the refrigerant through the outer pipe, or conversely, the refrigerant can be configured to circulate through the inner pipe and the insulating oil through the outer pipe, thereby cooling the insulating oil more efficiently.

[0050] FIG. 3 is a plan view showing silicon steel plates applied to the iron core of an inflow transformer according to an embodiment of the present invention, and FIG. 4 to 6 are perspective views showing an iron core formed by laminating the silicon steel plates of FIG. 3.

[0051] As shown in FIG. 3, the ventilation hole (200) of the iron core (120) is formed by forming a plurality of slit holes (122) at regular intervals in the silicon steel plate (121) in advance and stacking a plurality of silicon steel plates (121).

[0052] That is, as shown in FIGS. 4 to 6, the iron core (120) may include an upper yoke (123), a lower yoke (124), and a plurality of legs (125) disposed between the upper yoke (123) and the lower yoke (124) to connect the upper yoke (123) and the lower yoke (124).

[0053] The upper yoke (123) and / or lower yoke (124) may be formed integrally with one of the plurality of legs (125). The upper yoke (123), lower yoke (124), and leg (125) are each formed by stacking a plurality of silicon steel plates (121). To this end, two or more silicon steel plates (121) are first prepared, and each silicon steel plate (121) is processed into the cross-sectional shape of the yoke or leg (125) of the iron core (120) so that a plurality of slit holes (122) are formed.

[0054] For example, the silicon steel plate (121) can be slit to the width of the transformer core (120), and then the silicon steel plate (121) slit to the appropriate width can be cut and punched to match the shape of the joint part (126) of the core (120) to form the shape of the yoke (123, 124) and leg (125).

[0055] Thus, the silicon steel plate (121) can be formed to have the same cross-sectional shape as the upper yoke (123), lower yoke (124), and plurality of legs (125).

[0056] Meanwhile, the ventilation hole (200) formed in the above iron core (120) may be formed in the upper yoke (123), lower yoke (124), and leg (125), respectively, or may be formed only in the leg (125) or in the upper yoke (123) and lower yoke (124).

[0057] The silicon steel sheet (121) used in the above iron core (130) is not particularly limited, and a oriented electrical steel sheet or a non-oriented electrical steel sheet having a thickness of approximately 0.05 to 1.0 mm may be adopted.

[0058] If the thickness of the silicon steel plate (121) is less than 0.15 mm, the iron loss decreases, but the shape stability decreases. On the other hand, if the thickness of the silicon steel plate (121) exceeds 1.0 mm, the iron loss increases. Considering these factors, the thickness of the electrical steel plate can be limited to approximately 0.05 to 1.0 mm.

[0059] Meanwhile, although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited to the above embodiments, and various modifications and variations are possible from this description by those skilled in the art to which the present invention belongs. Accordingly, the concept of the present invention should be understood only by the claims set forth below, and all equivalent or analogous variations thereof shall be considered to fall within the scope of the concept of the present invention. Explanation of the symbols

[0060] 110 : Tank 120 : Iron core 130 : Winding 161, 162 : Heat dissipation pipes 170 : Heat sink 200 : Ventilation hole

Claims

Claim 1 A tank for storing insulating oil; an iron core provided inside the tank and formed by laminating a plurality of silicon steel plates; a winding wound around the iron core; and a heat dissipation plate disposed on the outside of the tank to exchange heat between the insulating oil inside and the outside air. The invention includes a heat dissipation pipe that connects the tank and the heat dissipation plate to form a circulation path for insulating oil, wherein each of the plurality of silicon steel plates has a plurality of slit holes formed at a predetermined interval in advance, and a plurality of ventilation holes through which insulating oil penetrates are formed along the longitudinal direction of the iron core by the lamination of the silicon steel plates, and the heat dissipation pipe and the heat dissipation plate are each formed as a double-pipe structure consisting of an inner tube and an outer tube, wherein the insulating oil circulates in one of the inner tube and the outer tube, and the refrigerant circulates in the other, and the heat dissipation pipe includes an outflow-side heat dissipation pipe through which insulating oil flows out from the tank to the heat dissipation plate, and an inflow-side heat dissipation pipe through which insulating oil cooled in the heat dissipation plate flows into the tank, and the inflow-side heat dissipation pipe is arranged to guide at least a portion of the cooled insulating oil flowing into the interior at the connection part with the tank toward the ventilation holes formed in the iron core, and the winding has a structure in which a plurality of layers are laminated and insulating paper is disposed between the plurality of layers. An inflow transformer characterized in that a plurality of ventilation holes are formed in the above winding to allow the insulating oil to pass through, an evaporator composed of a copper tube and a rolled fin tube inserted therein is provided inside the tank to absorb rising oil temperature, the iron core is configured such that the silicon steel plate located at the center in the width direction is the widest and the silicon steel plate placed at the edge is relatively narrow, forming an overall cylindrical shape, with a step difference existing between adjacent silicon steel plates, the iron core includes an upper yoke, a lower yoke, and a plurality of legs disposed between the upper yoke and the lower yoke to connect the upper yoke and the lower yoke, and the ventilation holes are formed in the upper yoke, lower yoke and the legs respectively, or are selectively formed only in the upper yoke and the lower yoke or only in the legs. Claim 2 delete Claim 3 delete

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