Reactor

Abstract

A reactor is disclosed. The reactor comprises: an upper core: a lower core positioned below the upper core: a leg core positioned between the upper core and the lower core and having an air gap region; and a coil part wound around the leg core, wherein the air gap region is made of a non-magnetic material and includes a plurality of first air gap plates that are sequentially stacked, and second air gap plates made of a magnetic material and inserted between the first air gap plates.

Description

reactor

[0001] The present invention relates to a reactor, and more particularly, to a reactor capable of efficiently discharging heat generated in a coil section during operation of the reactor to the outside, minimizing heat generation in the core due to the presence of an air gap, and increasing the cooling efficiency of the reactor.

[0002] A reactor is a component that converts electrical energy into magnetic energy and stores it. It uses the characteristic of the current flowing through the reactor not to change suddenly to smooth out the fluctuating current. A reactor is commonly made up of a coil wound around an iron core to strengthen the magnetic field and control the current. When current flows through the coil, a magnetic flux is generated in the core, and the presence of an air gap in the core causes leakage flux in the iron core. The leakage flux increases proportionally as the size of the air gap increases. The leakage flux generates heat in the core, and this heat generation consumes electrical energy, which can lead to energy loss and reduced power efficiency.

[0003] Conventional techniques for managing heat generation in reactors have included cooling the reactor through a cooling system that circulates a cooling medium around the core or within the reactor, and installing a heat exchanger that efficiently disperses heat between the cooling medium and the reactor. However, these techniques are difficult to design, operate, and maintain for reactor heat management, and their complex structures lead to low installation costs and low energy efficiency. Therefore, research is needed to address these issues.

[0004] The present invention provides a reactor capable of effectively discharging heat generated in a coil section.

[0005] In addition, the present invention provides a reactor capable of minimizing heat generation in a core portion.

[0006] A reactor according to an embodiment of the present invention includes an upper core; a lower core positioned below the upper core; a leg core positioned between the upper core and the lower core and having an air gap region; and a coil portion wound around the leg core, wherein the air gap region includes a first air gap plate provided with a non-magnetic material; and a second air gap plate provided with a magnetic material and in close contact with the first air gap plate.

[0007] Additionally, the air gap region may be located in any one of the upper region, the lower region, and the central region of the leg core.

[0008] In addition, the second air gap plate may be divided into a single or multiple plates, and the divided plates may be arranged parallel to each other at a predetermined interval.

[0009] In addition, the coil section may further include an inner coil wound around the leg core; an outer coil wound around the inner coil; and a cooling duct inserted between the inner coil and the outer coil and maintaining a predetermined gap between the inner coil and the outer coil, and an airflow forming section that forms an upward airflow in the space between the inner coil and the outer coil.

[0010] In addition, the airflow forming unit includes a housing having an inlet and an outlet formed therein; a fan provided within the housing; and a magnetic coil that generates current by utilizing leakage magnetic flux generated in the air gap of the leg core, wherein the current generated in the magnetic coil can be provided as a driving force for the fan.

[0011] According to the present invention, heat generated in a reactor can be effectively discharged.

[0012] Additionally, according to the present invention, the size of the reactor can be reduced.

[0013] In addition, according to the present invention, the productivity of the reactor can be increased, and the size of the leakage flux can be minimized to increase the conversion efficiency of the reactor.

[0014] In addition, according to the present invention, the cooling effect can be increased by using the leakage flux as an electric energy source.

[0015] Figure 1 is a perspective view showing a reactor according to an embodiment of the present invention.

[0016] Fig. 2 is a cross-sectional view of the reactor along line AB of Fig. 1.

[0017] Fig. 3 is a cross-sectional view of the reactor along the CD line of Fig. 1.

[0018] FIG. 4 is a drawing for explaining leg cores according to one embodiment of the present invention.

[0019] FIGS. 5 to 7 are perspective views showing leg cores according to various embodiments of the present invention.

[0020] Figure 8 is an exploded perspective view showing the air gap area.

[0021] Fig. 9 is a cross-sectional view showing a first coil portion (200) according to an embodiment of the present invention.

[0022] Fig. 10 is a perspective view showing an airflow forming unit according to one embodiment of the present invention.

[0023] Fig. 11 is a cross-sectional view showing an airflow forming part according to another embodiment of the present invention.

[0024] FIG. 12 is a drawing for explaining a process in which a current is generated by a leakage flux occurring in an air gap according to an embodiment of the present invention.

[0025] Fig. 13 is a perspective view showing an airflow change unit according to an embodiment of the present invention.

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to sufficiently convey the spirit of the present invention to those skilled in the art.

[0027] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. In addition, in the drawings, the thicknesses of films and regions are exaggerated for the purpose of effectively explaining the technical contents.

[0028] Also, although terms such as first, second, and third have been used to describe various components in various embodiments of this specification, these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, what is referred to as a first component in one embodiment may be referred to as a second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiments. Also, the term "and / or" has been used herein to mean including at least one of the components listed before and after.

[0029] In the specification, singular expressions include plural expressions unless the context clearly dictates otherwise. In addition, terms such as "comprise" or "have" are intended to specify the presence of a feature, number, step, component, or combination thereof described in the specification, and should not be construed as excluding the presence or addition of one or more other features, numbers, steps, components, or combinations thereof. In addition, the term "connection" is used in the present specification to mean both indirectly connecting multiple components and directly connecting them.

[0030] In addition, when describing the present invention below, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0031]

[0032] FIG. 1 is a perspective view showing a reactor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the reactor along line AB of FIG. 1, and FIG. 3 is a cross-sectional view of the reactor along line CD of FIG. 1.

[0033] Referring to FIGS. 1 to 3, a reactor (10) according to an embodiment of the present invention converts electric energy into magnetic energy and stores it. In the embodiment of the present invention, a three-phase reactor (10) is described as an example, but is not limited thereto, and can also be applied to a single-phase reactor (10). In addition, the core of the reactor (10) is described as being provided in a rectangular shape, but is not limited thereto, and can be provided in a Y-shape, a delta-shape, and a circular shape.

[0034] A reactor (10) according to an embodiment of the present invention includes a core portion (100), a first coil portion (200), a second coil portion (300), a third coil portion (400), an airflow forming portion (500), and an airflow changing portion (600).

[0035] The core portion (100) has a predetermined shape and is provided as an iron core. The core portion (100) includes an upper core (110), a lower core (120), a first leg core (130), a second leg core (140), and a third leg core (150).

[0036] The upper core (110), the lower core (120), the first leg core (130), the second leg core (140), and the third leg core (150) are provided in a hexahedral shape having a square cross-section. Alternatively, the upper core (110), the lower core (120), the first leg core (130), the second leg core (140), and the third leg core (150) may be provided in a cylindrical shape having a circular cross-section.

[0037] The upper core (110) is provided such that its length direction is parallel to the ground. Hereinafter, for convenience of explanation, the length direction of the upper core (110) is referred to as the first direction (11), the direction perpendicular to the first direction (11) is referred to as the second direction (12), and the direction perpendicular to the first direction (11) and the second direction (12) is referred to as the third direction (13).

[0038] The upper core (110) is provided as a magnetic material. According to an embodiment, the upper core (110) may be formed of a combination of metal powders, thermosetting resin, thermoplastic resin, and a curing agent. For example, the upper core (110) may be a super core, a permalloy core, a powder (e.g., sand dust, megaflux, iron, etc.) core, an amorphous core, a ferrosilicon (Fe-Si) core, a ferrite core, a nano crystalline core, an iron alloy core, etc.

[0039] The lower core (120) is located below the upper core (110) and is arranged facing the upper core (110). The lower core (120) is provided so that its length direction is the same as that of the upper core (110). The lower core (120) may be provided with the same thickness, shape, and material as the upper core (110).

[0040] The first leg core (130) is provided with a predetermined length, and its length direction is provided in the third direction (13). The first leg core (130) is located between one end of the upper core (110) and one end of the lower core (120). An air gap (130a) is formed between the upper end of the first leg core (130) and the upper core (110), and an air gap (130b) is formed between the lower end of the first leg core (130) and the lower core (120). Although not shown in the drawing, air gaps may be formed at predetermined intervals in the first leg core (130) along the third direction (13).

[0041] The second leg core (140) is provided with a predetermined length, and its length direction is provided in the third direction (13). The second leg core (140) is spaced apart from the first leg core (130) by a predetermined distance in the first direction (11) and is arranged parallel to the first leg core (130). The second leg core (140) is located between the center region of the upper core (110) and the center region of the lower core (120). An air gap (140a) is formed between the upper end of the second leg core (140) and the upper core (110), and an air gap (140b) is formed between the lower end of the second leg core (140) and the lower core (120). Although not shown in the drawing, air gaps may be formed at predetermined intervals in the second leg core (140) along the third direction (13).

[0042] The third leg core (150) is provided with a predetermined length, and its length direction is provided in the third direction (13). The third leg core (150) is spaced apart from the second leg core (140) by a predetermined distance in the first direction (11) and is arranged parallel to the second leg core (140). The third leg core (150) is located between the other end of the upper core (110) and the other end of the lower core (120). An air gap (150a) is formed between the upper end of the third leg core (150) and the upper core (110), and an air gap (150b) is formed between the lower end of the third leg core (150) and the lower core (120). Although not shown in the drawing, air gaps may be formed at predetermined intervals in the third direction (13) in the third leg core (150).

[0043] FIG. 4 is a drawing for explaining leg cores according to one embodiment of the present invention.

[0044] Referring to FIG. 4, when the first to third leg cores (130, 140, 150) have a rectangular shape, a three-phase reactor manufactured with the first to third leg cores (130, 140, 150) may have an error rate of 5% or more in the inductance values ​​of each phase (a, b, c). This is related to the magnetic path length (MPL) of the reactor. The magnetic path lengths (MPL1, MPL3) of phases a and c are the same, but the magnetic path length (MPL2) of phase b is relatively small, so the inductance value of phase b may theoretically be different in magnitude. The following [Formula 1] shows a mathematical formula for calculating the inductance value in each phase.

[0045] [Formula 1]

[0046] L=0.4πN on a, c 2 A c μ(10 -s ) / (MPL)

[0047] L=0.4πN on b 2 A c μ(10 -s) / (MPL*k)

[0048]

[0049] Here, the k value of b can have a value of 0.93 to 0.97.

[0050] In a general rectangular structure, a method to keep the L value of each phase that forms the three phases the same can be as shown in [Formula 2] below.

[0051]

[0052] [Formula 2]

[0053] L=0.4πN on a, c 2 A c μ1(10 -s ) / (MPL)+0.4πN 2 A c μ2(10 -s ) / (MPL')

[0054] L=0.4πN on b 2 A c μ1(10 -s ) / (MPL*k)+0.4πN 2 A c μ2(10 -s ) / (MPL")

[0055] Here, μ1 and μ2 represent the investment rates of each leg core (130, 140, 150), and MPL' and MPL" represent variables of the length of the conductor to make the inductance value in each phase the same.

[0056] That is, as can be seen from the above equation 2, in the case of a rectangular three-phase reactor, the inductance value of each phase can be made the same by changing the permeability and path length (MPL) of each leg core (130, 140, 150). In this rectangular three-phase reactor, the inductance value can be made the same by making the size of the molecular permeability different because the MPL is different rather than making the MPL the same through the middle part. In other words, in the case of a three-phase reactor having a rectangular yoke core, by forming the leg cores (130, 140, 150) using multiple cores with different permeability, the imbalance of the inductance caused by the different path lengths can be resolved, and the inductance value can be made the same.

[0057]

[0058] FIGS. 5 to 7 are perspective views illustrating leg cores according to various embodiments of the present invention, and FIG. 8 is an exploded perspective view illustrating an air gap region. At least one of the first to third leg cores (130, 140, 150) may be any of the leg cores described in FIGS. 5 to 8.

[0059] Referring to FIGS. 5 to 8, the leg core (130) has an air gap region (133). The air gap region (133) reduces leakage flux of the reactor (10), minimizes eddy current loss, and reduces heat generation in the coil section (200) and the core (130).

[0060] According to one embodiment, the air gap region (133) may be located in the central region of the leg core (130), as shown in FIG. 5. According to another embodiment, the air gap region (133) may be located at the upper end of the leg core (130), as shown in FIG. 6. According to yet another embodiment, the air gap region (133) may be located at the lower end of the leg core (130), as shown in FIG. 7.

[0061] The air gap region (133) includes a first air gap plate (134) and a second air gap plate (135).

[0062] The first air gap plate (134) is a thin plate and is provided with a non-magnetic material. According to an embodiment, the first air gap plate (134) is provided with a square shape. The material of the first air gap plate (134) may be provided with a synthetic resin. According to an embodiment, the first air gap plate (134) may be provided with a thermosetting resin or a thermoplastic resin, for example, acrylic or polyester. A plurality of first air gap plates (134) are provided and sequentially stacked in the third direction (13).

[0063] The second air gap plate (135) is individually inserted between the first air gap plates (134). The second air gap plate (135) is provided with a magnetic material. According to an embodiment, the second air gap plate (135) may be composed of any material used as a core material of a transformer or reactor, such as sendust, megaflux, iron powder, Ni-Fe, amorphous alloy, silicon (Fe-Si), and ferrite.

[0064] For example, the second air gap plate (135) may be provided as a thin plate with a size corresponding to that of the first air gap plate (134). The second air gap plate (135) may have a thickness thinner than that of the first air gap plate (134).

[0065] According to another embodiment, the second air gap plate (135) may be divided into a plurality of thin plates (135a to 135d), and the divided plates (135a to 135d) may be arranged at a predetermined interval in the second direction (12). The divided plates (135a to 135d) are provided as rectangular plates in which the length in the first direction (11) is longer than the width in the second direction. The divided plates (135a to 135d) are arranged parallel to each other. According to an embodiment, the second air gap plate (135) may be divided into four plates (135a to 135d).

[0066]

[0067] Referring again to FIGS. 1 to 3, the first coil portion (200) is provided to the first leg core (130), the second coil portion (300) is provided to the second leg core (140), and the third coil portion (400) is provided to the third leg core (150). The first to third coil portions (200, 300, 400) convert electric energy into magnetic energy. The first coil portion (200) to the third coil portion (400) are provided with the same structure. For the convenience of the following description, the first coil portion (200) will be described in detail by way of example.

[0068]

[0069] Fig. 9 is a cross-sectional view showing a first coil portion (200) according to an embodiment of the present invention.

[0070] Referring to FIG. 9, the first coil section (200) includes a first cooling duct (210), an inner coil (220), a second cooling duct (230), and an outer coil (240).

[0071] The first cooling duct (210) has a predetermined length and its longitudinal direction is provided in the third direction (13). A plurality of first cooling ducts (210) are provided, and are provided at each corner region of the first leg core (130) along the circumference of the first leg core (130). The first cooling duct (210) is provided with a cross-section having an ‘ㄱ’ shape. The first cooling duct (210) may have an inner surface facing the first leg core (130) and an outer surface facing the inner coil (220) bent. As a result, the first cooling duct (210) may be in close contact with the corner region of the first leg core (130).

[0072] According to one embodiment, the first cooling duct (210) may be provided with the same material as the first leg core (130). That is, the material of the first cooling duct (210) may be provided with a combination of a thermosetting resin, a thermoplastic resin, and a curing agent.

[0073] According to another embodiment, the first cooling duct (210) may be composed of a body provided with a combination of a thermosetting resin, a thermoplastic resin, and a curing agent, and a bonding member bonded to the exterior of the body. The bonding member may be made of at least one of glass fiber or plastic. As an example, the bonding member may be a coating layer formed on the surface of the body. As another example, the bonding member may be an external structure assembled to the body.

[0074] The combination of the first cooling duct (210) and the first leg core (130) described above can increase the cross-sectional area of ​​the first leg core (130) by integrating the cross-sectional area of ​​the first cooling duct (210) into the cross-sectional area of ​​the first leg core (130). For example, if the cross-sectional area of ​​the first leg core (130) is 80 cm 2 And, each of the first cooling ducts (210) has a cross-sectional area of ​​9 cm. 2 In this case, the cross-sectional areas of the four first cooling ducts (210) are integrated into the cross-sectional area of ​​one first leg core (130), so that the core cross-sectional area is 126 cm 2can be increased. This can result in a decrease in the number of turns of the inner coils (220). In addition, since the cooling ducts (210) can be operated without a separate structure, the operation speed for the reactor can be increased. In addition, since the cooling ducts (210) are not entirely made of glass fiber, the health of workers working on the reactor can be protected. In addition, there is no need to form a separate air gap other than the air layer for the reactor.

[0075] The inner coil (220) is wound multiple times around the circumference of the first leg core (130). The inner coil (220) maintains a predetermined distance from the first leg core (130) due to the first cooling duct (210). As a result, an air layer is formed between the first leg core (130) and the inner coil (220). The air layer (20) is formed on both sides of the first leg core (130) in the first direction (11) and the second direction (12) with the first leg core (130) interposed therebetween. The air layer (20) releases heat generated in the coils (220, 240) during operation of the reactor (10) to the outside. A cooling structure can be implemented due to the air layer (20).

[0076] The second cooling duct (230) may be provided with the same material as the first cooling duct (210). The second cooling duct (230) has a predetermined length, and its length direction is provided in the third direction (13). A plurality of second cooling ducts (230) are provided on each of the two facing sides of the inner coil (220) in the second direction (12), and are arranged spaced apart from each other in the first direction (11).

[0077] The outer coil (240) is wound multiple times around the inner coil (220). The outer coil (240) maintains a predetermined distance from both sides of the inner coil (220) facing each other in the second direction (12) due to the second cooling duct (230). In addition, the outer coil (240) is in close contact with both sides of the inner coil (220) in the first direction (11).

[0078] By providing the second cooling duct (230), an air layer (30) is formed between the inner coil (220) and the outer coil (240). The air layer (30) is formed on each side of the inner coil (220) in the second direction (12). The air layer (30) releases heat generated between the inner coil (220) and the outer coil (240) to the outside.

[0079]

[0080] Fig. 10 is a perspective view showing an airflow forming unit according to one embodiment of the present invention.

[0081] Referring to FIGS. 1, 9, and 10, the airflow forming unit (500) forms an upward airflow with the air layers (20, 30) formed in the first to third coil units (200, 300, 400). The airflow forming units (500) are provided at the front and rear of the lower core (120), respectively. Two airflow forming units (500) are provided at the front and rear of the lower core (120).

[0082] The airflow forming unit (500) includes a housing (510, 520). The housing (510, 520) is provided as an outer shape of the airflow forming unit (500).

[0083] According to one embodiment, the housing (510, 520) may be provided in a cylindrical shape with open upper and lower surfaces.

[0084] In another embodiment, the housing (510, 520) may have a generally Y-shape. In the present embodiment, the housing (510, 520) is provided in a Y-shape as an example, but is not limited thereto.

[0085] The housing (510, 520) is formed with air inlets (511, 521) and outlets (512, 513, 522, 523). The air inlets (511, 521) are provided on the bottom surface of the housing (510, 520) and serve as passages through which external air is introduced. The outlets (512, 513, 522, 523) are formed in pairs on the upper portion of the housing (510, 520) and serve as passages through which air introduced from the air inlets (511, 521) is discharged.

[0086] The rising air current discharged from one housing (510) flows into the air layer (20, 30) of the first coil section (200) and into the air layer (20, 30) of the second coil section (300). Specifically, the rising air current discharged from one outlet (512) of the housing (510) flows into the air layer (20, 30) of the first coil section (200), and the rising air current discharged from the other outlet (513) flows into the air layer (20, 30) of the second coil section (300).

[0087] The rising air current discharged from another housing (520) flows into the air layer (20, 30) of the second coil section (300) and into the air layer (20, 30) of the third coil section (400). Specifically, the rising air current discharged from one outlet (522) of the housing (520) flows into the air layer (20, 30) of the second coil section (300), and the rising air current discharged from the other outlet (523) flows into the air layer (20, 30) of the third coil section (400).

[0088] By the rising air current, the heat generated in the space between the leg core (130, 140, 150) and the inner coil (220) and the heat generated in the space between the inner coil (220) and the outer coil (230) can be quickly discharged to the outside.

[0089] Fig. 11 is a cross-sectional view showing an airflow forming part according to another embodiment of the present invention.

[0090] Referring to Fig. 11, the airflow forming unit (500) further includes a fan (530). The fan (530) is provided at the inlet (511) inside the housing (510). The fan (530) moves external air drawn into the air inlet (511) toward the outlets (512, 513). By driving the fan (530), a forced airflow is formed inside the housing (510), and the forced airflow is formed from the air inlet (511) side to the outlets (512, 513).

[0091] In one embodiment, the fan (530) can be driven by external power.

[0092] In another embodiment, the fan (530) may operate by utilizing current generated by leakage flux occurring in an air gap.

[0093]

[0094] Fig. 12 is a diagram for explaining a process in which a current is generated by a leakage magnetic flux occurring in an air gap according to an embodiment of the present invention. Fig. 12 (A) is a diagram showing a leg core provided with a magnetic coil, and (B) is a front view showing the magnetic coil.

[0095] Referring to FIG. 12, the airflow forming unit (500) may further include a magnetic coil (540). The magnetic coil (540) is provided to the leg core (130). According to an embodiment, the magnetic coil (540) may be located in an area of ​​the leg core (130) where an air gap (133) is formed. A current is generated in the magnetic coil (540) according to electromagnetic induction due to the leakage magnetic flux (50) generated in the air gap (130). As the magnitude of the current applied to the coil increases, the magnitude of the leakage magnetic flux (50) generated in the air gap (133) increases, and as the leakage magnetic flux (50) increases, the magnitude of the current generated in the magnetic coil (540) increases. When the generated current is provided to the fan (530) through an electric circuit, the fan (530) can be driven. The fan (530) may be a DC fan or an AC fan depending on the capacity of the reactor or the size of the leakage flux, and the failure or operation of the fan (530) may be checked using a motion sensor, etc.

[0096]

[0097] Fig. 13 is a perspective view showing an airflow change unit according to an embodiment of the present invention.

[0098] Referring to FIGS. 1, 2, and 13, an airflow changer (600) is provided in a space between the upper core (110) and the coil parts (200, 300, 400). A pair of airflow changer parts (600) is provided, with one airflow changer part (600) being provided across the first coil part (200) and the second coil part (300), and the other airflow changer part (600) being provided across the second coil part (300) and the third coil part (400).

[0099] Each airflow changer (600) is provided with a predetermined length and is arranged with its length direction in the first direction (11). The airflow changer (600) includes a first airflow guide surface (610), a second airflow guide surface (620), and an upper surface (630).

[0100] The first airflow guide surface (610) is provided on one side of the airflow change section, extends downward from one side of the upper surface (630), and its lower end is positioned on the same line as the central region of the upper surface (630) in the third direction (13). The first airflow guide surface (610) is provided in a longitudinal direction in the first direction (11), and a cross-section in the second direction (12) is provided in an arc shape having a predetermined curvature.

[0101] The second airflow guide surface (620) is provided on the other side of the airflow change section, extends downward from the other side of the upper surface (630), and its lower end is positioned on the same line as the center area of ​​the upper surface in the third direction (13). The second airflow guide surface (620) is provided in the same length direction as the first airflow guide surface (610), and the cross section in the second direction (12) is provided in an arc shape having the same curvature in the opposite direction to the first airflow guide surface (610).

[0102] The upper surface (630) is provided as a flat plane as the upper surface (630) of the airflow change section.

[0103] The airflow change portion of the above-described structure is provided in a convex shape in the direction in which the first airflow guide surface (610) and the second airflow guide surface (620) face each other.

[0104] The first airflow guide surface (610) and the second airflow guide surface (620) change the flow of the rising airflow generated in the space between the coil sections (200, 300, 400) due to the heat generation of the coil sections (200, 300, 400) to the front and rear of the reactor (10).

[0105] While the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to specific embodiments, and should be interpreted in accordance with the appended claims.

[0106] Additionally, those skilled in the art will understand that many modifications and variations can be made without departing from the scope of the present invention.

Claims

1. Upper core; A lower core located below the upper core; A leg core positioned between the upper core and the lower core and having an air gap region; and Including a coil part wound around the above leg core, The above air gap area is A first air gap plate provided with a non-magnetic material; and A reactor comprising a second air gap plate provided with a magnetic material and in close contact with the first air gap plate.

2. In paragraph 1, The above air gap area is A reactor located in any one of the upper region, lower region, and central region of the above leg core.

3. In paragraph 1, The above second air gap plate, A reactor divided into a plurality of plates, the divided plates being arranged parallel to each other at a predetermined interval.

4. In paragraph 1, The above coil part Inner coil wound around the above leg core; an outer coil wound around the circumference of the inner coil; and A cooling duct is inserted between the inner coil and the outer coil and maintains a predetermined gap between the inner coil and the outer coil. A reactor further comprising an airflow forming unit that forms an upward airflow in the space between the inner coil and the outer coil.

5. In paragraph 4, The above airflow forming part is, A housing having an inlet and an outlet formed therein; a fan provided within the housing; and Including a magnetic coil that generates current by utilizing the leakage magnetic flux occurring in the air gap of the above leg core, A reactor in which the current generated in the above magnetic coil is provided as driving power for the fan.

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