Power conversion device

Abstract

A power conversion device according to one embodiment of the present invention comprises: a housing; and an inductor disposed in the internal space of the housing, in which the inductor includes a core and a coil wound around the core, and is disposed such that a surface of the coil exposed to the outside faces an airflow direction inside the housing.

Description

Technical Field

[0001] This invention relates to a power conversion device, and more specifically to a power conversion device using an inductor with high heat dissipation performance. Background Technology

[0002] To support high-speed charging of hundreds of kilowatts, fast chargers for electric vehicles configure power modules with capacities of tens of kilowatts in parallel and output large amounts of power. When connected to an electric vehicle, the power modules receive alternating current (AC) from the grid and output direct current (DC) to charge the electric vehicle's battery.

[0003] During power conversion, a significant amount of heat is generated within the power module. The resonant inductor, which constitutes the resonant circuit of the power module, is one of the heat-generating components; therefore, to ensure product reliability, technologies that enhance the heat dissipation of the resonant inductor are needed. Summary of the Invention Technical topics

[0004] The technical problem to be solved by the present invention is to provide a power conversion device for an inductor with high heat dissipation effect. Technical solution

[0005] To solve the above-mentioned technical problems, a power conversion device according to an embodiment of the present invention includes: a housing; and an inductor disposed in the internal space of the housing, wherein the inductor includes a core and a coil wound around the core, and wherein the inductor is configured such that the surface of the coil exposed to the outside faces the airflow direction inside the housing.

[0006] In addition, the power conversion device may also include a fan disposed in the internal space of the housing to draw air toward the interior of the housing, and the airflow direction may be formed by the fan.

[0007] In addition, the fan can be located on one side of the housing, and the housing can include one or more holes for exhausting air to the outside on the side opposite to the side where the fan is located.

[0008] In addition, the central axis of the inductor core can be set in a direction perpendicular to the airflow direction.

[0009] In addition, the power conversion device may include a substrate disposed in the internal space of the housing, wherein an inductor is mounted on the substrate, and the central axis of the inductor core may be arranged in a direction perpendicular to the upper surface of the substrate.

[0010] Furthermore, the inductor may include multiple inductors, and these multiple inductors may be arranged in a direction perpendicular to the airflow direction.

[0011] In addition, the core may include a central column, wherein a central column air gap is formed in the center of the central column, and the separation direction of the central column air gap may be perpendicular to the airflow direction.

[0012] Furthermore, the core may not be formed in the region of the central column air gap.

[0013] In addition, the power conversion device may include a resonant LLC converter.

[0014] In addition, the inductor can be the resonant inductor of a resonant LLC converter. Beneficial effects

[0015] According to embodiments of the present invention, by arranging the coil surface of the resonant inductor so that it faces the airflow direction of the fan without using a bobbin, the heat dissipation effect caused by the fan airflow can be improved compared to using a bobbin or having the coil surface parallel to the airflow direction of the fan. Furthermore, by ensuring sufficient space for airflow between the center post and the coil, heat conduction between the core and the coil can be prevented, and the heat dissipation effect can be further improved. Attached Figure Description

[0016] Figure 1 A power conversion device according to an embodiment of the present invention is shown.

[0017] Figure 2 This is a block diagram of a power conversion device according to an embodiment of the present invention.

[0018] Figure 3 This is a circuit diagram of a power conversion device according to an embodiment of the present invention.

[0019] Figure 4 and Figure 5 This is a schematic diagram illustrating the inductor and fan of a power conversion device according to an embodiment of the present invention.

[0020] Figures 6 to 8 An inductor of a power conversion device according to an embodiment of the present invention is shown.

[0021] Figure 9 and Figure 10 An inductor of a power conversion device according to a comparative example of the present invention is shown. Detailed Implementation

[0022] Preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings.

[0023] However, the technical concept of the present invention is not limited to the embodiments described, but can be implemented in various forms, and within the scope of the technical concept of the present invention, one or more of the constituent elements can be selectively combined or substituted among embodiments.

[0024] Furthermore, unless explicitly defined and described, the terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having meanings that are generally understood by those skilled in the art, and commonly used terms (such as terms defined in a dictionary) may be interpreted in light of their meaning in the context of the relevant art.

[0025] Furthermore, the terminology used in this specification is for describing embodiments and is not intended to limit the invention. In this specification, unless specifically stated in the phrase, the singular form may include the plural form, and when described as “at least one (or more) of A, B, and C,” it may include one or more of all possible combinations of A, B, and C.

[0026] Furthermore, when describing the components of embodiments of the present invention, terms such as first, second, A, B, (a), (b) may be used.

[0027] These terms are intended only to distinguish components from other components, and they do not restrict the nature, order, or sequence of components.

[0028] Furthermore, when a component is described as “connected,” “coupled,” or “interconnected” to other components, the component is not only directly connected, coupled, or interconnected to other components, but may also include cases where another component is “connected,” “coupled,” or “interconnected” between those other components.

[0029] Furthermore, when described as being formed or set "above" or "below" each component, "above" or "below" means not only the case where two components are in direct contact, but also the case where one or more other components are formed or set between the two components. Additionally, when expressed as "above" or "below," it can include not only the meaning of an upward direction relative to a component, but also the meaning of a downward direction relative to a component.

[0030] Figure 1 A power conversion device according to an embodiment of the present invention is shown. The power conversion device 100 according to an embodiment of the present invention is configured with a housing 110 and an inductor 120, and may include a cover 130, a fan 140, a substrate 150, a resonant LLC converter 101, an AC-DC rectifier 102, a primary switching circuit 103, a resonant circuit 104, a transformer 105, and a secondary rectifier circuit 106.

[0031] The power conversion device 100 according to an embodiment of the present invention can be a power conversion device for an electric vehicle charging device. Here, the power conversion device 100 can be a power module of the electric vehicle charging device. The power module can receive AC power (50 / 60Hz) from the power grid and output it by converting it to DC power to charge the electric vehicle battery. The power module may include an AC-DC rectifier and an isolated DC-DC converter, and the power conversion device 100 according to an embodiment of the present invention may include an isolated DC-DC converter, and may include a resonant LLC converter between the isolated DC-DC converters.

[0032] The power conversion device 100 according to an embodiment of the present invention may include a primary switching circuit 103, a resonant circuit 104, a transformer 105, a secondary rectifier circuit 106, and an AC-DC rectifier 102. For example... Figure 2 As shown, the power conversion device 100 may include a resonant LLC converter 101 and may also include an AC-DC rectifier 102. Alternating current input from the grid 210 can be converted to direct current in the AC-DC rectifier 102 and output as power for charging the electric vehicle battery 220 by conversion in the resonant LLC converter 101. The resonant LLC converter 101 may include a primary switching circuit 103, a resonant circuit 104, a transformer 105, and a secondary rectifier circuit 106, and can be implemented as follows: Figure 3 The circuit shown. The primary switching circuit 103 inputs power to the primary side of the transformer, and the power input through the primary switching circuit 103 is output to the electric vehicle battery 220 via the transformer 105 and the secondary rectifier circuit 106. When the primary switching circuit 103 operates, zero switching can be achieved using the resonant frequency implemented in the resonant circuit 104, thereby reducing switching losses and improving efficiency. The resonant circuit 104 uses a resonant capacitor, a resonant inductor 120, and a magnetizing inductance included in the transformer; it is referred to as a resonant LLC converter 101.

[0033] The power conversion device 100 according to an embodiment of the present invention may include a housing 110 and a cover 130 covering the housing 110.

[0034] The components for power conversion are disposed within the internal space of the housing 110, and the components disposed within the internal space of the housing 110 include an inductor 120. Here, the inductor 120 may be a resonant inductor of the resonant circuit 104. Alternatively, the inductor 120 may be another inductor or coil included in the power conversion device 100.

[0035] Inductor 120 includes a core 123 and a coil 124 wound on the core 123. The core 123 includes a middle post and may include one or more outer posts. Inductor 120 may include various forms of inductors, including the coil 124 wound on the core 123.

[0036] Inductor 120 can be configured such that the externally exposed surface of coil 124 faces the airflow direction D1 inside housing 110. To effectively dissipate heat generated in inductor 120, inductor 120 does not include a bobbin, allowing coil 124 to be exposed to the outside. The externally exposed surface of coil 124 facing the airflow direction D1 inside housing 110 allows a larger area of ​​coil 124 to contact the flowing air, thereby improving the heat dissipation efficiency of inductor 120.

[0037] A fan 140 can be positioned within the interior space of the housing 110 to draw air inwards. The airflow direction D1 can be formed by the fan 140. Heat dissipation inside the housing 110 is achieved through a fan-air cooling method using the fan 140, and the airflow direction D1 can be set according to the direction of the fan 140. A frame may not be used around the coil 124, allowing the exposed surface of the inductor 120's coil 124 to contact the low-temperature external air drawn in by the fan 140. The inductor 120 can be positioned at a location overlapping with the airflow direction D1 formed by the fan 140 to improve heat dissipation. In locations not overlapping with the airflow direction, air may not be delivered smoothly, or the air temperature may be increased due to other components, potentially degrading the heat dissipation of the inductor 120. By placing the inductor 120 at a location overlapping with the airflow direction D1 formed by the fan 140, air can directly contact the inductor 120, thereby enhancing the heat dissipation of the inductor 120.

[0038] The fan 140 is disposed on one side of the housing 110, and the housing 110 may include one or more holes for exhausting air to the outside on the side opposite to the side where the fan 140 is disposed. The holes may be formed as a mesh, ventilation holes, etc.

[0039] The inductor includes multiple inductors 121 and 122, and multiple inductors 120 can be arranged in a direction perpendicular to the airflow direction D1. The multiple inductors 120 may include two or more inductors and can be arranged side-by-side in a direction perpendicular to the airflow direction D1. When the multiple inductors 120 are arranged parallel to the airflow direction D1, heat from the inductor that first comes into contact with the air is transferred to the air, thereby increasing the air temperature. Then, as the heated air flows towards subsequent inductors, the heat dissipation efficiency of the later inductors may deteriorate. Therefore, the multiple inductors 120 can be arranged side-by-side in a direction perpendicular to the airflow direction D1 to enhance heat dissipation.

[0040] The fan 140 may include multiple fans, and the multiple fans 140 may be arranged side by side along a direction perpendicular to the airflow direction D1. The multiple fans 140 may be located on one side of the housing 110 to introduce external air. Multiple inductors 121 and 122 may be located at positions overlapping with the airflow direction D1 formed by the multiple fans 140 to enhance heat dissipation.

[0041] The central axis of the core 123 of the inductor 120 can be arranged along a direction D2 perpendicular to the airflow direction D1. The inductor 120 can be disposed on a substrate 150, which is disposed within the internal space of the housing 110. The inductor 120 is mounted on the substrate 150, and the central axis of the core 123 of the inductor 120 can be arranged along a direction perpendicular to the upper surface of the substrate 150. Figures 6 to 8 As shown, the central axis of the core 123 can be set to face the direction D2 perpendicular to the airflow direction D1, so that the exposed surface of the coil 124 (rather than the core 123) faces the airflow direction D1 inside the housing 110.

[0042] According to the comparative example of the present invention, the inductor can be configured such that the central axis of the core 23 is parallel to the airflow direction D1, such as... Figure 9 and Figure 10 As shown. In this case, a space is formed between the core 23 and the coil 24, allowing air to flow smoothly. However, the area of ​​the coil 124 in contact with the air is concentrated only on the coil 24 in the airflow direction, while subsequent coils 24 only allow air to pass laterally and do not have an area in direct contact with the air, thus potentially degrading heat dissipation efficiency. In contrast, when the central axis of the core 123 is set to face a direction D2 perpendicular to the airflow direction D1, as shown... Figure 6 As shown, the exposed surface of the coil 124 (not the core 123) of the inductor 120 faces the airflow direction D1 inside the housing 110, which makes the area of ​​air contact with the coil 124 larger, thereby enhancing the heat dissipation effect.

[0043] The core 123 of the inductor 120 includes a central post, and a central post air gap 125 can be formed in the center of the central post. In this case, the separation direction of the central post air gap 125 can be perpendicular to the airflow direction D1. For example... Figure 7 and Figure 8 As shown, by forming the central column air gap 125, even if the central axis of the core 123 is set along the direction D2 perpendicular to the airflow direction D1, the airflow will not be obstructed, allowing for smooth airflow and thus enhancing the heat dissipation effect. Furthermore, since the core 123 is not formed in the central column air gap 125 region, the airflow can be even smoother.

[0044] A structure that forms a central column air gap 125 or does not form a core 123 in the region of the central column air gap 125 may not be necessary to ensure smooth airflow. Even if a central column air gap 125 is formed, the core 123 can still be formed in the region of the central column air gap 125, such as... Figure 6 As shown. Furthermore, the construction of the coil 124 winding around the core 123 of the inductor 120 can be implemented in various other forms.

[0045] In the inductor 120 according to an embodiment of the present invention and according to Figure 9 and Figure 10 In the case of a comparative inductor, the highest temperatures of the core and coil were compared. At this time, as a result of the comparison under the condition that the specifications of the fan 140, the inductor specifications, the inductor heat generation, and the use of the inductor core and coil were set to be the same, it can be confirmed that the inductor 120 according to the embodiment of the present invention and the inductor according to... Figure 9 and Figure 10 The core maximum temperatures of the comparative examples of inductors were 126.8°C and 153.7°C, respectively, which is about 27°C lower than that of the inductor 120 according to an embodiment of the present invention. Furthermore, the inductor 120 according to an embodiment of the present invention and the inductor according to... Figure 9 and Figure 10 The highest coil temperatures of the comparative examples of inductors were 130.4°C and 151.7°C, respectively, which is about 21°C lower than that of the inductor 120 according to an embodiment of the present invention. Therefore, it can be confirmed that the inductor 120 according to an embodiment of the present invention has high heat dissipation performance. [Table 1]

[0046] As described above, by arranging the coil 124 of the inductor 120 such that the exposed surface faces the airflow direction of the fan 140 without using a frame, the heat dissipation effect generated by the fan airflow can be enhanced compared to using a frame or having the coil surface parallel to the airflow direction of the fan. Furthermore, by ensuring sufficient space for airflow between the core and the coil, heat conduction between the core and the coil can be prevented, and the heat dissipation effect can be further enhanced.

[0047] Those skilled in the art will understand that the invention can be implemented in modified forms without departing from the essential features described above. Therefore, the disclosed methods should be considered illustrative rather than restrictive. The scope of the invention is defined by the claims rather than the foregoing description, and all differences within their equivalents should be interpreted as included within the scope of the invention.

Claims

1. A power conversion device, comprising: case; as well as An inductor is disposed within the internal space of the housing. The inductor includes a core and a coil wound around the core, and The inductor is configured such that the surface of the coil exposed to the outside faces the direction of airflow inside the housing.

2. The power conversion device according to claim 1, comprising: A fan is disposed within the interior space of the housing to draw air inward toward the interior of the housing. The airflow direction is formed by the fan.

3. The power conversion device according to claim 1, in, The fan is located on one side of the housing, and The housing includes one or more holes on the side opposite to the side where the fan is located, for discharging air to the outside.

4. The power conversion device according to claim 1, wherein, The central axis of the core of the inductor is arranged in a direction perpendicular to the airflow direction.

5. The power conversion device according to claim 1, comprising: The substrate is disposed within the internal space of the housing. The inductor is mounted on the substrate. The central axis of the core of the inductor is arranged in a direction perpendicular to the upper surface of the substrate.

6. The power conversion device according to claim 1, in, The inductor includes multiple inductors, and The plurality of inductors are arranged in a direction perpendicular to the airflow direction.

7. The power conversion device according to claim 1, in, The core includes a central column. The air gap in the middle column is formed in the center of the middle column, and The separation direction of the air gap in the middle column is perpendicular to the airflow direction.

8. The power conversion device according to claim 7, wherein, The core is not formed in the region of the air gap of the central column.

9. The power conversion device according to claim 1, wherein, The power conversion device includes a resonant LLC converter.

10. The power conversion device according to claim 9, wherein, The inductor is the resonant inductor of the resonant LLC converter.

Images