Power conversion device

Abstract

To provide a power conversion device that can achieve high stability and compactness by reducing the height of a power conversion device.SOLUTION: A power conversion device includes a housing, a power conversion unit arranged within the housing and having a first terminal and a second terminal, a first filter circuit unit arranged within the housing to form a stacked structure with the power conversion unit and having the first terminal and the second terminal connected to the first terminal of the power conversion unit, and a second filter circuit unit arranged within the housing and having the first terminal connected to the second terminal of the power conversion unit and the second terminal.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This disclosure relates to power conversion devices. [Background technology]

[0002] BACKGROUND ART Power conversion devices are known that convert AC power input from a power grid into DC power to charge a storage battery, or convert DC discharge power from a storage battery into AC power to supply to loads in a home.

[0003] For example, Patent Document 1 below discloses a stationary power conversion device used to charge the onboard battery of an electric vehicle. The stationary power conversion device disclosed in Patent Document 1 includes an input-side filter circuit that shapes AC power or DC power input from outside, a power conversion circuit board that converts the shaped AC power or DC power into predetermined DC power, an output-side filter circuit that shapes the predetermined DC power and outputs it to the outside, and a box-shaped housing that houses the input-side filter circuit, power conversion circuit board, and output-side filter circuit and is installed on an installation surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-36456 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology disclosed in Patent Document 1 places the input filter circuit in the lower part of the housing near the terminal block, the power conversion circuit board in the vertical center of the housing, and the output filter circuit in the upper part of the housing near the outlet for the charging cable. However, arranging the input filter circuit, power conversion circuit board, and output filter circuit in this manner increases the vertical length of the housing. This increases the center of gravity of the power conversion device, making it unstable and prone to tipping over. Another problem is that the power conversion device becomes larger.

[0006] Therefore, an object of this disclosure is to provide a power conversion device that can achieve high stability and miniaturization. [Means for solving the problem]

[0007] A power conversion device according to one aspect of this disclosure includes a housing, a power conversion unit disposed within the housing and having a first terminal and a second terminal, a first filter circuit unit disposed within the housing to form a stacked structure with the power conversion unit and having the first terminal and a second terminal connected to the first terminal of the power conversion unit, and a second filter circuit unit disposed within the housing and having a first terminal connected to the second terminal of the power conversion unit and a second terminal. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a power conversion device that can achieve high stability and miniaturization by reducing the height of the power conversion device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a power storage system. [Figure 2] FIG. 2 is a perspective view showing the appearance of the power conversion device according to the first embodiment of the present disclosure. [Figure 3] FIG. 3 is a diagram showing a vertical cross section of the power converter shown in FIG. 2 taken along line 3-3. [Figure 4] FIG. 4 is an exploded perspective view showing the internal configuration of the power conversion device. [Figure 5] FIG. 5 is an exploded perspective view showing a state in which the parts shown in FIG. 4 are partially assembled. [Figure 6] FIG. 6 is a diagram showing a method of assembling the filter circuit unit to the inner housing. [Figure 7] FIG. 7 is a diagram showing a state in which the filter circuit section is assembled into the inner housing. [Figure 8] FIG. 8 is a diagram showing a part of the internal structure of a power conversion device according to the second embodiment of the present disclosure. [Figure 9] FIG. 9 is a simplified view showing a part of a horizontal cross section of the power converter shown in FIG. 8 taken along line 9-9. [Figure 10] FIG. 10 is a simplified view showing a part of a vertical cross section of the power converter shown in FIG. 9 taken along line 10-10. [Figure 11] FIG. 11 is a simplified view showing a part of a vertical cross section of the power converter shown in FIG. 9 taken along line 11-11. [Figure 12] FIG. 12 is a diagram showing an example of an opening formed in a substrate corresponding to the boundary between an upper circuit section and a lower circuit section. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Description of the embodiments of this disclosure] The contents of the embodiments of this disclosure will be listed and explained below. At least some of the embodiments described below may be combined in any combination.

[0011] (1) A power conversion device according to one aspect of this disclosure includes a housing, a power conversion unit disposed within the housing and having a first terminal and a second terminal, a first filter circuit unit disposed within the housing to form a stacked structure with the power conversion unit and having the first terminal and a second terminal connected to the first terminal of the power conversion unit, and a second filter circuit unit disposed within the housing and having a first terminal connected to the second terminal of the power conversion unit and a second terminal.

[0012] This allows the size and height of the housing to be smaller than when the power conversion unit and the first filter circuit unit are arranged so as not to form a stacked structure. As a result, the center of gravity of the power conversion device can be lowered. Therefore, a power conversion device that can achieve high stability and compactness due to its low profile can be provided.

[0013] (2) In the above (1), the power conversion unit and the first filter circuit unit may be arranged such that the stacking direction of the stacked structure intersects with the direction of gravity during operation of the power conversion device. This allows the height of the housing to be more reliably reduced compared to a typical power conversion device in which the power conversion unit is arranged in the vertical center of the housing and the filter circuit units are arranged above and below the power conversion unit.

[0014] (3) In the above (1), the power conversion device may further include an inner housing made of a metal material and disposed inside the housing. The first filter circuit unit may be fixed inside the inner housing. This prevents externally generated electrical noise from affecting the operation of the first filter circuit unit, and conversely, prevents electrical noise generated during operation of the first filter circuit unit from leaking to the outside.

[0015] (4) In the above (3), the internal housing may be formed with a first opening for passing a harness connected to the first filter circuit unit and at least one second opening different from the first opening. This allows the first filter circuit unit to function without impeding the noise shielding effect, and allows heat generated during operation of the first filter circuit unit to be discharged from inside the internal housing to the outside via the second opening. As a result, heat can be dissipated at low cost without increasing the size of the internal housing.

[0016] (5) In the above (4), the second opening may be formed in the inner housing so as to be located above the stacked structure during operation of the power conversion device, thereby allowing air that is heated by heat generated during operation of the first filter circuit unit and moves above the stacked structure to be efficiently discharged to the outside through the second opening.

[0017] (6) In the above (4), the second opening may have a plurality of small openings, each of which may have a maximum diameter of 1 mm or more and 10 mm or less. This allows for more reliable heat dissipation without reducing the noise shielding effect.

[0018] (7) In the above (3), the power conversion device may further include a first fixing member and a second fixing member provided on two different inner surfaces of the inner housing for fixing two different ends of the first filter circuit unit to the inner housing. This allows for a simple configuration to form a stacked structure of the first filter circuit unit and the power conversion unit.

[0019] (8) In the above (1), the second filter circuit unit may be disposed below the power conversion unit and the first filter circuit unit when the power conversion unit is operating. This allows the power conversion unit, the first filter circuit unit, and the second filter circuit unit to be disposed efficiently without wasting space. This further ensures miniaturization of the power conversion device. Furthermore, the second filter circuit is disposed on the opposite side of the direction of flow of air heated by heat generated during operation of the power conversion circuit and the first filter circuit. This allows the second filter circuit to stably function without being affected by this air.

[0020] (9) In the above (8), the first filter circuit section may be arranged so that the first terminal of the first filter circuit section is located lower than the second terminal of the first filter circuit section, and the second filter circuit section may be arranged so that the second terminal of the second filter circuit section is located lower than the first terminal of the second filter circuit section. This allows the wiring for connecting the first filter circuit section, the power conversion section, and the second filter circuit section in this order to be short. Furthermore, the first terminal of the first filter circuit section and the second terminal of the second filter circuit section, which are connected to either the cable or the terminal block, are located lower. This lowers the center of gravity of the power conversion device, making it less likely for the power conversion device to tip over.

[0021] (10) In the above (1), the second filter circuit may be disposed away from the stacked structure of the power conversion unit and the first filter circuit and on the opposite side to the direction in which heat generated by the power conversion unit and the first filter circuit moves during operation of the power conversion device. This allows the second filter circuit to function more stably.

[0022] (11) In the above (1), the power conversion device may further include a heat sink provided in contact with the power conversion unit, and an air-cooling unit fixed to the housing and blowing air toward the heat sink, thereby efficiently cooling the air inside the housing.

[0023] [Details of the embodiments of this disclosure] In the following embodiments, the same components are denoted by the same reference numerals, and their names and functions are also the same, so detailed descriptions thereof will not be repeated.

[0024] (1) First embodiment (1-1) Configuration of the Power Storage System 50 FIG. 1 shows the configuration of a power storage system 50 according to a first embodiment of the present disclosure. Referring to FIG. 1, the power storage system 50 includes a house 60 that receives a supply of power from a power grid and an electric vehicle 62 that has an on-board storage battery compatible with V2H (Vehicle to Home). The power storage system 50 further includes a power conversion device 64. The power conversion device 64 functions bidirectionally. That is, as indicated by arrow 66, the power conversion device 64 has a function of charging the storage battery mounted on the electric vehicle 62 using AC power supplied from the power grid. This AC power is supplied to the power conversion device 64 via a distribution board installed in the house 60. The power conversion device 64 also has a function of converting DC power from the storage battery mounted on the electric vehicle 62 into AC power and outputting the AC power to loads such as electrical appliances in the house 60, as indicated by arrow 68.

[0025] (1-2) Configuration of the power conversion device 64 Fig. 2 shows the external appearance of the power conversion device 64. Referring to Fig. 2, the power conversion device 64 includes a substantially rectangular parallelepiped housing 80, a pair of legs 82 and 84 fixed to the bottom of the housing 80, and a charge / discharge cable 86 connected to a circuit inside the housing 80. A connector 88 is provided at a first end of the cable 86 for connecting the tip of the cable 86 to a charge / discharge port of the on-board storage battery of the electric vehicle 62. A second end of the cable 86 is connected to a circuit inside the power conversion device 64, and the cable 86 is drawn out from the bottom of the housing 80.

[0026] The housing 80 includes a rectangular front panel 102, a rear panel 104 of the same shape as the front panel 102 and disposed parallel to the front panel 102 at a predetermined distance, and a top panel 106, a left side panel 108, a right side panel 110, and a bottom panel 112 fixed to the front panel 102 and the rear panel 104 so as to connect the top, left, right, and bottom edges of the front panel 102 and the rear panel 104 to each other. A pair of left and right legs 82 and 84 are provided on the surface of the bottom panel 112 that faces the exterior of the housing 80. The housing 80 is installed on a horizontal surface (including an approximately horizontal surface, such as the ground) via the legs 82 and 84. As a result, the top panel 106 and the bottom panel 112 are disposed horizontally (including approximately horizontally), and the front panel 102, the rear panel 104, the left side panel 108, and the right side panel 110 are disposed vertically (including approximately vertically).

[0027] The front panel 102, rear panel 104, top panel 106, left side panel 108, right side panel 110, bottom panel 112, and legs 82 and 84 are all made of a metal material having a predetermined strength, such as iron or stainless steel, and the surfaces of these may all be coated with an insulating material.

[0028] 3 shows a vertical cross section of power conversion device 64 taken along line 3-3. Referring to FIG. 3, an internal housing 250 made of sheet metal and having six sides along the inner surface of housing 80 is formed inside housing 80. Inside internal housing 250, power conversion unit 130, system filter circuit unit 132, vehicle filter circuit unit 134, terminal block 136, etc. are housed. All of these are fixed to internal housing 250.

[0029] The power conversion unit 130 includes a metal plate 140 having a first surface and a second surface, a power conversion circuit unit 142 mounted on the first surface of the metal plate 140, a control board 138, and a heat sink 144 mounted on the metal plate 140 so as to contact the second surface of the metal plate 140. The metal plate 140 is formed of a metal material such as iron or stainless steel. The power conversion circuit unit 142 includes a magnetic member 150 such as a transformer and a reactor, and a power conversion circuit 152. The magnetic member 150 and the semiconductor switching elements and reactor on the power conversion circuit 152 constitute a heating element.

[0030] The heat sink 144 is made of a material with high thermal conductivity, such as aluminum, iron, or copper. The heat sink 144 is fixed to a position corresponding to the heat generating element of the power conversion circuit section 142. The heat generated by the heat generating element is transferred to the heat sink 144 via the metal plate 140 or the like, and is dissipated from the heat sink 144. The air flow generated by the air-cooling unit 120 shown in FIG. 1 dissipates this heat to the outside of the internal housing 250 and the housing 80.

[0031] The filter circuit unit 132 and the power conversion unit 130 are arranged to form a stacked structure. The stacked structure refers to a two-story structure in which, when viewed from a direction that maximizes the projected area of ​​the power conversion unit 130, the filter circuit unit 132 and the power conversion unit 130 appear to shield at least a portion of the other and a certain distance is maintained between them. The direction that maximizes the projected area of ​​the power conversion unit 130 refers to, for example, a direction perpendicular to the first surface (second surface) of the metal plate 140 of the power conversion unit 130. This direction is referred to as the stacking direction in this specification. In this embodiment, the stacked structure is formed so that the stacking direction intersects with the direction of gravity when the power conversion device 64 is installed on the ground. The filter circuit unit 132 includes a metal plate 160 having a first surface and a second surface, and a filter circuit 162 mounted on the first surface of the metal plate 160. The metal plate 160 is formed of a metal material such as iron or stainless steel. The upper portion of the metal plate 160 is bent toward the front side of the housing 80 at a right angle when viewed from the side. This bent portion is referred to as the eaves portion in this disclosure. As shown in FIG. 3, the magnetic member 150 is thicker than the power conversion circuit 152. Therefore, by forming the eaves portion, the length of the upper end of the filter circuit unit 132 is slightly shortened, ensuring space for arranging the magnetic member 150. In other words, the filter circuit 132 is arranged so that at least a portion of the magnetic member 150 does not come within the stacking direction. Note that the stacking structure and stacking direction in this embodiment are determined based on the first surface (second surface) of the board of the power conversion unit 130. However, the stacking structure and stacking direction can also be determined based on the filter circuit unit 132 rather than the power conversion unit 130. In this embodiment, most of the metal plate 160 of the filter circuit unit 132 is parallel to the first surface of the metal plate 140 of the power conversion unit 130, so the stacking direction is consistent regardless of which surface is used as the reference. However, if the metal plate 160 of the filter circuit section 132 and the metal plate 140 of the power conversion section are not parallel, the two may not coincide with each other.

[0032] Vehicle filter circuit unit 134 is fixed to the bottom surface of internal housing 250, at a position below power conversion unit 130 and filter circuit unit 132. In other words, filter circuit unit 134 is located away from the stacked structure formed by power conversion unit 130 and filter circuit unit 132 and on the opposite side to the direction in which heat generated by power conversion unit 130 and filter circuit unit 132 moves.

[0033] A wire harness is connected to the terminal block 136 for electrical connection with the filter circuit section 132. Openings (not shown) are formed in the bottom panel 112 and the bottom surface of the internal housing 250, and the terminal block 136 is connected to electrical wiring for electrical connection with the power grid and a load in the house 60 through these openings.

[0034] Power conversion circuit section 142 has a first terminal 154 electrically connected to filter circuit section 132 and a second terminal 156 electrically connected to filter circuit section 134. Filter circuit section 132 has a first terminal 164 electrically connected to terminal block 136 via a wire harness and a second terminal 166 electrically connected to power conversion circuit section 142. Filter circuit section 134 has a first terminal 170 electrically connected to power conversion circuit section 142 and a second terminal 172 electrically connected to the second end of cable 86.

[0035] Filter circuit units 132 and 134 shape and output the input AC power or DC power. Power conversion unit 130 converts the AC power input from filter circuit unit 132 into DC power and outputs it to filter circuit unit 134. Power conversion unit 130 also converts the DC power input from filter circuit unit 134 into AC power and outputs it to filter circuit unit 132.

[0036] The filter circuit section 132 is disposed such that the first terminal 164 is located lower than the second terminal 166. The power conversion circuit section 142 is disposed such that the second terminal 156 is located lower than the first terminal 154. Therefore, the second terminal 156 of the power conversion circuit section 142, the first terminal 170 of the filter circuit section 134, and the first terminal 164 of the filter circuit section 132 are located close to one another. Furthermore, the first terminal 154 of the power conversion circuit section 142 and the second terminal 166 of the filter circuit section 132 are located close to one another. As a result, the length of the wiring connecting the first terminal 170 of the filter circuit section 134 and the second terminal 156 of the power conversion circuit section 142 and the length of the wiring connecting the first terminal 154 of the power conversion circuit section 142 and the second terminal 166 of the filter circuit section 132 can be shortened.

[0037] In this embodiment, the control board 138 is provided on the underside of the top panel 106. The control board 138 may include part of a control circuit that controls the operation of the power conversion unit 130, such as the start of charging and discharging by the power conversion unit 130 and the control of each air-cooling fan in the air-cooling unit 120. Here, the case where the control circuit is provided on the control board 138 has been described, but this is not a limitation and the control board 138 may also be provided on the power conversion circuit 152 or the like. The control board 138 is also not limited to being provided on the top panel 106, but may also be provided on the front panel 102, rear panel 104, left side panel 108, right side panel 110, or the like.

[0038] Next, the internal configuration of the power conversion device 64 will be described in more detail. Fig. 4 is an exploded perspective view showing the internal configuration of the power conversion device 64. Fig. 5 shows a state in which the parts shown in Fig. 4 are partially assembled. With reference to Figs. 4 and 5, the internal housing 250 includes metal plates 182, 184, 186, 188, 190, and 192.

[0039] The metal plate 182 is attached to the metal plate 188 and the metal plate 140, and the metal plate 140 is screwed to the rear panel 104. The metal plate 184 is provided between the rear panel 104 and the power conversion unit 130. The metal plate 186 is provided between the top panel 106 and the power conversion unit 130 and the filter circuit unit 132. The control board 138 is fixed onto the metal plate 186, for example, by screws. The metal plate 188 is provided between the left side panel 108 and the power conversion unit 130 and the filter circuit unit 132. The metal plate 192 is attached to the bottom panel 112. These metal plates may be attached by welding instead of by screws.

[0040] An earth leakage breaker 116 is fixed to the surface of the metal plate 188 facing the left side panel 108. An opening for accessing the earth leakage breaker 116 is formed in the left side panel 108 at a position opposite the earth leakage breaker 116. A cover member 118 is removably attached to this opening in the left side panel 108 with screws. The user can access the earth leakage breaker 116 by removing the cover member 118 from the left side panel 108.

[0041] An air-cooling unit 120 is also attached to the left side panel 108. The air-cooling unit 120 includes a mounting member and multiple (three in this case) air-cooling fans fixed to the mounting member. The multiple air-cooling fans are fixed to the left side panel 108 via the mounting member. The multiple air-cooling fans cool the heat sink 144 by blowing air toward the heat sink 144 through openings (not shown) formed in the metal plate 188. The air-cooling unit 120 is disposed eccentrically toward the rear side of the housing 80 in the front-to-rear direction. This is so that the air flow generated by the air-cooling unit 120 can efficiently remove heat from the heat sink 144 of the power conversion unit 130.

[0042] Openings are formed in right side panel 110 and in metal plate 190 arranged inside right side panel 110 at positions facing air-cooling unit 120. Air sent from air-cooling unit 120 into housing 80 and internal housing 250 passes through the interior of housing 80 and internal housing 250 and is released to the outside of housing 80 through the openings in metal plate 190 and the openings in right side panel 110, discharging heat from inside housing 80 and internal housing 250 to the outside in the process. A wire mesh is fixed to right side panel 110 to prevent foreign matter from entering from the outside.

[0043] Fig. 6 shows a method of assembling the filter circuit unit 132 to the inner housing 250. Note that Fig. 6 shows the main parts in Fig. 4 rotated 90 degrees counterclockwise. In Fig. 6, the filter circuit 162 of the filter circuit unit 132 and the power conversion circuit unit 142 of the power conversion unit 130 are omitted from the illustration.

[0044] 6, a rail 220, which is a member for fixing the filter circuit unit 132 to the metal sheet 190, is fixed to the metal sheet 190 by, for example, welding. A rail 240 for fixing the filter circuit unit 132 to the metal sheet 188 is fixed to the metal sheet 188. The rails 220 and 240 are both elongated plate-like members, and are arranged to extend vertically in FIG. 4, parallel to the upper surface of the metal sheet 184, and facing each other. The rails 220 and 240 are made of a metal material such as iron or stainless steel. The rails 220 and 240 are provided on the right and left sides, respectively, of the interior of the internal housing 250, perpendicular to the surface of the metal sheet 160 of the filter circuit unit 132 excluding the eaves portion.

[0045] When the power conversion unit 130 and the filter circuit unit 132 are attached to the internal housing 250, first, both horizontal ends of the metal plate 140 of the power conversion unit 130 are screwed to the metal plate 190 and the metal plate 188, respectively. As a result, the power conversion unit 130 is fixed inside the internal housing 250 so that the surface on which the power conversion circuit unit 142 is mounted faces the front side of the housing 80. After the power conversion unit 130 is attached, the filter circuit unit 132 is assembled to the internal housing 250 from the front side of the internal housing 250.

[0046] 7 shows a state in which the filter circuit unit 132 is assembled to the internal housing 250. In FIG. 7 as well, the filter circuit 162 of the filter circuit unit 132 and the power conversion circuit unit 142 of the power conversion unit 130 are omitted from the illustration. Referring to FIG. 7, both side portions of the metal plate 160 of the filter circuit unit 132 that intersect with the side on which the eaves portion is formed (i.e., both horizontal end portions excluding the eaves portion) are fixed by screws to the rails 220 and 240, respectively. As a result, the filter circuit unit 132 is fixed closer to the front of the housing 80 than the power conversion unit 130, so that the surface on which the filter circuit 162 is mounted faces the front side of the housing 80.

[0047] Thus, in this embodiment, the power conversion unit 130 and the filter circuit unit 132 are arranged so that they overlap each other when viewed from the front side of the housing 80 and so that their boards are parallel to each other. Specifically, the power conversion unit 130 and the filter circuit unit 132 are arranged so that the first surface of the metal plate 140 and the first surface of the metal plate 160 are parallel to the front and back surfaces of the housing 80. Note that this arrangement is merely an example. The boards of the power conversion unit 130 and the filter circuit unit 132 do not need to be parallel to each other. As long as they form a so-called two-story stacked structure in which they are arranged apart from each other, they do not have to be parallel to each other.

[0048] The power conversion device 64 has the two-story stacked structure described above. Therefore, the filter circuit 162 cannot be disposed so as to be in contact with the heat sink 144. Therefore, heat generated by the filter circuit 162 during operation cannot be released to the heat sink 144. To solve this problem, in this embodiment, as shown in FIG. 6, an opening 260 is formed in the eaves portion of the metal plate 160 to allow heat generated by the filter circuit 162 to be released upward. The eaves portion also has a plurality of openings 262 formed therein to allow a wire harness to pass through for electrically connecting the second terminal 166 of the filter circuit 162 to the power conversion unit 130.

[0049] A wire mesh covering the opening 260 is provided. The size of each of the meshes (small openings) of the wire mesh is not particularly limited as long as it does not interfere with the noise shielding effect of the metal plate 160 and allows heat to be dissipated from the filter circuit 162, but it is preferable that the maximum diameter be 1 mm or more and 10 mm or less. By forming the opening 260 in the eaves portion, heat generated by the filter circuit 162 rises and is dissipated through the opening 260 into the internal housing 250. Note that in this embodiment, the opening 260 is covered with a wire mesh. However, this disclosure is not limited to such an embodiment. For example, instead of the opening 260, this portion of the eaves portion may be punched.

[0050] (1-3) Operation of the power conversion device 64 The power converter 64 operates as follows.

[0051] 1 and 2, the user connects connector 88 of cable 86 to the storage battery of electric vehicle 62, and inputs an instruction to start charging or discharging electricity.

[0052] When the control circuit receives the instruction to start storing power, it causes each unit of power conversion device 64 to operate as follows. Specifically, filter circuit unit 132 suppresses noise components in the AC power received from the power grid and provides the power to power conversion unit 130. Power conversion unit 130 converts the AC power from filter circuit unit 132 into DC power and provides it to filter circuit unit 134. Filter circuit unit 134 suppresses noise components in the DC power from power conversion unit 130 and outputs the DC power to electric vehicle 62 via cable 86 and connector 88, thereby charging the storage battery of electric vehicle 62.

[0053] When the control circuit receives an instruction to start discharging, it causes each unit of the power conversion device 64 to operate as follows. That is, the filter circuit unit 134 shapes the DC power discharged from the storage battery of the electric vehicle 62 and input via the cable 86, and provides the DC power to the power conversion unit 130. The power conversion unit 130 converts the shaped DC power into AC power and provides the AC power to the filter circuit unit 132. The filter circuit unit 132 shapes the AC power output by the power conversion unit 130, and outputs the AC power to a load inside the house 60.

[0054] 3 to 7, while a charging operation or a discharging operation is being performed, the multiple cooling fans of the cooling unit 120 blow air toward the heat sink 144 and the power conversion unit 130 under the control of the control circuit. Heat generated during operation of the power conversion circuit unit 142 mounted on the power conversion unit 130 is dissipated from the heat sink 144 and is air-cooled by the air blown from the multiple cooling fans.

[0055] Meanwhile, the surrounding air is heated by the heat generated during operation of filter circuit 162. The heated air has a lower specific gravity and therefore moves to the upper part of internal housing 250, is discharged to the outside of internal housing 250 through the mesh of the wire mesh that covers opening 260 formed above the laminated structure, and is further discharged to the outside of housing 80 by the air flow from air-cooling unit 120 via heat sink 144. In this way, the heat generated by filter circuit 162 is discharged from filter circuit 162 to the outside of housing 80.

[0056] When receiving an instruction to stop charging or an instruction to stop discharging, the control circuit stops the operations of the power conversion unit 130, the filter circuit unit 132, the filter circuit unit 134, and the air-cooling unit 120.

[0057] According to the first embodiment, in the power converter 64, the power conversion unit 130 and the filter circuit unit 132 are arranged in a stacked structure within the housing 80, as shown in FIG. 3 . That is, the power conversion unit 130 and the filter circuit unit 132 are arranged parallel to each other at a distance from each other so that the metal plate 140 of the power conversion unit 130 and the portion of the metal plate 160 of the filter circuit unit 132 other than the eaves portion overlap when viewed from the front of the housing 80. This allows the size of the housing 80 to be smaller than that of the device disclosed in Patent Document 1, and therefore the height of the housing 80 can be reduced. As a result, the center of gravity of the power converter 64 can be lowered. Therefore, a power converter 64 can be provided that can achieve high stability and compactness due to its low profile.

[0058] 3, the power conversion unit 130 and the filter circuit unit 132 are arranged so that the stacking direction of the stacked structure intersects with the direction of gravity (in this embodiment, perpendicular to the direction of gravity) during operation of the power conversion device 64. This makes it possible to further reduce the height of the housing 80 compared to the device disclosed in Patent Document 1.

[0059] 3, the filter circuit section 132 is provided inside the housing 80 and fixed inside the inner housing 250 made of a metal material. This prevents externally generated electrical noise from affecting the operation of the power conversion device 64, and conversely prevents electrical noise generated during operation of the power conversion device 64 from leaking to the outside.

[0060] 6, the internal housing 250 is provided with an opening 262 for passing a wire harness connected to the second terminal 166 of the filter circuit section 132, and an opening 260 in which a wire mesh having a plurality of meshes (small openings) is provided. This allows the function of the filter circuit section 132 to be realized without impeding the noise shielding effect, and allows heat generated during operation of the filter circuit section 132 to be discharged from the inside of the internal housing 250 to the outside of the internal housing 250 via the meshes (small openings), and further allows the heat to be dissipated to the outside of the housing 80 by the air flow from the air-cooling unit 120. As a result, heat can be dissipated at a lower cost without increasing the size of the internal housing 250, compared to when an air-cooling fan is provided inside the internal housing 250 or when the wire diameter of the coil mounted in the filter circuit section 132 is increased.

[0061] Furthermore, according to the first embodiment, the opening 260 is formed in the internal housing 250 so as to be located above the stacked structure during operation of the power conversion device 64. This allows air that is warmed by heat generated during operation of the filter circuit unit 132 and moves to the upper part of the internal housing 250, i.e., above the stacked structure, to be efficiently discharged to the outside through the opening 260.

[0062] Furthermore, according to the first embodiment, the maximum diameter of each of the meshes (small openings) of the plurality of wire meshes is set to be between 1 mm and 10 mm, which allows for more reliable heat dissipation without reducing the noise shielding effect.

[0063] Furthermore, according to the first embodiment, the power conversion device 64 includes rails 220 and 240 that are provided on the right and left sides, respectively, inside the internal housing 250, and that secure both horizontal ends of the filter circuit unit 132 to the internal housing 250. This allows the filter circuit unit 132 to be arranged with a simple configuration so as to form a so-called two-story stacked structure in which the metal plate 140 of the power conversion unit 130 and the metal plate 160 of the filter circuit unit 132 are spaced apart from each other. As a result, the internal space of the housing 80 can be used efficiently.

[0064] 3 to 5, the filter circuit unit 134 is disposed below the power conversion unit 130 and the filter circuit unit 132 when the power conversion device 64 is in operation. This allows the power conversion unit 130, the filter circuit unit 132, and the filter circuit unit 134 to be efficiently disposed within the inner housing 250 without creating wasted space. This further ensures that the power conversion device 64 is miniaturized. The filter circuit unit 134 is disposed on the opposite side of the direction of movement of air heated by heat generated during operation of the power conversion unit 130 and the filter circuit unit 132. This allows the filter circuit unit 134 to stably function without being affected by this air.

[0065] Furthermore, according to the first embodiment, as shown in FIG. 3 , the length of the wiring connecting the first terminal 170 of the filter circuit unit 134 to the second terminal 156 of the power conversion circuit unit 142 and the length of the wiring connecting the first terminal 154 of the power conversion circuit unit 142 to the second terminal 166 of the filter circuit unit 132 can be shortened. Furthermore, the cable 86 is connected to the second terminal 172 of the filter circuit unit 134 and is drawn out from the bottom of the housing 80 together with a cable connecting the first terminal 164 of the filter circuit unit 132 to the terminal block 136. This arrangement can shorten the wiring inside the power conversion device 64 and may also shorten the wiring connecting to the power grid. Furthermore, the second terminal of the filter circuit unit 134 connected to the cable 86 is located downward. This lowers the center of gravity of the power conversion device 64. Furthermore, because the cable 86 is drawn out from the bottom of the housing 80, shaking of the power conversion device 64 when the cable 86 is operated can be prevented. As a result, the power conversion device 64 is less likely to tip over.

[0066] 3 to 5, the filter circuit section 134 is disposed away from the stacked structure of the power conversion section 130 and the filter circuit section 132 and on the opposite side to the direction in which heat generated by the power conversion section 130 and the filter circuit section 132 moves during operation of the power conversion device 64. This allows the function of the filter circuit section 134 to be realized more stably.

[0067] 3, the power conversion device 64 further includes a heat sink 144 provided in contact with the power conversion section 130, and an air-cooling unit 120 fixed to the housing 80 and blowing air toward the heat sink 144. This allows the air inside the housing 80 and the inner housing 250 to be efficiently cooled.

[0068] (2) Second embodiment In the first embodiment described above, the power conversion unit 130 and the filter circuit unit 132 are arranged side by side in this order from the rear side to the front side of the housing 80. However, this disclosure is not limited to such an embodiment. FIG. 8 shows a part of the internal structure of a power conversion device 300 according to a second embodiment of this disclosure. In the following explanation, differences between the power conversion device 300 according to the second embodiment and the power conversion device 64 according to the first embodiment will be explained, and the same configuration will not be explained repeatedly.

[0069] (2-1) Configuration of the power conversion device 300 8, the main components of the power converter 300 include an internal housing (not shown), and an upper circuit unit 312 and a lower circuit unit 314 that are provided inside the internal housing and form a two-story stacked structure. Note that FIG. 8 shows the power converter 300 rotated 90 degrees counterclockwise. That is, when the power converter 300 is in use, the upper circuit unit 312 and the lower circuit unit 314 are fixed inside the internal housing so that the upper left direction in FIG. 8 is the top and the lower right direction is the bottom.

[0070] Upper-stage circuit unit 312 is formed from a metal material such as iron or stainless steel, and includes a metal plate 320 having a first surface and a second surface, a power conversion circuit 321 mounted on a portion of the first surface of metal plate 320, a vehicle filter circuit 322 mounted on the remaining portion of the first surface of metal plate 320, and a heat sink (see FIGS. 9 and 11; not shown in FIG. 8) provided on a portion of the second surface of metal plate 320 corresponding to power conversion circuit 321. Power conversion circuit 321 includes a circuit board 324 and a heat-generating circuit unit 326 including a magnetic member such as a transformer. Circuit board 324 also generates heat, but the amount of heat generated is smaller than that of heat-generating circuit unit 326.

[0071] The lower circuit section 314 includes a metal plate 330 having a first surface and a second surface, which forms a part of the internal housing, and a filter circuit 332 for the system, which is mounted on the first surface of the metal plate 330. In other words, the metal plate 330 functions as a substrate for the filter circuit 332.

[0072] The power converter 300 further includes a metal plate 310 for fixing the upper stage circuit section 312 to the internal housing.

[0073] FIG. 9 shows a simplified horizontal cross section of the power converter 300. FIG. 9 shows a cross section taken along line 9-9 in FIG. 8. FIGS. 10 and 11 show simplified vertical cross sections of the power converter 300. FIG. 10 shows a cross section taken along line 10-10 in FIG. 9. FIG. 11 shows a cross section taken along line 11-11 in FIG. 9. FIG. 10 corresponds to a cross section of the power converter 300 shown in FIG. 8 taken along a plane slightly away from and parallel to the first surface of the metal plate 320.

[0074] 9, the internal housing of the power conversion device 300 includes metal plates 372, 374, and 376 in addition to the above-described metal plate 330. In FIG. 9, the metal plate 330 forms the back surface of the internal housing. The metal plate 372 forms the left side surface of the internal housing. The metal plate 374 forms the right side surface of the internal housing. The metal plate 376 forms the front surface of the internal housing. The metal plate 320 is fixed to the metal plates 372 and 374 at a certain distance from the metal plate 330 so as to be parallel to the metal plate 330.

[0075] The power conversion device 300 further includes a metal plate 378. The metal plate 378 is provided on the first surface of the metal plate 330 so as to separate the filter circuit 332 and the heat sink 370. As described above, the heat sink 370 is mounted on the second surface of the metal plate 320. The heat sink 370 is fixed to a position on the metal plate 320 corresponding to the heat-generating circuit section 326. Heat generated by the heat-generating circuit section 326 is transferred to the heat sink 370 and dissipated from the heat sink 370.

[0076] In the lower-stage circuit unit 314, the filter circuit 332 is disposed on the first surface of the metal plate 330 in an area that does not interfere with the heat sink 370 when the upper-stage circuit unit 312 is disposed above the lower-stage circuit unit 314. In the second embodiment, an air-cooling unit similar to the air-cooling unit 120 shown in FIG. 1 is attached to the metal plate 330 so that the air flow is directed toward the heat sink 370. As a result, the exhaust heat from the heat-generating circuit unit 326 is efficiently discharged to the outside of the housing via the heat sink 370.

[0077] 10, the internal housing of the power conversion device 300 further includes a metal plate 311 and a metal plate 390. Both ends of the metal plate 311 are fixed to the upper ends of the metal plates 372 and 374 in FIG. 10. Both ends of the metal plate 390 are fixed to the lower ends of the metal plates 372 and 374 in FIG. 10. As a result, the internal housing is formed by the metal plates 330, 372, 374, 376, 311, and 390 shown in FIGS. 9 and 10.

[0078] The filter circuit 322 is disposed on the first surface of the metal plate 320, at a position below the heat-generating circuit section 326. That is, the filter circuit 322 is disposed in the opposite direction to the direction in which exhaust heat from the heat-generating circuit section 326 moves (upward in FIG. 10 ) during operation of the power conversion device 300. Therefore, the possibility that the heat from the heat-generating circuit section 326 will have an effect on the filter circuit 322 is reduced.

[0079] The power conversion circuit 321 of the upper stage circuit unit 312 has a first terminal electrically connected to the filter circuit 332 and a second terminal electrically connected to the filter circuit 322. The filter circuit 332 of the lower stage circuit unit 314 has a first terminal electrically connected to the terminal block 136 via a wire harness and a second terminal electrically connected to the power conversion circuit 321 of the upper stage circuit unit 312. The filter circuit 322 of the upper stage circuit unit 312 has a first terminal electrically connected to the power conversion circuit 321 of the upper stage circuit unit 312 and a second terminal electrically connected to a second end of the cable 86 (see FIGS. 1 and 4).

[0080] The filter circuit 332 and the filter circuit 322 shape and output the input AC power or DC power. The power conversion circuit 321 of the upper circuit section 312 receives AC power from the filter circuit 332, converts it into DC power, and outputs it to the filter circuit 322. The power conversion circuit 321 also receives DC power from the filter circuit 322, converts it into AC power, and outputs it to the filter circuit 332.

[0081] Lower-stage circuit unit 314 is disposed on the first surface of metal plate 330 such that the first terminal of filter circuit 332 is positioned lower than the second terminal. Upper-stage circuit unit 312 is disposed such that the second terminal of filter circuit 322 is positioned lower than the first terminal. Upper-stage circuit unit 312 is disposed substantially parallel to lower-stage circuit unit 314 so as to overlap the entire lower-stage circuit unit 314. At this time, upper-stage circuit unit 312 is fixed closer to the front than lower-stage circuit unit 314 so that the first surface of metal plate 320, i.e., the surface on which power conversion circuit 321 and filter circuit 322 are mounted, faces the front side of the housing.

[0082] In this way, the upper circuit section 312 and the lower circuit section 314 are arranged side by side in this order in the power conversion device 300. The upper circuit section 312 and the lower circuit section 314 are also arranged spaced apart and substantially parallel to each other so as to overlap each other when viewed from the front of the power conversion device 300.

[0083] 12 is a diagram showing an example of openings 510, 512, and 514 formed in metal plate 320. Referring to FIG. 12, metal plate 320 corresponding to the boundary between upper-stage circuit portion 312 and lower-stage circuit portion 314 is formed with opening 510 for dissipating heat from upper-stage circuit portion 312, opening 512 for a wire harness connecting upper-stage circuit portion 312 and lower-stage circuit portion 314, and opening 514 for a wire harness connecting lower-stage circuit portion 314 to a terminal block for a system. A wire mesh covering opening 510 is provided. The size of each of the multiple meshes (small openings) of the wire mesh is not particularly limited as long as it does not interfere with the noise shielding effect and allows heat to be dissipated from filter circuit 332, but it is preferable that the maximum diameter be 1 mm or more and 10 mm or less.

[0084] (2-2) Operation of the power conversion device 300 The operation of the power conversion device 300 will be described below.

[0085] When a command to start charging is received, the filter circuit 332, under control of a control circuit (not shown), shapes the AC power received from the power grid via a terminal block and provides the power to the power conversion circuit 321. The power conversion circuit 321, under control of the control circuit, converts the AC power from the filter circuit 332 into DC power and provides the DC power to the filter circuit 322. The filter circuit 322 shapes the converted DC power and outputs it to the storage battery of the electric vehicle 62 via the connector 88 of the cable 86. As a result, the storage battery of the electric vehicle 62 is charged.

[0086] When an instruction to start discharging is received, filter circuit 322, under control of a control circuit not shown, receives DC power from the storage battery of electric vehicle 62 via cable 86, shapes the power, and provides it to power conversion circuit 321. Power conversion circuit 321, under control of the control circuit, converts the DC power received from filter circuit 322 into AC power and provides it to filter circuit 332. Filter circuit 332 shapes the AC power received from power conversion circuit 321 and outputs it to a load in user's house 60.

[0087] As the charging or discharging operation is performed, the air-cooling unit blows air toward the portion where the heat sink 370 is located. Heat generated during operation of the filter circuit 332 of the lower circuit section 314 is discharged from the opening 510 to the upper circuit section 312, and is then discharged to the outside of the housing by the air blown from the heat sink 370 and the air-cooling unit.

[0088] On the other hand, the air heated by the heat generated by the filter circuit 322 of the upper circuit section 312 and the air heated by part of the heat generated by the power conversion circuit 321 are both discharged to the outside of the housing by air from the air-cooling unit via the heat sink 370.

[0089] Thus, in the power conversion device 300 according to the second embodiment, the upper-stage circuit unit 312 and the lower-stage circuit unit 314 are disposed parallel to and spaced apart from each other so that at least a portion of the upper-stage circuit unit 312 and the lower-stage circuit unit 314 overlap when viewed from the front of the power conversion device 300, forming a two-story stacked structure. Furthermore, the lower-stage circuit unit 314 is disposed in an area that does not interfere with the heat sink 370. This reduces wasted space within the housing. Furthermore, the height of the housing that houses the main components of the power conversion device 300 can be reduced. This allows the center of gravity of the power conversion device 300 to be lowered. Furthermore, in this embodiment, the lower-stage circuit unit 314, the power conversion circuit 321, and the upper-stage circuit unit 312 are disposed in a folded-back configuration along the direction of current flow. Furthermore, the connection portion of the cable 86 for connection to the vehicle battery and the connection portion for connection to the grid are both disposed at the bottom of the power conversion device 300. As a result, the wire harness for connecting the internal circuits of the power conversion device 300 to each other can be shortened. Furthermore, the cable 86 for connection to the vehicle battery is drawn out from the bottom of the housing of the power conversion device 300, reducing the risk of the power conversion device 300 being shaken by manipulation of the cable. As a result, it is possible to provide a power conversion device 300 that is less likely to tip over, and that can be made highly stable and compact.

[0090] Furthermore, air heated by heat generated by the filter circuit 332 during operation of the lower circuit unit 314 is discharged toward the upper circuit unit 312 through the mesh of the wire mesh covering the opening 510, and is then discharged to the outside of the housing by the heat sink and the air-cooling unit. Therefore, heat generated during operation of the power conversion device 300 can be discharged to the outside without impeding the noise shielding effect. As a result, heat can be dissipated efficiently and at reduced cost without increasing the size of the housing of the power conversion device 300.

[0091] (3) Other variations In the first and second embodiments, the power conversion device 64 and the power conversion device 300 are used when charging or discharging a storage battery of the electric vehicle 62. However, this disclosure is not limited to such embodiments. For example, the power conversion device 64 and the power conversion device 300 may be used when discharging a storage battery used in a solar power generation system.

[0092] Although the power conversion device 64 and the power conversion device 300 are capable of power conversion in both charging and discharging operations, this disclosure is not limited to such an embodiment. For example, the power conversion device 64 and the power conversion device 300 may be configured to be capable of power conversion only in either charging or discharging.

[0093] Although the disclosure has been described above by explaining the embodiments, the above-described embodiments are merely examples, and the disclosure is not limited to only the above-described embodiments. The scope of the disclosure is defined by the claims in the claims, taking into consideration the description of the detailed description of the invention, and includes all modifications within the meaning and scope equivalent to the wordings described therein. [Explanation of symbols]

[0094] 50 Energy Storage System 60 Housing 62 Electric Vehicles 64,300 Power conversion equipment 66, 68 Arrows 80 cabinets 82, 84 Legs 86 Cable 88 Connector 102 Front Panel 104 Rear Panel 106 Top panel 108 Left side panel 110 Right side panel 112 Bottom Panel 116 Earth leakage breaker 118 Cover member 120 Air Cooling Unit 130 Power conversion unit 132, 134 Filter circuit section 136 Terminal block 138 Control Board 142 Power conversion circuit section 144, 370 heat sink 150 Magnetic components 152, 321 Power conversion circuits 154, 164, 170 1st terminal 156, 166, 172 2nd terminal 162, 322, 332 filter circuits 140, 160, 182, 184, 186, 188, 190, 192, 310, 311, 320, 330, 372, 374, 376, 378, 390 Sheet metal 220, 240 rail 250 Internal Housing 260, 262, 510, 512, 514 aperture 312 Upper circuit section 314 Lower circuit section 324 Circuit Board 326 Heating circuit section

Claims

1. The housing and a power conversion unit disposed within the housing and having a first terminal and a second terminal; a first filter circuit unit disposed in the housing so as to form a stacked structure with the power conversion unit, the first filter circuit unit having a first terminal and a second terminal connected to the first terminal of the power conversion unit; a second filter circuit unit disposed within the housing and having a first terminal connected to the second terminal of the power conversion unit, and a second terminal;

2. 2. The power conversion device according to claim 1, wherein the power conversion unit and the first filter circuit unit are arranged such that a stacking direction of the stacked structure intersects with a direction of gravity when the power conversion device is in operation.

3. The device further includes an inner housing made of a metal material and provided inside the housing, The power conversion device according to claim 1 or 2, wherein the first filter circuit section is fixed inside the internal housing.

4. 4. The power conversion device according to claim 3, wherein the internal housing is formed with a first opening for passing a harness connected to the first filter circuit portion, and at least one second opening different from the first opening.

5. The power converter according to claim 4 , wherein the second opening is formed in the inner housing so as to be located above the stacked structure when the power converter is in operation.

6. The power conversion device according to claim 4 , wherein the second opening has a plurality of small openings, and each of the plurality of small openings has a maximum diameter of not less than 1 mm and not more than 10 mm.

7. 4. The power conversion device according to claim 3, further comprising: a first fixing member and a second fixing member provided on two different inner surfaces of the internal housing, the first fixing member and the second fixing member configured to fix two different ends of the first filter circuit unit to the internal housing.

8. The power conversion device according to claim 1 , wherein the second filter circuit unit is disposed below the power conversion unit and the first filter circuit unit when the power conversion unit is in operation.

9. the first filter circuit section is arranged such that the first terminal of the first filter circuit section is located lower than the second terminal of the first filter circuit section; The power conversion device according to claim 8 , wherein the second filter circuit section is arranged such that the second terminal of the second filter circuit section is located lower than the first terminal of the second filter circuit section.

10. 2. The power conversion device according to claim 1, wherein the second filter circuit section is arranged away from the stacked structure of the power conversion section and the first filter circuit section and on an opposite side to a direction in which heat generated by the power conversion section and the first filter circuit section moves during operation of the power conversion device.

11. a heat sink provided in contact with the power conversion unit; The power conversion device according to claim 1 , further comprising: an air-cooling unit fixed to the housing and blowing air toward the heat sink.

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