Cooling system for power conversion device

Abstract

The present invention relates to a cooling system for a power conversion device, which comprises: an enclosure; a plurality of power conversion modules installed in the enclosure to convert between direct current and alternating current; and a cooling module installed to be in surface contact with the power conversion modules, and is provided with an inlet through which cooling fluid is introduced and an outlet through which the cooling fluid is discharged, and a plurality of branch flow passage parts connected between the inlet and the outlet to allow the cooling fluid to be distributed to each of the power conversion modules to exchange heat, wherein the plurality of branch flow passage parts are arranged in parallel for respective phases.

Description

Cooling system of power converter

[0001] The present invention relates to a cooling system for a power converter, and more specifically, to a cooling system for a power converter utilizing a cooling fluid and a parallel cooling method.

[0002] Generally, power converters receive direct current (DC) power as input and convert it into alternating current (AC) for output. While energy stored using solar or renewable sources is direct current, the power actually used for household and industrial purposes is primarily AC; therefore, power converters are necessary to convert and supply this power.

[0003] In this case, the capacity that a power converter can convert at once or the capacity of AC power that can be stored at once can be referred to as the “power conversion capacity.”

[0004] Power conversion devices can be installed and used in Energy Storage Systems (ESS). The power conversion capacity of a power conversion device is an important factor in determining the capacity of the ESS in which the device is installed. It is natural that energy storage devices with a larger power conversion capacity per unit volume are more efficient.

[0005] Inverters and filters can be cited as components of a power conversion device. The inverter performs the function of converting the input DC power into AC power. The filter performs filtering to remove noise from the AC power converted by the inverter.

[0006] A power conversion device according to the prior art includes a DC panel that receives DC power, an inverter panel that converts DC power into AC power, a filter panel for filtering the converted AC power, and an AC panel for outputting the converted AC power.

[0007] At this time, the DC panel receives direct current power, and the AC panel receives alternating current power.

[0008] The panels of these power conversion devices may be provided in multiple numbers or integrated into a single panel.

[0009] FIG. 1 shows an inverter device (10), which is a major component of a power conversion device according to the prior art. FIG. 2 is an internal configuration diagram of FIG. 1. The inverter device (10) applied to the power conversion device has a first device part (20) including an inverter module (21) and a second device part (30) including a filter (31).

[0010] The first device part (20) and the second device part (30) are installed in a cabinet-shaped housing (11).

[0011] The inverter module (21) includes a capacitor (22), a power conversion module (23), and a heat sink (24).

[0012] Each device part (20, 30) is provided with a blower part (25, 35) for air cooling. An exhaust port (26, 36) is provided on the rear surface of the housing (11).

[0013] As described above, in the power conversion device that converts DC and AC, a power conversion module (23) is used for each phase in the conversion section that converts DC and AC to each other. Since a lot of heat is generated in these power conversion modules (23), a heat dissipation or cooling device is required.

[0014] The conventional heat sink (24) and blower (25) used in the power conversion device are air-cooled cooling systems that release heat using the flow of air.

[0015] However, such air-cooled cooling systems have the disadvantages of occupying a large amount of space, having relatively poor cooling efficiency, and generating significant noise.

[0016] In particular, since the amount of heat generated in high-capacity power conversion modules (23) is large, a design is required to effectively dissipate it. In addition, it is important to maintain the heat generated in each phase of the power conversion module at a uniform temperature.

[0017] Reference can be made to Korean Registered Patent No. 10-2222270, 'Power Conversion Device', as prior art.

[0018] The present invention was devised to solve the aforementioned problems, and its purpose is to provide a cooling system for a power converter with improved cooling efficiency.

[0019] In addition, it provides a cooling system for a power converter that effectively dissipates heat generated in each phase's power conversion module and maintains it at the same thermal equilibrium temperature.

[0020] In addition, it provides a cooling system for power converters that occupies minimal space.

[0021] In addition, it provides a cooling system for power converters that generates low noise.

[0022] A cooling system for a power conversion device according to one embodiment of the present invention comprises: an enclosure; a plurality of power conversion modules installed within the enclosure and mutually converting direct current and alternating current; and a cooling module installed to be in contact with the power conversion modules, wherein the cooling module comprises an inlet for receiving a cooling fluid and an outlet for receiving the cooling fluid; and a plurality of branching passages connected between the inlet and the outlet to allow the cooling fluid to be branched to each of the power conversion modules for heat exchange, and the plurality of branching passages are arranged in parallel for each phase.

[0023] Here, the above-mentioned enclosure is provided with a fluid injection part connected to the inlet to supply the cooling fluid; and a fluid discharge part connected to the outlet to discharge the cooling fluid.

[0024] In addition, a fluid injection passage through which the cooling fluid flows is formed through the fluid injection section, and an inflow air circulation passage is provided adjacent to the fluid injection passage.

[0025] In addition, a fluid discharge passage through which the cooling fluid flows is formed through the fluid discharge section, and a discharge air circulation path is provided adjacent to the fluid discharge passage.

[0026] In addition, an inlet pipe connected to the inlet is provided at the middle or end portion of the fluid injection passage.

[0027] In addition, a discharge pipe connected to the outlet is provided at the middle or end of the fluid discharge passage.

[0028] In addition, the branch inlets leading from the above inlet to the branch flow path of each phase are formed with the same diameter, the same height from the ground, and the same volume.

[0029] Additionally, the cooling module comprises an upper cooling plate that is in direct contact with the power conversion module and is provided with the branching channel; and a lower cooling plate that is coupled to the upper cooling plate and is provided with the inlet and outlet.

[0030] In addition, the upper cooling plate and the lower cooling plate are sealedly joined by a welding method.

[0031] In addition, the inlet and outlet are formed as grooves on the lower surface of the lower cooling plate, and the inlet and outlet are positioned at different horizontal and vertical positions on the lower surface of the lower cooling plate.

[0032] In addition, a first main flow path connected to the inlet and a second main flow path connected to the outlet are arranged in parallel at a predetermined interval in the lower cooling plate.

[0033] In addition, the inlet and the first main channel are arranged along the centerline in the width direction of the lower surface of the lower cooling plate.

[0034] In addition, at one end of the first main flow path and the second main flow path, a plug insertion part is provided that extends to one side of the lower cooling plate and opens, and a plug is provided in the plug insertion part.

[0035] In addition, a branch inlet penetrating the upper surface of the lower cooling plate is formed in each phase of the first main flow path, and a branch outlet penetrating the upper surface of the lower cooling plate is formed in each phase of the second main flow path.

[0036] In addition, the branch inlet and branch outlet are positioned at different horizontal locations on the lower surface of the lower cooling plate.

[0037] In addition, the branch inlet and branch outlet are each positioned at the bottom of the power conversion module.

[0038] Additionally, the branch flow path includes a branch start section connected to the branch inlet; a branch end section connected to the branch outlet; and a branch intermediate section connecting the branch start section and the branch end section.

[0039] In addition, the aforementioned middle section of the branch is formed in a spiral shape that expands outward while rotating in a swirling form around the branch starting point.

[0040] In addition, the branching channel is formed as a groove on the lower surface of the upper cooling plate.

[0041] In addition, the transverse cross-section of the branching channel is formed in a semicircular or 'U' shape.

[0042] In addition, the aforementioned branching intermediate section alternately connects straight sections and curved sections.

[0043] In addition, an outer groove is formed on the lower surface of the upper cooling plate to surround the branch flow paths of each phase.

[0044] The cooling system of a power converter according to one embodiment of the present invention applies a cooling method based on heat exchange of a cooling fluid, and thus has superior cooling performance compared to an air-cooled cooling system.

[0045] In particular, cooling performance is further enhanced when water is applied as the cooling fluid.

[0046] In addition, since no air flow space is required, the space occupied by the cooling system is reduced.

[0047] In addition, since a cooling fan is not used, noise generation is reduced.

[0048] Here, a cooling module is provided in contact with the power conversion module of each phase, and the cooling fluid supplied from the cooling module to the power conversion module of each phase is provided with the same temperature and the same pressure so that the thermal equilibrium temperature of each phase is uniformly maintained.

[0049] Furthermore, the branch flow paths of each phase are formed such that cooling fluid is supplied from the center of the power conversion module and flows outward, allowing for efficient heat exchange in areas with high heat generation.

[0050] FIG. 1 is an inverter device of a power conversion device according to the prior art.

[0051] Figure 2 is an internal configuration diagram of Figure 1.

[0052] FIG. 3 is a perspective view of a power conversion device according to one embodiment of the present invention.

[0053] FIG. 4 is an internal configuration diagram of a power conversion device according to one embodiment of the present invention.

[0054] Figure 5 is a perspective view with some components removed from Figure 3.

[0055] Figure 6 is an exploded perspective view of the lower plate of the enclosure and the cooling module in Figure 5.

[0056] Figure 7 is an exploded perspective view of the cooling module.

[0057] FIGS. 8 to 11 are a lower perspective view, a side perspective view, a top view, and a cross-sectional view AA of the lower cooling plate among the cooling modules.

[0058] FIGS. 12 to 14 are a perspective view, a bottom view, and a BB cross-sectional view of the upper cooling plate among the cooling modules.

[0059] FIG. 15 is a perspective view showing the fluid flow path of the cooling module.

[0060] FIG. 16 is another embodiment of the spiral portion of the cooling module.

[0061] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, this description is intended to be detailed enough for a person skilled in the art to easily practice the invention, and it does not imply that the technical scope and concept of the present invention are limited by these drawings.

[0062] The terms "part" or "part" used to refer to components in this invention are not used for any limiting purpose and may be omitted.

[0063] FIG. 3 is a perspective view of a power conversion device according to one embodiment of the present invention, and FIG. 4 is an internal configuration diagram of a power conversion device according to one embodiment of the present invention. With reference to the drawings, a cooling system of a power conversion device according to each embodiment of the present invention will be described in detail.

[0064] A cooling system of a power conversion device according to one embodiment of the present invention comprises a plurality of power conversion modules (520) that convert direct current into alternating current; and a cooling module (1000) installed to be in contact with the power conversion modules (520). The cooling module (1000) includes an inlet (1115) into which a cooling fluid is introduced and an outlet (1125) into which the cooling fluid is discharged; and a branching channel (1210) between the inlet (1115) and the outlet (1125) that allows the cooling fluid to be branched to each of the power conversion modules (520) for cooling, which are arranged in parallel for each phase.

[0065] First, let us examine the basic configuration of the power conversion device (100). FIG. 3 shows a perspective view of a power conversion device according to one embodiment of the present invention, and FIG. 4 shows an internal configuration diagram of a power conversion device according to one embodiment of the present invention.

[0066] The power conversion device (100) includes a DC input section (200), an input rectifier section (250), an input protection section (300), an input switch section (350), a storage section (400), a power conversion section (500), a reactor section (600), an output switch section (650), an output protection section (700), an output rectifier section (750), and an AC output section (800).

[0067] The DC input section (200) receives external DC. Energy extracted from sources such as solar power and new / renewable energy is stored as DC. These DC currents are stored in an energy storage device (ESS), etc. The DC input section (200) is connected to a DC storage device, such as an energy storage device or a battery, so that DC power is input.

[0068] The input rectifier (250) rectifies the DC current received through the DC input (200). A rectifier filter may be provided for this rectification.

[0069] An input protection unit (300) is provided to protect the incoming DC current. If the incoming DC current is an abnormal current or a fault current, the input protection unit (300) operates to block the incoming current. A single-use fuse or a repeatedly used circuit breaker may be applied as this input protection unit (300).

[0070] The input switch unit (350) is provided to open and close the power supply according to the user's intention. The input switch unit (350) is also commonly referred to as a relay.

[0071] A storage unit (400) is provided to temporarily store the incoming current. A capacitor may be used as such a storage unit (400).

[0072] The power conversion unit (500) is a core part that converts the input direct current (DC) into alternating current (AC). The power conversion unit (500) includes a power board (510) and a power conversion module (520).

[0073] The reactor section (600) is a device that stabilizes the converted alternating current to prevent sudden currents, such as sudden currents, from occurring. The reactor section (600) is composed of a reactance coil, etc. Since there is heat generated in the reactor section (600), a cooling system may be applied.

[0074] The output switch unit (650) is provided to open and close the power supply according to the user's intention. The output switch unit (650) is also commonly referred to as a relay.

[0075] An output protection unit (700) is provided to protect the converted alternating current. If the converted alternating current is an abnormal current or a fault current, the output protection unit (700) operates to cut off the flow of current. A single-use fuse or a repeatedly used circuit breaker may be applied as this output protection unit (700).

[0076] The output rectifier (750) rectifies the converted alternating current. A rectifier filter may be provided for this rectification.

[0077] The AC output section (800) is provided to connect the converted AC to an external line. In the case of a three-phase circuit, the output AC is separated into R, S, and T three phases and output.

[0078] The power conversion device (100) is housed in an enclosure (110). The power conversion device (100) may be composed of one panel or multiple panels.

[0079] The outer casing (110) may be formed in the shape of a cabinet. The outer casing (110) may also be referred to as a housing. The outer casing (110) may be formed from a metal material such as steel or a plastic material such as a synthetic resin. The outer casing (110) must have durability, such as rigidity, to support components installed inside.

[0080] The power converter (100) is described based on the assumption that it is installed in a lying position.

[0081] The outer casing (110) is formed in the shape of a rectangular prism and may be equipped with an upper plate (111), a lower plate (112), a side plate (113), a rear plate (115), and a front plate (116).

[0082] A support frame (120) is provided at the bottom of the bottom plate (112). The support frame (120) may be made of a metal material such as steel. The support frame (120) may be composed of a '□'-shaped, 'I'-shaped, or 'H'-shaped beam.

[0083] The support frame (120) supports the power conversion device (100). The support frame (120) may be made of a metal material with consideration for rigidity to provide sufficient support.

[0084] FIG. 5 is a perspective view with some components removed from FIG. 3, and FIG. 6 is a separated perspective view of the lower plate of the enclosure and the cooling module from FIG. 5.

[0085] A fluid injection part (130) and a fluid discharge part (140) are provided on the upper part of the lower plate (112).

[0086] The fluid injection unit (130) may be provided in the form of a frame or a beam. The fluid injection unit (130) is positioned on one side of the bottom plate (112). For example, FIG. 5 shows the fluid injection unit (130) positioned on the right side of the bottom plate (112).

[0087] A fluid injection passage (131) is formed through the fluid injection section (130) along the longitudinal direction. Cooling fluid is supplied to the cooling module (1000) through the fluid injection passage (131).

[0088] In the fluid injection section (130), an inflow air circulation path (133) is provided adjacent to the fluid injection passage (131). The inflow air circulation path (133) is formed through the side of the fluid injection passage (131). The cooling fluid in the fluid injection passage (131) also obtains the effect of air cooling through the air flowing in the inflow air circulation path (133).

[0089] The fluid injection section (130) is provided with a supply pipe section (135) at the inlet of the fluid injection passage (131). The supply pipe section (135) may be provided as a pipe. The supply pipe section (135) is connected to an external oil supply pipe or water supply pipe.

[0090] In the fluid injection section (130), an inlet pipe section (1010) is provided at the middle or end of the fluid injection passage (131). The inlet pipe section (1010) may be provided as a circular pipe. The inlet pipe section (1010) is connected to the inlet port (1115) of the cooling module (1000) (see FIG. 8).

[0091] The fluid discharge section (140) may be provided in the form of a frame or a beam. The fluid discharge section (140) is positioned on one side of the bottom plate (112). For example, FIG. 5 shows the fluid discharge section (140) positioned on the left side of the bottom plate (112).

[0092] A fluid discharge passage (141) is formed through the fluid discharge section (140) along the longitudinal direction. The cooling fluid discharged from the cooling module (1000) is discharged to the outside along the fluid discharge passage (141).

[0093] In the fluid discharge section (140), an exhaust air circulation path (143) is provided adjacent to the fluid discharge passage (141). The exhaust air circulation path (143) is formed through the side of the fluid discharge passage (141). The cooling fluid in the fluid discharge passage (141) also obtains the effect of air cooling through the air flowing in the exhaust air circulation path (143).

[0094] The fluid discharge section (140) is provided with a discharge pipe section (145) at the inlet of the fluid discharge passage (141). The discharge pipe section (145) may be provided as a circular pipe. The discharge pipe section (145) is connected to an external discharge pipe.

[0095] In the fluid discharge section (140), an outlet pipe section (1020) is provided at the middle or end of the fluid discharge passage (141). The outlet pipe section (1020) may be provided as a pipe. The outlet pipe section (1020) is connected to the outlet (1125) of the cooling module (1000).

[0096] The core part of the power conversion device is the power conversion unit (500). The power conversion unit (500) is a part that converts the applied direct current into alternating current, and the power conversion device is also called an inverter device.

[0097] The power conversion unit (500) has a power substrate (510).

[0098] The power board (510) may be provided as a PCB board. The power board (510) incorporates circuits necessary for power conversion, including a power conversion module (520). The power board (510) is configured with circuits for converting direct current and alternating current to each other.

[0099] The power substrate (510) can be formed as a rectangular plate. The power substrate (510) is illustrated in FIG. 5. A power conversion module (520) is mounted on the upper or lower surface of the power substrate (510).

[0100] A power conversion module (520) is provided on a power substrate (510). The power conversion module (520) is provided on each of a plurality of phases. For example, the figure shows a power conversion module (520) composed of three phases: an R-phase power conversion module (520a, first phase power conversion module), an S-phase power conversion module (520b, second phase power conversion module), and a T-phase power conversion module (520c, third phase power conversion module).

[0101] The power conversion module (520) can be composed of an IGBT, Si IGBT, IGCT, or MOSFET. In particular, the power conversion module (520) can be composed of a Si MOSFET. Si MOSFETs have the advantage of reducing switching losses and miniaturizing the cooling device. In addition, Si MOSFETs enable high-frequency driving that is impossible with IGBTs, which is advantageous for miniaturizing components.

[0102] A cooling module (1000) is provided at the bottom of the power conversion module (520). The cooling module (1000) is provided to cool the heat generated in the power conversion module (520). In an embodiment of the present invention, the cooling module (1000) utilizes a cooling system based on fluid cooling through heat exchange of fluid.

[0103] Here, water can be used as the cooling fluid. That is, a water cooling system is applied. Water has a high specific heat, so it offers excellent cooling efficiency.

[0104] FIG. 7 is an exploded perspective view of the cooling module. FIGS. 8 to 11 are a bottom perspective view, a side perspective view, a top view, and a cross-sectional view AA of the lower cooling plate in the cooling module. Here, for better understanding, the branching flow path (1210) of the upper cooling plate is indicated by a dashed line in FIG. 10.

[0105] Also, FIGS. 12 to 14 are a perspective view, a bottom view, and a BB cross-sectional view of the upper cooling plate among the cooling modules.

[0106] The above cooling module (1000) is composed of an upper cooling plate (1200) that is in direct contact with the power conversion module (520) and a lower cooling plate (1100) that is provided with a main flow path (1110, 1120) through which cooling fluid is supplied.

[0107] The upper cooling plate (1200) and the lower cooling plate (1100) are joined together to form a single unit. The upper cooling plate (1200) and the lower cooling plate (1100) are joined by welding or the like for a sealed connection.

[0108] First, the lower cooling plate (1100) will be described.

[0109] The lower cooling plate (1100) is made of a material with high thermal conductivity, such as aluminum. The lower cooling plate (1100) is formed of a material with excellent heat dissipation properties.

[0110] The lower cooling plate (1100) may be formed in a rectangular shape. At each corner of the lower cooling plate (1100), a portion excluding the lower portion (1101) is cut and formed. That is, at the corner of the lower cooling plate (1100), a lower cut portion (1105) is formed, in which the upper surface is open and the lower surface is closed.

[0111] A fastening hole (1103) is formed through the lower portion (1101) of the lower cooling plate (1100). The lower cooling plate (1100) is coupled to the fluid injection portion (130) and the fluid discharge portion (140) by a fastening member inserted into the fastening hole (1103) of the lower portion (1101).

[0112] The lower cooling plate (1100) is provided with an inlet (1115) through which cooling fluid flows in and an outlet (1125) through which fluid flows out.

[0113] The inlet (1115) and the outlet (1125) are formed as grooves on the lower surface of the lower cooling plate (1100). That is, the inlet (1115) and the outlet (1125) are formed open toward the lower surface of the lower cooling plate (1100). At this time, the inlet (1115) and the outlet (1125) are positioned at different horizontal and vertical positions. That is, as shown in FIG. 11, if the horizontal and vertical axes on the lower surface of the lower cooling plate (1100) are set as the horizontal axis (x-axis) and the vertical axis (y-axis), the inlet (1115) and the outlet (1125) are formed at different horizontal and vertical positions. If explained with reference to FIG. 11, the inlet (1115) is formed on the right side of the lower cooling plate (1100), and the outlet (1125) is formed on the left side of the lower cooling plate (1100), but is formed at a different height from the height of the horizontal line where the inlet (1115) is formed. This is because the inlet (1115) and the outlet (1125) are respectively connected to different main channels (1110, 1120) that are arranged along the length direction (horizontal direction) but are arranged side by side with a predetermined distance from each other in the width direction (vertical direction).

[0114] The lower cooling plate (1100) is provided with a first main channel (1110) through which cooling fluid is supplied and a second main channel (1120) through which cooling fluid is discharged.

[0115] The first main flow path (1110) and the second main flow path (1120) are arranged in parallel. The first main flow path (1110) and the second main flow path (1120) are arranged along the length direction of the lower cooling plate (1100) but are arranged with a predetermined spacing from each other in the width direction (vertical direction).

[0116] In FIG. 11, the first main flow path (1110) is formed along the horizontal axis (x-axis) and is positioned at a specific location on the vertical axis (y-axis). At this time, it is preferable that the first main flow path (1110) be positioned at the middle of the vertical direction (width direction) of the lower cooling plate (1100). Accordingly, a branch inlet (1117) connected to the first main flow path (1110) is formed in the middle of the vertical direction, and a branch start (1211) of the branch flow path section (1210) of the upper cooling plate (1200) is positioned in the middle of the vertical direction.

[0117] The first main channel (1110) is connected to the inlet (1115). The cooling fluid entering through the inlet (1115) flows along the first main channel (1110).

[0118] One end of the first main channel (1110) extends and opens to one side of the lower cooling plate (1100). A first plug insertion part (1112) is provided at one end of the first main channel (1110), and a first plug (1119) is provided in the first plug insertion part (1112). In a normal state, the first plug (1119) is fitted into the first plug insertion part (1112) to close it. If the user wishes to discharge air inside the first main channel (1110) or manually discharge fluid inside the first main channel (1110), the user can perform this operation by removing the first plug (1119).

[0119] A branch inlet (1117) is connected to the first main flow path (1110). The branch inlet (1117) is a through hole connected to the first main flow path (1110) from the upper surface of the lower cooling plate (1100). The branch inlet (1117) is provided for each phase. In the case of a three-phase circuit, three branch inlets (1117) are formed. Since a power conversion module (520) is mounted for each phase, each branch inlet (1117) is provided at the bottom of each power conversion module (520). Each phase is distinguished using the subscripts a, b, and c. In the case of a three-phase circuit, it consists of a first phase branch inlet (1117a), a second phase branch inlet (1117b), and a third phase branch inlet (1117c). Each branch inlet (1117) is arranged at a predetermined interval.

[0120] The first main flow path (1110) is extended along the horizontal axis, and each branch inlet (1117) is provided at the same height from the ground. Additionally, each branch inlet (1117) has the same shape and the same size. If the branch inlet (1117) is circular, it has the same diameter. Accordingly, the cooling fluid flowing into each phase's branch flow path (1210) has the same temperature and the same pressure. This ensures that the same thermal equilibrium temperature is maintained when cooling each phase's power conversion module (520).

[0121] The second main channel (1120) is formed lengthwise along the horizontal axis (x-axis) and is positioned at a specific location on the vertical axis (y-axis). At this time, it is preferable that the second main channel (1120) be positioned at a location offset to one side in the vertical direction (width direction) of the lower cooling plate (1100). That is, the second main channel (1120) is positioned away from the middle part in the vertical direction (width direction) of the lower cooling plate (1100). This ensures that the second main channel (1120) does not overlap with the first main channel (1110) and that the second main channel (1120) has a predetermined distance from the first main channel (1110). Accordingly, the branch outlet (1127) communicating with the second main flow path (1120) is positioned off-center in the vertical direction, and the second main flow path (1120) is connected to the branch end portion (1221) of the branch flow path portion (1210) of the upper cooling plate (1200).

[0122] The second main channel (1120) is connected to an outlet (1125). The fluid flowing through the second main channel (1120) exits to the fluid discharge section (140) through the outlet (1125).

[0123] One end of the second main channel (1120) extends and opens to one side of the lower cooling plate (1100). A second plug insertion part (1122) is provided at one end of the second main channel (1120), and a second plug (1129) is provided in the second plug insertion part (1122). In a normal state, the second plug (1129) is fitted into the second plug insertion part (1122) to close it. If the user wishes to discharge air inside the second main channel (1120) or manually discharge fluid inside the second main channel (1120), this operation can be performed by removing the second plug (1129).

[0124] A branch outlet (1127) is connected to the second main flow path (1120). The branch outlet (1127) is a through hole connected to the second main flow path (1120) from the upper surface of the lower cooling plate (1100). A branch outlet (1127) is provided for each phase. In the case of a three-phase circuit, three branch outlets (1127) are formed. Since a power conversion module (520) is mounted for each phase, each branch outlet (1127) is provided at the bottom of each power conversion module (520). Each phase is distinguished using the subscripts a, b, and c. In the case of a three-phase circuit, it consists of a second phase branch outlet (1127a), a second phase branch outlet (1127b), and a third phase branch outlet (1127c). Each branch outlet (1127) is arranged at a predetermined interval.

[0125] The branch outlet (1127) of each phase is positioned differently in the horizontal direction from the branch inlet (1117) of each phase. As shown in FIG. 11, the branch outlet (1127) of each phase is positioned to the right of the branch inlet (1117) of each phase.

[0126] A plurality of ventilation grooves (1130) are provided on the upper surface of the lower cooling plate (1100). The ventilation grooves (1130) are positioned on the outer edge of the upper surface of the lower cooling plate (1100). The ventilation grooves (1130) are formed as grooves. The ventilation grooves (1130) serve to accommodate deformation of the surface portion that occurs when the lower cooling plate (1100) is joined to the upper cooling plate (1200) by a thermal joining method such as welding. The ventilation grooves (1130) of the lower cooling plate (1100) communicate with the ventilation holes (1230) of the upper cooling plate (1200).

[0127] Next, the upper cooling plate (1200) will be described.

[0128] The upper cooling plate (1200) is made of a material with high thermal conductivity, such as aluminum. The upper cooling plate (1200) is formed of a material with excellent heat dissipation properties.

[0129] The upper cooling plate (1200) may be formed in a rectangular shape. An upper cut (1205) is formed at each corner of the upper cooling plate (1200) and connected to the lower cut (1105) of the lower cooling plate (1100).

[0130] A plurality of fastening grooves (1231) are formed on the upper surface of the upper cooling plate (1200). A fastening member (1051) for connecting a power conversion module (520) or a fastening member (1050) for connecting a power substrate (510) is inserted and connected into the fastening grooves (1231).

[0131] A plurality of ventilation holes (1230) are provided in the upper cooling plate (1200). The ventilation holes (1230) are arranged along the outer edge of the upper cooling plate (1200). The ventilation holes (1230) are formed as through holes that penetrate the upper and lower surfaces of the upper cooling plate (1200). The ventilation holes (1230) serve to accommodate deformation of the surface portion that occurs when the upper cooling plate (1200) is joined to the lower cooling plate (1100) by a thermal bonding method such as welding. The ventilation holes (1230) of the upper cooling plate (1200) communicate with the ventilation grooves (1130) of the lower cooling plate (1100).

[0132] A branch flow path (1210) is provided in the upper cooling plate (1200). The branch flow path (1210) is positioned in the power conversion module (520) portion to release heat generated in the power conversion module (520) through heat exchange with the cooling fluid.

[0133] The branching channel (1210) has a spiral shape. That is, the branching channel (1210) is formed in a shape that rotates in a swirling form around the branching starter (1211) and turns outward.

[0134] The branch flow path section (1210) includes a branch start section (1211), a branch middle section (1212–1220), and a branch end section (1221). Since the branch flow path section (1210) is formed on the same plane, the branch start section (1211), the branch middle section (1212–1220), and the branch end section (1221) are all formed on the same plane.

[0135] The branch starter (1211) is connected to the branch inlet (1117) of the lower cooling plate (1100). The branch starter (1211) is connected to the first main flow path (1110) through the branch inlet (1117). The fluid flowing in the first main flow path (1110) enters the branch starter (1211) of the branch flow path section (1210) through the branch inlet (1117).

[0136] The branch start section (1211) is connected to the branch middle section (1212~1220). The branch start section (1211) is connected to the first branch straight section (1212).

[0137] The branch intermediate section (1212–1220) connects the branch start section (1211) and the branch end section (1221). The branch intermediate section (1212–1220) has a spiral shape with a radius expanding from the center outward. The simplest embodiment of the branch intermediate section is shown in FIG. 16. Here, the branch intermediate section (1225) is shown to have a spiral shape with a radius expanding from the branch start section (1211) outward.

[0138] Referring to FIGS. 12 and 13, the branching intermediate sections (1212–1220) may be composed of straight sections and curved sections. Here, the straight sections and curved sections are arranged alternately. For example, an embodiment is shown in which the first branching straight section (1212), the first branching curved section (1213), the second branching straight section (1214), the second branching curved section (1215), the third branching straight section (1216), the third branching curved section (1217), the fourth branching straight section (1218), the fourth branching curved section (1219), and the fifth branching straight section (1220) are sequentially connected from the branching start section (1211). Here, although an example having five branching straight sections is shown, depending on the embodiment, the straight sections may be composed of n (where n is a natural number greater than or equal to 2).

[0139] Each straight section of the branch intermediate section (1212~1220) is arranged in parallel along the vertical direction (width direction) of the upper cooling plate (1200). The straight sections are provided to cover the power conversion module (520) when it is formed in a rectangular shape.

[0140] Each curved section of the intermediate section (1212~1220) connects the straight section and the straight section. Each curved section can be formed in the shape of an arc.

[0141] The branch end section (1221) is connected to the branch intermediate sections (1212–1220). The branch end section (1221) is connected to the fifth branch straight section (1220). Generally, in a branch flow path section (1210) having n straight sections, the branch end section (1221) is connected to the nth branch straight section.

[0142] The branch end (1221) is connected to the branch outlet (1127) of the lower cooling plate (1100). The branch end (1221) is connected to the second main flow path (1120) through the branch outlet (1127). The fluid flowing through the branch flow path (1210) flows into the second main flow path (1120) through the branch end (1221) and the branch outlet (1127).

[0143] The fluid flows into the branch start section (1211) located in the center of the branch flow path (1210), passes through the branch middle section (1212~1220), and exits through the branch end section (1221) located in the outer part of the branch flow path (1210). Since the fluid starts flowing from the center of the branch flow path (1210), cooling occurs starting from the center of the power conversion module (520) where heat is generated, thereby increasing the cooling effect. That is, the part with a low temperature of the cooling fluid comes into contact with the part of the power conversion module (520) with the highest heat generation amount, so that the heat exchange effect is maximized.

[0144] The branch flow path (1210) is formed in the shape of a groove on the lower surface of the upper cooling plate (1200). That is, the branch flow path (1210) is formed openly on the lower surface of the upper cooling plate (1200). The branch flow path (1210) is formed as a groove having a predetermined width and depth. At this time, the transverse cross-section of the branch flow path (1210) is formed in a semicircular or U-shape. That is, the groove forming the branch flow path (1210) is formed with the widest width at the part that contacts the lower surface of the upper cooling plate (1200).

[0145] An outer groove (1240) is formed on the lower surface of the upper cooling plate (1200) to surround all branch flow paths (1210). The outer groove (1240) accommodates the fluid flowing through the branch flow paths (1210) in the event of leakage and prevents it from flowing out to the outside.

[0146] The upper cooling plate (1200) is joined to the lower cooling plate (1100). At this time, the upper cooling plate (1200) and the lower cooling plate (1100) are joined so as to be sealed by welding or the like. The upper cooling plate (1200) and the lower cooling plate (1100) are sealedly joined to each other so that the fluid flowing through the branching channel (1210) does not leak to the outside. For such a sealed joining, face-to-face welding or the like can be utilized.

[0147] The lower surface of the upper cooling plate (1200) is surface-bonded to the upper surface of the lower cooling plate (1100). Accordingly, the lower surface of the branch flow path (1210) of the upper cooling plate (1200) is closed. Strictly speaking, the lower surface of the branch intermediate section (1212~1220) of the branch flow path (1210) of the upper cooling plate (1200) is closed. In other words, the branch start section (1211) of the branch flow path (1210) is connected to the branch inlet (1117) of the lower cooling plate (1100) so that fluid flows, and the branch end section (1221) of the branch flow path (1210) is connected to the branch outlet (1127) of the lower cooling plate (1100) so that fluid flows.

[0148] The branch flow paths (1210) are provided in multiple numbers and arranged for each phase. In the case of a three-phase circuit, they consist of a first phase branch flow path (1210a), a second phase branch flow path (1210b), and a third phase branch flow path (1210c). At this time, each branch flow path (1210) can be formed identically. That is, each branch flow path (1210) is formed with the same height and width. In addition, the diameter of the branch inlet (1117) connected to each branch flow path (1210) is formed identically. Accordingly, the fluid flowing through each phase cools the power conversion module (520) at the same temperature and pressure. As a result, the thermal equilibrium temperature formed in each phase becomes uniform.

[0149] The paths through which the cooling fluid flows are listed in sequence as follows. The paths of the cooling fluid are illustrated in Fig. 15.

[0150] Fluid injection section (130): supply pipe section (135) - fluid injection passage (131) - inlet pipe section (1010)

[0151] Cooling module (1000): Inlet (1115) - First main flow path (1110) - Branch inlet (1117) - Branch flow path section (1210) - Second main flow path (1120) - Branch outlet (1127) - Outlet (1125)

[0152] Fluid discharge section (140): Outlet pipe section (1020) - Fluid discharge passage (141) - Discharge pipe section (145)

[0153] The cooling fluid flows into the cooling module (1000) through the fluid injection part (130) connected to the external supply pipe along the above path to cool the heat of the power conversion module (520), and exits to the outside through the fluid discharge part (140).

[0154] Here, the branch inlets (1117) connecting the first main flow path (1110) to the branch flow path section (1210) are arranged in parallel with each other, formed with the same size, and placed at the same height from the ground. Accordingly, the cooling fluid is supplied to the branch flow path section (1210) of each phase at the same temperature and the same pressure, and the thermal equilibrium temperature through heat exchange with the power conversion module (520) of each phase is maintained uniformly.

[0155] The cooling system of a power converter according to one embodiment of the present invention applies a cooling method based on heat exchange of a cooling fluid, and thus has superior cooling performance compared to an air-cooled cooling system.

[0156] In particular, cooling performance is further enhanced when water is applied as the cooling fluid.

[0157] In addition, since no air flow space is required, the space occupied by the cooling system is reduced.

[0158] In addition, since no cooling fan is used, noise generation is reduced.

[0159] Here, a cooling module is provided in contact with the power conversion module of each phase, and the cooling fluid supplied from the cooling module to the power conversion module of each phase is provided with the same temperature and the same pressure so that the thermal equilibrium temperature of each phase is uniformly maintained.

[0160] Furthermore, the branch flow paths of each phase are formed such that cooling fluid is supplied from the center of the power conversion module and flows outward, allowing for efficient heat exchange in areas with high heat generation.

[0161] The embodiments described above illustrate the best embodiments for implementing the present invention, and those skilled in the art will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, these embodiments are merely for illustrative purposes, not for limiting the technical concept of the present invention. Consequently, it should be understood that the scope of the technical concept of the present invention is not limited by these embodiments. That is, the scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

[0162] (Explanation of symbols)

[0163] 100 power converters

[0164] 110 outer casing

[0165] 130 Fluid Injection Section

[0166] 131 Fluid injection passage

[0167] 133 Inflow Air Circulation Route

[0168] 135 Supply Pipeline

[0169] 140 Fluid discharge section

[0170] 141 Fluid discharge passage

[0171] 143 Exhaust air circulation path

[0172] 145 Discharge pipe section

[0173] 200 DC input section

[0174] 250 input rectifier

[0175] 300 Input Protection

[0176] 350 Input Switch Section

[0177] 400 storage units

[0178] 500 power converter

[0179] 510 Power Board

[0180] 520 Power Conversion Module

[0181] 600 Reactor Section

[0182] 650 output switch section

[0183] 700 output protection

[0184] 750 output rectifier

[0185] 800 AC output section

[0186] 1000 cooling modules

[0187] 1010 Inflow pipe section

[0188] 1020 Outflow Control Section

[0189] 1100 lower cooling plate

[0190] 1110 1st Main Euro

[0191] 1115 Inlet

[0192] 1117 Quarter Inflow

[0193] 1120 2nd Main Euro

[0194] 1125 Outlet

[0195] 1127 Quarter Outlet

[0196] 1130 Ventilation groove

[0197] 1200 upper cooling plate

[0198] Eurozone in the 1210 quarter

[0199] Start of the 1211th quarter

[0200] Middle of the 1212–1220 quarter

[0201] 1221 Quarter End

[0202] 1230 Ventilation hole section

[0203] 1240 outer home

Claims

1. Enclosure; A plurality of power conversion modules installed within the above enclosure and mutually converting direct current and alternating current; and It includes a cooling module installed to be in contact with the power conversion module above, and The above cooling module is, An inlet for the inflow of a cooling fluid and an outlet for the outflow of the cooling fluid; and A plurality of branching passages are provided, connected between the inlet and the outlet, to allow the cooling fluid to be branched to each of the power conversion modules for heat exchange. The above plurality of branch flow paths are a cooling system for power conversion devices arranged in parallel for each phase.

2. In Paragraph 1, In the above enclosure, A fluid injection unit connected to the above inlet to supply the cooling fluid; and A cooling system for a power converter, provided with a fluid discharge section connected to the above-mentioned outlet to discharge the cooling fluid.

3. In Paragraph 2, In the above fluid injection part, A fluid injection passage through which the above cooling fluid flows is formed, and In the above fluid discharge section, A cooling system for a power converter in which a fluid discharge passage through which the above-mentioned cooling fluid flows is formed.

4. In Paragraph 1, The branch inlet leading from the above inlet to the branch flow path of each phase is, A cooling system for a power converter formed with the same diameter, the same height from the ground, and the same volume.

5. In Paragraph 4, The above cooling module is, An upper cooling plate that is in direct contact with the power conversion module and is provided with the branch flow path; and A cooling system for a power converter comprising a lower cooling plate coupled to the upper cooling plate, wherein the above-mentioned inlet and outlet are provided.

6. In Paragraph 5, The above inlet and outlet are formed as grooves on the lower surface of the lower cooling plate, and The above inlet and outlet are positioned at different horizontal and vertical positions on the lower surface of the lower cooling plate, forming a cooling system for a power conversion device.

7. In Paragraph 5, A cooling system for a power converter in which a first main flow path connected to the inlet and a second main flow path connected to the outlet are arranged in parallel at a predetermined interval on the lower cooling plate.

8. In Paragraph 7, The above inlet and the first main flow path are, A cooling system for a power converter arranged along the centerline in the width direction of the lower surface of the lower cooling plate.

9. In Paragraph 7, At one end of the first main flow path and the second main flow path, a plug insertion part is provided that extends to one side of the lower cooling plate and opens. A cooling system for a power converter in which a plug is provided in the plug insertion part above.

10. In Paragraph 7, In the first main flow path, the branch inlet that penetrates to the upper surface of the lower cooling plate is formed in each phase, and A cooling system for a power converter in which a branch outlet penetrating the upper surface of the lower cooling plate is formed in each phase of the second main flow path.

11. In Paragraph 10, The above branch inlet and branch outlet are, A cooling system for a power converter positioned at different horizontal positions on the lower surface of the above-mentioned lower cooling plate.

12. In Paragraph 9, The above branch inlet and branch outlet are, A cooling system for a power conversion device, each positioned at the bottom of the above-mentioned power conversion module.

13. In Paragraph 10, The above branching section is, A branch start connected to the above branch inlet; A branch end connected to the branch outlet above; and A cooling system for a power converter including a branch intermediate section connecting the branch start section and the branch end section.

14. In Paragraph 13, A cooling system for a power converter in which the above-mentioned branch middle section is formed in a spiral shape that expands outward while rotating in a vortex shape around the branch start section.

15. In Paragraph 7, The above branching channel is a cooling system of a power conversion device formed as a groove on the lower surface of the upper cooling plate.

16. In Paragraph 15, A cooling system for a power converter in which the transverse cross-section of the branching channel is formed in a semicircular or 'U' shape.

17. In Paragraph 13, The above-mentioned branch intermediate section is a cooling system for a power conversion device in which straight sections and curved sections are alternately connected.

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