Power Conversion Device

Abstract

This power conversion device comprises a power module having a semiconductor device for converting DC power to AC power and a cooling flow path for cooling the semiconductor device. The power conversion device has a metal housing member thermally connected to the cooling flow path at the bottom via a thermally conductive member. The housing member houses a plurality of smoothing capacitors for smoothing the DC power. The plurality of smoothing capacitors are electrically connected to the semiconductor device via a DC bus-bar that is connected to the semiconductor device and inputs the DC power to the semiconductor device.

Description

[Technical Field]

[0001] The present invention relates to a power conversion device. [Background technology]

[0002] In the design of power conversion equipment, there is a concept of standardizing components, which involves combining multiple standard components to cover these specification differences. However, assembling multiple components into a device is less easy to assemble than assembling a single component. Furthermore, in power conversion equipment that requires high output and compactness, cooling the heat generated during operation is an issue. In light of these points, a complex internal structure of the device can hinder proper heat dissipation in each part, which can lead to component deterioration and a shortened lifespan due to heat, thereby reducing reliability. Therefore, there is a demand for devices that can maintain ease of assembly while simplifying the internal structure.

[0003] Patent Document 1 listed below discloses a configuration in which cooling flow paths are arranged on both sides of a power module, and a capacitor unit 23 is arranged on the heat dissipation surface of the flow path opposite the power module to dissipate heat, thereby improving cooling efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-161797 Summary of the Invention [Problem to be solved by the invention]

[0005] Although Patent Document 1 is expected to improve cooling efficiency and prevent the device from becoming too large, it does not specifically disclose how to attach the capacitor unit, and there remain issues with the ease of assembling the device. In view of this, an object of the present invention is to provide a power conversion device that achieves both improved ease of assembly and maintaining the heat dissipation performance of the device. [Means for solving the problem]

[0006] The power conversion device is a power conversion device equipped with a power module having a semiconductor device that converts DC power to AC power and a cooling flow path that cools the semiconductor device, and has a metal housing member that is thermally connected to the cooling flow path at its bottom surface via a heat conduction member, and the housing member houses a plurality of smoothing capacitors that smooth the DC power, and the plurality of smoothing capacitors are electrically connected to the semiconductor device via a DC bus bar that is connected to the semiconductor device and inputs the DC power to the semiconductor device. [Effects of the Invention]

[0007] It is possible to provide a power conversion device that achieves both improved assembly efficiency and maintenance of the device's heat dissipation properties. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is an exploded view of the overall structure of the power conversion device. [Figure 2] FIG. 2 is an exploded structural view in which some of the components in FIG. 1, such as the power module, are housed in a housing. [Figure 3] 10 is a diagram illustrating the inside of a housing that accommodates some of the components such as a second DC bus bar and a power module. FIG. [Figure 4] FIG. 2 is a diagram illustrating a unit of a DC circuit module. [Figure 5] FIG. 2 is a diagram illustrating a noise filter. [Figure 6] FIG. 2 is a diagram illustrating two DC bus bars according to an embodiment of the present invention. [Figure 7] 7 is a view of the two DC bus bars in FIG. 6 as viewed from the direction B. FIG. [Figure 8] 5 is a view of the DC circuit housing member of FIG. 4 as seen from direction A. FIG. [Figure 9] 1 is a cross-sectional view of a power conversion device according to an embodiment of the present invention. [Figure 10] FIG. 10 is a view of components housed in the DC circuit housing member as seen from the upper opening side. [Figure 11] 10 is a simplified diagram of the cross-sectional structure of the power converter of FIG. 9 according to one embodiment of the present invention. [Figure 12] FIG. 2 is an electrical circuit diagram of the power conversion device. [Figure 13] This is the first modified example. [Figure 14] This is the second modified example.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0010] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0011] (One embodiment and overall configuration) (Fig. 1, Fig. 2) The power conversion device 100 (hereinafter referred to as inverter 100) includes a first DC bus bar 1, an EMC filter 2, a smoothing capacitor 3, a DC circuit housing member 4 (hereinafter referred to as case 4), a second DC bus bar 6, an AC bus bar 7, an L-shaped AC bus bar 7a (hereinafter referred to as L-shaped AC bus bar 7a), an AC sensor 8, a power module unit 9 (hereinafter referred to as power module 9), and a gate drive board 10 housed inside a housing 11. An MC (Motor Control) board 12 is disposed on the opposite side of the housing 11 from the opening side that houses the above-mentioned internal components (on the outside of the bottom). A cover 13 is disposed on the outside of the bottom of the housing 11 so as to cover and protect the MC board 12.

[0012] The housing 11 is made of metal such as aluminum or iron, and can be formed by casting, for example, aluminum die casting. The housing 11 is formed in a box shape with a bottom and an open top. The housing 11 not only houses the components of the inverter 100, but also functions as a cooling channel formation body to allow a coolant that cools the power module 9 to flow throughout the housing 11. As a result, the coolant supplied from outside the housing 11 flows through a channel formed in the housing 11 and into a cooling channel 15 (described later in FIG. 9) provided in the power module 9, thereby cooling the semiconductor device 16 (described later in FIG. 9). The housing 11 is also connected to the same potential as the earth potential (ground potential) via the components installed therein.

[0013] The MC board 12 is an electronic control board that is connected to the inverter 100 and controls the operation of a motor (described later in FIG. 12) driven by AC power. The MC board 12 is disposed opposite the power module 9 with the bottom of the housing 11 in between, and is thermally connected to the housing 11 via a heat conductive member 26 (described later in FIG. 13). This is expected to ensure the cooling performance of the MC board 12 and improve noise resistance, contributing to improved reliability of the inverter 100.

[0014] The first DC bus bar 1, the EMC filter 2, the smoothing capacitor 3, and the case 4 are unitized and function as a DC circuit module 5 (hereinafter referred to as a DC circuit body 5). The L-shaped AC bus bar 7a is an AC bus bar formed in an L shape along the inner wall of the housing 11.

[0015] (Figure 3) The AC bus bar 7 is electrically connected to an AC power input / output section (not shown) of the power module 9. Note that although welding is used to connect the AC bus bar 7 and the power module 9, other connection methods may also be used. The second DC bus bar 6 is connected to a DC power input / output section (not shown) of the power module 9. The AC bus bar 7 is disposed opposite the second DC bus bar 6 with the power module 9 in between.

[0016] The AC current sensor 8 has a circular shape with a hole in the center, and is arranged so that the AC bus bar 7 passes through the center of the AC current sensor 8 to measure the current flowing through the AC bus bar 7. The AC bus bar 7 is connected to the L-shaped AC bus bar 7a. Although this connection is made by screw fastening, it is not limited to this connection method. The number of parts shown in the figure is also not limited to this.

[0017] The L-shaped AC bus bar 7a is gathered at one end of the long side of the housing 11 and protrudes (extends) upward. The AC bus bar 7a is connected to a motor (not shown) at the portion extending upward, but this connection does not affect the connection position with the motor.

[0018] (Figure 4) Case 4, a metal housing member, houses a plurality of smoothing capacitors 3 that form a DC circuit and smooth the DC power, an EMC filter (noise filter) 2 that removes high-frequency noise from the DC power, and a first DC bus bar 1 that electrically connects the plurality of smoothing capacitors 3 and the EMC filter 2. By housing the first DC bus bar 1, EMC filter 2, and plurality of smoothing capacitors 3 in case 4, they function as an integrated (unitized) DC circuit body 5.

[0019] The case 4 is a housing member having two smoothing capacitor housing sections 4b that house a plurality of smoothing capacitors 3, and a filter housing section 4c that houses the EMC filter 2 that constitutes the noise filter circuit. The two smoothing capacitor housing sections 4b each house the same number of capacitors 3.

[0020] The first DC bus bar 1 is connected to an EMC filter 2 and a smoothing capacitor 3 housed in a case 4. The first DC bus bar 1 has a protruding portion 1a formed in a downwardly projecting shape. Furthermore, in the case 4, of the two smoothing capacitor housings 4b, the smoothing capacitor housing 4b on the left side of FIG. 4 is the first smoothing capacitor housing, and the smoothing capacitor housing 4b on the right side of FIG. 4 is the second smoothing capacitor housing. A hole 4a is provided between the first smoothing capacitor housing 4b and the second smoothing capacitor housing 4b, and the first smoothing capacitor housing 4b and the second smoothing capacitor housing 4b are disposed with the hole 4a sandwiched between them. The hole 4a has a through structure so that the protruding portion 1a of the first DC bus bar 1 can be connected to the second DC bus bar 6.

[0021] The case 4 is at the same potential as the ground potential by being connected to the housing 11. Therefore, the case 4 serves as a grounding for the EMC filter 2 and also serves as a shield against electromagnetic noise generated during switching in the power module 9 that is switched.

[0022] In this way, by accommodating the smoothing capacitor 3 and the EMC filter 2 as a unit in the case 4, even if individual components are used, such as by using capacitors grouped in a cluster (cluster CAP), they can be arranged without impairing assembly simply by installing the case 4.

[0023] The number of smoothing capacitors 3 for each smoothing capacitor housing section 4b does not have to be limited to four as shown in FIG. 4. Also, the number of filter capacitors 21, 22 (described later in FIG. 5) mounted on the EMC filter 2 side may be reduced to increase the number of accommodated smoothing capacitors 3. By reducing the number of filter capacitors 21, 22, the length from the hole 4a to the EMC filter 2 (or the filter housing section 4c) in the case 4 may be shortened, thereby reducing the space required for housing. Also, although the smoothing capacitors 3 are connected to the first DC bus bar 1 by welding, this connection may be made by other methods such as crimping or screw fastening.

[0024] The case 4 is not limited to a bag-like structure such as the housing portions 4b and 4c shown in FIG. 4, and may be, for example, plate-shaped, as long as it can accommodate the EMC filter 2 and the smoothing capacitor 3.

[0025] (Figure 5) The EMC filter 2 includes a first filter capacitor 21, a second filter capacitor 22, a core member 23, and a molded bus bar 18. The EMC filter 2 is provided between a high-voltage battery 101 (described later in FIG. 12) and a smoothing capacitor 3, and suppresses electromagnetic noise generated during power conversion operation (switching) of the power module 9.

[0026] The EMC filter 2 is connected to the first DC bus bar 1. Although this connection is made by welding, it is not limited to this and other methods such as crimping or screw fastening may also be used.

[0027] The EMC filter 2 includes a positive bus bar 19 and a negative bus bar 20, which are DC bus bars for transmitting DC power. One end of a first filter capacitor 21 is electrically connected to the positive bus bar 19, and the other end is electrically connected to the negative bus bar 20. One end of a second filter capacitor 22 is electrically connected to either the positive bus bar 19 or the negative bus bar 20, and the other end is electrically connected to a ground bus bar 17 for grounding to the ground potential.

[0028] The core member 23 is made of a magnetic material and absorbs electromagnetic noise from the current flowing through the bus bars 19, 20 of the EMC filter 2. The core member 23 has a hollow cylindrical shape, and the positive bus bar 19 and negative bus bar 20, which are circuit components of the EMC filter 2, pass through a central through-hole. Therefore, the core member 23 is disposed so as to surround these two DC bus bars 19, 20. In this embodiment, the shape of the core member 23 matches the shape of the resin that constitutes the molded bus bar 18 so that the core member 23 can be stored in the filter accommodating section 4c, but the installation method of the core member 23 is not limited to this.

[0029] The positive bus bar 19 and the negative bus bar 20 electrically connect the high-voltage battery 101 and the power module 9. The positive bus bar 19 and the negative bus bar 20 also have terminal portions for electrically connecting the first filter capacitor 21 and the second filter capacitor 22. Note that in this embodiment, the positive bus bar 19 and the negative bus bar 20 are connected to the first filter capacitor 21 and the second filter capacitor 22 by welding, but other methods such as crimping or screw fastening may also be used.

[0030] The ground bus bar 17 is connected to one terminal of the second filter capacitor 22. The ground bus bar 17 is fixed to the case 4 by screw fastening, and is electrically connected to the same potential as the ground potential via the housing 11 fastened to the case 4. From the viewpoint of noise resistance, it is desirable that the connection position of the ground bus bar 17 and the case 4 be as close as possible to the fastening position between the case 4 and the housing 11. Furthermore, the ground bus bar 17 may be directly connected to the housing 11 instead of being indirectly connected to the housing 11 via the case 4.

[0031] The EMC filter 2 is housed in a case 4 that is thermally connected to the cooling flow path 15 of the power module 9, and heat can be transferred via the resin material filled in the gap, thereby improving heat dissipation and contributing to the reliability of the device 100.

[0032] (Fig. 6, Fig. 7) The two DC bus bars 1 and 6 will now be described. The first DC bus bar 1 is electrically connected to the second DC bus bar 6 via the protrusion 1a. This electrically connects the EMC filter 2 and smoothing capacitor 3 housed in the case 4 to the power module 9. Note that in this embodiment, this connection is made by screw fastening, but is not limited to this and other methods such as crimping may also be used.

[0033] (Figure 8) The case 4 is made of a metal such as aluminum or iron, and is formed by casting such as aluminum die casting. The case 4 has a bottom and is formed in a bag shape with an open top. The bottom of the case 4 has a cooling channel contact portion 24, which is a protrusion for thermally contacting the cooling channel 15 of the power module 9 via a heat conduction member 26.

[0034] By connecting the first DC bus bar 1 and the case 4, the convex portion 1a provided on the first DC bus bar 1 is fitted into the hole portion 4a provided in the case 4. As shown in Fig. 8, the hole portion 4a has a through structure, and therefore the convex portion 1a can be seen from the back surface of the case 4. This allows the first DC bus bar 1 provided on the case 4 to be connected to the second DC bus bar 6 via the convex portion 1a, as described above with reference to Figs. 6 and 7.

[0035] (Figure 9) Inside the housing 11, a power module 9 with an accompanying cooling flow path 15 is arranged horizontally relative to the bottom. The power module 9 is composed of a semiconductor device 16 that converts DC power to AC power, and a pair of cooling flow paths 15 that sandwich the semiconductor device 16. The cooling flow paths 15 are not limited to being provided on both sides of the semiconductor device 16, and may be provided on only one side of the semiconductor device 16 (as will be described later with reference to FIG. 14).

[0036] Above the power module 9 are arranged the smoothing capacitor 3, which is composed of a combination of packages for each element, the first DC bus bar 1 equipped with a positive bus bar and a negative bus bar that form the main circuit between the capacitor and power module, and the case 4, which is a metal member that stores and fixes these. The gap between the bottom surface of the internal plate of this case 4 and a housing 11 that is attached to the power module 9 and functions as a flow path formation body is filled with a resin heat conductive member 26 (described later in FIG. 10), thereby thermally connecting the case 4 and the power module 9. As a result, the smoothing capacitor 3 and EMC filter 2 mounted in the metal case 4 are in indirect contact with the cooling flow path 15 via the case 4 and the heat conductive member 26.

[0037] Furthermore, while the DC circuit body 5 unitized by the case 4 solves the problem from the viewpoint of ease of assembly, the fact that the housing 11 and the case 4 are separate bodies poses an issue with cooling performance, and there is concern that the self-heating of the EMC filter 2 and smoothing capacitor 3 and the blown heat from the nearby bus bar may cause deterioration or destruction. Therefore, as mentioned above, by adopting a configuration in which the case 4 and the cooling flow path 15 on the top surface of the power module 9 are thermally connected by contacting them with the heat conductive member 26, it is possible to improve cooling performance without impairing ease of assembly.

[0038] This ensures cooling performance and improves assembly without impairing the heat dissipation of the components of the DC circuit body 5. In addition, it is possible to suppress heat generation that occurs when the bus bar path is shortened in order to reduce the main circuit inductance while taking assembly into consideration.

[0039] The gate drive board 10 is equipped with heat-generating components such as a transformer that converts high voltage. On the other hand, the housing 11 is a flow path formation body through which a coolant that cools the power module 9 flows, and therefore has a lower temperature than the other components that make up the inverter 100. Therefore, by filling the gap between the gate drive board 10 and the housing 11 with a thermally conductive member 26 (described below) and thermally connecting them, the cooling performance of the gate drive board 10 is improved. Furthermore, by reducing the risk of heat-induced failure of the components mounted on the gate drive board 10, the reliability of the inverter 10 can be improved (described below in FIG. 13).

[0040] (Figure 10) A resin member (potting resin) 25 is filled between the first and second smoothing capacitor housing portions 4b and the filter housing portion 4c (see FIG. 4) of the case 4 and the plurality of smoothing capacitors 3 and the EMC filter 2.

[0041] The resin member 25 is a resin member having thermal conductivity and electrical insulation properties, and hardens when filled between the components housed in the case 4, thereby fixing the relative positions of the components housed in the case 4 and improving cooling performance by being indirectly thermally connected to the cooling water passage 15 of the power module 9. Note that the filling rate of the resin member 25 relative to the volume of the housing in the case 4 is not specified, but from the viewpoint of cooling, it is preferable that the filling rate is as high as possible.

[0042] Although the components housed in the case 4 are fixed by the resin member 25, this fixing method is not limited to this, and other fixing methods such as screw fastening may also be used. Furthermore, the housing portions 4b and 4c of the case 4 are not limited to being used as the housing portions 4b and 4c for housing the smoothing capacitor 3 and the EMC filter 2, and may also have the function of housing portions for other components.

[0043] (Figure 11) The components of the power conversion device 100, such as the power module 9, can be assembled to the housing 11 from one direction (the upward direction in Figure 11), eliminating the need for rotation and facilitating assembly. Furthermore, by configuring the cooling flow path 15 on the power module 9 side, for which heat dissipation performance is important, and the DC circuit body 5, for which the strength of the case 4 and customizability according to specifications are important, as separate components, it is possible to standardize the components within the device 100 while also improving the degree of freedom in optimal layout design.

[0044] The case 4, which is a metal housing member, is connected to the power module 9, in which the semiconductor device 16 and the cooling channel 15 are integrated, via a heat conductive member 26 at a cooling channel contact portion 24 provided on the bottom surface. The power module 9 faces the first DC bus bar 1, the EMC filter 2, and the smoothing capacitor 3, with the case 4 between them.

[0045] As a result, in the past, when these were mounted in the same space, the heat from the power module 9 was mainly affected by components such as the EMC filter 2 and smoothing capacitor 3, which caused problems with heat dissipation efficiency. However, by using the case 4 according to the present invention, the DC circuit body 5 and the power module 9 can be separated, which maintains ease of assembly and does not impair heat dissipation.

[0046] Power modules 9 are arranged within the inverter 100. The power modules 9 are connected to motors 200 (described later in FIG. 12) that are mainly used for driving and power generation. The power modules 9 are connected to the first DC bus bar 1 via the second DC bus bar 6. In other words, the smoothing capacitor 3 and the EMC filter 2 are electrically connected to the semiconductor device 16 via the DC bus bars 1 and 6.

[0047] The first DC bus bar 1 and the second DC bus bar 6 are wired using the space between the two power modules 9. As described above, the first DC bus bar 1 has the first and second smoothing capacitor housings 4b arranged on both sides of the hole 4a in the case 4. This arrangement makes it possible to shorten the bus bar path connecting the smoothing capacitor 3 to the power module 9 compared to conventional arrangements, thereby suppressing an increase in inductance in the main circuit. This also reduces the risk of damage to the components of the power conversion device 100 (the EMC filter 2, the smoothing capacitor 3) due to an increase in surge voltage caused by switching the power module 9 and an excess voltage exceeding the withstand voltage, thereby contributing to improved reliability of the power conversion device 100.

[0048] The housing 11 serves as a flow path forming body that forms a flow path, thereby forming a cooling flow path 28, and by connecting the cooling flow path 28 to the cooling flow path 15 of the power module 9, a refrigerant is circulated inside. In addition, a DC connector (not shown) that is connected to a high-voltage cable 106 (described later in FIG. 12 ) that is connected to the high-voltage battery 101 is attached to the housing 11, and is electrically connected to the first DC bus bar 1, EMC filter 2, smoothing capacitor 3, and case 4, which are components of the DC circuit body 5, via a separate connection bus bar (not shown), thereby supplying DC power to the power conversion device 100. Note that the connection form with the high-voltage battery 101 is not limited to this.

[0049] (Figure 12) The three-phase inverter circuit 110 included in the inverter 100 is connected in parallel to a battery 101 and a smoothing capacitor 3, and receives DC power from the battery 101. The DC power is smoothed by the smoothing capacitor 3 connected in parallel. The smoothed DC power is converted into AC power by a semiconductor device 16 and output to a motor 200.

[0050] The three-phase inverter circuit 110 has a three-phase one-leg inverter 108 that combines the semiconductor device 16 and the control circuit 10 (gate drive board 10), and outputs three-phase AC to the motor 200 by switching each of the three-phase one-leg inverters 108 ON and OFF. Note that Fig. 12 shows only one phase of the three-phase one-leg inverter 108, and the other two phases are not shown.

[0051] The current flowing through the upper arm element 23 a and the lower arm element 23 b of the semiconductor device 16 is switched ON / OFF as described above by a control signal output from the control circuit 10. This converts DC power into AC power. The control signal output from the control circuit 10 is input to the upper arm element 23 a and the lower arm element 23 b via signal wiring and gate resistor 105.

[0052] The semiconductor device 16 is an IGBT (Insulated Gate MOSFET) that operates as the upper arm. The power supply has a switching element such as an insulated gate bipolar transistor (BIP) and a diode, and a switching element such as an IGBT and a diode that operates as a lower arm.

[0053] The three-phase semiconductor devices 16 are connected in parallel to the high-voltage side input wiring 106 and the low-voltage side input wiring 107. The three-phase inverter circuit 110 is connected to the three-phase stator winding 200a of the motor 200 at the midpoint between the series connection of the upper arm semiconductor element 23a and the lower arm semiconductor element 23b.

[0054] Three-phase semiconductor device 16 is connected in parallel to high-voltage side input wiring 106 and low-voltage side input wiring 107, and further includes signal wiring for semiconductor device 16, a signal wiring board (not shown), and control circuit 10, whereby upper arm semiconductor elements 23a and lower arm semiconductor elements 23b are controlled by signals input from control circuit 10 via the signal wiring, thereby functioning as a three-phase inverter circuit 110, which is an electric circuit device. Furthermore, motor output terminals (not shown) are connected to three-phase stator winding 200a of motor 200, smoothing capacitor 3 is connected to high-voltage side input wiring 106 and low-voltage side input wiring 107, and battery 101 is connected to DC voltage input terminals (not shown), thereby functioning as inverter 100 that converts DC power to AC power.

[0055] The smoothing capacitor 3 is connected between the high-voltage battery 101 and the semiconductor device 16, and smooths the DC power and supplies it to the semiconductor device 16. Note that the smoothing capacitor 3 is mounted in multiple packages, each containing a single element, but multiple elements may also be incorporated into a single package.

[0056] (First Modification) (Figure 13) 13 is a diagram showing the embodiment described in FIG. 11 equipped with a gate drive board 10 and an MC board 12. The MC board 12 sends control signals to the gate drive board 10 to control the operation of the motor 200. The gate drive board 10 sends drive control signals to the power module 9 based on signals from the MC board 12. The gate drive board 10 and the MC board 12 are disposed opposite the smoothing capacitor 3 with the power module 9 in between, and are supported by the housing 11 by being thermally connected to the housing 11 via a heat conductive member 26.

[0057] As described above, the housing 11 is connected to the ground potential. The case 4 is also electrically connected to the housing 11. The housing 11 has a wall disposed between the power module 9 and the gate drive board 10. Therefore, the housing 11 functions as a shield that absorbs noise from the power module 9, reducing the risk of malfunction of the gate drive board 10 and contributing to improving the reliability of the inverter 100.

[0058] The MC board 12 is supported by the housing 11 by being thermally connected to the housing 11 via the heat conduction member 26. This reduces the temperature of the housing 11, which includes the cooling flow path 15 that cools the power module 9, and allows the MC board 12 to be cooled. A processor such as a CPU (Central Processing Unit) is mounted on the MC board 12, and since the CPU generates heat when the inverter 100 is running, cooling the MC board 12 reduces the risk of failure due to heat in the CPU and other board-mounted components, contributing to improved reliability of the inverter 100.

[0059] (Second Modification) (Figure 14) 14(a) is a front view of a modified example of the inverter 100, and FIG. 14(b) is a side view of the modified example of the inverter 100. As shown in FIGS. 14(a) and 14(b), the present invention is also applicable to the inverter 100 in which the cooling water channels 15 of the power module 9 are arranged on one side instead of both sides.

[0060] The present invention has been described above, and in addition to the above-mentioned effects, it can also accommodate the standardization of components across different models. Also, while the above description has been given of a configuration in which two dual-type power modules 9 that control the input and output of two motors 200 are arranged in parallel, the present invention is not limited to this arrangement and can be applied to other configurations.

[0061] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0062] (1) The power conversion device 100 includes a power module 9 having a semiconductor device 16 that converts DC power to AC power and a cooling channel 15 that cools the semiconductor device 16. The power conversion device 100 also includes a metal housing member 4 that is thermally connected to the cooling channel 15 at its bottom surface via a heat-conducting member 26, and the housing member 4 houses a plurality of smoothing capacitors 3 that smooth the DC power. The plurality of smoothing capacitors 3 are electrically connected to the semiconductor device 16 via DC bus bars 1, 6 that are connected to the semiconductor device 16 and input the DC power to the semiconductor device 16. This configuration makes it possible to provide a power conversion device 100 that achieves both improved assembly ease and maintained heat dissipation performance of the device.

[0063] (2) The power module 9 includes a first power module having a three-phase AC output and a second power module having a three-phase AC output independent of the first power module, and the DC bus bar 6 passes through the space between the first power module and the second power module. This arrangement makes it possible to shorten the bus bar path connecting the smoothing capacitor 3 to the power module 9 compared to conventional arrangements, thereby suppressing an increase in inductance in the main circuit.

[0064] (3) The accommodating member 4 has first and second smoothing capacitor accommodating sections 4b that accommodate a plurality of smoothing capacitors 3 and a hole 4a through which the DC bus bar 1 penetrates the accommodating member 4, and the first and second smoothing capacitor accommodating sections 4b are arranged with the hole 4a sandwiched between them. This allows for placement without impairing assembly by simply installing the accommodating member 4.

[0065] (4) The power conversion device 100 further includes a noise filter 2 that is electrically connected to the smoothing capacitor 3 and the semiconductor device 16 via the DC bus bars 1 and 6 and removes high-frequency noise from the DC power. The housing member 4 has a filter housing portion 4c that houses the noise filter 2 and first and second smoothing capacitor housing portions 4b that house the smoothing capacitor 3. This allows the components of the DC circuit body 5 to be arranged without impairing assembly.

[0066] (5) A resin member 25 is filled between the filter housing portion 4c and the noise filter 2, and between the first and second smoothing capacitor housing portions 4b and the plurality of smoothing capacitors 3. This fixes the relative positions of the housed components in the case 4 and improves cooling performance.

[0067] (6) The noise filter 2 includes a DC bus bar that transmits DC power, a magnetic core member 23 that is arranged to surround the DC bus bar, and a filter capacitor connected to the DC bus bar. The DC bus bar has a positive bus bar 19 and a negative bus bar 20, and the filter capacitor has a first filter capacitor 21 and a second filter capacitor 22. The first filter capacitor 21 has one end connected to the positive bus bar 19 and the other end connected to the negative bus bar 20, and the second filter capacitor 22 has one end connected to either the positive bus bar 19 or the negative bus bar 20 and the other end grounded to ground potential. This configuration suppresses electromagnetic noise generated during power conversion operation (switching) of the power module 9 in the power conversion device 100.

[0068] (7) The power conversion device 100 includes a gate drive board 10 that sends control signals to the semiconductor device 16 and a housing 11 that is a flow path forming body that forms a cooling flow path, and the gate drive board 10 is disposed opposite a plurality of smoothing capacitors 3 with the power module 9 therebetween, and the gate drive board 10 is supported by the housing 11 by connecting it to the housing 11 with a heat conductive member 26. This contributes to improving the cooling performance of the gate drive board 10 and reducing the risk of heat-induced failure of the components mounted on the gate drive board 10, thereby contributing to improving the reliability of the power conversion device 100.

[0069] (8) The power converter 100 further includes an electronic control board 12 that controls the operation of the motor 200 driven by AC power. The housing 11 is connected to a ground potential, and the accommodating member 4 is electrically connected to the housing 11. The electronic control board 12 is disposed opposite the plurality of smoothing capacitors 3 with the power module 9 therebetween, and is also disposed opposite the power module 9 with the housing 11 therebetween. The electronic control board 12 is supported by the housing 11 by connecting it to the housing 11 with a heat conductive member 26. This configuration allows the MC board 12 to be cooled via the housing 11 connected to the cooling flow path 15, reducing the risk of heat-induced failure of board-mounted components such as the CPU on the MC board 12, and contributing to improved reliability of the power converter 100.

[0070] The present invention is not limited to the above-described embodiments, and various modifications and combinations of other configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted. [Explanation of symbols]

[0071] 1. First DC bus bar 1a Convex part 2 EMC filter (noise filter) 3 smoothing capacitors 4 DC circuit housing (case) 4a Hole 4b (First and second) smoothing capacitor housing 4c Filter housing 5 DC circuit module (DC circuit body) 6 Second DC bus bar (power module connection side) 7 AC bus bar 7a L-shaped AC busbar 8 AC current sensors 9 Power Module Unit 10 Gate drive board 11 Housing (flow path forming body) 12 MC (Motor Control) board 13 Cover 14 DC connector 15 Cooling channel (power module side) 16 Semiconductor Devices 17 Ground bus bar 18 Molded bus bar 19 Positive bus bar 20 Negative bus bar 21 First filter capacitor 22 Second filter capacitor 23 Core member 24 Cooling channel contact area 25 Resin parts (potting resin) 26 Thermal Conductive Materials 27 Heat Transfer 28 Cooling Channel 100 Power conversion device

Claims

1. A power conversion device including a power module having a semiconductor device that converts DC power into AC power and a cooling flow path that cools the semiconductor device, a metal housing member whose bottom surface is thermally connected to the cooling flow path via a heat conduction member; the housing member houses a plurality of smoothing capacitors that smooth the DC power; the plurality of smoothing capacitors are electrically connected to the semiconductor device via a DC bus bar that is connected to the semiconductor device and inputs the DC power to the semiconductor device; the power modules include a first power module having a three-phase AC output and a second power module having a three-phase AC output independent of the first power module; The DC bus bar passes through a space between the first power module and the second power module. Power conversion device.

2. The power conversion device according to claim 1, the accommodating member has first and second smoothing capacitor accommodating portions that accommodate the plurality of smoothing capacitors, and a hole portion through which the DC bus bar passes through the accommodating member, The first and second smoothing capacitor housings are arranged with the hole therebetween. Power conversion device.

3. The power conversion device according to claim 2, a noise filter electrically connected to the smoothing capacitor and the semiconductor device via the DC bus bar, and removing high-frequency noise from the DC power; The housing member has a filter housing portion that houses the noise filter, and the first and second smoothing capacitor housing portions that house the plurality of smoothing capacitors. Power conversion device.

4. The power conversion device according to claim 3, A resin member is filled between the filter housing portion and the noise filter, and between the first and second smoothing capacitor housing portions and the plurality of smoothing capacitors. Power conversion device.

5. 5. The power conversion device according to claim 3, the noise filter includes the DC bus bar that transmits the DC power, a magnetic core member that is arranged to surround the DC bus bar, and a filter capacitor that is connected to the DC bus bar, The DC bus bar has a positive bus bar and a negative bus bar, the filter capacitor includes a first filter capacitor and a second filter capacitor; The first filter capacitor has one end connected to the positive bus bar and the other end connected to the negative bus bar, and the second filter capacitor has one end connected to either the positive bus bar or the negative bus bar and the other end grounded to ground potential. Power conversion device.

6. The power conversion device according to any one of claims 1 to 5, a gate drive board for sending control signals to the semiconductor device; a housing that is a flow path forming body that forms the cooling flow path, the gate drive substrate is disposed opposite the plurality of smoothing capacitors with the power module interposed therebetween; The gate drive board is supported by the housing by connecting the gate drive board to the housing via the thermal conductive member. Power conversion device.

7. 7. The power conversion device according to claim 6, an electronic control board for controlling the operation of the motor driven by the AC power; the housing is connected to a ground potential; the receiving member is electrically connected to the housing; the electronic control board is disposed opposite the plurality of smoothing capacitors with the power module interposed therebetween, and is also disposed opposite the power module with the housing interposed therebetween; The electronic control board is supported by the housing by connecting the electronic control board to the housing via the thermal conductive member. Power conversion device.

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