Power conversion device

Abstract

The power conversion device of the present application includes: a capacitor for smoothing direct current power; a plurality of power modules for converting the direct current power into alternating current power; a first substrate, wherein a plurality of the power modules are disposed on the first substrate; a second substrate configured opposite to the first substrate; a first flow path forming body that forms a flow path for a cooling medium to flow together with a face of the first substrate and a face of the second substrate; and a second flow path forming body that forms the flow path together with the face of the first substrate, wherein both faces of the power modules are cooled by the cooling medium.

Description

Technical Field

[0001] This invention relates to power conversion devices. Background Technology

[0002] In industrial machinery and vehicles (such as motor vehicles and railway vehicles), the electrification and electronic control of power sources are rapidly advancing from the perspectives of energy conservation and precise driving control. Consequently, for power modules that have traditionally been used for power control of power sources, and for the circuit devices that use these power modules for power conversion (power conversion), such as in electric vehicles equipped with power conversion devices and electric motors, the power conversion devices are required to be made thinner in order to increase interior space.

[0003] The following patent document 1 is known as background technology for this application. Patent document 1 discloses a technology that miniaturizes a power conversion device by employing a structure in which a power module and a capacitor module of the power conversion device are sandwiched between a cooling water flow path.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-44891 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] Regarding the technology in Patent Document 1, it is difficult to meet the requirement of further miniaturization of power conversion devices by changing the structure. In view of this, considering the cooling performance that can efficiently cool the power conversion components, power smoothing components, wiring, etc. on the circuit board, and the sealing performance that prevents the cooling medium flowing inside the flow path from leaking to the outside, there is a problem of how to provide a thin power conversion device that balances cooling performance and sealing performance.

[0009] Technical means to solve the problem

[0010] The power conversion device of the present invention includes: a capacitor for smoothing direct current power; a plurality of power modules for converting the direct current power into alternating current power; a first substrate, wherein the plurality of power modules are disposed on the first substrate; a second substrate disposed opposite to the first substrate; a first flow path forming a flow path for a cooling medium to flow together with a surface of the first substrate and a surface of the second substrate; and a second flow path forming a flow path together with a surface of the first substrate, wherein both surfaces of the power modules are cooled by the cooling medium.

[0011] Invention Effects

[0012] The present invention enables the miniaturization of power conversion devices that balance cooling and sealing performance. Attached Figure Description

[0013] Figure 1 This is a circuit diagram of the power conversion device of the present invention.

[0014] Figure 2 This is an explanatory diagram of the power conversion device according to the first embodiment of the present invention.

[0015] Figure 3 Is Figure 2 The diagram shows the upper part of the flow path forming body 27 and the control circuit board installed in the middle.

[0016] Figure 4 From Figure 2 The diagram shows the first circuit board after the flow path forming body 27 has been removed.

[0017] Figure 5 From Figure 4 An explanatory diagram of the flow path formation 3 after the first circuit board 1 has been removed.

[0018] Figure 6 yes Figure 5 AA′ cross section diagram.

[0019] Figure 7 This is a diagram showing the second circuit board 2.

[0020] Figure 8 From Figure 7 After removing the second circuit board 2, the flow path formation body 3 ( Figure 5 Explanatory diagram (on the back).

[0021] Figure 9 yes Figure 8 BB′ cross-sectional view.

[0022] Figure 10 This is an explanatory diagram of a power conversion device according to a second embodiment of the present invention.

[0023] Figure 11 yes Figure 10 An explanatory diagram of the flow path formation 27A formed around the power module 4A.

[0024] Figure 12 From Figure 10 An explanatory diagram of the flow path formation 3A after the first circuit board 1A is removed.

[0025] Figure 13 yes Figure 12 The back of the flow path forming body 3A is shown in the figure.

[0026] Figure 14This is an explanatory diagram of a power conversion device according to a third embodiment of the present invention.

[0027] Figure 15 This is an explanatory diagram of the power conversion device according to the fourth embodiment of the present invention. Detailed Implementation

[0028] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0029] (Circuit structure of the power conversion device)

[0030] Figure 1 This is a circuit diagram of the power conversion device of the present invention.

[0031] The power conversion device converts the direct current (DC) power supplied by the battery in the vehicle into alternating current (AC) power, and smooths the power output to the electric motor using capacitors connected in parallel. Additionally, the power conversion device includes a three-phase single-bridge power module 4 consisting of two semiconductor elements connected in series.

[0032] In each single-arm power module 4, the current flowing through the semiconductor elements of the upper and lower arms is controlled by switching ON / OFF using a control signal input from a signal wiring connected via a gate resistor. The three-phase single-arm power modules 4 are connected in parallel to the high-voltage side input wiring 106 and the low-voltage side input wiring 107, respectively, and are connected to the stator winding of the motor at the midpoint of the series-connected semiconductor elements.

[0033] In addition, the three-phase single-arm inverters 15, which are composed of the single-arm power module 4 and the control circuit, are connected in parallel to the high-voltage side input wiring 106 and the low-voltage side input wiring 107, and output three-phase AC to the motor by performing ON / OFF control.

[0034] The single-bridge power module 4 is, for example, a combination of IGBT (Insulated Gate Bipolar Transistor) and diode, or is composed of MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor).

[0035] (First Implementation)

[0036] Figure 2 This is an explanatory diagram of the power conversion device according to the first embodiment of the present invention.

[0037] Figure 2This is a diagram of a first circuit board 1, on which three phase power modules 4 of a power conversion device are respectively arranged in the circumferential direction. A flow path forming body 27 is provided on its circuit board surface to form a flow path for the flow of cooling medium for cooling each power module 4.

[0038] The first circuit board 1 is fixed to the flow path forming body 3, which is larger in the radial direction than the circuit board, and is fitted and fixed along the edge of the circumference. In order to fix the first circuit board 1 to the flow path forming body 3, a plurality of screw holes 31 are provided on the circumference.

[0039] The flow path forming body 27 forms a flow path together with the surface of the first circuit board. It is configured such that each power module 4 has a through hole 34 in its portion, and the power modules 4 are cooled by a fluid, i.e., a cooling medium, flowing within the flow path forming body 27. Specifically, the flow path forming body 27 includes through holes 34 that function as module flow path sections, which individually cool multiple power modules 4. The cooling medium flowing through the flow path forming body 27 flows as indicated by arrow 21, from the flow path outlet 29 through the flow path holes 25 of the first circuit board (described later), and towards the flow path opening 20 of the flow path forming body 3 (see reference). Figure 5 ).

[0040] In addition, the flow path forming body 27 is fixed to the circuit board surface of the circuit board 1 via a plurality of screw holes 33. The plurality of screw holes 33 are located at the four corners of each through hole 34 and are fastening holes that can simultaneously fix the flow path forming body 27 to the first circuit board 1 and the flow path forming body 3.

[0041] In addition, to prevent corrosion of electrical components, the flow path forming body 27 is only in close contact with the first circuit board 1 around the periphery of the resin covering the power module 4. The flow path forming body 27 is formed so as not to contact the signal control elements, connection terminals 9c, 9d, and crimp terminals 10a, 10b located on the signal wiring section 8 described later.

[0042] Figure 3 Is Figure 2 The diagram shows the upper part of the flow path forming body 27 and the control circuit board 30. The control circuit board 30 has three phases. Figure 1 The control circuit outputs control signals for each power module 4.

[0043] The flow path forming body 27 uses its upper part to prevent the fluid flowing inside from leaking to the outside. In addition, the upper part of the flow path forming body 27 has a flow path inlet 32 ​​for the cooling medium flowing into the entire power conversion device. In addition, a plurality of screw holes 33 are also provided in the same location on the upper part of the flow path forming body 27 as described above, which are also fastening holes that can simultaneously fix the flow path forming body 27 to the first circuit board 1 and the flow path forming body 3.

[0044] The electrical connections of the control circuit board 30 will be described first. The control circuit board 30 is connected to the signal wiring section 8 (see reference 8) configured on the first circuit board 1 via cables and connectors. Figure 4 The circuit board 30 includes an integrated circuit (not shown) that generates an output AC waveform by providing high or low output voltage signals for issuing control signals. The integrated circuit has terminals and wiring on the control circuit board 30 for connecting to the main control unit of the power conversion device. This allows for simultaneous control of the motor with integrated circuits from other power conversion devices, enabling coordinated driving of the motor.

[0045] Next, the configuration of the control circuit board 30 will be described. To prevent the integrated circuit of the control circuit board 30 from reaching high temperatures, the control circuit board 30 is disposed on the opposite side of the flow path forming body 27 to the side that contacts the first circuit board 1, and is fixed by screwing (fixed by threaded engagement) or the like. That is, in the flow path forming body 27 having two opposing sides, one side contacts the first circuit board 1, and the control circuit board 30 is disposed on the other side. Thus, the control circuit board 30 is indirectly cooled via the flow path forming body 27. Alternatively, it can be configured such that a through hole is formed in the upper part of the flow path forming body 27, and the control circuit board 30 is fitted therein, thereby directly cooling it using fluid.

[0046] In addition, the control circuit board 30 is positioned as far away as possible from the crimp terminals 10a and 10b through which DC power flows and the power module 4, so that the integrated circuits on the control circuit board 30 will not be affected by electrostatic noise and radiated noise caused by high-frequency voltage and current during switching operations, thus preventing malfunctions.

[0047] Figure 4 From Figure 2 or Figure 3 The diagram shows the power conversion device after the flow path forming body 27 has been removed.

[0048] The first circuit board 1 has a multi-layer structure, separating the high-voltage side and low-voltage side of the wiring for the voltage input to the power module 4 through an insulator. As described above, a three-phase power module 4 is provided on the first circuit board 1 of the power conversion device. Furthermore, the single-bridge inverter 15 is configured to include the power module 4, capacitor 5, signal wiring section 8, and output wiring section 11a. The capacitor 5 is used to smooth the DC power supplied from the battery, and the multiple power modules 4 convert the DC power into AC power.

[0049] The three-phase single-arm inverter 15 is configured opposite to the first circuit board. Figure 7The second circuit board 2, described later, is electrically connected to form a circuit for the flow of main current for three-phase AC conversion. In addition, the first circuit board 1 has a flow path hole 25, through which the cooling medium flowing out from the flow path outlet 29 of the flow path forming body 27 flows to the flow path formed by the flow path forming body 3 described later.

[0050] The electrical connections of the first circuit board 1 (and the electrical connections of the second circuit board 2, described later) will be explained. The power module 4 is formed by soldering the upper and lower parts of a semiconductor element together with copper foil sandwiching the semiconductor element, thereby extending the output terminal to the copper foil portion. Furthermore, the power module 4 includes a power conversion element (a combination of an IGBT and a diode, or a MOSFET) that switches the low-voltage side to the output side and vice versa, and a semiconductor element that switches the high-voltage side to the output side. The high-voltage DC wiring section 6a connects to the circuit described later via connection terminal 9a. Figure 7 The high-voltage DC wiring section 6b of the second circuit board 2 is connected. The low-voltage DC wiring section 7a is connected to the low-voltage DC wiring section 7b of the second circuit board 2 via the connection terminal 9b. The output wiring section 11a connected to the power module 4 is connected to the output wiring section 11a of the second circuit board via the connection terminal 9e.

[0051] Figure 4 The high-voltage DC wiring section 6c, shown at the bottom of the paper, is connected to the high-voltage DC wiring section 6b of the second circuit board 2 via the connecting terminal 9c. Additionally, the high-voltage DC wiring section 6c is connected to the high-voltage side of the battery via the crimp terminal 10a. Similarly, the low-voltage DC wiring section 7c is connected to the low-voltage DC wiring section 7b of the second circuit board via the connecting terminal 9d, and is connected to the low-voltage side of the battery via the crimp terminal 10b.

[0052] When the semiconductor element on the high-voltage side of power module 4 is turned on, the high-voltage DC wiring section 6a is connected to the output terminal 13, and the output terminal 13 becomes a high-voltage voltage. Conversely, when the semiconductor element on the low-voltage side is turned on, the low-voltage DC wiring section 7a is connected to the output terminal 13 (described later), and the output terminal 13 becomes a low-voltage voltage. Since ripple current is generated at this time, the current is smoothed by using multiple capacitors 5 between the high-voltage DC wiring section 6a and the low-voltage DC wiring section 7a, and by capacitors 14 on the second circuit board 2 connected to the high-voltage DC wiring section 6b and the low-voltage DC wiring section 7b, thereby suppressing the impact of ripple current on the battery.

[0053] Figure 5 From Figure 4 An explanatory diagram of the flow path formation 3 after the first circuit board 1 has been removed.

[0054] The flow path forming body 3 is formed by the first circuit board 1 and the following. Figure 7The second circuit board 2 is sandwiched between the circuit boards and fixed to each other by screwing through multiple screw holes 22 provided on the circumference and around the rotation axis. That is, a flow path for the flow of cooling medium is formed together with the surface of the first circuit board 1 and the surface of the second circuit board 2. In addition, in order to prevent the cooling medium from leaking to the outside, the flow path forming body 3 needs to be in close contact with the circuit boards in the axial direction. Therefore, it has a recess 16a along the flow path wall, and a flexible component is inserted here to prevent the cooling medium from leaking.

[0055] The functions of the various through holes in the flow path forming body 3 will be explained. Through holes 17 are respectively provided corresponding to the positions of the power modules 4 disposed on the first circuit board 1. With this structure, the power modules 4 disposed on the first circuit board 1 are cooled not only by the cooling medium flowing in the flow path forming body 27 but also by the cooling medium flowing in the flow path forming body 3, so the power modules 4 can be cooled from both sides in the axial direction. Through holes 23 are holes through which connection terminals 9a to 9e pass to facilitate electrical connection between the circuit boards that sandwich the flow path forming body 3 vertically in the axial direction. Through holes 18 are through holes other than those 17 and 23.

[0056] The flow path openings 19 and 20 of the flow path forming body 3 will be described. The flow path opening 20 is the inlet for the cooling medium flowing inside the flow path forming body 27 to flow into the flow path forming body 3 through the flow path outlet 29 and the flow path hole 25. The cooling medium flowing into the flow path forming body 3 flows through the recess 24 provided in the flow path forming body 3 as shown by arrow 21 (details will be described later). The flow path opening 19 is the outlet for the cooling medium flowing through the flow path of the flow path forming body 3 to be discharged from the flow path outlet 26 of the second circuit board, which will be described later.

[0057] Figure 6 yes Figure 5 AA′ cross section diagram.

[0058] As described above, the region of the flow path forming body 3 that is closer to the circumferential edge is formed into a structure in which the first circuit board 1 and the second circuit board 2 are sandwiched in the vertical direction of the rotation axis. Furthermore, in the flow path forming body 3, on the side opposite to the side that engages with the first circuit board 1, a recess 16b is also formed to prevent leakage of the cooling medium, allowing for the insertion of a flexible component. Therefore, leakage of the cooling medium can also be prevented when the second circuit board 2 is engaged with the flow path forming body 3.

[0059] Figure 7 This indicates that it is configured in Figures 2-4 The diagram shows the first circuit board 1 and the second circuit board 2 on the back side of the flow path forming body 3. A detailed description of the electrical connection between the first circuit board 1 and the second circuit board 2 is as described above. Figure 4As described above, the explanation is omitted.

[0060] The second circuit board 2 secures the output terminal 13 and the output wiring section 11b with screws via the fastening hole 12, thereby making the output of the power module 4 of the first circuit board 1 electrically connected to the output terminal 13.

[0061] In addition, a flow path outlet 26 is provided on the second circuit board 2. As described above, the cooling medium that flows from the flow path forming body 27 through the flow path forming body 3 to the flow path opening 19 is discharged to the outside from the flow path outlet 26.

[0062] Figure 8 From Figure 7 After removing the second circuit board 2, the flow path formation body 3 ( Figure 5 The diagram shows the back side of the structure. Figure 5 The same parts that have already been explained are omitted.

[0063] The fastening hole 12 is used to fasten the second circuit board 2 to the output terminal 13 and the output wiring portion 11b with screws. Additionally, the screw hole 22 is used to screw the second circuit board 2 to the flow path forming body 3. By fixing the second circuit board 2 to the flow path forming body 3, not only is a flow path formed, but the low-voltage DC wiring portion 7b of the second circuit board 2 is also cooled, thus cooling the circuit board whose temperature rises due to heat generated during power-on.

[0064] A recess 24 is provided in a portion of the flow path forming body 3, extending from the circumferential edge of the flow path forming body 3 towards the center to form a through hole 17. The recess 24 is provided to allow the cooling medium to pass through, and two recesses 24 are formed in the circumferential direction of each through hole 17. This portion of the flow path forming body 3 acts as a support, preventing the flow path of the flow path forming body 3 from narrowing due to deformation of the circuit boards when the first circuit board 1 and the second circuit board 2 are fitted together by clamping the flow path forming body 3 vertically in the axial direction. Recesses 24 are provided on a portion of the flow path forming body 3 to form a flow path for the cooling medium.

[0065] Figure 9 yes Figure 8 The BB′ cross-sectional view. Among them, with Figure 6 The configuration is different; the second circuit board 2 is located above the figure, and the first circuit board 1 is located below the figure.

[0066] The screw hole 22, the recess 16a, and the recess 24 are configured to not overlap each other in the vertical direction, ensuring a thickness that prevents the flow path forming body 3 from deforming. By adopting such a structure, both the conductivity and stability of the flow path in the flow path forming body 3 are ensured.

[0067] According to the first embodiment of the present invention described above, the following effects can be achieved.

[0068] (1) The power conversion device includes: a capacitor 5 for smoothing direct current power; multiple power modules 4 for converting direct current power into alternating current power; a first substrate 1 on which the multiple power modules 4 are disposed; a second substrate 2 disposed opposite to the first substrate 1; a first flow path forming body 3 forming (and cooperating to form) a flow path for cooling medium flow together with the surface of the first substrate 1 and the surface of the second substrate 2; and a second flow path forming body 27 forming (and cooperating to form) a flow path together with the surface of the first substrate 1, wherein the front and back surfaces of the power modules 4 are cooled by the cooling medium. This structure enables the power conversion device to be made thinner while maintaining both cooling and sealing performance.

[0069] (2) The first flow path forming body 3 of the power conversion device has multiple through holes 17 for cooling multiple power modules 4 respectively. With this structure, the flow path width can be stably maintained while cooling the heat-generating electrical components.

[0070] (3) Multiple power modules 4 of the power conversion device are arranged circumferentially on the substrate, and the second flow path forming body 27 has a module flow path section 34 for cooling each of the multiple power modules 4 individually. With this structure, the heat-generating electrical components can be cooled by using a cooling medium flowing in a continuous flow path.

[0071] (4) A control circuit board 30 is included, which is electrically connected to the first substrate 1 of the power conversion device and is used to output control signals for multiple power modules 4. The second flow path forming body 27 has two opposing sides, one side of which contacts the first substrate 1, and the control circuit board 30 is disposed on the other side. With this structure, the control circuit board 30 can be cooled efficiently without being affected by heat generation.

[0072] (5) The first flow path forming body 3 of the power conversion device has a plurality of recesses 24 for the passage of cooling medium. With this structure, it is possible to ensure a conductive flow path while stably maintaining the flow path width.

[0073] (Second Implementation)

[0074] Figure 10 This is an explanatory diagram of a power conversion device according to a second embodiment of the present invention.

[0075] The first circuit board 1A is formed separately for each power module 4A. Similarly, the flow path forming body 27A is not a continuous shape, but is formed separately for each power module 4A. That is, each power module 4A on each first circuit board 1A is independently surrounded by the flow path forming body 27A. Figure 10 In order to facilitate understanding of the power module 4A housed within the flow path forming body 27A, the upper part of the flow path forming body 27A is shown as absent. However, normally, like the other two flow path forming bodies 27A, the upper part of the flow path forming body 27A is covered. Details are in... Figure 11 This will be discussed later.

[0076] Furthermore, the output terminal 13A of the first circuit board 1A is configured to be screwed and fixed to the first circuit board 1A, and extends axially from the first circuit board 1A to the second circuit board 2 along the rotation axis. Additionally, the flow path hole 25A is the insertion port for fluid to enter the power conversion device.

[0077] The control circuit board 30A is not mounted on the first circuit board 1A but on the flow path forming body 3A. That is, the control circuit board 30A improves the mounting area by concentrating the high-voltage DC wiring section 6c, the low-voltage DC wiring section 7c, the connection terminals 9c and 9d, and the crimp terminals 10c and 10d connected to the battery output in one place. Furthermore, while the second embodiment does not show a diagram of the second circuit board 2, the electrical wiring connections are the same as in the first embodiment.

[0078] With this structure, the control circuit board 30A can be positioned at a lower height in the axial direction of the power conversion device compared to the one provided on the flow path forming body 27 in the first embodiment, thereby reducing the overall thickness of the power conversion device.

[0079] Figure 11 yes Figure 10 An explanatory diagram of the flow path forming body 27A formed in the power module 4A. Additionally, Figure 10 The internal structure of any flow path forming body 27A is the same.

[0080] like Figure 11 As shown, a flow path forming body 27A is formed around the power module 4A. This is achieved by forming the flow path forming body 27A to cover the periphery of the resin coated on the circuit board in a manner that surrounds the power module 4A.

[0081] Furthermore, a signal wiring section 8 is provided around the flow path forming body 27A. On the other hand, an output wiring section 11c is provided around the plurality of through holes 36a and 36b located inside the flow path forming body 27A, extending radially toward the center of the rotation axis. A fastening hole 43 is provided on the output wiring section 11c, which is fastened and electrically connected to the output terminal 13A located below it by screwing.

[0082] The cooling medium flows inside the flow path forming body 27A. After flowing through the flow path forming body 3A (described later), the cooling medium flows into the flow path forming body 27A through the through hole 36a, flows within the flow path separated by the baffle 42 as shown by arrow 21, and flows back into the flow path forming body 3A through the through hole 36b (details described later). That is, the first circuit board 1A has multiple through holes for cooling the power module 4A.

[0083] Figure 12 From Figure 10 An explanatory diagram of the flow path formation 3A after the first circuit board 1A is removed.

[0084] Since it lacks the flow path forming body 27 described in the first embodiment, the flow path forming body 3A can increase its thickness in the direction on the paper surface. Therefore, it is possible to make the following... Figure 13 The width of the flow path is increased, or the width of the flow path is narrowed near the through hole 37 that overlaps with the power module 4A.

[0085] Therefore, the flow rate can be adjusted using the flow path forming body 3A, and the flow path can be narrowed at specific locations. This limits the cooling of the circuit board to the wiring sections where heat is present. Furthermore, by narrowing the flow path and increasing the flow rate, it is easier to efficiently cool the wiring and reduce the circuit board temperature. Therefore, no additional flow path is required, which helps to achieve a thinner power conversion device. In addition, because the thickness of the flow path forming body 3A is increased, screw holes can be provided in the flow path forming body 3A at a deeper depth compared to the first embodiment.

[0086] The multiple through holes 37 of the flow path forming body 3A will be explained. These multiple through holes 37 are for cooling from both the upper and lower surfaces in the axial direction using a cooling medium. Figure 10 and Figure 11 The power module 4A is formed. Furthermore, baffles 38, arranged to separate the multiple through holes 37, are used to control the flow of the cooling medium and form the desired flow path. Additionally, the flow of the cooling medium (arrows 21a-21c, 21e, 21f, 21h, 21i) will be explained later. Figure 13 The description is detailed therein.

[0087] Through holes 39a to 39c are for connecting terminals of the first circuit board 1A and the second circuit board 2 to pass through, and through hole 40 is for connecting terminals for connecting to the battery to pass through.

[0088] A flexible component is inserted into the recess 16a so that the cooling medium will not leak to the outside when the first circuit board 1A is fixed on the flow path forming body 3A.

[0089] Figure 13 yes Figure 12An explanatory diagram of the back side of the flow path forming body 3A. The second circuit board 2, which is fitted and fixed to the surface of the flow path forming body 3A in the axial direction, is not shown.

[0090] For the flow mode of the cooling medium flowing inside the flow path forming body 3A and the flow path forming body 27A, using Figures 11-13 Please provide an explanation.

[0091] First, from Figure 11 and Figure 12 The cooling medium flowing into the flow path orifice 25A shown in the figure is from... Figure 13 The flow path inlet 32 ​​flows as indicated by arrow 21a. Then, the cooling medium flows into the through-hole 41a, as... Figure 12 The flow is indicated by arrow 21b in the through hole 37. At this time, the cooling medium directly cools the surface of one side of the flow path forming body 3A in the power module 4A.

[0092] Then, the cooling medium passes through the first circuit board 1A. Figure 11 The through-hole 36a allows water to flow into the surface opposite to the first circuit board 1A, following the flow path formed by the flow path forming body 27A and the baffle 42, and flowing onto the surface of the power module 4A as shown by arrow 21. This structure allows the power module 4A to be cooled from the surface opposite to the flow path forming body 3A, thus enabling cooling of the power module 4A from both the front and back sides.

[0093] Then, the cooling medium passes through the circuit board 1A. Figure 11 The through hole 36b flows in again Figure 12 The flow is as shown by arrow 21c in the through hole 37, and flows from the through hole 41b to the back side of the flow path forming body 3A, as shown by arrow 21d.

[0094] Similarly, after the cooling medium flows into the through hole 41c, as... Figure 12 The flow is indicated by arrow 21e in the through hole 37, and from... Figure 11 The through-hole 36a flows into the surface of the power module 4A and into the flow path forming body 27A. Then, from the through-hole 36b... Figure 12 The flow is as shown by arrow 21f, and then flows through the through hole 41d as shown by arrow 21g.

[0095] The cooling of the other power module 4A is similar, with the cooling medium flowing in the following order: arrow 21g, through hole 41e, arrow 21h, through hole 36a, arrow 21 ( Figure 11 The flow is as follows: through hole 36b, arrow 21i, through hole 41f, and arrow 21j.

[0096] After the cooling medium advances as indicated by arrow 21j, it is discharged from the flow path outlet 26 provided on the second circuit board 2 (not shown).

[0097] According to the second embodiment of the present invention described above, the following effects can be achieved.

[0098] (6) The first substrate 1A of the power conversion device has multiple through holes 36a, 36b for cooling the power module 4A. This structure helps to reduce the thickness of the power conversion device while cooling the power module 4A.

[0099] (7) Multiple power modules 4A of the power conversion device are arranged circumferentially on the substrate, and the second flow path forming body 27A is provided separately for each of the multiple power modules 4A. This structure helps to make the power conversion device thinner.

[0100] (Third Implementation)

[0101] Figure 14 This is an explanatory diagram of an electric motor including a power conversion device according to the third embodiment of the present invention.

[0102] Figure 14 This describes the structure of an electric motor, taking an external rotor type motor as an example. The motor includes a rotor 45 and a stator housing 46. On the stator housing 46, flow path forming body 3B and flow path forming body 27B are provided on the side opposite to the side where the rotor 45 is located.

[0103] A power conversion device (not shown) is located on the surface of the flow path forming body 27B that contacts the stator, and an output terminal 13B is connected to the front end of the output wiring section extending from there. The output terminal 13B is connected to the wiring extending from the front end of the stator coil 44 through the interior of the stator housing 46 of the motor, thereby forming a three-phase AC circuit with the stator coil 44 as the load. A rotating magnetic field is generated by flowing three-phase AC current through the stator coil 44, causing the rotor 45 located outside the stator to rotate with the rotating magnetic field.

[0104] The capacitor 14B is arranged inside the stator housing 46, which is radially inward of the stator shaft, thus effectively utilizing the space between the stator and the shaft in the radial direction. Furthermore, for the same reason, the output current sensor 47, the stator current path inlet 48, and the stator current path outlet 49 are arranged radially inward relative to the stator coil 44.

[0105] The flow path outlet (not shown) of the power conversion device is connected to the flow path inlet 48 of the stator, allowing the cooling medium to flow as indicated by arrow 21B, and then discharge it from the flow path outlet 49 of the flow path forming body 3B. This ensures that the cooling medium flowing in the motor and the power conversion device is the same, enabling simultaneous cooling of the heat-generating equipment.

[0106] Alternatively, the power conversion device can be positioned such that the inlet and outlet of the cooling medium, the connection points of the output wiring section and the crimp terminals, and the connection points of the control signal wiring terminals are all located on the same side of the circuit board, and the power conversion device is placed between the stator and the rotor.

[0107] (Fourth Implementation)

[0108] Figure 15 This is an explanatory diagram of the power conversion device according to the fourth embodiment of the present invention.

[0109] Figure 15 and Figure 14 The difference compared to the third embodiment is that the rotor 45 is disposed on a surface of the flow path forming bodies 3C and 27C provided on the stator. The flow path inlet 48C of the stator is provided as a flow path outlet for the cooling medium that cools the stator coil 44, and it is a flow path that continues to the flow path inlet (not shown) of the flow path forming body 3C. Thus, the cooling medium flows as shown by arrow 21C, flows into the power conversion device, and is discharged from the flow path outlet (not shown) of the flow path forming body 3C to the flow path outlet 50 as shown by arrow 21C.

[0110] Furthermore, the DC power input wirings 52a and 52b, located inside the stator coils, are connected to the input terminals on a second circuit board (not shown) located in the gap between the flow path forming body 3C and the stator housing 46, thereby electrically connecting to the wiring of the second circuit board. In this case, the connection terminals shown in the first and second embodiments, which function as electrical connections between circuit boards, are not required. Instead, the signal input wiring 51 is connected to the control circuit, thereby enabling the input of power and control signals from the outside.

[0111] The above embodiments are merely examples, and are not limited to the specific structures described, as long as the features of the invention are not impaired. For example, a portion of the structure of an embodiment can be replaced with a structure familiar to those skilled in the art. Furthermore, structures familiar to those skilled in the art can be added to the structure of an embodiment. That is, in this invention, a portion of the structure of an embodiment described in this specification can be deleted / replaced with other structures / added with other structures without departing from the inventive concept; such solutions are also included within the scope of this invention.

[0112] Explanation of reference numerals in the attached figures

[0113] 1.1A First Circuit Board

[0114] 2 Second Circuit Board

[0115] 3, 3A~3C, 27, 27A Flow path forming body

[0116] 4 Power Modules

[0117] 5, 14 capacitors

[0118] 12, 43 Fastening holes

[0119] 15 Single-bridge inverter

[0120] 16a, 16b, 24 concavity

[0121] Through holes 17, 18, 23, 34, 36, 37, 40, 41a, 41b

[0122] 19, 20 intersection

[0123] 20, 32, 48 Flow path entrance

[0124] Arrows 21, 21a~21k, 21B, and 21C indicate the flow of the cooling medium (fluid).

[0125] Screw holes 22, 31, and 33

[0126] 25, 25A flow hole

[0127] 26, 29, 49, 50 Flow path outlet

[0128] 30, 30A control circuit board

[0129] 38, 42 baffles

[0130] 44 Stator coils

[0131] 45 rotor

[0132] 46 Stator Housing

Claims

1. A power conversion device, characterized in that, include: Capacitors used to smooth DC power; Multiple power modules for converting the DC power into AC power; A first substrate, wherein a plurality of the power modules are disposed on the first substrate; A second substrate disposed opposite to the first substrate; A first flow path form, which together with the surfaces of the first substrate and the second substrate, forms a flow path for the flow of a cooling medium; and The second flow path form, together with the surface of the first substrate, forms a flow path for the cooling medium to flow. The power module is cooled on both sides by the cooling medium.

2. The power conversion device as described in claim 1, characterized in that: The first flow path forming body has a plurality of through holes for cooling the plurality of power modules respectively.

3. The power conversion device as described in claim 1, characterized in that: The plurality of power modules are respectively arranged in the circumferential direction on the substrate; The second flow path form includes a module flow path section for individually cooling each of the plurality of power modules.

4. The power conversion device as described in claim 1, characterized in that: This includes a control circuit board electrically connected to the first substrate and used to output control signals to the plurality of power modules. The second flow path form has two opposing sides, one of which is in contact with the first substrate, and the control circuit board is disposed on the other side.

5. The power conversion device as described in claim 1, characterized in that: The first flow path form has a plurality of recesses for allowing the cooling medium to pass through.

6. The power conversion device as described in claim 1, characterized in that: The first substrate has a plurality of through holes for cooling the power module.

7. The power conversion device as described in claim 6, characterized in that: The plurality of power modules are respectively arranged in the circumferential direction on the substrate. The second flow path formwork is configured individually for each of the plurality of power modules.

Images