JP2022160942A - Power conversion device - Google Patents

Abstract

To provide a power conversion device capable of efficiently cooling a plurality of semiconductor modules even when arranging three or more semiconductor modules including switching elements on a common cooling surface.SOLUTION: A power conversion device 100 includes semiconductor modules 11, 12, and 13 each of which includes a switching element. The semiconductor modules 11 and 13 are arranged side by side on a cooling surface 81a in a α direction separated from each other. The semiconductor module 12 is arranged on the cooling surface 81a separated from the semiconductor modules 11 and 13 on a β direction side crossing the α direction.SELECTED DRAWING: Figure 8

Description

The present invention relates to a power conversion device, and more particularly to a power conversion device including a plurality of semiconductor modules.

2. Description of the Related Art Conventionally, a power conversion device including a plurality of semiconductor modules is known (see Patent Document 1, for example).

The power converter described in Patent Literature 1 includes a plurality of semiconductor modules. In a plurality of semiconductor modules, two current switch circuits each composed of a parallel connection circuit of a semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) and a diode are arranged in series. . In the power converter described in Patent Document 1, four semiconductor modules out of the plurality of semiconductor modules are arranged vertically so as to be in contact with the cooler.

WO2019/146179

However, in the power conversion device described in Patent Document 1, four semiconductor modules each including a semiconductor element (switching element) that becomes a heat source by switching operation are arranged vertically and arranged in the cooler. becomes relatively close. Therefore, when three or more semiconductor modules having switching elements are arranged on a common cooling surface (cooler), there is a problem that the cooling efficiency of the semiconductor modules is lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a method for arranging three or more semiconductor modules having switching elements on a common cooling surface. Another object of the present invention is to provide a power converter capable of efficiently cooling a plurality of semiconductor modules.

To achieve the above object, a power conversion device according to one aspect of the present invention has a power conversion section including a plurality of semiconductor modules having switching elements, and a cooling surface on which each of the plurality of semiconductor modules is arranged. and a cooling body for cooling each of the plurality of semiconductor modules arranged on the cooling surface, the plurality of semiconductor modules each having a switching element, a first semiconductor module, a second semiconductor module, and a third semiconductor module. a first semiconductor module and a third semiconductor module are arranged side by side in a first direction at a distance from each other on the cooling surface of the cooling body; are arranged on the cooling surface of the cooling body so as to be spaced apart in a second direction crossing the first direction.

In the power converter according to one aspect of the present invention, as described above, the first semiconductor module and the third semiconductor module are arranged side by side in the first direction while being separated from each other on the cooling surface of the cooling body. The second semiconductor module is arranged on the cooling surface of the cooling body so as to be separated from the first semiconductor module and the third semiconductor module in the second direction crossing the first direction. Thus, on the common cooling surface, the first semiconductor module and the third semiconductor module are arranged side by side in the first direction, and the second semiconductor module is arranged apart in the second direction crossing the first direction. Therefore, compared to the case where the first semiconductor module, the second semiconductor module and the third semiconductor module are arranged in the same direction and arranged on a common cooling surface, the first semiconductor module, the second semiconductor module, Also, the mutual distance on the cooling surface between the third semiconductor modules can be increased. Therefore, it is possible to increase the distance between the plurality of switching elements that serve as heat sources and are included in each of the first semiconductor module, the second semiconductor module, and the third semiconductor module. As a result, the distance between the heat sources can be increased, so even when three or more semiconductor modules having switching elements are arranged on a common cooling surface, the plurality of semiconductor modules can be efficiently cooled. can.

In the power conversion device according to the above aspect, each of the first semiconductor module, the second semiconductor module, and the third semiconductor module preferably has a rectangular parallelepiped shape having a rectangular surface to be cooled in contact with the cooling surface of the cooling body. the first semiconductor module and the third semiconductor module are spaced apart from each other and arranged side by side in parallel so that the short side of the surface to be cooled extends along the first direction; are arranged along a second direction perpendicular to the first direction. According to this structure, the rectangular surface to be cooled of the second semiconductor module and the rectangular surfaces to be cooled of the first semiconductor module and the third semiconductor module can be arranged in directions perpendicular to each other. Therefore, on the cooling surface, unlike the case where the second semiconductor module is arranged in a direction that obliquely intersects the first semiconductor module and the third semiconductor module that are arranged in parallel, , and the distance from the second semiconductor module to the third semiconductor module can be made equal. can be suppressed. As a result, the plurality of semiconductor modules can be evenly cooled, so that the semiconductor modules can be efficiently cooled.

The power conversion device according to the above aspect preferably further includes a first power conversion group and a second power conversion group each including a power conversion unit and configured to individually switch and output power, The cooling body has one surface serving as a cooling surface on which each of the plurality of semiconductor modules of the power conversion units included in the first power conversion group is arranged, and the plurality of semiconductor modules of the power conversion units included in the second power conversion group. and a plate-like cooling plate portion having the other surface which is a cooling surface on which each of the is arranged. With this configuration, by arranging the first power conversion group and the second power conversion group, which are configured to individually switch and output power, on one side and the other side of the common cooling plate portion Allow to cool. Therefore, compared to the case where the first power conversion group and the second power conversion group are arranged on the same side surface of one cooling plate unit, by using a common cooling plate unit while switching the power output operation, the cooling plate It is possible to reduce the area of the cooling surface of the part. As a result, it is possible to efficiently cool a plurality of semiconductor modules while miniaturizing the device configuration and reducing the number of parts.

In this case, preferably, the cooling body is connected to the cooling plate part so as to be able to exchange heat, and includes a heat dissipation part that is commonly used for the first power conversion group and the second power conversion group. With this configuration, by connecting the heat dissipating portion commonly used to the cooling plate portion commonly used for the first power conversion group and the second power conversion group so as to be able to exchange heat, A plurality of semiconductor modules can be cooled. Therefore, by sharing not only the cooling plate portion but also the heat radiating portion, it is possible to efficiently cool a plurality of semiconductor modules while further reducing the size of the device configuration and the number of parts.

In the power converter according to the above aspect, preferably each of the first semiconductor module and the third semiconductor module has one switching element, and the second semiconductor module has two switching elements. According to this structure, the first semiconductor module and the third semiconductor module each having one switching element are arranged side by side in the first direction, and the second semiconductor module each having two switching elements is connected to the first semiconductor module and the third semiconductor module. It can be spaced apart in a second direction side different from the first direction in which the three semiconductor modules are arranged. Therefore, by arranging only the second semiconductor module having many heat sources away from each other in the second direction, which is a different direction, the plurality of semiconductor modules are arranged so as to prevent the plurality of heat sources from becoming too close to each other. be able to. As a result, it is possible to suppress the occurrence of a difference in the cooling efficiency of each semiconductor module due to the cooling body, so that it is possible to cool the plurality of semiconductor modules more efficiently.

In the power conversion device according to the above aspect, preferably, a plate-shaped first connection conductor electrically connecting the first semiconductor module and the second semiconductor module, and the second semiconductor module and the third semiconductor module are electrically connected to each other. and a plate-shaped second connection conductor that is physically connected, and the first connection conductor and the second connection conductor are laminated while being insulated from each other. With this configuration, the first connection conductor and the second connection conductor are laminated while being insulated from each other, so that the current flowing from the first semiconductor module toward the second semiconductor module and the second semiconductor module The current flowing from the second semiconductor module to the third semiconductor module can be flowed in a state of being adjacent to each other. Therefore, the parasitic inductance generated in the first connection conductor and the second connection conductor can be reduced by causing currents to flow in the first connection conductor and the second connection conductor in opposition to each other. As a result, the first semiconductor module and the third semiconductor module are arranged side by side in the first direction, and the second semiconductor module is arranged separately in the second direction crossing the first direction, and then connected to each other. By stacking the first connection conductors and the second connection conductors on each other, it is possible to efficiently cool the plurality of semiconductor modules and to suppress a decrease in power conversion efficiency due to parasitic inductance.

In the power conversion device according to the above aspect, preferably, the power conversion section is configured to output power at three levels of potentials, namely, an upper potential, an intermediate potential, and a lower potential. A smoothing capacitor module that includes a positive electrode capacitor and a negative electrode capacitor that are connected in series with a negative electrode and that smoothes input power; and a positive terminal of a first semiconductor module that is provided on the positive electrode. , the positive side conductor electrically connecting the positive side terminal of the smoothing capacitor module connected to the positive side of the positive side capacitor, and the middle of the smoothing capacitor module connected to the negative side of the positive side capacitor and the positive side of the negative side capacitor an intermediate conductor for electrically connecting the terminal, the negative terminal of the first semiconductor module provided on the positive electrode side, and the positive terminal of the third semiconductor module provided on the negative electrode side; a negative conductor electrically connecting the negative terminal of the third semiconductor module and the negative terminal of the smoothing capacitor module connected to the negative side of the negative capacitor, the positive conductor and the intermediate conductor; , and the negative conductor are laminated in this order while being insulated from each other. According to this configuration, in a three-level inverter that outputs three levels of potential power, the positive side conductor and the intermediate conductor are laminated so as to be adjacent to each other, and the negative side conductor and the intermediate conductor are laminated so as to be adjacent to each other. Can be stacked. Therefore, by making the current flowing in the positive conductor and the current flowing in the intermediate conductor face each other, the parasitic inductance generated in the positive conductor and the intermediate conductor can be reduced. Parasitic inductance generated in the negative conductor and the intermediate conductor can be reduced by opposing the flowing current. As a result, it is possible to reduce the parasitic inductance generated in the positive conductor, the intermediate conductor, and the negative conductor. A decrease in conversion efficiency can be suppressed.

In this case, preferably, the smoothing capacitor module has a rectangular parallelepiped shape and is arranged so as to face the cooling surface of the cooling body on which each of the plurality of semiconductor modules is arranged. The terminal and the intermediate terminal are arranged on a common terminal arrangement surface adjacent to the surface facing the cooling surface in the first direction in the smoothing capacitor module having a rectangular parallelepiped shape. , and the negative conductor are L-shaped plates bent from the direction along the cooling surface to the direction along the terminal arrangement surface. With this configuration, the positive conductor, the intermediate conductor, and the negative conductor are L-shaped plates bent from the direction along the cooling surface to the direction along the terminal arrangement surface. Even when the module and the smoothing capacitor module are arranged close to each other, the positive conductor, the intermediate conductor, the negative conductor, and the smoothing capacitor module are connected to each other on the terminal arrangement surface adjacent to the surface facing the cooling surface. can be easily connected. Therefore, even when the plurality of semiconductor modules and the smoothing capacitor module are arranged close to each other, the assembly work for connecting the terminals can be easily performed. As a result, by arranging the plurality of semiconductor modules and the smoothing capacitor module close to each other, it is possible to reduce the size of the device configuration and improve the workability of the assembly work.

In the power conversion device according to the above aspect, preferably, four intermediate terminals of the smoothing capacitor module are arranged in a row along the side of the surface facing the cooling surface on the terminal arrangement surface, and the smoothing capacitor Two positive terminals of the module are arranged adjacent to each other, two negative terminals of the smoothing capacitor module are arranged adjacent to each other, and each of the two positive terminals and the two negative terminals is , are arranged in a row so as to be adjacent to each of the four intermediate terminals arranged in a row on the terminal arrangement surface. With this configuration, compared to the case where each of the positive side terminal and the negative side terminal is not arranged adjacent to the intermediate terminal, the overlapping portion of each of the positive side conductor and the negative side conductor and the intermediate conductor is reduced. Distance can be greater. Therefore, in each of the positive-side conductor and the negative-side conductor and the intermediate conductor, the distance between the portions where the flowing currents face can be increased. As a result, the inductance generated in the positive conductor, the intermediate conductor, and the negative conductor can be further reduced, thereby further suppressing a decrease in power conversion efficiency.

In the power conversion device according to the above aspect, preferably, a first-phase power conversion unit and a second-phase power each including a power conversion section and outputting AC power of each phase of three-phase AC power further comprising a conversion unit and a third phase power conversion unit, wherein the cooling body is provided for cooling each of the plurality of semiconductor modules included in the first phase power conversion unit and the second phase power conversion unit; a second cooling body that cools each of the plurality of semiconductor modules included; and a third cooling body that cools each of the plurality of semiconductor modules included in the third phase power conversion unit. With this configuration, the plurality of semiconductor modules included in each of the first-phase power conversion unit, the second-phase power conversion unit, and the third-phase power conversion unit can be cooled by separate cooling bodies. . Therefore, in each of the first-phase power conversion unit, the second-phase power conversion unit, and the third-phase power conversion unit, it is possible to arrange a plurality of semiconductor modules in each cooling body so as to increase the mutual distance. Therefore, it is possible to efficiently cool a plurality of semiconductor modules having switching elements. Therefore, even when the AC power of each phase of the three-phase AC power is separately output, the plurality of semiconductor modules having the switching elements can be efficiently cooled.

In the power conversion device according to the above aspect, the power conversion unit is preferably mounted on a railway vehicle and configured to output AC power to an auxiliary power supply line for supplying auxiliary power to the railway vehicle. there is With this configuration, even when AC power is output to an auxiliary power supply line for supplying auxiliary power to a railway vehicle, the plurality of semiconductor modules having switching elements in the power conversion unit can be efficiently cooled. can be done. Therefore, a more stable auxiliary power supply can be supplied to the railway vehicle.

According to the present invention, as described above, even when three or more semiconductor modules having switching elements are arranged on a common cooling surface, the power converter can efficiently cool the plurality of semiconductor modules. Equipment can be provided.

1 is a schematic diagram showing a railway vehicle equipped with a power conversion device according to an embodiment; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram for demonstrating the structure of the power converter device by this embodiment. 1 is a circuit diagram of a power converter according to this embodiment; FIG. FIG. 4 is a circuit diagram of a first power conversion group in a first phase power conversion unit; FIG. 3 is a diagram showing three semiconductor modules; FIG. 3 is a schematic diagram for explaining connections between a smoothing capacitor module and three semiconductor modules; FIG. 3 is a perspective view for explaining the structure of a cooling body; FIG. 3 is a diagram for explaining the arrangement of semiconductor modules on a cooling surface of a cooling body; FIG. 4 is a diagram showing the arrangement of terminals in a smoothing capacitor module; FIG. 4 is a diagram for explaining connection conductors; FIG. 4 is a diagram for explaining connection between a semiconductor module and a smoothing capacitor module by a connection conductor; It is a figure for demonstrating arrangement|positioning of a 1st power conversion group and a 2nd power conversion group. It is the figure which showed the structure of the smoothing capacitor module by the modification of this invention.

Embodiments embodying the present invention will be described below with reference to the drawings.

A configuration of a power converter 100 according to the present embodiment will be described with reference to FIGS. 1 to 12. FIG. Note that the power conversion device 100 is mounted on a railway vehicle 101 .

(Railway vehicle configuration)
As shown in FIG. 1, a railway vehicle 101 is configured to run on rails using electric power supplied from an overhead wire 102 as a DC power supply. In the following description, the traveling direction of the railroad vehicle 101 is the X direction, the horizontal direction of the railroad vehicle 101 is the Y direction, and the vertical direction (vertical direction) of the railroad vehicle 101 is the Z direction.

The railway vehicle 101 includes a pantograph 101a, a circuit breaker 101b (see FIG. 3), an auxiliary power supply line 101c, a load 101d, and a power converter 100. The pantograph 101 a receives (collects) power supplied to the overhead wire 102 . The circuit breaker 101b releases the electric circuit when an overcurrent occurs. Circuit breaker 101b includes, for example, a high speed circuit breaker. The auxiliary power line 101c is a power line for supplying auxiliary power to the railroad vehicle 101 . Specifically, the auxiliary power line 101c is a power line for supplying the load 101d with power from the power conversion device 100, which will be described later. The load 101d includes air conditioners, control devices, and the like mounted on the railcar 101 . The load 101d operates with AC power supplied from the power converter 100 through the auxiliary power supply line 101c.

The power converter 100 is an auxiliary power supply that converts the DC power from the overhead wire 102 into three-phase AC power and supplies it to the load 101d. Further, the power conversion device 100 is attached to the lower side (Z2 side) of the bottom portion of the vehicle body of the railway vehicle 101 .

(Overall configuration of power converter)
As shown in FIG. 2, in this embodiment, the power conversion device 100 includes three power conversion units. Specifically, the power converter 100 includes a first phase power conversion unit 100a, a second phase power conversion unit 100b, and a third phase power conversion unit 100c. The first-phase power conversion unit 100a, the second-phase power conversion unit 100b, and the third-phase power conversion unit 100c are each configured to output each of three-phase AC power. Specifically, the first phase power conversion unit 100a is configured to output U-phase AC power. The second phase power conversion unit 100b is configured to output V-phase AC power. The third phase power conversion unit 100c is configured to output W-phase AC power.

As shown in FIG. 3 , the power conversion device 100 is a standby redundant power conversion device configured to be capable of switching between two power conversion operations on the first group side and the second group side. The first phase power conversion unit 100a includes a first power conversion group 1a and a second power conversion group 2a. Also, the second phase power conversion unit 100b includes a first power conversion group 1b and a second power conversion group 2b. Also, the third phase power conversion unit 100c includes a first power conversion group 1c and a second power conversion group 2c.

In this embodiment, the first power conversion group 1a and the second power conversion group 2a respectively include power conversion units 10 and 20 that perform power conversion operations. And the 1st power conversion group 1a and the 2nd power conversion group 2a are comprised so that an electric power may be switched and output individually. Specifically, a first phase power conversion unit 100a that outputs U-phase AC power includes a first power conversion group 1a that outputs a U-phase and a second power conversion group 2a that outputs a U-phase. Similarly, the second phase power conversion unit 100b that outputs the V phase includes a first power conversion group 1b that outputs the V phase and a second power conversion group 2b that outputs the V phase. Similarly, the third phase power conversion unit 100c that outputs the W phase also includes a first power conversion group 1c that outputs the W phase and a second power conversion group 2c that outputs the W phase. The first power conversion groups 1a, 1b, and 1c constitute the first group side, and the second power conversion groups 2a, 2b, and 2c constitute the second group side.

The first phase power conversion unit 100a normally operates the first power conversion group 1a on the first group side without operating the second power conversion group 2a on the second group side to convert the input DC power. output U-phase AC power. Then, when a problem such as a failure occurs in the first power conversion group 1a on the first group side, the power converter 100 changes the output from the first power conversion group 1a to the output from the second power conversion group 2a. configured to switch. Similarly, the second phase power conversion unit 100b and the third phase power conversion unit 100c are configured to switch to the second group side and perform the power conversion operation when a problem occurs in the first group side.

The power conversion device 100 also includes switches 3a, 3b, 3c, and 3d. The switches 3a to 3d are configured to open and close in order to switch between the output from the first group side and the output from the second group side. Power conversion device 100 conducts switches 3a and 3c when operating the first group (first power conversion groups 1a, 1b, and 1c) based on a control signal from a control unit (not shown). Then, the power conversion device 100 conducts the switches 3b and 3d when operating the second group side (the second power conversion groups 2a, 2b, and 2c) based on the control signal from the control unit. Switches 3a-3d include, for example, electromagnetic contactors.

(power conversion unit)
Next, the configuration of the first phase power conversion unit 100a will be described with reference to FIGS. 2 to 12. FIG. The second-phase power conversion unit 100b and the third-phase power conversion unit 100c have the same configuration as the first-phase power conversion unit 100a, so description thereof will be omitted.

As shown in FIGS. 2 to 4, the first power conversion group 1a on the first group side of the first phase power conversion unit 100a includes a power conversion section 10, a smoothing capacitor module 30, and a connection conductor 50. FIG. A second power conversion group 2 a on the second group side of the first phase power conversion unit 100 a includes a power conversion section 20 , a smoothing capacitor module 40 , and a connection conductor 60 .

As shown in FIGS. 3 and 4, in the present embodiment, the power conversion unit 10 is configured to output power of three levels of potentials, ie, an upper potential, a middle potential, and a lower potential. Specifically, the power conversion unit 10 performs a power conversion operation based on the input of the positive side, which is the input of the DC voltage from the pantograph 101a, and the negative side, which is grounded, and outputs potentials of three levels. It has a three-level inverter circuit that In this embodiment, the power converters 10 and 20 mounted on the railcar 101 are configured to output AC power to the auxiliary power supply line 101c.

<Semiconductor module>
As shown in FIG. 5, the power conversion unit 10 of the first power conversion group 1a includes three semiconductor modules (semiconductor module 11, semiconductor module 12, and semiconductor module 13). The semiconductor module 11 has one switching element Q1. Semiconductor module 12 has two switching elements Q2 and Q3. The semiconductor module 13 has one switching element Q4. Switching elements Q1-Q4 are, for example, IGBTs. The three semiconductor modules 11, 12, and 13 are examples of "a plurality of semiconductor modules" in the claims. Also, the semiconductor modules 11, 12 and 13 are examples of the "first semiconductor module", the "second semiconductor module" and the "third semiconductor module" in the claims, respectively.

In this embodiment, the semiconductor module 11 is provided on the positive electrode side. The semiconductor module 11 has a switching circuit arranged on the positive side in which the switching element Q1 and the diode D1 are connected in parallel, and a diode D2 arranged on the negative side. In the semiconductor module 11, the switching circuit arranged on the positive side and the diode D2 arranged on the negative side are connected in series. The semiconductor module 11 has a terminal P1, a terminal C1, a terminal N1, and a terminal G1. Terminal P1 is connected to the positive side of semiconductor module 11 . Terminal N1 is connected to the negative side of semiconductor module 11 . The terminal C1 is connected between the switching circuit arranged on the positive side of the semiconductor module 11 and the diode D2 arranged on the negative side. A terminal G1 is connected to a gate terminal of a switching element Q1 to which a gate signal from a gate substrate 70, which will be described later, is input. The terminal P1 and the terminal N1 are examples of the "positive terminal of the first semiconductor module" and the "negative terminal of the first semiconductor module", respectively, in the claims.

In this embodiment, the semiconductor module 12 includes a switching circuit arranged on the positive side where the switching element Q2 and the diode D3 are connected in parallel, and a switching circuit arranged on the negative side where the switching element Q3 and the diode D4 are connected in parallel. It has two switching circuits with the switching circuit being In the semiconductor module 12, two switching circuits are connected in series. The semiconductor module 12 has a terminal P2, a terminal C2, a terminal N2, a terminal G2, and a terminal G3. Terminal P2 is connected to the positive side of semiconductor module 12 . Terminal N2 is connected to the negative side of semiconductor module 12 . The terminal C2 is connected between a switching circuit arranged on the positive side of the semiconductor module 12 and a switching circuit arranged on the negative side. A terminal G2 is connected to a gate terminal of a switching element Q2 to which a gate signal from a gate substrate 70, which will be described later, is input. Similarly, terminal G3 is connected to the gate terminal of switching element Q3 to which a gate signal from gate substrate 70, which will be described later, is input.

Moreover, in this embodiment, the semiconductor module 13 is provided on the negative electrode side. The semiconductor module 13 has a diode D5 arranged on the positive side and a switching circuit arranged on the negative side in which the switching element Q4 and the diode D6 are connected in parallel. In the semiconductor module 13, the diode D5 arranged on the positive side and the switching circuit arranged on the negative side are connected in series. The semiconductor module 13 has a terminal P3, a terminal C3, a terminal N3, and a terminal G4. Terminal P3 is connected to the positive side of semiconductor module 13 . Terminal N3 is connected to the negative side of semiconductor module 13 . The terminal C3 is connected between the diode D5 arranged on the positive side of the semiconductor module 13 and the switching circuit arranged on the negative side. A terminal G4 is connected to a gate terminal of a switching element Q4 to which a gate signal from a gate substrate 70, which will be described later, is input. The terminal P3 and the terminal N3 are examples of the "positive terminal of the third semiconductor module" and the "negative terminal of the third semiconductor module", respectively, in the claims.

As shown in FIGS. 2 and 4 , first phase power conversion unit 100 a includes gate substrate 70 . The gate substrate 70 outputs gate signals for controlling switching operations of the switching elements Q1 to Q4 based on control signals from a control section (not shown). The gate signal is, for example, a PWM (pulse width modulation) signal. The gate substrate 70 similarly outputs gate signals to the power conversion units 20 of the second power conversion group 2a on the second group side. The gate substrate 70 is arranged along the XZ plane on the Y1 direction side of the first phase power conversion unit 100a.

<Smoothing capacitor module>
As shown in FIG. 4 , the smoothing capacitor module 30 of the first power conversion group 1a has capacitors 31 and 32 . In this embodiment, the smoothing capacitor module 30 smoothes the input power. The capacitors 31 and 32 are configured to be connected in series between the positive and negative sides of the input in the first power conversion group 1a. Specifically, the smoothing capacitor module 30 is configured such that a capacitor 31 is connected to the positive electrode side and a capacitor 32 is connected to the negative electrode side. Capacitors 31 and 32 are, for example, film capacitors. Note that the capacitor 31 is an example of a "positive capacitor" in the scope of claims. Also, the capacitor 32 is an example of a "negative capacitor" in the claims.

The smoothing capacitor module 30 also has a terminal P4, a terminal C4, and a terminal N4. Terminal P4 is connected to the positive electrode side of smoothing capacitor module 30 . That is, terminal P4 is connected to the positive electrode side of capacitor 31 . Terminal N4 is connected to the negative electrode side of smoothing capacitor module 30 . That is, terminal N4 is connected to the negative electrode side of capacitor 32 . A terminal C<b>4 is an intermediate terminal of the smoothing capacitor module 30 . That is, terminal C4 is connected between capacitors 31 and 32 . Specifically, terminal C4 is connected to the negative electrode side of capacitor 31 and the positive electrode side of capacitor 32 .

<Electrical connection between semiconductor module and capacitor>
As shown in FIGS. 4 and 6, connection conductors 50 electrically connect power converter 10 (semiconductor modules 11 to 13) and smoothing capacitor module 30 . Specifically, connection conductors 50 include conductors 51 , 52 , 53 , 54 and 55 . The conductor 51 is an example of the "first connection conductor" in the claims. Also, the conductor 52 is an example of a "second connection conductor" in the claims. Also, the conductor 53 is an example of a "positive conductor" in the claims. Also, the conductor 54 is an example of an "intermediate conductor" in the claims. Also, the conductor 55 is an example of a "negative conductor" in the claims.

In this embodiment, the conductor 51 electrically connects the semiconductor module 11 and the semiconductor module 12 . Specifically, conductor 51 connects terminal C<b>1 of semiconductor module 11 and terminal P<b>2 of semiconductor module 12 . Also, the conductor 52 electrically connects the semiconductor module 12 and the semiconductor module 13 . Specifically, conductor 52 connects terminal N2 of semiconductor module 12 and terminal C3 of semiconductor module 13 .

In this embodiment, the conductor 53 electrically connects the terminal P1 of the semiconductor module 11 and the terminal P4 of the smoothing capacitor module 30 provided on the positive electrode side. Conductor 53 is also electrically connected to the positive side of the input. The conductor 54 electrically connects the terminal C4 of the smoothing capacitor module 30, the terminal N1 of the semiconductor module 11 provided on the positive side, and the terminal P3 of the semiconductor module 13 provided on the negative side. The conductor 55 electrically connects the terminal N3 of the semiconductor module 13 provided on the negative electrode side and the terminal N4 of the smoothing capacitor module 30 .

As described above, in the first power conversion group 1a, the power conversion section 10, the smoothing capacitor module 30, and the connection conductor 50 constitute a three-level inverter circuit. In addition, the second power conversion group 2a on the side of the second group constitutes a three-level inverter circuit with a configuration electrically similar to the configuration of the first power conversion group 1a on the side of the first group. That is, the power conversion section 20, the smoothing capacitor module 40, and the connection conductor 60 on the second group side are electrically similar in configuration to the power conversion section 10, the smoothing capacitor module 30, and the connection conductor 50, respectively.

<Cooling body>
Moreover, as shown in FIG. 2, the power conversion device 100 includes a cooling body 80 in this embodiment. Cooling body 80 cools each of the plurality of semiconductor modules (U-phase semiconductor modules 11 to 13 and a plurality of V-phase and W-phase semiconductor modules). Also, the cooling body 80 includes a cooling body 80a, a cooling body 80b, and a cooling body 80c. Cooling body 80a cools each of the plurality of semiconductor modules (semiconductor modules 11 to 13) included in first phase power conversion unit 100a. Cooling body 80b cools each of the plurality of semiconductor modules included in second phase power conversion unit 100b. Cooling body 80c cools each of the plurality of semiconductor modules included in third-phase power conversion unit 100c. The cooling body 80a is an example of a "first cooling body" in the claims. Also, the cooling body 80b is an example of a "second cooling body" in the claims. The cooling body 80c is an example of a "third cooling body" in the claims.

As shown in FIG. 7 , in this embodiment, the cooling body 80 a has a cooling plate portion 81 , a heat radiation portion 82 and refrigerant pipes 83 . In this embodiment, the cooling plate portion 81 of the cooling body 80a is a plate-like member having a cooling surface 81a and a cooling surface 81b. Each of the plurality of semiconductor modules is arranged on cooling surfaces 81a and 81b. Cooling body 80a cools each of the plurality of semiconductor modules arranged on cooling surfaces 81a and 81b. Specifically, a plurality of semiconductor modules 11 to 13 of the power conversion section 10 included in the first power conversion group 1a (first group side) are arranged on the cooling surface 81a. A plurality of semiconductor modules of the power conversion units 20 included in the second power conversion group 2a (second group side) are arranged on the cooling surface 81b. That is, the cooling plate portion 81 of the cooling body 80a is commonly used for the first power conversion group 1a on the first group side and the second power conversion group 2a on the second group side. The cooling surface 81a is an example of "one surface" and "cooling surface" in the claims. Also, the cooling surface 81b is an example of the "other surface" and the "cooling surface" in the claims.

Moreover, like the cooling plate part 81, the heat radiation part 82 is used in common with respect to the 1st power conversion group 1a and the 2nd power conversion group 2a. The heat radiating portion 82 is configured to be heat exchangeable with the cooling plate portion 81 . The radiator 82 has a plurality of plate-like fins. The heat dissipation unit 82 performs heat exchange with the surrounding air by natural convection via a plurality of plate-shaped fins, thereby performing power conversion of the power conversion unit 10 of the first power conversion group 1a and the power conversion of the second power conversion group 2a. It is configured to cool the section 20 .

The refrigerant pipe 83 has a refrigerant channel through which cooling water, which is a refrigerant, flows. The cooling water in the refrigerant pipe 83 is heated on the cooling plate portion 81 side and vaporized. Then, the heated cooling water is cooled on the heat radiating portion 82 side and returns to liquid. Thereby, heat exchange is performed between the cooling plate portion 81 and the heat radiating portion 82 . The cooling body 80a is tilted 7 degrees from the horizontal plane (XY plane) so that the cooling plate portion 81 side is lower than the heat radiation portion 82 side so that the cooling water that has returned to liquid flows into the cooling plate portion 81 side by gravity. (See FIGS. 7 and 8).

Cooling element 80b and cooling element 80c, like cooling element 80a, cool the first group side and second group side of second-phase power conversion unit 100b and third-phase power conversion unit 100c, respectively. is configured to

<Arrangement of each part of the power conversion unit>
As shown in FIGS. 7 and 8, semiconductor modules 11 to 13 of power converter 10 are arranged on cooling surface 81a of cooling body 80a. In this embodiment, the semiconductor module 11 and the semiconductor module 13 are spaced apart from each other and arranged side by side in the α direction (see FIG. 8) on the cooling surface 81a of the cooling body 80a. The semiconductor module 12 is arranged on the cooling surface 81a of the cooling body 80a so as to be separated from the semiconductor module 11 and the semiconductor module 13 in the β direction (see FIG. 8) crossing the α direction. Note that the α direction is an example of the "first direction" in the scope of claims. Also, the β direction is an example of a "second direction" in the scope of claims.

Specifically, in this embodiment, each of the semiconductor module 11, the semiconductor module 12, and the semiconductor module 13 has a rectangular parallelepiped shape. Semiconductor module 11, semiconductor module 12, and semiconductor module 13 each have rectangular surfaces to be cooled 11a, 12a, and 13a (see FIG. 7) in contact with cooling surface 81a of cooling body 80a. The semiconductor modules 11 to 13 are fixed to the cooling surface 81a by fastening members such as screws (not shown). The semiconductor module 11 and the semiconductor module 13 are spaced apart from each other and arranged in parallel such that the short sides 11b and 13b (see FIG. 8) of the surfaces to be cooled 11a and 13a are aligned in the α direction. The semiconductor module 12 is arranged such that the short side 12b (see FIG. 8) of the surface 12a to be cooled extends along the β direction orthogonal to the α direction. Specifically, the semiconductor module 11 is arranged on the side of the radiator 82 (Y2 direction side) of the cooling body 80a in the α direction. The semiconductor module 13 is arranged on the gate substrate 70 side (Y1 direction side) in the α direction. The semiconductor module 12 is arranged on the vertically upward side (Z1 direction side). Further, the short side 11b of the semiconductor module 11 and the short side 13b of the semiconductor module 13 are arranged so as to be aligned along the α direction. The two short sides 12b of the semiconductor module 12 are aligned with the long side 11c (see FIG. 8) of the semiconductor module 11 and the long side 13c (see FIG. 8) of the semiconductor module 13 along the β direction. They are arranged side by side. As a result, the semiconductor modules 11 to 13 have holes into which fastening members such as screws are inserted on the long sides 11c and 13c of the semiconductor modules 11 and 13, and fastening members such as screws on the short side 12b of the semiconductor module 12. By arranging them in line with the holes into which the components are inserted, the assembly work can be easily performed.

Since the cooling plate portion 81 (cooling body 80a) is arranged at an angle of 7 degrees from the horizontal plane, the α direction in which the semiconductor module 11 and the semiconductor module 13 are arranged side by side is the direction inclined at an angle of 7 degrees from the Y direction. Become. Similarly, the β direction is a direction inclined 7 degrees from the Z direction (vertical direction).

As shown in FIG. 8, in the semiconductor module 11, the terminal N1, the terminal P1, the terminal N1, the terminal P1, and the terminal C1 are arranged in this order from the Z1 direction side (semiconductor module 12 side) to the Z2 direction along the β direction. They are arranged in a line facing the direction side. Similarly, in the semiconductor module 13, the terminal N3, the terminal P3, the terminal N3, the terminal P3, and the terminal C3 are connected in this order from the Z1 direction side (semiconductor module 12 side) to the Z2 direction side along the β direction. arranged in rows. In the semiconductor module 12, the terminal N2, the terminal P2, the terminal N2, the terminal P2, and the terminal C2 are arranged in this order along the α direction from the Y1 direction side to the Y2 direction side (the side of the radiator 82 of the cooling body 80a). They are arranged in a line facing each other. In addition, the terminal G1 of the semiconductor module 11 and the terminal G4 of the semiconductor module 13 are arranged on the Z2 direction side (the side opposite to the semiconductor module 12). The terminals G2 and G3 of the semiconductor module 12 are arranged on the Y2 direction side (the side of the radiator 82 of the cooling body 80a).

Moreover, as shown in FIG. 9, in this embodiment, the smoothing capacitor module 30 has a rectangular parallelepiped shape. Smoothing capacitor module 30 is arranged to face cooling surface 81a of cooling body 80a on which each of semiconductor modules 11 to 13 is arranged. Specifically, smoothing capacitor module 30 is arranged such that surface 30a in FIG. 9 faces cooling surface 81a. The surface 30a has a rectangular shape, and each side is arranged along the α direction and the β direction. The surface 30a is an example of "a surface facing the cooling surface" in the scope of claims.

The smoothing capacitor module 30 also has a surface 30b adjacent to the surface 30a. In this embodiment, the surface 30b is a surface adjacent to the surface 30a in the α direction in the smoothing capacitor module 30 having a rectangular parallelepiped shape. Specifically, with respect to the surface 30a, the surface 30b is arranged on the opposite side (the Y1 direction side) of the heat radiating portion 82 of the cooling body 80a in the α direction. The surface 30b is an example of a "terminal arrangement surface" in the claims.

In this embodiment, terminal P4, terminal C4, and terminal N4 of smoothing capacitor module 30 are arranged on common surface 30b. Specifically, four terminals C4 are arranged in a row along the side of the surface 30a (along the β direction) on the surface 30b. Two terminals P4 of the smoothing capacitor module 30 are arranged adjacent to each other. Similarly, two terminals N4 of the smoothing capacitor module 30 are arranged adjacent to each other. Two terminals P4 and two terminals N4 are each arranged in a row on surface 30b so as to be adjacent to each of four terminals C4 arranged in a row.

Specifically, four terminals C4 are arranged in a row along the X2-direction side of the surface 30b. Two terminals P4 and two terminals N4 are arranged in this order in a row along the X1-direction side of the surface 30b. The four terminals C4 are electrically at the same potential (see FIG. 4). and the terminal C4 on the capacitor 32 side (the two terminals C4 arranged on the Z2 direction side) are not electrically connected (insulated). Therefore, the smoothing capacitor module 30 on the side of the first group and the smoothing capacitor module 40 on the side of the second group can be configured using a common module without changing the arrangement direction.

As shown in FIGS. 10 and 11, conductors 51 and 52 are plate-shaped in this embodiment. The conductors 51 and 52 are laminated while being insulated from each other. Specifically, conductors 51 and 52 are laminated between surface 30a of smoothing capacitor module 30 and cooling surface 81a of cooling plate portion 81 of cooling body 80a. The conductors 53, 54, and 55 are L-shaped plates that are bent from the direction along the surface 30a of the smoothing capacitor module 30 to the direction along the surface 30b. That is, the conductors 53 to 55 are plate-shaped, bent along the X direction from the direction along the YZ plane. The conductors 53, 54, and 55 are laminated in this order while being insulated from each other.

Also, as shown in FIG. 11, the conductors 51 and 52 and the conductors 53, 54 and 55 are similarly laminated while being insulated from each other. The conductors 51 to 55 are, for example, laminated busbars in which insulating film sheets are laminated on metal conductors such as aluminum. The conductor 51 is connected to the terminal C1 of the semiconductor module 11 in the area indicated by the dotted line L1 in FIG. 11, and is connected to the terminal P2 of the semiconductor module 12 in the area indicated by the dotted line L2 in FIG. The conductor 52 is connected to the terminal C3 of the semiconductor module 13 in the area indicated by the dotted line L3 in FIG. 11, and is connected to the terminal N2 of the semiconductor module 12 in the area indicated by the dotted line L2 in FIG. Conductor 53 is connected to terminal P1 of semiconductor module 11 in the area indicated by dotted line L1 in FIG. 11, and is connected to terminal P4 of smoothing capacitor module 30 in the area indicated by dotted line L4 in FIG. 11, the conductor 54 is connected to the terminal N1 of the semiconductor module 11 in the area indicated by the dotted line L1 in FIG. 11, is connected to the terminal P3 of the semiconductor module 13 in the area indicated by the dotted line L3 in FIG. region, it is connected to the terminal C4 of the smoothing capacitor module 30 . Conductor 55 is connected to terminal N3 of semiconductor module 13 in the area indicated by dotted line L3 in FIG. 11, and is connected to terminal N4 of smoothing capacitor module 30 in the area indicated by dotted line L4 in FIG.

As shown in FIG. 12, the power conversion unit 20, the smoothing capacitor module 40, and the connection conductor 60 on the second group side are the power conversion unit 10, the smoothing capacitor module 30, and the connection conductor 50 on the first group side, respectively. They are arranged symmetrically. Also, the input and output of the first phase power conversion unit 100a are connected by a connection conductor (bus bar) not shown. Further, the gate terminals (terminals G1 to G4) of the semiconductor modules 11 to 13 and the gate substrate 70 are connected by conducting wires (not shown).

(Effect of this embodiment)
The following effects can be obtained in this embodiment.

In this embodiment, the semiconductor module 11 (first semiconductor module) and the semiconductor module 13 (third semiconductor module) are arranged side by side in the α direction (first direction) while being separated from each other on the cooling surface 81a of the cooling body 80a. there is Then, the semiconductor module 12 (second semiconductor module) is separated from the semiconductor module 11 and the semiconductor module 13 in the β direction (second direction) crossing the α direction, and is located on the cooling surface 81a of the cooling body 80a. are placed. As a result, on the common cooling surface 81a, the semiconductor modules 11 and 13 are arranged side by side in the α direction, and the semiconductor modules 12 are arranged apart in the β direction crossing the α direction. , the semiconductor modules 12, and the semiconductor modules 13 are aligned in the same direction and arranged on the common cooling surface 81a. The distance between them on 81a can be increased. Therefore, it is possible to increase the distance between the plurality of switching elements Q1 to Q4 serving as heat sources included in each of the semiconductor module 11, the semiconductor module 12, and the semiconductor module 13. FIG. As a result, the distance between the heat sources can be increased. Therefore, even when three or more semiconductor modules (semiconductor modules 11 to 13) are arranged on the common cooling surface 81a, the switching elements Q1 to Q4 are provided. Even when three or more semiconductor modules (semiconductor modules 11 to 13) are arranged on the common cooling surface 81a, the plurality of semiconductor modules (semiconductor modules 11 to 13) can be efficiently cooled.

Moreover, in the present embodiment, each of the semiconductor module 11 (first semiconductor module), the semiconductor module 12 (second semiconductor module), and the semiconductor module 13 (third semiconductor module) is connected to the cooling surface 81a of the cooling body 80a. The semiconductor module 11 and the semiconductor module 13 have rectangular parallelepiped shapes having contacting rectangular surfaces to be cooled 11a to 13a, and the semiconductor module 11 and the semiconductor module 13 are arranged so that the short sides 11b and 13b of the surfaces to be cooled 11a and 13a are along the α direction (first direction). The semiconductor modules 12 are spaced apart from each other and arranged parallel to each other, and the semiconductor modules 12 are arranged such that the short sides 12b of the surfaces to be cooled 12a extend along the β direction (second direction) orthogonal to the α direction. Thereby, the rectangular surface to be cooled 12a of the semiconductor module 12 and the rectangular surfaces to be cooled 11a and 13a of the semiconductor modules 11 and 13 can be arranged in directions perpendicular to each other. Therefore, on the cooling surface 81a, unlike the case where the semiconductor module 12 is arranged in a direction that obliquely intersects the semiconductor modules 11 and 13 that are arranged in parallel, the distance from the semiconductor module 12 to the semiconductor module 11 , and the distance from the semiconductor module 12 to the semiconductor module 13 can be made equal. Therefore, it is possible to suppress unevenness in cooling efficiency between the semiconductor module 11 side and the semiconductor module 13 side. As a result, the plurality of semiconductor modules 11 to 13 can be cooled equally, so that the semiconductor modules 11 to 13 can be efficiently cooled.

In addition, in the present embodiment, the first power conversion group 1a and the second power conversion group 2a, which include power conversion units 10 and 20 and are configured to individually switch and output power, are provided, and cooling The body 80a has a cooling surface 81a (one surface) on which each of the plurality of semiconductor modules 11 to 13 of the power conversion unit 10 included in the first power conversion group 1a is arranged, and a power module included in the second power conversion group 2a. It includes a plate-like cooling plate portion 81 having a cooling surface 81b (the other surface) on which each of the plurality of semiconductor modules of conversion portion 20 is arranged. Thereby, the first power conversion group 1a and the second power conversion group 2a configured to individually switch and output power are arranged on the cooling surface 81a and the cooling surface 81b of the common cooling plate portion 81. can be cooled by Therefore, compared to the case where the first power conversion group 1a and the second power conversion group 2a are arranged on the same side surface of one cooling plate unit 81, the common cooling plate unit 81 can be used while switching the power output operation. Thus, the area of the cooling surface 81a (cooling surface 81b) of the cooling plate portion 81 can be reduced. As a result, it is possible to efficiently cool a plurality of semiconductor modules while miniaturizing the device configuration and reducing the number of parts.

In addition, in the present embodiment, the cooling body 80a is connected to the cooling plate portion 81 so as to be capable of exchanging heat, and a heat dissipation device that is commonly used for the first power conversion group 1a and the second power conversion group 2a. Includes portion 82 . As a result, by connecting the heat radiating unit 82 used in common to the cooling plate unit 81 used in common for the first power conversion group 1a and the second power conversion group 2a so as to be able to exchange heat, A plurality of semiconductor modules can be cooled. Therefore, by sharing not only the cooling plate portion 81 but also the heat radiating portion 82, it is possible to efficiently cool a plurality of semiconductor modules while further miniaturizing the device configuration and reducing the number of parts.

Further, in this embodiment, each of the semiconductor module 11 (first semiconductor module) and the semiconductor module 13 (third semiconductor module) has one switching element Q1 (Q4), and the semiconductor module 12 (second semiconductor module) has one switching element Q1 (Q4). ) has two switching elements Q2 and Q3. As a result, the semiconductor module 11 and the semiconductor module 13 each having one switching element Q1 (Q4) are arranged side by side in the α direction (first direction), and the semiconductor module 12 having two switching elements Q2 and Q3 are arranged as semiconductor modules. 11 and the semiconductor module 13 can be spaced apart in the β-direction (second direction) side different from the α-direction in which the semiconductor modules 13 are arranged. Therefore, by arranging only the semiconductor modules 12 with many heat sources away from each other in the direction β, which is a different direction, the plurality of semiconductor modules (semiconductor modules 11 to 13) can be placed. As a result, it is possible to suppress the difference in cooling efficiency between the semiconductor modules 11 to 13 by the cooling body 80a, so that the plurality of semiconductor modules 11 to 13 can be cooled more efficiently.

In addition, in the present embodiment, the plate-like conductor 51 (first connection conductor) electrically connecting the semiconductor module 11 (first semiconductor module) and the semiconductor module 12 (second semiconductor module), and the semiconductor module 12 A plate-shaped conductor 52 (second connection conductor) electrically connecting to the semiconductor module 13 (third semiconductor module) is further provided, and the conductor 51 and the conductor 52 are laminated while being insulated from each other. . As a result, since the conductors 51 and 52 are laminated while being insulated from each other, the current flowing from the semiconductor module 11 to the semiconductor module 12 and the current flowing from the semiconductor module 12 to the semiconductor module 13 are They can be made to flow facing each other while being adjacent to each other. Therefore, the parasitic inductance generated in the conductors 51 and 52 can be reduced by the currents flowing in the conductors 51 and 52 facing each other. As a result, in a state in which the semiconductor module 11 and the semiconductor module 13 are arranged side by side in the α direction (first direction) and the semiconductor module 12 is arranged apart in the β direction (second direction) crossing the α direction, By stacking the conductors 51 and 52 that connect them together, the plurality of semiconductor modules 11 to 13 can be efficiently cooled, and a decrease in power conversion efficiency due to parasitic inductance can be suppressed.

Further, in the present embodiment, the power converters 10 and 20 are configured to output electric power at three levels of potentials, that is, an upper potential, an intermediate potential, and a lower potential. A smoothing capacitor module 30 for smoothing input power, which includes a capacitor 31 (positive side capacitor) and a capacitor 32 (negative side capacitor) connected in series between the semiconductor module 11 provided on the positive side and a semiconductor module 11 provided on the positive side. A conductor 53 (positive conductor) that electrically connects the terminal P1 (positive terminal) of the (first semiconductor module) and the terminal P4 (positive terminal) of the smoothing capacitor module 30 connected to the positive side of the capacitor 31. , a terminal C4 (intermediate terminal) of the smoothing capacitor module 30 connected to the negative side of the capacitor 31 and the positive side of the capacitor 32, a terminal N1 (negative side terminal) of the semiconductor module 11 provided on the positive side, and a negative side. A conductor 54 (intermediate conductor) electrically connecting the terminal P3 (positive side terminal) of the semiconductor module 13 (third semiconductor module) provided on the side of the conductor 54 (intermediate conductor) and the terminal N3 (negative side terminal) of the semiconductor module 13 provided on the negative side. side terminal) and a conductor 55 (negative side conductor) electrically connecting the terminal N4 (negative side terminal) of the smoothing capacitor module 30 connected to the negative side of the capacitor 32, the conductor 53 and the conductor 54 and conductor 55 are laminated in this order while being insulated from each other. As a result, the conductors 53 and 54 can be stacked adjacent to each other, and the conductors 55 and 54 can be stacked adjacent to each other in a three-level inverter that outputs three levels of potential power. Therefore, by making the current flowing through the conductor 53 and the current flowing through the conductor 54 face each other, the parasitic inductance generated in the conductor 53 and the conductor 54 can be reduced. By facing each other, the parasitic inductance generated between the conductors 55 and 54 can be reduced. As a result, the parasitic inductance generated in the conductor 53, the conductor 54, and the conductor 55 can be reduced. A decrease in power conversion efficiency can be suppressed.

Further, in the present embodiment, the smoothing capacitor module 30 has a rectangular parallelepiped shape and is arranged so as to face the cooling surface 81a of the cooling body 80a on which each of the plurality of semiconductor modules 11 to 13 is arranged. Terminal P4 (positive side terminal), terminal N4 (negative side terminal), and terminal C4 (intermediate terminal) of 30 are connected to surface 30a (surface facing cooling surface 81a) of smoothing capacitor module 30 having a rectangular parallelepiped shape. The conductors 53 (positive conductor), 54 (intermediate conductor), and 55 (negative conductor) are arranged on a common surface 30b (terminal arrangement surface) adjacent to each other in the α direction (first direction). The conductor) is an L-shaped plate bent from the direction along the cooling surface 81a to the direction along the surface 30b. As a result, the conductors 53, 54, and 55 are L-shaped plates bent from the direction along the cooling surface 81a to the direction along the surface 30b. Even when the capacitor module 30 is arranged close to the capacitor module 30, the smoothing capacitor module 30 and the conductors 53, 54, and 55 can be easily connected to each other on the surface 30b adjacent to the surface 30a facing the cooling surface 81a. can be connected. Therefore, even when the plurality of semiconductor modules 11 to 13 and the smoothing capacitor module 30 are arranged close to each other, the assembly work for connecting the terminals can be easily performed. As a result, by arranging the plurality of semiconductor modules 11 to 13 and the smoothing capacitor module 30 close to each other, it is possible to reduce the size of the device configuration and improve the workability of the assembly work.

Further, in the present embodiment, the terminals C4 (intermediate terminals) of the smoothing capacitor module 30 are arranged four in a line along the side of the surface 30a (the surface facing the cooling surface 81a) on the surface 30b (terminal arrangement surface). Two terminals P4 (positive terminal) of the smoothing capacitor module 30 are arranged adjacent to each other, and two terminals N4 (negative terminal) of the smoothing capacitor module 30 are arranged adjacent to each other. Each of the two terminals P4 and the two terminals N4 is arranged in a line so as to be adjacent to each of the four terminals C4 arranged in a line on the surface 30b. As a result, the conductor 53 (positive conductor) and the conductor 55 (negative conductor) and the conductor 54 (intermediate conductor), respectively, are arranged more than the case where the terminal P4 and the terminal N4 are not arranged adjacent to the terminal C4. ) can be made larger. Therefore, in each of the conductors 53 and 55 and the conductor 54, the distance between the portions where the flowing currents face can be increased. As a result, the inductance generated in the conductors 53, 54, and 55 can be made smaller, so that the reduction in power conversion efficiency can be further suppressed.

Further, in the present embodiment, the first phase power conversion unit 100a, the second phase power conversion unit 100b, and the , a third phase power conversion unit 100c, and the cooling body 80 includes a cooling body 80a (first cooling body) for cooling each of the plurality of semiconductor modules included in the first phase power conversion unit 100a A cooling body 80b (second cooling body) for cooling each of the plurality of semiconductor modules included in the power conversion unit 100b and a cooling body 80c (for cooling each of the plurality of semiconductor modules included in the third phase power conversion unit 100c) third cooling body). Thereby, a plurality of semiconductor modules included in each of the first phase power conversion unit 100a, the second phase power conversion unit 100b, and the third phase power conversion unit 100c are cooled by separate cooling bodies 80 (80a to 80c). Allow to cool. Therefore, in each of the first-phase power conversion unit 100a, the second-phase power conversion unit 100b, and the third-phase power conversion unit 100c, a plurality of semiconductor modules are arranged in respective cooling bodies 80a to 80c so as to increase the mutual distance. 80c, it is possible to efficiently cool a plurality of semiconductor modules having switching elements. Therefore, even when the AC power of each phase of the three-phase AC power is separately output, the plurality of semiconductor modules having the switching elements can be efficiently cooled.

Further, in the present embodiment, the power conversion unit 10 is mounted on the railroad vehicle 101 and configured to output AC power to the auxiliary power supply line 101c for supplying auxiliary power to the railroad vehicle 101 . With this configuration, even when AC power is output to the auxiliary power supply line 101c for supplying auxiliary power to the railway vehicle 101, the plurality of semiconductor modules having the switching elements Q1 to Q4 in the power conversion unit 10 11 to 13 can be efficiently cooled. Therefore, in the railway vehicle 101, a more stable auxiliary power supply can be supplied.

[Modification]
The embodiments disclosed this time should be considered illustrative and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and includes all modifications (modifications) within the scope and meaning equivalent to the scope of the claims.

For example, in the above embodiment, semiconductor module 11 (first semiconductor module) and semiconductor module 13 (third semiconductor module) have short sides 11b and 13b of surfaces to be cooled 11a and 13a along the α direction (first direction). , and the semiconductor modules 12 are arranged such that the short sides 12b of the surfaces to be cooled 12a are arranged along the β direction (second direction) orthogonal to the α direction. However, the present invention is not limited to this. For example, in the present invention, the α direction in which the semiconductor modules 11 and 13 are arranged side by side and the β direction in which the semiconductor module 12 is arranged apart from each other may not be orthogonal.

Further, in the above embodiment, the cooling body 80a is a plate having a cooling surface 81a (one surface) for cooling the first power conversion group 1a and a cooling surface 81b (other surface) for cooling the second power conversion group 2a. Although an example including the cooling plate portion 81 having a shape is shown, the present invention is not limited to this. For example, the first power conversion group 1a and the second power conversion group 2a may be configured to be cooled by a common cooling surface.

Moreover, although the said embodiment showed the example containing the thermal radiation part 82 used commonly with respect to the 1st power conversion group 1a and the 2nd power conversion group 2a, this invention is not limited to this. For example, two heat dissipation units used separately may be included for each of the first power conversion group 1a and the second power conversion group 2a.

In addition, in the above-described embodiment, the heat radiation part 82 has shown an example including air-cooled heat radiation fins, but the present invention is not limited to this. For example, the radiator 82 may be water-cooled.

Further, in the above embodiment, each of the semiconductor module 11 (first semiconductor module) and the semiconductor module 13 (third semiconductor module) has one switching element Q1 (Q4), and the semiconductor module 12 (second semiconductor module) has one switching element Q1 (Q4). ) showed an example having two switching elements Q2 and Q3, but the present invention is not limited to this. For example, the first semiconductor module may have two switching elements, and the second semiconductor module and the third semiconductor module may have one switching element. Also, each of the first semiconductor module, the second semiconductor module and the third semiconductor module may be configured to have two switching elements.

Further, in the above embodiment, the conductor 51 (first connection conductor) and the conductor 52 (second connection conductor) are laminated while being insulated from each other, but the present invention is not limited to this. . For example, conductors 51 and 52 may be arranged parallel to each other and not stacked.

Further, in the above embodiment, the power conversion unit 10 has shown an example in which it constitutes a three-level inverter circuit that outputs power of three levels of potentials, that is, an upper potential, an intermediate potential, and a lower potential. is not limited to For example, the power conversion section may constitute a two-level three-phase inverter circuit or a two-level three-phase converter circuit. In that case, the three semiconductor modules may each include two switching elements. In that case, the two-level three-phase inverters or two-level three-phase converters of the first group side and the second group side are arranged on each of the two cooling surfaces of the cooling plate portion of the cooling body. may Also, the two two-level three-phase inverters or two-level three-phase converters on the first group side and the second group side may be connected in parallel to one load or power supply, or may be connected to two different loads or power supplies. good too.

In the above-described embodiment, the terminals of the smoothing capacitor module 30 are arranged in common on the surface 30b (terminal arrangement surface) on the side of the gate substrate 70 (Y1 direction side). Not limited. For example, the smoothing capacitor module may be configured such that the terminals are arranged on the surface of the heat dissipation portion (heat dissipation fin) side opposite to the gate substrate side. Further, the smoothing capacitor module may be configured such that the terminals are arranged on the vertically upward side or the vertically downward side. Also, the smoothing capacitor module may be configured such that the terminals are not collectively arranged on one common surface, but arranged separately on two or more different surfaces.

In the above embodiment, the two terminals P4 (positive side terminals) and the two terminals N4 (negative side terminals) of the smoothing capacitor module 30 are arranged in a line on the surface 30b (terminal arrangement surface). Although an example in which they are arranged in a line so as to be adjacent to each of the four terminals C4 (intermediate terminals) has been shown, the present invention is not limited to this. For example, like the smoothing capacitor module 230 according to the modified example shown in FIG. 13, the positive terminal P204, the intermediate terminal C204, and the negative terminal N204 may be arranged in two rows in this order. By arranging the terminals as in the smoothing capacitor module 30 according to the embodiment, it is possible to increase the length of the overlapping portion of the connection conductors compared to the smoothing capacitor module 230 according to the modification. parasitic inductance can be further reduced.

Further, in the above embodiment, the first-phase power conversion unit 100a, the second-phase power conversion unit 100b, and the third-phase power conversion unit 100c output the AC power of each phase of the three-phase AC power. Although the example provided with is shown, this invention is not limited to this. For example, it may be configured to include one power conversion unit and output three-phase AC power.

In the above embodiment, the power conversion unit 10 (20) is mounted on the railroad vehicle 101 and configured to output AC power to the auxiliary power supply line 101c for supplying auxiliary power to the railroad vehicle 101. Although an example is shown, the present invention is not limited to this. For example, it may be configured to supply electric power for driving the railway vehicle 101 . Moreover, it may be configured to be mounted on a vehicle such as an electric vehicle instead of a railroad vehicle. Alternatively, the electric power may be supplied to a stationary electric motor (motor) instead of the vehicle.

Further, in the above embodiment, the semiconductor module 12 (second semiconductor module) is positioned vertically upward (Z1 direction side) with respect to the semiconductor module 11 (first semiconductor module) and the semiconductor module 13 (third semiconductor module). Although an example of arrangement has been shown, the present invention is not limited to this. For example, the second semiconductor module may be arranged vertically downward with respect to the first semiconductor module and the third semiconductor module. Further, the semiconductor module 11 and the semiconductor module 13 may be arranged along the vertical direction, and the semiconductor module 12 may be arranged so as to be spaced apart in the horizontal direction.

1a, 1b, 1c first power conversion group 2a, 2b, 2c second power conversion group 10, 20 power conversion unit 11 semiconductor module (first semiconductor module, plurality of semiconductor modules)
11a surface to be cooled 11b short side 12 semiconductor module (second semiconductor module, plurality of semiconductor modules)
12a surface to be cooled 12b short side 13 semiconductor module (third semiconductor module, plurality of semiconductor modules)
13a surface to be cooled 13b short side 30, 40, 230 smoothing capacitor module 30a surface (surface facing the cooling surface)
30b surface (terminal arrangement surface)
31 capacitor (positive electrode side capacitor)
32 capacitor (negative electrode side capacitor)
51 conductor (first connection conductor)
52 conductor (second connection conductor)
53 conductor (positive conductor)
54 conductor (intermediate conductor)
55 conductor (negative conductor)
80, 80a, 80b, 80c cooling body 81 cooling plate portion 82 heat radiation portion 81a cooling surface (one surface)
81b cooling surface (other surface)
100 power conversion device 100a first phase power conversion unit 100b second phase power conversion unit 100c third phase power conversion unit 101 railway car 101c auxiliary power supply line

Claims (11)

a power conversion unit including a plurality of semiconductor modules having switching elements;
a cooling body having a cooling surface on which each of the plurality of semiconductor modules is arranged, and cooling each of the plurality of semiconductor modules arranged on the cooling surface;
the plurality of semiconductor modules each include a first semiconductor module, a second semiconductor module, and a third semiconductor module each having the switching element;
the first semiconductor module and the third semiconductor module are spaced apart from each other and arranged side by side in a first direction on the cooling surface of the cooling body;
The second semiconductor module is arranged on the cooling surface of the cooling body so as to be separated from the first semiconductor module and the third semiconductor module in a second direction crossing the first direction. , power converter. each of the first semiconductor module, the second semiconductor module, and the third semiconductor module has a rectangular parallelepiped shape having a rectangular surface to be cooled in contact with the cooling surface of the cooling body;
the first semiconductor module and the third semiconductor module are spaced apart from each other and arranged in parallel such that the short side of the surface to be cooled extends along the first direction;
2. The power converter according to claim 1, wherein said second semiconductor module is arranged such that a short side of said surface to be cooled extends along said second direction orthogonal to said first direction. Further comprising a first power conversion group and a second power conversion group each including the power conversion unit and configured to individually switch and output power,
The cooling body has one surface which is the cooling surface on which each of the plurality of semiconductor modules of the power conversion unit included in the first power conversion group is arranged, and the power conversion unit included in the second power conversion group. 3. The power converter according to claim 1, further comprising a plate-shaped cooling plate portion having the other surface serving as the cooling surface on which each of the plurality of semiconductor modules of the conversion unit is arranged. 4. The cooling body is connected to the cooling plate part so as to be able to exchange heat, and includes a heat dissipation part that is commonly used for the first power conversion group and the second power conversion group. The power conversion device according to . each of the first semiconductor module and the third semiconductor module has one switching element;
5. The power converter according to claim 1, wherein said second semiconductor module has two said switching elements. a plate-shaped first connection conductor that electrically connects the first semiconductor module and the second semiconductor module;
a plate-shaped second connection conductor electrically connecting the second semiconductor module and the third semiconductor module;
6. The power converter according to claim 1, wherein said first connection conductor and said second connection conductor are laminated while being insulated from each other. The power conversion unit is configured to output power of three levels of potentials, that is, an upper potential, an intermediate potential, and a lower potential,
a smoothing capacitor module that includes a positive side capacitor and a negative side capacitor that are connected in series between the positive side and the negative side of an input and that smoothes input power;
a positive conductor electrically connecting the positive terminal of the first semiconductor module provided on the positive electrode side and the positive terminal of the smoothing capacitor module connected to the positive side of the positive electrode capacitor;
an intermediate terminal of the smoothing capacitor module connected to the negative side of the positive side capacitor and the positive side of the negative side capacitor; a negative side terminal of the first semiconductor module provided on the positive side; an intermediate conductor electrically connecting to the positive terminal of the third semiconductor module;
a negative conductor electrically connecting the negative terminal of the third semiconductor module provided on the negative electrode side and the negative terminal of the smoothing capacitor module connected to the negative side of the negative capacitor; prepared,
7. The power converter according to claim 1, wherein said positive conductor, said intermediate conductor, and said negative conductor are laminated in this order while being insulated from each other. the smoothing capacitor module has a rectangular parallelepiped shape and is arranged to face the cooling surface of the cooling body on which each of the plurality of semiconductor modules is arranged;
The positive side terminal, the negative side terminal, and the intermediate terminal of the smoothing capacitor module are adjacent to the surface facing the cooling surface in the first direction in the smoothing capacitor module having a rectangular parallelepiped shape. Arranged on a common terminal arrangement surface,
8. The positive-side conductor, the intermediate conductor, and the negative-side conductor according to claim 7, wherein the L-shaped plate is bent from a direction along the cooling surface to a direction along the terminal arrangement surface. Power converter. The intermediate terminals of the smoothing capacitor module are arranged four in a row along the side of the terminal arrangement surface facing the cooling surface,
Two of the positive terminals of the smoothing capacitor module are arranged adjacent to each other,
Two of the negative terminals of the smoothing capacitor module are arranged adjacent to each other,
Each of the two positive terminals and the two negative terminals is arranged in a row on the terminal arrangement surface so as to be adjacent to each of the four intermediate terminals arranged in a row. Item 9. The power converter according to Item 8. a first-phase power conversion unit, a second-phase power conversion unit, and a third-phase power conversion unit each including the power conversion unit and outputting AC power of each phase of three-phase AC power, further prepared,
The cooling body includes a first cooling body that cools each of the plurality of semiconductor modules included in the first phase power conversion unit, and a first cooling body that cools each of the plurality of semiconductor modules included in the second phase power conversion unit. and a third cooling body for cooling each of the plurality of semiconductor modules included in the third phase power conversion unit. conversion device. 11. Any one of claims 1 to 10, wherein the power conversion unit is mounted on a railway vehicle and configured to output AC power to an auxiliary power supply line for supplying auxiliary power to the railway vehicle. The power conversion device according to the item.

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