Power conversion device

Abstract

A power conversion device according to an embodiment of the present invention comprises: a plurality of semiconductor modules connected in parallel, each having two switching elements connected in series, and arranged side by side in a first direction; an AC wiring extending in the first direction and commonly connecting the AC terminals of the plurality of semiconductor modules; and an AC lead-out wire configured to lead out the AC wire to the output terminal along the first direction. The AC lead-out wiring has a connection portion connected to the AC wiring, and an extension portion arranged side by side with the AC wiring. The center of the connection portion of the AC lead-out wire in the first direction is set further away from the output terminal than the center of the whole of the plurality of semiconductor modules in the first direction.

Description

Technical Field

[0001] Embodiments of the present invention relate to a power conversion device. Background Art

[0002] Power conversion devices are used in converters and inverters for driving elevator hoists. The power conversion device includes semiconductor modules for each phase of three-phase AC power, and each semiconductor module includes two switching elements (e.g., IGBTs) connected in series. In a power conversion device for high-speed and high-capacity applications, multiple semiconductor modules are connected in parallel and used.

[0003] Conventionally, the AC terminals of multiple semiconductor modules connected in parallel are connected into one by equal-length wiring, and an output terminal is led out from the power conversion device. In this case, an inductance difference occurs in the multiple wirings connected to the multiple semiconductor modules, so that current tends to bias toward the semiconductor module closer to the output terminal. That is, the inductance of the semiconductor module closest to the output terminal is small, so the current becomes large, and the inductance of the semiconductor module farthest from the output terminal is large, so the current becomes small.

[0004] Even if the characteristics of multiple semiconductor modules connected in parallel are uniform, an inductance difference occurs in the multiple semiconductor modules due to the wiring structure, resulting in current imbalance. Due to the current imbalance, the heat generation of a specific semiconductor module increases, leading to a decrease in the efficiency of the power conversion device. In addition, a specific semiconductor module may fail due to thermal fatigue life.

[0005] Patent Document 1: Japanese Patent No. 4209421 Summary of the Invention

[0006] The problem to be solved by the present invention is to provide a power conversion device capable of suppressing current imbalance in multiple semiconductor modules connected in parallel.

[0007] The power conversion device according to the embodiment includes: multiple semiconductor modules connected in parallel, each having two switching elements connected in series, and arranged in a first direction; an AC wiring extending along the first direction and commonly connecting the AC terminals of the multiple semiconductor modules; and an AC lead-out wiring extending along the first direction and configured to lead out the AC wiring to an output terminal. The connection portion of the AC lead-out wiring connected to the AC wiring and the extension portion arranged in parallel with the AC wiring are provided. The center of the connection portion of the AC lead-out wiring in the first direction is set on a side farther from the output terminal than the center of the multiple semiconductor modules as a whole in the first direction. Brief Description of the Drawings

[0008] Figure 1It is a circuit diagram of the power conversion device of the first embodiment.

[0009] Figure 2 It is a perspective view showing the wiring structure of the power conversion device of the first embodiment.

[0010] Figure 3 It is a perspective view showing the wiring structure of the power conversion device of the comparative example.

[0011] Figure 4 It is a perspective view showing the wiring structure of the power conversion device of the second embodiment.

[0012] Figure 5 It is a perspective view showing the wiring structure of the power conversion device of the third embodiment.

[0013] Figure 6 It is a perspective view showing the wiring structure of the power conversion device of the fourth embodiment.

[0014] Figure 7 It is a perspective view showing the wiring structure of the power conversion device of the fifth embodiment.

[0015] Figure 8 It is a front view showing the wiring structure of the power conversion device of the sixth embodiment.

[0016] Figure 9 It is a side view showing the wiring structure of the power conversion device of the seventh embodiment.

[0017] Explanation of symbols

[0018] 1: Power conversion device, 10-1 to 10-4: Semiconductor modules, 11-1, 11-2: Switching elements, 12-1, 12-2: Diodes, 13: Output terminal, 14: Positive terminal, 15: Negative terminal, 16: Capacitor, 20, 21: Connection wirings, 22: AC wiring, 23: AC lead-out wiring, T1: Positive-side power supply terminal, T2: Negative-side power supply terminal, T3: AC terminal. Detailed implementation manners

[0019] Hereinafter, the embodiments will be described with reference to the drawings. The following several embodiments illustrate devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is not determined by the shape, structure, configuration, etc. of the constituent components. In addition, in the following description, elements having the same functions and configurations are denoted by the same reference numerals and repeated descriptions are omitted.

[0020] [1] First embodiment

[0021] [1-1] Configuration of the power conversion device 1

[0022] Figure 1 This is the circuit diagram of the power conversion device 1 of the first embodiment. Figure 1 The power conversion device 1 is a single-phase device of a converter or an inverter. For example, when it constitutes an inverter, Figure 1 such a device is used by connecting three phases in parallel.

[0023] The power conversion device 1 includes a plurality of semiconductor modules 10, connection wirings 20, 21, an AC wiring 22, an AC lead-out wiring 23, an output terminal 13, a positive terminal 14, a negative terminal 15, and a capacitor 16.

[0024] In Figure 1 as an example, four semiconductor modules 10-1 to 10-4 are shown. The semiconductor modules 10-1 to 10-4 are connected in parallel between the positive terminal 14 and the negative terminal 15. The semiconductor modules 10-1 to 10-4 have the same configuration. The number of the semiconductor modules 10 is not limited to four, and can be set to any number of two or more. In the following description, when it is not necessary to distinguish the semiconductor modules 10-1 to 10-4, the suffix is omitted and they are referred to as the semiconductor module 10. The description of the semiconductor module 10 is common to the four semiconductor modules 10-1 to 10-4. The same applies to other reference symbols with suffixes.

[0025] The semiconductor module 10 includes two switching elements 11-1, 11-2, a positive-side power supply terminal T1, a negative-side power supply terminal T2, and an AC terminal T3.

[0026] The positive-side power supply terminal T1 is connected to the positive terminal 14. The negative-side power supply terminal T2 is connected to the negative terminal 15. The AC terminal T3 is connected to the connection wirings 20, 21. The AC terminal T3 is a terminal for outputting AC power.

[0027] The switching element 11 is constituted by, for example, a SiC power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) and is an N-channel MOSFET. The SiC power MOSFET is a compound semiconductor and is a MOSFET using SiC as a substrate. The switching element can also be a MOSFET other than SiC, a bipolar transistor, or an IGBT (Insulated Gate Bipolar Transistor).

[0028] The switching elements 11-1 and 11-2 are connected in series between the positive power supply terminal T1 and the negative power supply terminal T2. Specifically, the drain of the switching element 11-1 is connected to the positive power supply terminal T1. The source of the switching element 11-1 is connected to the AC terminal T3. The drain of the switching element 11-2 is connected to the AC terminal T3. The source of the switching element 11-2 is connected to the negative power supply terminal T2.

[0029] Diodes 12-1 and 12-2 are respectively anti-parallel connected to the switching elements 11-1 and 11-2. The diode 12 is a freewheeling diode and has the function of protecting the switching element 11 when a reverse current is supplied to the switching element 11. The diode 12 is constituted by a parasitic diode of a transistor. It is also possible to separately provide a diode 12 and connect it in anti-parallel with the switching element 11.

[0030] In Figure 1 the gate terminal, source terminal, and drain terminal of the MOSFET are represented by unsigned white circles. The gate terminal, source terminal, and drain terminal of the MOSFET are connected to a control circuit (not shown), and their potentials are controlled.

[0031] The connection wiring 20 connects the AC terminal T3 of the semiconductor module 10-1 and the AC terminal T3 of the semiconductor module 10-2. The connection wiring 21 connects the AC terminal T3 of the semiconductor module 10-3 and the AC terminal T3 of the semiconductor module 10-4. The AC wiring 22 connects the connection wiring 20 and the connection wiring 21. The AC wiring 22 is connected to the AC lead-out wiring 23.

[0032] The AC lead-out wiring 23 is connected to the output terminal 13. The output terminal 13 is a terminal connected to an external AC power line or an AC load. When the power conversion device 1 is used for an inverter, the output terminal 13 outputs AC power.

[0033] The positive terminal 14 is a terminal connected to an external positive power line. The positive terminal 14 is supplied with positive power. The negative terminal 15 is a terminal connected to an external negative power line. The negative terminal 15 is supplied with negative power.

[0034] The capacitor 16 is connected between the positive terminal 14 and the negative terminal 15. The capacitor 16 has the function of smoothing the voltage.

[0035] [1-2] Regarding the wiring structure of the power conversion device 1

[0036] Next, the wiring structure of the power conversion device 1 will be described.

[0037] Figure 2 is a perspective view showing the wiring structure of the power conversion device 1. In Figure 2In this case, the X direction is the direction in which multiple semiconductor modules 10 are arranged, the Y direction is the direction orthogonal to the X direction within the plane, and the Z direction is the direction orthogonal to the XY plane. The semiconductor modules 10-1 to 10-4 are arranged and configured in the X direction.

[0038] The AC terminal T3 of the semiconductor module 10-1 and the AC terminal T3 of the semiconductor module 10-2 are connected by a connection wiring 20. Specifically, the connection wiring 20 is formed by sequentially connecting an extension portion 20A extending along the X direction, a protruding portion 20B protruding in the Z direction, and an extension portion 20C extending along the X direction. The protruding portion 20B has an inverted U shape. The extension portion 20A of the connection wiring 20 is connected to the AC terminal T3 of the semiconductor module 10-1 and is fixed to the AC terminal T3 by a screw (not shown). The extension portion 20C of the connection wiring 20 is connected to the AC terminal T3 of the semiconductor module 10-2 and is fixed to the AC terminal T3 by a screw (not shown).

[0039] The AC terminal T3 of the semiconductor module 10-3 and the AC terminal T3 of the semiconductor module 10-4 are connected by a connection wiring 21. Specifically, the connection wiring 21 is formed by sequentially connecting an extension portion 21A extending along the X direction, a protruding portion 21B protruding in the Z direction, and an extension portion 21C extending along the X direction. The protruding portion 21B has an inverted U shape. The extension portion 21A of the connection wiring 21 is connected to the AC terminal T3 of the semiconductor module 10-3 and is fixed to the AC terminal T3 by a screw (not shown). The extension portion 21C of the connection wiring 21 is connected to the AC terminal T3 of the semiconductor module 10-4 and is fixed to the AC terminal T3 by a screw (not shown).

[0040] The AC wiring 22 is a wiring extending along the X direction. The AC wiring 22 connects the connection wiring 20 and the connection wiring 21. Specifically, one end of the AC wiring 22 is connected to the protruding portion 20B of the connection wiring 20 and is fixed to the protruding portion 20B by a screw (not shown). The other end of the AC wiring 22 is connected to the protruding portion 21B of the connection wiring 21 and is fixed to the protruding portion 21B by a screw (not shown).

[0041] The AC lead-out wiring 23 is a wiring extending along the X direction. The AC lead-out wiring 23 connects the AC wiring 22 and the output terminal 13. The AC lead-out wiring 23 is configured to extend from the AC wiring 22 in the Z direction and then along the X direction. The AC lead-out wiring 23 includes a connection portion 23A connected to the AC wiring 22 and an extension portion 23B extending from the connection portion 23A in the X direction. The connection portion 23A is configured to include a curved portion extending in the Z direction. The extension portion 23B is arranged and configured in parallel with the AC wiring 22.

[0042] Here, the line passing through the center of the AC wiring 22 in the X direction is referred to as the center line C1. The line passing through the center of the connection portion 23A of the AC lead-out wiring 23 in the X direction is referred to as the center line C2. The center line C1 has the same meaning as the line passing through the center of the entire semiconductor modules 10-1 to 10-4 in the X direction.

[0043] In the present embodiment, the center line C2 of the connection portion 23A of the AC lead-out wiring 23 is set to be offset from the center line C1 of the AC wiring 22 toward the side away from the output terminal 13. In other words, the AC lead-out wiring 23 is offset from the center of the AC wiring 22 in the X direction toward the side away from the output terminal 13 and is connected to the AC wiring 22.

[0044] The AC wiring 22 and the AC lead-out wiring 23 may be configured by electrically connecting different components, or may be integrally formed.

[0045] [1-3] Function

[0046] The function of the power conversion device 1 configured as described above will be described.

[0047] DC power is supplied to the positive terminal 14 and the negative terminal 15 from the outside. The positive terminal 14 is supplied with a positive-side power supply, and the negative terminal 15 is supplied with a negative-side power supply.

[0048] A gate voltage is applied to the gates of the switching elements 11-1 and 11-2 included in the semiconductor module 10-1 from a control circuit (not shown). The switching elements 11-1 and 11-2 perform switching operations. The semiconductor modules 10-2 to 10-4 connected in parallel with the semiconductor module 10-1 also perform the same operations as the semiconductor module 10-1. Thereby, the power conversion device 1 can output single-phase AC power from the output terminal 13.

[0049] As Figure 2 shown, the AC current of the semiconductor module 10-1 closest to the output terminal 13 flows through the AC lead-out wiring 23 from the AC wiring 22. The AC current flowing from the semiconductor module 10-1 to the AC wiring 22 and the AC current flowing in the AC lead-out wiring 23 are in opposite directions and face each other. Thus, due to mutual induction, they act in the direction of decreasing inductance, so the current of the semiconductor module 10-1 increases.

[0050] On the other hand, the alternating current of the semiconductor module 10-4 that is farthest from the output terminal 13 also flows from the AC wiring 22 into the AC lead-out wiring 23. The alternating current flowing from the semiconductor module 10-4 to the AC wiring 22 is not opposed to the alternating current flowing in the AC lead-out wiring 23. As a result, there is almost no mutual induction and it does not contribute to the increase or decrease of the inductance. Therefore, the inductance of the semiconductor module 10-4 is larger than that of the semiconductor module 10-1.

[0051] The inductances of the semiconductor modules 10-2 and 10-3 are in the middle between the semiconductor module 10-1 and the semiconductor module 10-4.

[0052] Here, by configuring the wiring structure as Figure 2 such, the wiring path of the semiconductor module 10-4 can be shortened, and thus the inductance from the semiconductor module 10-4 to the output terminal 13 can be reduced. On the other hand, although the wiring path of the semiconductor module 10-1 becomes longer, there is almost no increase or decrease in inductance due to mutual induction. That is, due to the effect of suppressing the inductance difference of the four parallel-connected semiconductor modules, the current imbalance can be reduced.

[0053] [1-4] Comparative Example

[0054] Next, the configuration of the comparative example will be described. Figure 3 FIG. is a perspective view showing the wiring structure of the power conversion device of the comparative example.

[0055] The power conversion device includes semiconductor modules 10-1 to 10-4 connected in parallel. The AC wiring 22 connects the connection wiring 20 and the connection wiring 21. The AC lead-out wiring 23 connects the AC wiring 22 and the output terminal 13.

[0056] In the comparative example, the AC lead-out wiring 23 is connected to the AC wiring 22 at the center of the AC wiring 22. That is, the center line C1 of the AC wiring 22 is set at the same position as the center line C2 of the connection portion with the AC lead-out wiring 23.

[0057] In the semiconductor module 10-1 closest to the output terminal 13, due to mutual induction, it acts in the direction of reducing the inductance, so the current flowing through the semiconductor module 10-1 increases. On the other hand, in the semiconductor module 10-4 farthest from the output terminal 13, there is almost no mutual induction and the wiring path is long, so the inductance increases. In addition, there is a tendency for the current to bias towards the semiconductor modules 10-1 to 10-4 according to the distance from the output terminal 13. As a result, in the comparative example, the imbalance of the output currents of the semiconductor modules 10-1 to 10-4 increases.

[0058] On the other hand, in the present embodiment, compared with the comparative example, the inductance difference between the semiconductor modules 10-1 to 10-4 connected in parallel can be reduced, so that the imbalance of the output currents of the semiconductor modules 10-1 to 10-4 can be reduced.

[0059] [1-5] Effects of the First Embodiment

[0060] According to the first embodiment, the inductance difference between the semiconductor modules 10-1 to 10-4 connected in parallel can be reduced, so that the imbalance of the output currents of the semiconductor modules 10-1 to 10-4 can be reduced. In addition, an increase in heat loss of a specific semiconductor module can be suppressed. In addition, the power conversion efficiency of the power conversion device 1 can be improved.

[0061] In addition, a reduction in the thermal fatigue life of a specific semiconductor module can be suppressed. As a result, the occurrence of a failure in the power conversion device 1 can be suppressed.

[0062] [2] Second Embodiment

[0063] In the second embodiment, the connection position of the AC wiring 22 and the AC lead-out wiring 23 is set to be further away from the output terminal 13.

[0064] [2-1] Wiring Structure of the Power Conversion Device 1

[0065] Figure 4 is a perspective view showing the wiring structure of the power conversion device 1 according to the second embodiment. In Figure 4 the illustration of the semiconductor modules 10-1 to 10-4 is omitted, but their configurations are the same as Figure 2 the same.

[0066] The center line C2 of the connection portion 23A of the AC lead-out wiring 23 is set to be further away from the center line C1 of the AC wiring 22. In other words, the AC lead-out wiring 23 is offset from the center of the AC wiring 22 in the X direction further away from the output terminal 13 and connected to the AC wiring 22.

[0067] The end portion on the side of the AC wiring 22 away from the output terminal 13 is referred to as the end region AR. In the present embodiment, the length of the end region AR of the AC wiring 22 in the X direction is shortened. The end region AR of the AC wiring 22 is set to the minimum length required for fixing the AC wiring 22 and the protruding portion 21B of the connection wiring 21 with screws. The width (length in the Y direction) of the AC wiring 22 can be configured to be the same as that of the first embodiment.

[0068] The operation of the second embodiment is the same as that of the first embodiment.

[0069] [2-2] Effects of the Second Embodiment

[0070] According to the second embodiment, it is possible to further reduce the inductance difference compared to the first embodiment while keeping the dimension in the depth direction the same as that of the first embodiment. Other effects are the same as those of the first embodiment.

[0071] [3] Third embodiment

[0072] In the third embodiment, the inductance difference between the semiconductor modules 10-1 to 10-4 is reduced by lengthening the path of the AC wiring 22.

[0073] [3-1] Wiring structure of the power conversion device 1

[0074] Figure 5 is a perspective view showing the wiring structure of the power conversion device 1 according to the third embodiment. In Figure 5 the illustration of the semiconductor modules 10-1 to 10-4 is omitted, but their configurations are the same as Figure 2 those.

[0075] The AC wiring 22 is constituted by successively connecting an extension portion 22A extending along the X direction, a protruding portion 22B protruding in the Z direction, and an extension portion 22C extending along the X direction. The protruding portion 22B has an inverted U shape. The extension portion 22A of the AC wiring 22 is connected to the protruding portion 20B of the connection wiring 20 and is fixed to the protruding portion 20B by a screw (not shown). The protruding portion 22B of the AC wiring 22 is disposed at a position closer to the output terminal 13 than the connection portion 23A of the AC lead-out wiring 23.

[0076] The extension portion 22C of the AC wiring 22 is connected to the protruding portion 21B of the connection wiring 21 and is fixed to the protruding portion 21B by a screw (not shown). In addition, the extension portion 22C of the AC wiring 22 is connected to the connection portion 23A of the AC lead-out wiring 23.

[0077] The center line C2 of the connection portion 23A of the AC lead-out wiring 23 is set to be offset from the center line C1 of the AC wiring 22 toward the side away from the output terminal 13.

[0078] Since the AC wiring 22 has the protruding portion 22B, it is possible to lengthen the wiring path from the semiconductor modules 10-1 and 10-2 close to the output terminal 13 to the AC lead-out wiring 23.

[0079] [3-2] Function

[0080] The operation of the power conversion device 1 configured as described above will be described.

[0081] The AC wiring 22 has a protruding portion 22B, whereby the wiring paths of the semiconductor modules 10-1 and 10-2 become longer, and thus the inductance increases. As a result, the inductance difference between the semiconductor modules 10-1 and 10-2 and the semiconductor module 10-4 becomes smaller. Thereby, the inductance difference between the semiconductor modules 10-1 to 10-4 can be reduced, and thus the imbalance of the output current can be decreased.

[0082] [3-3] Effects of the Third Embodiment

[0083] According to the third embodiment, it is possible to further reduce the inductance difference compared to the first embodiment while keeping the dimension in the depth direction the same as that of the first embodiment. Other effects are the same as those of the first embodiment.

[0084] [4] Fourth Embodiment

[0085] In the fourth embodiment, the inductance difference between the semiconductor modules 10-1 to 10-4 is reduced by shortening the wiring path of the semiconductor module 10-4 that is farthest from the output terminal 13.

[0086] [4-1] Wiring Structure of the Power Conversion Device 1

[0087] Figure 6 FIG. is a perspective view showing the wiring structure of the power conversion device 1 according to the fourth embodiment.

[0088] The AC lead-out wiring 23 reaches the semiconductor module 10-4 that is farthest from the output terminal 13 and is connected to the AC wiring 22. In addition, the AC lead-out wiring 23 reaches the boundary between the semiconductor modules 10-3 and 10-4 that are far from the output terminal 13 and is connected to the AC wiring 22. In other words, the connection portion 23A of the AC lead-out wiring 23 is configured to reach the semiconductor module 10-4 that is farthest from the output terminal 13. In addition, the connection portion 23A of the AC lead-out wiring 23 is configured to reach the boundary between the semiconductor modules 10-3 and 10-4 that are far from the output terminal 13.

[0089] In Figure 6 In the configuration example, it is configured that the AC lead-out wiring 23 is connected to the AC wiring 22 at the end of the AC wiring 22. That is, the connection portion 23A of the AC lead-out wiring 23 is disposed at the end of the AC wiring 22.

[0090] Since it is necessary to ensure the area of the screw head for connecting the AC wiring 22, the connection portion 23A of the AC lead-out wiring 23 is configured to be led out in the Y direction compared to the first embodiment. The length from the end of the AC wiring 22 to the end of the AC lead-out wiring 23 in the Y direction is referred to as L1. In the fourth embodiment, the length L1 is longer than that in the first embodiment.

[0091] [4-2] Operation

[0092] The operation of the power conversion device 1 configured as described above will be described.

[0093] By being configured as Figure 6 described above, the wiring path of the semiconductor module 10-4 can be made shorter than that of the first embodiment. As a result, the inductance from the semiconductor module 10-4 to the output terminal 13 can be reduced.

[0094] On the other hand, the wiring path of the semiconductor module 10-1 is longer than that of the first embodiment, but there is almost no increase or decrease in inductance due to mutual induction. That is, due to the effect of suppressing the inductance difference between the four parallel-connected semiconductor modules, current imbalance can be reduced.

[0095] In the fourth embodiment, the inductance difference is smaller than that of the first embodiment, and current imbalance can be suppressed. However, since it is necessary to ensure the area of the screw head connecting the AC wiring 22, the length L1 becomes longer than that of the first embodiment. By making the length L1 longer, the distance between the AC wiring 22 and the AC lead-out wiring 23 becomes longer than that of the first embodiment. Therefore, the effect of reducing the inductance due to mutual induction becomes weaker. As a result, the inductance of the semiconductor module 10-1 can be increased, and the inductance difference between the four parallel-connected semiconductor modules can be suppressed. Thereby, current imbalance can be reduced.

[0096] In the fourth embodiment, the same effect as that of the first embodiment can also be obtained.

[0097] [5] Fifth Embodiment

[0098] The fifth embodiment is a configuration example of three parallel-connected semiconductor modules.

[0099] [5-1] Regarding the Wiring Structure of the Power Conversion Device 1

[0100] Figure 7 FIG. is a perspective view showing the wiring structure of the power conversion device 1 according to the fifth embodiment. The power conversion device 1 includes three semiconductor modules 10-1 to 10-3. The semiconductor modules 10-1 to 10-3 are connected in parallel between the positive terminal 14 and the negative terminal 15. The semiconductor modules 10-1 to 10-3 are arranged and configured in the X direction.

[0101] The connection wiring 20 is formed by connecting an extension portion 20A extending along the X direction and a protruding portion 20B protruding in the Z direction. The protruding portion 20B has an inverted L shape. The extension portion 20A of the connection wiring 20 is connected to the AC terminal T3 of the semiconductor module 10-1 and is fixed to the AC terminal T3 by a screw (not shown).

[0102] The AC terminal T3 of the semiconductor module 10-2 is connected to the AC terminal T3 of the semiconductor module 10-3 by a connection wiring 21. Specifically, the connection wiring 21 is formed by sequentially connecting an extension portion 21A extending along the X direction, a protruding portion 21B protruding in the Z direction, and an extension portion 21C extending along the X direction. The extension portion 21A of the connection wiring 21 is connected to the AC terminal T3 of the semiconductor module 10-2 and is fixed to the AC terminal T3 by a screw (not shown). The extension portion 21C of the connection wiring 21 is connected to the AC terminal T3 of the semiconductor module 10-3 and is fixed to the AC terminal T3 by a screw (not shown).

[0103] An AC wiring 22 connects the connection wiring 20 and the connection wiring 21. Specifically, one end of the AC wiring 22 is connected to the protruding portion 20B of the connection wiring 20 and is fixed to the protruding portion 20B by a screw (not shown), and the other end of the AC wiring 22 is connected to the protruding portion 21B of the connection wiring 21 and is fixed to the protruding portion 21B by a screw (not shown).

[0104] An AC lead-out wiring 23 connects the AC wiring 22 and the output terminal 13. The AC lead-out wiring 23 is configured to extend from the AC wiring 22 in the Z direction and extend along the X direction. The AC lead-out wiring 23 includes a connection portion 23A connected to the AC wiring 22 and an extension portion 23B extending from the connection portion 23A in the X direction. The connection portion 23A is configured to include a curved portion extending in the Z direction.

[0105] The center line C2 of the connection portion 23A of the AC lead-out wiring 23 is set to be offset from the center line C1 of the AC wiring 22 to the side away from the output terminal 13. In other words, the AC lead-out wiring 23 is offset from the center of the AC wiring 22 in the X direction to the side away from the output terminal 13 and is connected to the AC wiring 22.

[0106] The length in the longitudinal direction (the length in the X direction) of the AC wiring 22 is referred to as L2. The length (the length in the X direction) of the connection portion 23A of the AC lead-out wiring 23 is referred to as L3. The length L3 of the connection portion 23A of the AC lead-out wiring 23 is set to be shorter than half of the length in the longitudinal direction L2 of the AC wiring 22.

[0107] [5-2] Function

[0108] The function of the power conversion device 1 configured as described above will be described.

[0109] By such as Figure 7It is configured in this way, so that the wiring path of the semiconductor module 10-1 can be lengthened. Thus, the inductance from the semiconductor module 10-1 to the output terminal 13 can be increased. That is, due to the effect of suppressing the inductance difference of the three parallel-connected semiconductor modules, the current imbalance can be reduced.

[0110] When the connection width (length L3) between the AC wiring 22 and the AC lead-out wiring 23 is large, the inductance from the semiconductor module 10-1 to the output terminal 13 becomes small. Therefore, the inductance difference of the three parallel-connected semiconductor modules becomes large. However, in the present embodiment, the length L3 of the connection portion 23A is set to be shorter than half of the length L2 in the length direction of the AC wiring 22. Thus, the wiring path of the semiconductor module 10-1 can be lengthened.

[0111] In the fifth embodiment, the same effect as the first embodiment can also be obtained.

[0112] [6] Sixth Embodiment

[0113] In the sixth embodiment, by increasing the distance between the AC wiring 22 and the AC lead-out wiring 23, the inductance reduction effect based on mutual induction is reduced in the semiconductor module 10-1 closest to the output terminal 13 side.

[0114] [6-1] Wiring Structure of the Power Conversion Device 1

[0115] The basic configuration of the power conversion device 1 is the same as that of the fifth embodiment. Figure 7 Same. Figure 8 It is a front view showing the wiring structure of the power conversion device 1 of the sixth embodiment. Figure 8 It is a front view of the wiring structure observed from the Y direction. The power conversion device 1 includes three semiconductor modules 10-1 to 10-3.

[0116] The thickness of the AC wiring 22 is referred to as T. The distance between the AC wiring 22 and the extension portion 23B of the AC lead-out wiring 23 is referred to as D. The distance D between the AC wiring 22 and the AC lead-out wiring 23 is set to be greater than the thickness T of the AC wiring 22.

[0117] [6-2] Function

[0118] The function of the power conversion device 1 configured as described above will be described.

[0119] In the present embodiment, by increasing the distance between the AC wiring 22 and the AC lead-out wiring 23, the inductance reduction effect based on mutual induction becomes small. Thus, the inductance from the semiconductor module 10-1 to the output terminal 13 can be increased.

[0120] On the other hand, regarding the inductance from the semiconductor module 10-3 to the output terminal 13, there is almost no mutual inductance between the AC wiring 22 and the AC lead-out wiring 23, which does not contribute to the increase or decrease of the inductance. That is, due to the effect of suppressing the inductance difference of the three parallel semiconductor modules, the current imbalance can be reduced.

[0121] In the sixth embodiment, the same effect as that of the first embodiment can also be obtained.

[0122] The sixth embodiment can also be applied to four parallel semiconductor modules. In addition, the sixth embodiment can also be applied to the first to fifth embodiments.

[0123] [7] Seventh Embodiment

[0124] In the seventh embodiment, it is configured such that the extension portion 23B of the AC wiring 22 and the AC lead-out wiring 23 forms a right angle.

[0125] [7-1] Wiring Structure of the Power Conversion Device 1

[0126] The basic configuration of the power conversion device 1 is the same as that of the fifth embodiment. Figure 7 Same. Figure 9 It is a side view showing the wiring structure of the power conversion device 1 of the seventh embodiment. Figure 9 It is a side view of the wiring structure observed from the X direction. The power conversion device 1 includes three semiconductor modules 10-1 to 10-3.

[0127] The extension portion 23B of the AC wiring 22 and the AC lead-out wiring 23 is configured to form a right angle. In other words, the AC wiring 22 and the AC lead-out wiring 23 are configured such that their respective planar portions form a right angle.

[0128] [7-2] Function

[0129] The operation of the power conversion device 1 configured as described above will be described.

[0130] In this embodiment, by arranging the respective planar portions of the AC wiring 22 and the AC lead-out wiring 23 at right angles, the inductance reduction effect based on mutual inductance becomes smaller. Therefore, the inductance from the semiconductor module 10-1 to the output terminal 13 can be increased.

[0131] On the other hand, regarding the inductance from the semiconductor module 10-3 to the output terminal 13, there is almost no mutual inductance between the AC wiring 22 and the AC lead-out wiring 23, which does not contribute to the increase or decrease of the inductance. That is, due to the effect of suppressing the inductance difference of the three parallel semiconductor modules, the current imbalance can be reduced.

[0132] In the seventh embodiment, the same effect as that of the first embodiment can also be obtained.

[0133] The seventh embodiment can also be applied to four parallel-connected semiconductor modules. In addition, the seventh embodiment can also be applied to the first to sixth embodiments.

[0134] The power conversion device 1 of each of the above embodiments can be applied to various devices and systems that process AC power. In particular, the power conversion device 1 of each of the above embodiments can be applied to a power conversion device for driving an elevator hoist.

[0135] Several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope.

Claims

1. A power conversion device comprising: The plurality of semiconductor modules connected in parallel each have two switching elements connected in series and are arranged side by side in a first direction; AC wiring extending along the first direction and connecting the AC terminals of the plurality of semiconductor modules together; as well as an AC lead-out wiring extending along the first direction and configured to lead the AC lead-out wiring to an output terminal, The AC lead-out wiring has a connection portion connected to the AC wiring and an extension portion arranged in parallel with the AC wiring. The center of the connection portion of the AC lead-out wiring in the first direction is set on a side farther from the output terminal than the center of the plurality of semiconductor modules as a whole in the first direction.

2. The power conversion device according to claim 1, wherein: The AC wiring includes a protruding portion protruding upward in a wiring path from the semiconductor module closest to the output terminal to the AC lead-out wiring.

3. The power conversion device according to claim 1, wherein: The connection portion of the AC lead-out wiring is arranged to reach a boundary between two semiconductor modules on a side away from the output terminal.

4. The power conversion device according to claim 1, wherein: The length of the connection portion of the AC lead-out wiring in the first direction is set shorter than half the length of the AC wiring in the first direction.

5. The power conversion device according to claim 1, wherein: A distance between the AC wiring and the extended portion of the AC lead-out wiring is set larger than a thickness of the AC wiring.

6. The power conversion device according to claim 1, wherein: The AC wiring and the extended portion of the AC lead-out wiring are formed at a right angle.

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