TWI907172B - Power conversion device - Google Patents

Abstract

The power conversion device of the embodiment includes: multiple semiconductor modules, each having two switching elements connected in series, arranged in a first direction and connected in parallel; AC wiring extending in the first direction and commonly connected to the AC terminals of the multiple semiconductor modules; and AC lead-out wiring extending in the first direction and extending to the output terminal. The AC lead-out wiring has: a connection portion connected to the AC wiring, and an extension portion arranged with the AC wiring. The center of the connection portion of the AC lead-out wiring in the first direction is located further away from the output terminal than the center of the multiple semiconductor modules as a whole in the first direction.

Description

Power conversion device

The embodiments of this invention relate to power conversion devices.

Power conversion devices are used in the transformers and inverters that drive elevator winches. Each phase of the three-phase AC power supply in the power conversion device has a semiconductor module, which has two switching elements (e.g., IGBTs) connected in series. In high-speed, high-capacity power conversion devices, multiple semiconductor modules connected in parallel are used.

Traditionally, multiple semiconductor modules connected in parallel using equal-length wiring are combined into a single output terminal, which is then routed from the power conversion device. In this case, the inductance difference between the multiple wirings connecting the various semiconductor modules results in a current imbalance in the semiconductor modules closer to the output terminal. Specifically, the semiconductor module closest to the output terminal has a lower inductance, resulting in a higher current; conversely, the semiconductor module furthest from the output terminal has a higher inductance, resulting in a lower current.

Even if multiple semiconductor modules connected in parallel have uniform characteristics, wiring structure factors can create inductance differences among them, resulting in current imbalance. This current imbalance leads to increased heat generation in certain semiconductor modules and decreased efficiency of the power conversion device. Furthermore, some semiconductor modules may fail due to thermal fatigue life. [Previous Art Documents][Patent Documents]

[Patent Document 1] Japanese Patent No. 4209421

[Problem to be Solved by the Invention] The problem to be solved by this invention is to provide a power conversion device that can suppress current imbalance in multiple semiconductor modules connected in parallel. [Means for Solving the Problem]

The power conversion device according to the embodiment includes: a plurality of semiconductor modules, each having two switching elements connected in series, arranged in a first direction and connected in parallel; an AC wiring extending in the first direction and commonly connected to the AC terminals of the plurality of semiconductor modules; and an AC lead-out wiring configured to extend in the first direction and lead out to an output terminal; wherein the AC lead-out wiring has: a connection portion connected to the AC wiring and an extension portion arranged in the same manner as the AC wiring; the center of the connection portion of the AC lead-out wiring in the first direction is located further away from the output terminal than the center of the plurality of semiconductor modules as a whole in the first direction.

The following description refers to the accompanying drawings and illustrates the embodiments. The various embodiments shown below are merely illustrative of apparatuses and methods for embodying the technical concept of the present invention, and do not define the technical concept of the present invention based on the shape, structure, or arrangement of the constituent parts. Furthermore, in the following description, elements with the same function and structure are given the same component symbols, and repeated descriptions are omitted.

[1] First Embodiment [1-1] Configuration of Power Conversion Device 1 Figure 1 is a circuit diagram of the power conversion device 1 according to the first embodiment. The power conversion device 1 of Figure 1 is a device for one phase of a transformer or an inverter. For example, in the case of configuring an inverter, the device of Figure 1 is used by connecting three phases in parallel.

The power conversion device 1 includes: multiple semiconductor modules 10, connecting wiring 20, 21, AC wiring 22, AC lead wiring 23, output terminal 13, positive terminal 14, negative terminal 15, and capacitor 16.

Figure 1 shows four semiconductor modules 10-1 to 10-4 as an example. Semiconductor modules 10-1 to 10-4 are connected in parallel between the positive terminal 14 and the negative terminal 15. Semiconductor modules 10-1 to 10-4 have the same configuration. The number of semiconductor modules 10 is not limited to four; it can be any number of two or more. In the following description, unless it is necessary to distinguish between semiconductor modules 10-1 to 10-4, the additional characters are omitted and the term "semiconductor module 10" is used. The description of semiconductor modules 10 is the same for all four semiconductor modules 10-1 to 10-4. The same applies to other reference symbols with additional characters.

The semiconductor module 10 has: two switching elements 11-1 and 11-2, a positive power terminal T1, a negative power terminal T2, and an AC terminal T3.

Positive power terminal T1 is connected to positive terminal 14. Negative power terminal T2 is connected to negative terminal 15. AC terminal T3 is connected to wiring 20 and 21. AC terminal T3 is the terminal for outputting AC power.

The switching element 11 is constructed, for example, using a SiC power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or an N-channel MOSFET. The SiC power MOSFET is a compound semiconductor, which is a MOSFET that uses SiC on a substrate. The switching element can be a MOSFET other than SiC, a bipolar transistor, or an IGBT (Insulated Gate Bipolar Transistor).

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

Switching elements 11-1 and 11-2 are connected in reverse parallel to diodes 12-1 and 12-2, respectively. Diode 12 is a flywheel diode, which protects switching element 11 when a reverse current is supplied. Diode 12 is constructed as a parasitic diode of a transistor. Alternatively, diode 12 can be separately provided and connected in reverse parallel to switching element 11.

In Figure 1, the gate, source, and drain terminals of a MOSFET are represented by white dots without component symbols. The gate, source, and drain terminals of the MOSFET are connected to a control circuit (not shown) that controls the potential of these terminals.

Connection cable 20 connects to AC terminal T3 of semiconductor module 10-1 and AC terminal T3 of semiconductor module 10-2. Connection cable 21 connects to AC terminal T3 of semiconductor module 10-3 and AC terminal T3 of semiconductor module 10-4. AC cable 22 connects to connection cable 20 and connection cable 21. AC cable 22 connects to AC lead-out cable 23.

AC lead-out wiring 23 is connected to output terminal 13. Output terminal 13 is a terminal that connects to an external AC power supply or AC load. When the power conversion device 1 is used as an inverter, output terminal 13 outputs AC power.

The positive terminal 14 is connected to an external positive power supply line. Positive power is supplied to the positive terminal 14. The negative terminal 15 is connected to an external negative power supply line. Negative power is supplied to the negative terminal 15.

Capacitor 16 is connected between positive terminal 14 and negative terminal 15. Capacitor 16 has the function of smoothing voltage.

[1-2] Wiring structure of power conversion device 1 Next, the wiring structure of power conversion device 1 will be described.

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

The AC terminal T3 of semiconductor module 10-1 and the AC terminal T3 of semiconductor module 10-2 are connected via connecting cable 20. Specifically, connecting cable 20 is configured to sequentially connect: an extension portion 20A extending in the X direction, a protruding portion 20B protruding in the Z direction, and an extension portion 20C extending in the X direction. The protruding portion 20B has an inverted U-shape. The extension portion 20A of connecting cable 20 is connected to the AC terminal T3 of semiconductor module 10-1 and is fixed to the AC terminal T3 by a screw (not shown). The extension portion 20C of connecting cable 20 is connected to the AC terminal T3 of semiconductor module 10-2 and is fixed to the AC terminal T3 by a screw (not shown).

The AC terminal T3 of semiconductor module 10-3 and the AC terminal T3 of semiconductor module 10-4 are connected via connecting cable 21. Specifically, connecting cable 21 is configured to sequentially connect: an extension portion 21A extending in the X direction, a protruding portion 21B protruding in the Z direction, and an extension portion 21C extending in the X direction. The protruding portion 21B has an inverted U-shape. The extension portion 21A of connecting cable 21 is connected to the AC terminal T3 of semiconductor module 10-3 and is fixed to the AC terminal T3 by a screw (not shown). The extension portion 21C of connecting cable 21 is connected to the AC terminal T3 of semiconductor module 10-4 and is fixed to the AC terminal T3 by a screw (not shown).

AC wiring 22 is a wiring extending in the X direction. AC wiring 22 connects connecting wiring 20 and connecting wiring 21. Specifically, one end of AC wiring 22 is connected to the protrusion 20B of connecting wiring 20 and is secured to the protrusion 20B by a screw (not shown). The other end of AC wiring 22 is connected to the protrusion 21B of connecting wiring 21 and is secured to the protrusion 21B by a screw (not shown).

The AC lead-out wiring 23 is a wiring extending in the X direction. AC lead-out wiring 23 connects AC wiring 22 and output terminal 13. AC lead-out wiring 23 is configured to extend from AC wiring 22 in the Z direction and also in the X direction. AC lead-out wiring 23 includes a connection portion 23A connected to AC wiring 22, and an extension portion 23B extending from connection portion 23A in the X direction. Connection portion 23A includes a curved portion extended in the Z direction. Extension portions 23B are arranged on AC wiring 22.

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

In this 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 to a side farther away from the output terminal 13. In other words, the AC lead-out wiring 23 is connected to the AC wiring 22 from the center of the AC wiring 22 in the X direction, offset to a side farther away from the output terminal 13.

The AC wiring 22 and the AC lead-out wiring 23 can be electrically connected to individual components or can be integrated into one piece.

[1-3] Explanation of function: This relates to the function of the power conversion device 1 that constitutes the above-described power conversion device.

DC power is supplied from the outside to the positive terminal 14 and the negative terminal 15. Positive power is supplied to the positive terminal 14, and negative power is supplied to the negative terminal 15.

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

As shown in Figure 2, the AC current of the semiconductor module 10-1 closest to the output terminal 13 flows from AC wiring 22 to AC lead wiring 23. The AC current flowing from the semiconductor module 10-1 to AC wiring 22 and the AC current flowing in AC lead wiring 23 are in opposite directions. This mutual induction causes the inductor to operate in a decreasing direction, thus increasing the current in the semiconductor module 10-1.

On the other hand, the AC current of the semiconductor module 10-4, which is furthest from the output terminal 13, also flows from AC wiring 22 to AC lead wiring 23. The AC current flowing from semiconductor module 10-4 to AC wiring 22 and the AC current flowing in AC lead wiring 23 are not opposite to each other. Therefore, there is almost no mutual induction, and it does not contribute to the increase or decrease of inductance. So, relative to semiconductor module 10-1, the inductance of semiconductor module 10-4 is larger.

The inductors of semiconductor modules 10-2 and 10-3 are located between semiconductor modules 10-1 and 10-4.

Here, by constructing the wiring structure shown in Figure 2, the wiring path of semiconductor module 10-4 can be shortened, thereby reducing the inductance from semiconductor module 10-4 to output terminal 13. On the other hand, the wiring path of semiconductor module 10-1 becomes longer, but due to mutual inductance, the increase or decrease in inductance is almost negligible. That is, by suppressing the inductance difference of the four parallel semiconductor modules, current imbalance can be reduced.

[1-4] Comparative Examples Next, the configuration of the comparative examples will be explained. Figure 3 is a three-dimensional view showing the wiring structure of the power conversion device of the comparative examples.

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

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

In the semiconductor module 10-1 closest to the output terminal 13, the inductance decreases due to mutual induction, resulting in a larger current flow. On the other hand, in the semiconductor module 10-4 furthest from the output terminal 13, there is almost no mutual induction, and the inductance increases due to the longer wiring path. Furthermore, due to the distance from the output terminal 13, there is a tendency for current imbalance in semiconductor modules 10-1 to 10-4. As a result, in the comparative example, the current imbalance in the outputs of semiconductor modules 10-1 to 10-4 is greater.

On the other hand, in this embodiment, compared with the comparative example, the inductance difference between the parallel-connected semiconductor modules 10-1 to 10-4 can be reduced, so the imbalance of the output current of the semiconductor modules 10-1 to 10-4 can be reduced.

[1-5] Effects of the First Embodiment According to the first embodiment, the inductance difference between the parallel-connected semiconductor modules 10-1 to 10-4 can be reduced, thus reducing the imbalance of the output current of the semiconductor modules 10-1 to 10-4. Furthermore, the increase in heat loss of specific semiconductor modules can be suppressed. Moreover, the power conversion efficiency of the power conversion device 1 can be improved.

Furthermore, it can suppress the decline in the thermal fatigue life of specific semiconductor modules. In this way, it can suppress the failure of power conversion device 1.

[2] Second embodiment The second embodiment is configured such that the connection position of the AC wiring 22 and the AC lead wiring 23 is further away from the output terminal 13.

[2-1] Regarding the wiring structure of the power conversion device 1, 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 semiconductor modules 10-1 to 10-4 are omitted, and these are the same as those in Figure 2.

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

The end of AC wiring 22 furthest from output terminal 13 is referred to as the end region AR. In this embodiment, the length of the end region AR of AC wiring 22 in the X direction is shortened. The end region AR of AC wiring 22 is set to the minimum length necessary for screwing AC wiring 22 to the protrusion 21B of connecting wiring 21. The width (length in the Y direction) of AC wiring 22 can be configured the same as in the first embodiment.

The second implementation method has the same effect as the first implementation method.

[2-2] The effect of the second embodiment: According to the second embodiment, with the same depth dimension as the first embodiment, the inductance difference can be reduced more than that of the first embodiment. Other effects are the same as those of the first embodiment.

[3] Third embodiment The third embodiment reduces the inductance difference between semiconductor modules 10-1 to 10-4 by lengthening the path of AC wiring 22.

[3-1] Regarding the wiring structure of the power conversion device 1, 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 semiconductor modules 10-1 to 10-4 are omitted, and these are the same as those in Figure 2.

The AC wiring 22 is configured to be connected in sequence as follows: an extension portion 22A extending in the X direction, a protruding portion 22B protruding in the Z direction, and an extension portion 22C extending in 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 connecting wiring 20 and is secured to the protruding portion 20B by a screw (not shown). The protruding portion 22B of the AC wiring 22 is positioned closer to the output terminal 13 than the connecting portion 23A of the AC lead-out wiring 23.

The extension portion 22C of the AC wiring 22 is connected to the protruding portion 21B of the connecting wiring 21, and is secured to the protruding portion 21B by a screw (not shown). Furthermore, the extension portion 22C of the AC wiring 22 is connected to the connecting portion 23A of the AC lead-out wiring 23.

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 a side farther away from the output terminal 13.

By having a protruding portion 22B on the AC wiring 22, the wiring path that extends from the semiconductor modules 10-1 and 10-2 close to the output terminal 13 up to the AC lead-out wiring 23 can be lengthened.

[3-2] Explanation of function: This relates to the function of the power conversion device 1 that constitutes the above-described power conversion device.

With the AC wiring 22 having a protruding portion 22B, the wiring paths of semiconductor modules 10-1 and 10-2 become longer, thus increasing the inductance. This reduces the inductance difference between semiconductor modules 10-1 and 10-2 and semiconductor module 10-4. Therefore, the inductance difference between semiconductor modules 10-1 and 10-4 can be reduced, thereby decreasing the output current imbalance.

[3-3] The effect of the third embodiment: According to the third embodiment, with the same depth dimension as the first embodiment, the inductance difference can be reduced more than that of the first embodiment. Other effects are the same as those of the first embodiment.

[4] Fourth embodiment The fourth embodiment reduces the inductance difference between semiconductor modules 10-1 and 10-4 by shortening the wiring path of the semiconductor module 10-4 furthest from the output terminal 13.

[4-1] Figure 6 is a perspective view showing the wiring structure of the power conversion device 1 in relation to the fourth embodiment.

The AC lead-out wiring 23 is configured to connect to the AC lead-out wiring 22 via the semiconductor module 10-4 furthest from the output terminal 13. Furthermore, the AC lead-out wiring 23 is configured to connect to the boundaries of the semiconductor modules 10-3 and 10-4 that are further away from the output terminal 13. In other words, the connection portion 23A of the AC lead-out wiring 23 is configured to connect to the semiconductor module 10-4 furthest from the output terminal 13. Moreover, the connection portion 23A of the AC lead-out wiring 23 is configured to connect to the boundaries of the semiconductor modules 10-3 and 10-4 that are further away from the output terminal 13.

In the configuration example of Figure 6, the AC lead-out wiring 23 is configured to be connected to the AC wiring 22 at one end. That is, the connection portion 23A of the AC lead-out wiring 23 is disposed at the end of the AC wiring 22.

Because it is necessary to ensure the area of the screw head connecting AC wiring 22, the connection portion 23A of AC lead wiring 23 is configured to extend in the Y direction, as in the first embodiment. The length from the end of AC wiring 22 in the Y direction to the end of AC lead wiring 23 is called L1. In the fourth embodiment, the length L1 is longer than that in the first embodiment.

[4-2] Explanation of function: This relates to the function of the power conversion device 1 that constitutes the above-described power conversion device.

The wiring path of the semiconductor module 10-4 can be shortened by configuring it as shown in Figure 6 compared to the first embodiment. This reduces the inductance from the semiconductor module 10-4 all the way to the output terminal 13.

On the other hand, the wiring path of semiconductor module 10-1 is longer than that of the first embodiment, but the increase or decrease in inductance is almost negligible due to mutual inductance. That is, current imbalance can be reduced by suppressing the inductance difference of the four parallel semiconductor modules.

The fourth embodiment has a smaller inductance difference than the first embodiment, which can suppress current imbalance. However, because it is necessary to ensure the area of the screw head connecting the AC wiring 22, the length L1 is longer than that of the first embodiment. By increasing the length L1, the distance between the AC wiring 22 and the AC lead-out wiring 23 is also longer than in the first embodiment, thus weakening the effect of the reduced inductance due to mutual induction. This increases the inductance of the semiconductor module 10-1, suppressing the inductance difference of the four parallel semiconductor modules. Therefore, current imbalance can be reduced.

In the fourth implementation, the same effect as in the first implementation can be achieved.

[5] Fifth embodiment The fifth embodiment is a configuration example of a semiconductor module with three parallel connections.

[5-1] Wiring Structure of Power Conversion Device 1 Figure 7 is a perspective view showing the wiring structure of power conversion device 1 according to the fifth embodiment. Power conversion device 1 includes: three semiconductor modules 10-1 to 10-3. Semiconductor modules 10-1 to 10-3 are connected in parallel between positive terminal 14 and negative terminal 15. Semiconductor modules 10-1 to 10-3 are arranged in the X direction.

The connecting wiring 20 constitutes a connection: an extension portion 20A extending in 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 connecting 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 AC terminal T3 of semiconductor module 10-2 and the AC terminal T3 of semiconductor module 10-3 are connected via connecting cable 21. Specifically, connecting cable 21 is configured to connect in sequence: an extension portion 21A extending in the X direction, a protrusion portion 21B protruding in the Z direction, and an extension portion 21C extending in the X direction. The extension portion 21A of connecting cable 21 is connected to the AC terminal T3 of semiconductor module 10-2 and is fixed to the AC terminal T3 by a screw (not shown). The extension portion 21C of connecting cable 21 is connected to the AC terminal T3 of semiconductor module 10-3 and is fixed to the AC terminal T3 by a screw (not shown).

AC wiring 22 connects to connecting wiring 20 and connecting wiring 21. Specifically, one end of AC wiring 22 is connected to the protrusion 20B of connecting wiring 20 and is fixed to the protrusion 20B by a screw (not shown). The other end of AC wiring 22 is connected to the protrusion 21B of connecting wiring 21 and is fixed to the protrusion 21B by a screw (not shown).

AC lead-out wiring 23 connects AC lead-out wiring 22 and output terminal 13. AC lead-out wiring 23 is configured to extend from AC lead-out wiring 22 in the Z direction and extend in the X direction. AC lead-out wiring 23 includes a connection portion 23A connected to AC lead-out wiring 22, and an extension portion 23B extending from connection portion 23A in the X direction. Connection portion 23A includes a curved portion extended in the Z direction.

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 a side farther away from the output terminal 13. In other words, the AC lead-out wiring 23 is connected to the AC wiring 22 from the center of the AC wiring 22 in the X direction, offset to a side farther away from the output terminal 13.

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

[5-2] Explanation of function: This relates to the function of the power conversion device 1 that constitutes the above-described power conversion device.

By configuring it as shown in Figure 7, the wiring path of semiconductor module 10-1 can be increased. This increases the inductance from semiconductor module 10-1 all the way to output terminal 13. That is, by suppressing the inductance difference of the three parallel semiconductor modules, current imbalance can be reduced.

If the connection width (length L3) of AC wiring 22 and AC lead-out wiring 23 is large, the inductance from semiconductor module 10-1 to output terminal 13 will be smaller. This would result in a larger inductance difference between the three parallel semiconductor modules. However, in this embodiment, the length L3 of the connection portion 23A is set to be shorter than half the longitudinal length L2 of AC wiring 22. This allows for a longer wiring path for semiconductor module 10-1.

In the fifth embodiment, the same effect as in the first embodiment can be obtained.

[6] Sixth embodiment The sixth embodiment achieves the effect of reducing the inductance caused by mutual induction in the semiconductor module 10-1 closest to the output terminal 13 by increasing the distance between the AC wiring 22 and the AC lead wiring 23.

[6-1] Wiring Structure of Power Conversion Device 1 The basic configuration of power conversion device 1 is the same as that shown in Figure 7 of the fifth embodiment. Figure 8 is a front view showing the wiring structure of power conversion device 1 according to the sixth embodiment. Figure 8 is a front view of the wiring structure viewed from the Y direction. Power conversion device 1 includes: 3 semiconductor modules 10-1 to 10-3.

The thickness of AC wiring 22 is called T. The distance between AC wiring 22 and the extension portion 23B of AC lead wiring 23 is called D. The distance D between AC wiring 22 and AC lead wiring 23 is set to be larger than the thickness T of AC wiring 22.

[6-2] Explanation of function: This relates to the function of the power conversion device 1 that constitutes the above-described power conversion device.

In this embodiment, by increasing the distance between AC wiring 22 and AC lead wiring 23, the inductance reduction effect caused by mutual induction is reduced. In this way, the inductance from semiconductor module 10-1 all the way to output terminal 13 can be increased.

On the other hand, regarding the inductance from semiconductor module 10-3 all the way to output terminal 13, the mutual inductance between AC wiring 22 and AC lead wiring 23 is almost non-existent, and does not contribute to the increase or decrease of inductance. That is, because of the effect of suppressing the inductance difference of the 3 parallel semiconductor modules, the current imbalance can be reduced.

In the sixth embodiment, the same effect as in the first embodiment can be achieved.

The sixth embodiment can also be applied to a 4-parallel semiconductor module. Furthermore, the sixth embodiment can also be applied to the first through fifth embodiments.

[7] Seventh Embodiment In the seventh embodiment, the extension portion 23B of the AC wiring 22 and the AC lead-out wiring 23 are at right angles. [7-1] Wiring Structure of Power Conversion Device 1 The basic structure of power conversion device 1 is the same as that in Figure 7 of the fifth embodiment. Figure 9 is a side view showing the wiring structure of power conversion device 1 according to the seventh embodiment. Figure 9 is a side view of the wiring structure viewed from the X direction. Power conversion device 1 has: 3 semiconductor modules 10-1 to 10-3.

The extension portion 23B of AC wiring 22 and AC lead-out wiring 23 is formed at a right angle. In other words, the planar portions of AC wiring 22 and AC lead-out wiring 23 are formed at right angles.

[7-2] Explanation of function: This relates to the function of the power conversion device 1 that constitutes the above-described power conversion device.

In this embodiment, by arranging the planar portions of AC wiring 22 and AC lead-out wiring 23 at right angles, the inductance reduction effect caused by mutual induction is reduced. As a result, the inductance from semiconductor module 10-1 all the way to output terminal 13 can be increased.

On the other hand, regarding the inductance from semiconductor module 10-3 all the way to output terminal 13, the mutual inductance between AC wiring 22 and AC lead wiring 23 is almost non-existent, and does not contribute to the increase or decrease of inductance. That is, because of the effect of suppressing the inductance difference of the 3 parallel semiconductor modules, the current imbalance can be reduced.

In the seventh embodiment, the same effect as in the first embodiment can be obtained.

The seventh embodiment can also be applied to a 4-parallel semiconductor module. Furthermore, the seventh embodiment can also be applied to the first through sixth embodiments.

The power conversion device 1 of the above embodiments can be applied to various machines or systems that process AC power. In particular, the power conversion device 1 of the above embodiments can be applied to a power conversion device for driving an elevator hoist.

Several embodiments of the present invention have been described, but these embodiments are merely illustrative and not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, with omissions, substitutions, and modifications made without departing from the spirit of the invention. These embodiments or their variations are included within the scope or spirit of the invention, and also within the scope of the invention described in the patent application and its equivalents.

1: Power conversion device; 10-1~10-4: Semiconductor module; 11-1, 11-2: Switching element; 12-1, 12-2: Diode; 13: Output terminal; 14: Positive terminal; 15: Negative terminal; 16: Capacitor; 20, 21: Connection wiring; 22: AC wiring; 23: AC lead wiring; T1: Positive power terminal; T2: Negative power terminal; T3: AC terminal.

[Figure 1] Figure 1 is a circuit diagram of the power conversion device according to the first embodiment. [Figure 2] Figure 2 is a perspective view showing the wiring structure of the power conversion device according to the first embodiment. [Figure 3] Figure 3 is a perspective view showing the wiring structure of the power conversion device according to a comparative example. [Figure 4] Figure 4 is a perspective view showing the wiring structure of the power conversion device according to the second embodiment. [Figure 5] Figure 5 is a perspective view showing the wiring structure of the power conversion device according to the third embodiment. [Figure 6] Figure 6 is a perspective view showing the wiring structure of the power conversion device according to the fourth embodiment. [Figure 7] Figure 7 is a perspective view showing the wiring structure of the power conversion device according to the fifth embodiment. [Figure 8] Figure 8 is a front view showing the wiring structure of the power conversion device according to the sixth embodiment. [Figure 9] Figure 9 is a side view showing the wiring structure of the power conversion device according to the seventh embodiment.

10-1~10-4: Semiconductor Module 13: Output Terminals 20, 21: Connecting Wiring 20A: Extension in the X direction 20B: Protrusion in the Z direction 20C: Extension in the X direction 21A: Extension in the X direction 21B: Protrusion in the Z direction 21C: Extension in the X direction 22: AC Wiring 23: AC Lead-out Wiring 23A: Connecting portion of AC Lead-out Wiring 23 23B: Extension in the X direction

Claims (6)

A power conversion device includes: a plurality of semiconductor modules, each having two switching elements connected in series, arranged in a first direction and connected in parallel; an AC wiring extending in the first direction and commonly connected to the AC terminals of the plurality of semiconductor modules; and an AC lead-out wiring configured to extend in the first direction and lead out to an output terminal; wherein the AC lead-out wiring has: a connection portion connected to the AC wiring and an extension portion arranged in the same direction as the AC wiring; the center of the connection portion of the AC lead-out wiring in the first direction is located further away from the output terminal than the center of the plurality of semiconductor modules as a whole in the first direction. As in the power conversion device of claim 1, the aforementioned AC wiring includes an upwardly projecting portion in the wiring path from the semiconductor module closest to the aforementioned output terminal to the aforementioned AC lead-out wiring. As in the power conversion device of claim 1, the aforementioned connection portion of the aforementioned AC lead-out wiring is configured to connect to the boundary of two semiconductor modules on the side farther from the aforementioned output terminal. As in the power conversion device of claim 1, the length of the aforementioned connection portion of the aforementioned AC lead-out wiring in the aforementioned first direction is configured to be shorter than half the length of the aforementioned AC wiring in the aforementioned first direction. As in the power conversion device of claim 1, the distance between the aforementioned AC wiring and the aforementioned extended portion of the aforementioned AC lead wiring is set to be greater than the thickness of the aforementioned AC wiring. As in the power conversion device of claim 1, there is a portion of the aforementioned extension constituting the aforementioned AC wiring and the aforementioned AC lead wiring that is perpendicular to each other.