WO2025094240A1 - Power conversion device - Google Patents

Abstract

This power conversion device (101) comprises: a first power conversion unit (11) and a second power conversion unit (12) that are adjacent to each other in a first direction (DR1); and a first insulating housing (21) and a second insulating housing (22) that are adjacent to each other in the first direction. The first power conversion unit is supported by the first insulating housing. The second power conversion unit is supported by the second insulating housing. The first insulating housing and the second insulating housing respectively have wall parts (20A, 20B) disposed between the first power conversion unit and the second power conversion unit. The power conversion device further comprises at least one first coupling member (41) that passes through and couples the respective wall parts of the first insulating housing and the second insulating housing. Terminals (31, 32A) of the first power conversion unit and the second power conversion unit are electrically connected to each other via the at least one first coupling member.

Description

Power Conversion Equipment

This disclosure relates to a power conversion device.

A power conversion device that includes multiple submodules (power conversion units) and an insulating housing is known as a power conversion device used in high voltage direct current (HVDC) transmission and the like (see, for example, Japanese Patent No. 6995259 (Patent Document 1)). The insulating housing supports each of the multiple power conversion units and is provided to insulate the multiple power conversion units from each other and to insulate each power conversion unit from surrounding grounded objects such as walls.

Patent No. 6995259

In the power conversion device described in Patent Document 1, an opening is formed in the insulating housing in front of each power conversion unit, and a conductive member protruding from the opening to the outside of the insulating housing electrically connects adjacent power conversion units. In the above power conversion device, the electric field on the surface of the conductive member located outside the insulating housing is high, so there is room for improvement in terms of suppressing the occurrence of dielectric breakdown.

The main objective of this disclosure is to provide a power conversion device that can suppress the occurrence of insulation breakdown.

The power conversion device according to the present disclosure includes a plurality of power conversion units each having a first power conversion unit and a second power conversion unit adjacent to each other in a first direction, and a plurality of insulating housings each having a first insulating housing and a second insulating housing adjacent to each other in the first direction. The first power conversion unit is supported by the first insulating housing. The second power conversion unit is supported by the second insulating housing. Each of the first power conversion unit and the second power conversion unit has a terminal. Each of the first insulating housing and the second insulating housing has a wall portion disposed between the first power conversion unit and the second power conversion unit. The power conversion device further includes at least one first connecting member that penetrates and connects the respective wall portions of the first insulating housing and the second insulating housing. The respective terminals of the first power conversion unit and the second power conversion unit are electrically connected to each other via at least one first connecting member.

The power conversion device disclosed herein can suppress the occurrence of insulation breakdown.

1 is a circuit diagram of a power conversion device 100 according to an embodiment of the present disclosure. 2 is a circuit diagram of the power conversion unit 10 shown in FIG. 1. FIG. 2 is a perspective view for explaining the basic configuration of one power conversion unit 10 and one insulating casing 20 supporting the power conversion unit. 1 is a plan view of a power conversion device 101 according to a first embodiment. 1 is a partially enlarged plan view of a connection portion between a first insulating casing 21 and a second insulating casing 22 adjacent to each other in the X direction in a power conversion device 101. FIG. 10 is a partially enlarged plan view of a connection portion between a first insulating casing 21 and a second insulating casing 22 adjacent to each other in the X direction in a power conversion device 102 according to a second embodiment. FIG. 11 is a partially enlarged cross-sectional view of a connection portion between a first insulating casing 21 and a second insulating casing 22 adjacent to each other in the X direction in a power conversion device 103 according to a third embodiment. FIG. FIG. 11 is a plan view of a power conversion device 104 according to a fourth embodiment. FIG. 13 is a plan view of a power conversion device 105 according to a fifth embodiment. FIG. 13 is a plan view showing a modified example of the power conversion device 105 according to the fifth embodiment. FIG. 13 is a plan view of a power conversion device 106 according to a sixth embodiment. 10 is a partially enlarged plan view showing an example of the configuration of a connection portion between a first insulating casing 21 and a second insulating casing 22 adjacent to each other in the Z direction in a power conversion device 106. FIG. FIG. 13 is a plan view of a power conversion device 107 according to a seventh embodiment. FIG. 2 is a plan view of a power conversion device 200 according to a comparative example.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following, the same or corresponding parts are denoted by the same reference characters, and overlapping descriptions will not be repeated.
<Configuration of power conversion device 100>
The power conversion device 100 is, for example, a multilevel modular converter (MMC) type high voltage DC (HVDC) converter. However, the power conversion device 100 is not limited to this.

As shown in FIG. 1, the power conversion device 100 has multiple sets of upper arms 110 and lower arms 120. The upper arms 110 and lower arms 120 are electrically connected in series. Each of the multiple sets of upper arms 110 and lower arms 120 is electrically connected in parallel. A transformer 130 is connected between the upper arms 110 and the lower arms 120. Each of the upper arms 110 and lower arms 120 has multiple power conversion units 10 and connection lines 140 that electrically connect each of the multiple power conversion units 10 in series.

In addition, in multiple power conversion units 10 electrically connected in series, the potential of the power conversion unit 10 at the DC end is generally higher than the potential of the power conversion unit 10 at the AC end. The potential difference between the DC end and the AC end is divided by the number of power conversion units 10, and the potential difference between power conversion units 10 that are directly and electrically connected is constant when expressed without taking into account ripples during operation, etc.

The power conversion device 100 may further include, for example, at least one of piping for cooling the power conversion unit 10, communication equipment, other electrical equipment, and mechanical support equipment. Illustrations and descriptions of these are omitted in this disclosure.

As shown in FIG. 2, the power conversion unit 10 includes, for example, switching elements 1a and 1b, diodes 2a and 2b, a capacitor 3, and connection lines 4a and 4b.

Switching element 1a and switching element 1b are, for example, IGBTs (Insulated Gate Bipolar Transistors). Switching element 1a and switching element 1b are connected in series.

Diode 2a and diode 2b are electrically connected in parallel to be reverse biased to switching element 1a and switching element 1b, respectively. Capacitor 3 is electrically connected in parallel to switching element 1a and switching element 1b, which are electrically connected in series.

The connection line 4a is connected to the emitter of the switching element 1a and the collector of the switching element 1b. The connection line 4b is connected to the emitter of the switching element 1b. The connection line 4a of one power conversion unit 10 is connected to the connection line 4b of the other adjacent power conversion unit 10. In this way, the power conversion unit 10 constitutes a half-bridge type converter cell. Note that the power conversion unit 10 may also constitute a full-bridge type converter cell.

In the power conversion device 100, each of the multiple power conversion units 10 is supported by an insulating housing.

FIG. 3 is a perspective view for explaining the basic configuration of one power conversion unit 10 and one insulating housing 20 that supports it in the power conversion device 100. In the following, the mutually orthogonal X, Y, and Z directions are introduced. The X and Y directions correspond to the horizontal direction. The Z direction corresponds to the up-down direction.

As shown in FIG. 3, each power conversion unit 10 has a first side 10A, a second side 10B, a bottom surface 10C, a top surface 10D, a front surface 10E, and a back surface (not shown). Note that the first side surface 10A, the second side surface 10B, the bottom surface 10C, the top surface 10D, the front surface 10E, and the back surface are surfaces of the case of the power conversion unit 10. This case is made of, for example, metal.

The first side 10A and second side 10B of each power conversion unit 10 face one side and the other side in the X direction, respectively. The bottom surface 10C and top surface 10D of each power conversion unit 10 face one side and the other side in the Z direction. The front surface 10E and rear surface of each power conversion unit 10 face one side and the other side in the Y direction. Hereinafter, the side facing the front surface 10E in the Y direction will be referred to as the front side, and the opposite side will be referred to as the rear side.

The material constituting the insulating housing 20 is a material having electrical insulation properties. The material constituting the insulating housing 20 may be any material having electrical insulation properties, but may be at least one selected from the group consisting of, for example, FRP (Fiber Reinforced Plastic), glass epoxy resin, cast epoxy resin, polyethylene, polyvinyl chloride, silicone, fluorine-based synthetic rubber, nylon, and electrically insulating ceramics.

Each insulating housing 20 has a first side wall portion 20A, a second side wall portion 20B, a bottom wall portion 20C, and an upper wall portion 20D. In each insulating housing 20, the first side wall portion 20A and the second side wall portion 20B face each other with a gap in the X direction. In each insulating housing 20, the bottom wall portion 20C and the upper wall portion 20D face each other with a gap in the Z direction. One end (lower end) in the Z direction of each of the first side wall portion 20A and the second side wall portion 20B is continuous with the bottom wall portion 20C. The other end (upper end) in the Z direction of each of the first side wall portion 20A and the second side wall portion 20B is continuous with the upper wall portion 20D.

Each insulating housing 20 has a space defined by a first side wall portion 20A, a second side wall portion 20B, a bottom wall portion 20C, and an upper wall portion 20D. Each power conversion unit 10 is disposed within the space of each insulating housing 20. Note that multiple power conversion units 10 may be disposed within the space of one insulating housing 20.

Each power conversion unit 10 is fixed to each insulating housing 20. The power conversion unit 10 may be fixed to the insulating housing 20 by any structure, but is fixed to the insulating housing 20 by, for example, adhesive or bolts.

The first side surface 10A is spaced apart from the first side wall portion 20A. The second side surface 10B is spaced apart from the second side wall portion 20B. The bottom surface 10C is in contact with the bottom wall portion 20C. The top surface 10D is spaced apart from the top wall portion 20D. The front surface 10E is, for example, located rearward of the front surfaces of the first side wall portion 20A, the second side wall portion 20B, the bottom wall portion 20C, and the top wall portion 20D of the insulating housing 20.

Each of the multiple power conversion units 10 has a terminal electrically connected to the connection line 140 shown in FIG. 1.

Below, power conversion devices 101 to 105 according to embodiments 1 to 5 will be described with reference to Figs. 3 to 12 as configuration examples of the power conversion device 100.

Embodiment 1.
4 and 5, the power conversion device 101 includes a plurality of power conversion units 10, a plurality of insulating housings 20, and a plurality of first connecting members 40. Each of the plurality of power conversion units 10 and the plurality of insulating housings 20 has the basic configuration shown in FIG.

The multiple power conversion units 10 have a first power conversion unit 11 and a second power conversion unit 12 that are adjacent to each other in the first direction DR1.

The multiple power conversion units 10 further include, for example, a third power conversion unit 13 arranged to overlap the first power conversion unit 11 in a second direction DR2 perpendicular to the first direction DR1, and a fourth power conversion unit 14 adjacent to the second power conversion unit 12 in the first direction DR1.

In the power conversion device 101, the first direction DR1 is along the X direction, and the second direction DR2 is along the Z direction.

Each of the multiple power conversion units 10 has at least one terminal 30. The terminal 30 is provided, for example, on the front surface 10E of each power conversion unit 10. The terminal 30 is attached to the front surface 10E, for example, by a bolt or adhesive. The material constituting the terminal 30 may be any material having electrical conductivity, and may include at least one selected from the group consisting of stainless steel, brass, copper, aluminum, titanium, nickel, iron, gold, platinum, silver, zirconium, Inconel, Hastelloy, molybdenum, and tungsten. The terminal 30 may be configured, for example, as a bus bar or an electric wire. The terminal 30 may have a coating film for improving at least one of the voltage resistance, waterproof performance, dustproof performance, and rustproof performance. The terminal 30 may have a coating film made of an electrically insulating material formed by lamination processing or the like, or a coating film made of a metal material formed by plating processing or the like.

The terminal 30 has a first portion 301 extending along a first direction DR1 and a second portion 302 extending along a second direction DR2. The second portion 302 is in contact with, for example, the first side wall portion 20A or the second side wall portion 20B of the insulating housing 20.

The first power conversion unit 11 has a terminal 31. The second power conversion unit 12 has a terminal 32A and a terminal 32B. The fourth power conversion unit 14 has a terminal 34.

The multiple insulating housings 20 include a first insulating housing 21 and a second insulating housing 22 that are adjacent to each other in the first direction DR1.

The first power conversion unit 11 is disposed in the above-mentioned space of the first insulating housing 21 and is supported by the first insulating housing 21. The first power conversion unit 11 is fixed to the bottom wall portion 20C of the first insulating housing 21. The terminals 30 of the first power conversion unit 11 are disposed in the above-mentioned space of the first insulating housing 21. The terminals 30 of the first power conversion unit 11 do not protrude outside the above-mentioned space of the first insulating housing 21.

The second power conversion unit 12 is disposed in the above-mentioned space of the second insulating housing 22 and is supported by the second insulating housing 22. The second power conversion unit 12 is fixed to the bottom wall portion 20C of the second insulating housing 22. The terminals 30 of the second power conversion unit 12 are disposed in the above-mentioned space of the second insulating housing 22. The terminals 30 of the second power conversion unit 12 do not protrude outside the above-mentioned space of the second insulating housing 22.

The first side wall portion 20A of the first insulating housing 21 faces the second side wall portion 20B of the second insulating housing 22. The first side wall portion 20A of the first insulating housing 21 is in contact with, for example, the second side wall portion 20B of the second insulating housing 22. The first side wall portion 20A of the first insulating housing 21 and the second side wall portion 20B of the second insulating housing 22 are disposed between the first power conversion unit 11 and the second power conversion unit 12 in the first direction DR1.

The upper wall portion 20D of the first insulating housing 21 faces the bottom wall portion 20C of the third insulating housing 23. The upper wall portion 20D of the first insulating housing 21 is in contact with, for example, the bottom wall portion 20C of the third insulating housing 23. The upper wall portion 20D of the first insulating housing 21 and the bottom wall portion 20C of the third insulating housing 23 are disposed between the first power conversion unit 11 and the third power conversion unit 13.

Each of the multiple first connecting members 40 penetrates one of the first side wall portions 20A and the other of the second side wall portions 20B of two insulating housings 20 adjacent to each other in the first direction DR1, and connects them. Each of the multiple first connecting members 40 is composed of a portion penetrating one of the first side wall portions 20A and the other of the second side wall portions 20B of two insulating housings 20 adjacent to each other in the first direction DR1, a portion disposed in the above-mentioned space of the one insulating housing, and a portion disposed in the above-mentioned space of the other insulating housing. Each of the multiple first connecting members 40 does not have a portion protruding forward or backward from the above-mentioned space of each insulating housing 20. Each of the multiple first connecting members 40 does not have a bent portion, for example, U-shaped. Note that each of the multiple first connecting members 40 may have a bent portion, such as a U-shaped portion. The bent portion of each of the multiple first connecting members 40 is disposed within the above-mentioned space of one of the two insulating housings 20 adjacent to each other in the first direction DR1. The two ends of each of the multiple first connecting members 40 located on the opposite side of the bent portion are disposed within the above-mentioned space of the other of the two adjacent insulating housings 20. In such a first connecting member 40, it is sufficient that the two portions disposed within the above-mentioned space of the other are fastened.

Each of the multiple first connecting members 40 may have any structure capable of penetrating one first side wall portion 20A and the other second side wall portion 20B of two insulating housings 20 adjacent to each other in the first direction DR1 and connecting them. Each of the multiple first connecting members 40 may have a fastening structure having, for example, a bolt and a nut. Each of the multiple first connecting members 40 may have an adhesive bonding structure.

The material constituting each of the multiple first connecting members 40 is a material having electrical conductivity. The multiple first connecting members 40 are arranged at intervals from each other in the second direction DR2, for example.

The multiple first connecting members 40 include multiple first connecting members 41 that penetrate each of the first side wall portion 20A of the first insulating housing 21 and the second side wall portion 20B of the second insulating housing 22 to connect them, and multiple first connecting members 42 that penetrate each of the first side wall portion 20A of the second insulating housing 22 and the second side wall portion 20B of the fourth insulating housing 24 to connect them.

The terminal 31 of the first power conversion unit 11 and the terminal 32A of the second power conversion unit 12 are electrically and mechanically connected to each of the multiple first connecting members 41. The terminal 31 of the first power conversion unit 11 and the terminal 32A of the second power conversion unit 12 are electrically connected to each other via each of the multiple first connecting members 41.

The terminal 32B of the second power conversion unit 12 and the terminal 34 of the fourth power conversion unit 14 are electrically and mechanically connected to each of the multiple first connecting members 42. The terminal 32B of the second power conversion unit 12 and the terminal 34 of the fourth power conversion unit 14 are electrically connected to each other via each of the multiple first connecting members 42. Each of the multiple first connecting members 41, 42 constitutes the connection line 140 shown in FIG. 1.

As shown in FIG. 3, the power conversion device 101 further includes a plurality of second connecting members 50. Each of the plurality of second connecting members 50 is provided to mechanically connect two adjacent insulating housings 20 that support two power conversion units 10 that are not electrically connected to each other. Each of the plurality of second connecting members 50 mechanically connects two adjacent insulating housings 20 in the second direction DR2, for example. The material constituting each second connecting member 50 may be a conductive material or an electrically insulating material.

FIG. 5 shows an example in which each of the multiple first connecting members 41 has the above-mentioned fastening structure. Each of the first connecting members 41 shown in FIG. 5 has a bolt 411 and a nut 412. The material that constitutes the bolt 411 and the nut 412 is a conductive material.

The second portion 312 of the terminal 31 of the first power conversion unit 11 is in contact with, for example, the first side wall portion 20A of the first insulating housing 21. The second portion 322 of the terminal 32A of the second power conversion unit 12 is in contact with, for example, the second side wall portion 20B of the second insulating housing 22.

The second portion 312 of the terminal 31, the first side wall portion 20A of the first insulating housing 21, the second side wall portion 20B of the second insulating housing 22, and the second portion 322 of the terminal 32A each have a through hole formed therein, which is continuous with the first direction DR1. The diameter of the through hole is larger than the outer diameter of the bolt 411 and smaller than the outer diameter of the nut 412. The bolt 411 is inserted through the through hole. The nut 412 is fastened to the tip of the bolt 411. The bolt 411 and the nut 412 face the first side surface 10A of the first power conversion unit 11 or the second side surface 10B of the second power conversion unit 12 with a gap therebetween.

<Effects of the power conversion device 101>
The effects of the power conversion device 101 will be described based on a comparison with a comparative example 200 shown in FIG.

In the comparative example 200 shown in FIG. 14, a conductive member 230 protruding to the outside from an opening formed in each of two adjacent insulating housings 220 electrically connects the power conversion units 210 housed in each insulating housing 220. Therefore, in the comparative example, even if a coating film made of an electrically insulating material is formed on the surface of the conductive member 230 by lamination or the like, electric field concentration is likely to occur at the tip of the protruding portion of the conductive member 230, and this part of the conductive member 230 may become the starting point of discharge and cause insulation breakdown.

In addition, in the comparative example 200, when the connecting member connecting two adjacent insulating housings 220 has a conductive portion made of a conductive material, a floating potential is generated in the connecting member according to the potential difference between the power conversion unit 210 and the surrounding structure. This floating potential can be several kV or more. In other words, the connecting member that is electrically floating with respect to each power conversion unit 210 is a portion where an electric field is likely to concentrate, and is likely to become a base point for discharge.

In addition, in the comparative example 200, the conductive member 230 has a bent portion bent into a U-shape, so that the electric field lines are concentrated around the conductive member 230, and the electric field tends to concentrate on the surface of the conductive member 230.

In contrast, in the power conversion device 101, the first connecting members 40 do not protrude outside the above-mentioned space of each insulating housing 20, so the electric field on the surface of each first connecting member 40 is lower than in the comparative example 200. Therefore, in the power conversion device 101, electric field concentration is less likely to occur in the first connecting members 40 than in the comparative example 200, and the occurrence of insulation breakdown with each first connecting member 40 as the starting point of discharge can be suppressed.

Furthermore, in the power conversion device 101, each first connecting member 40 is electrically connected to the terminal 30 of each power conversion unit 10, so that each first connecting member 40 is not electrically floating with respect to each power conversion unit 10. Therefore, in the power conversion device 101, the occurrence of dielectric breakdown with each first connecting member 40 as the starting point of discharge can be more effectively suppressed.

Furthermore, in the power conversion device 101, each first connecting member 41 does not need to have a bent portion bent into a U-shape. The density of the electric field lines generated around each first connecting member 41 that does not have a bent portion bent into a U-shape is lower than that of the electric field lines generated around the conductive member 230 of the comparative example 200. Therefore, in the power conversion device 101, the occurrence of dielectric breakdown with each first connecting member 40 as the starting point of discharge can be more effectively suppressed.

<Modification of power conversion device 101>
The number of each of the power conversion units 10, the insulating housings 20, the terminals 30, and the first connecting members 40 in the power conversion device 101 can be set individually and arbitrarily. The power conversion device 101 only needs to include at least one first connecting member 40. When the power conversion device 101 is required to have high resistance to vibrations such as earthquakes, the number of each of the first connecting members 40 and the second connecting members 50 connecting two adjacent insulating housings 20 may be more than two.

Preferably, each insulating housing 20 further has a front wall portion and a rear wall portion that face each other with a gap in the Y direction. The front end of each of the first side wall portion 20A and the second side wall portion 20B is connected to the front wall portion. The rear end of each of the first side wall portion 20A and the second side wall portion 20B is connected to the rear wall portion. In the power conversion device 101, since an opening for protruding to the outside of the above-mentioned space is not required, each insulating housing 20 can be configured as a container that houses each power conversion unit 10. In this case, each insulating housing 20 is configured as a container that houses each power conversion unit 10. Preferably, the above-mentioned space defined by the first side wall portion 20A, the second side wall portion 20B, the bottom wall portion 20C, the upper wall portion 20D, the front wall portion, and the rear wall portion of each insulating housing 20 may be filled with, for example, an insulating gas.

In the comparative example 200, the portion where the conductive member 230 and the insulating housing 220 are in contact is a triple junction where the air, the conductor, and the insulator are in contact with each other. Therefore, this portion is also a portion where the electric field is likely to concentrate, and is likely to become the starting point of discharge. In contrast, in this modified example, the triple junction is not formed, so the occurrence of insulation breakdown that originates from the discharge at the triple junction can be suppressed.

Embodiment 2.
Unless otherwise specified, the power conversion device according to the second embodiment has the same configuration and the same effects as those of the first embodiment. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

As shown in FIG. 6, in the power conversion device 102 according to the second embodiment, in the second direction DR2, each first connecting member 40 and each terminal 31, 32A of the first power conversion unit 11 and the second power conversion unit 12 are disposed inside the outer periphery of each of the first power conversion unit 11 and the second power conversion unit 12.

In FIG. 6, height H1 indicates the height of the top surface 10D relative to the bottom surface 10C of the first power conversion unit 11, and height H2 indicates the maximum height of the terminal 31 and the first connecting member 41 relative to the bottom surface 10C. The power conversion device 102 differs from the power conversion device 101 in that the height H2 is limited to be equal to or less than the height H1.

Similarly, in the power conversion device 102, the maximum height of the terminal 32A and the first connecting member 41 relative to the bottom surface 10C of the second power conversion unit 12 is equal to or less than the height of the top surface 10D relative to the bottom surface 10C of the second power conversion unit 12. The height of the top surface 10D relative to the bottom surface 10C of the second power conversion unit 12 is equal to the height H1, for example. The maximum height of the terminal 32A and the first connecting member 41 relative to the bottom surface 10C of the second power conversion unit 12 is equal to the height H2, for example.

In the second direction DR2, if each first connecting member 40 and each terminal 31, 32A of the first power conversion unit 11 and the second power conversion unit 12 have a portion that is located outside the outer periphery of each of the first power conversion unit 11 and the second power conversion unit 12, there is a risk of dielectric breakdown occurring with this portion as the starting point of discharge.

In the power conversion device 102, in the second direction DR2, each first connecting member 40 and each terminal 31, 32A of the first power conversion unit 11 and the second power conversion unit 12 are arranged inside the outer periphery of each of the first power conversion unit 11 and the second power conversion unit 12. Therefore, in the power conversion device 102, the occurrence of dielectric breakdown with each terminal 31, 32A and each first connecting member 41 as the starting point of discharge can be more effectively suppressed.

<Modification of power conversion device 102>
The power conversion device 102 can also be modified in the same manner as the power conversion device 101. Third Embodiment
Unless otherwise specified, the power conversion device according to the third embodiment has the same configuration and the same operational effects as those of the first embodiment. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

As shown in FIG. 7, the power conversion device 103 according to the third embodiment further includes a third connecting member 61 that connects the walls of the first insulating housing 21 and the second insulating housing 22 that are adjacent to each other in the first direction DR1.

The third connecting member 61 has an insulating portion 610. The insulating portion 610 electrically insulates between the terminal 31 of the first power conversion unit 11 and the terminal 32A of the second power conversion unit 12. The material constituting the insulating portion 610 may be any material having electrical insulation properties, and may include at least one selected from the group consisting of FRP, glass epoxy resin, cast epoxy resin, polyethylene, polyvinyl chloride, silicone, fluorine-based synthetic rubber, nylon, and electrically insulating ceramics.

The insulating portion 610 is disposed, for example, in the space of the second insulating housing 22. The third connecting member 61 further has, for example, a through portion 611. The through portion 611 penetrates the first side wall portion 20A of the first insulating housing 21 and the second side wall portion of the second insulating housing. The material constituting the through portion 611 may be a conductive material. In this case, the insulating portion 610 mechanically connects the terminal 32A and the through portion 611, and electrically insulates the terminal 32A of the second power conversion unit 12 and the through portion 611. The insulating portion 610 may be configured as an insulator, a terminal block, or a joint made of an electrically insulating material.

In the power conversion device 103, of the first connecting member 41 and the third connecting member 61 that connect the first insulating housing 21 and the second insulating housing 22, only the first connecting member 41 forms part of the current path between the terminal 31 and the terminal 32A. According to the power conversion device 103, when the number of connecting members that connect the first insulating housing 21 and the second insulating housing 22 is increased, it is possible to prevent the number of main current paths from increasing.

<Modification of power conversion device 103>
The power conversion device 103 may include at least one third connecting member 61. The power conversion device 103 may have a similar configuration to the power conversion device 102, except for including at least one third connecting member 61. The power conversion device 103 may be modified in the same manner as the power conversion devices 101 and 102.

Embodiment 4.
Unless otherwise specified, the power conversion device according to the fourth embodiment has the same configuration and the same action and effect as those of the first embodiment. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

As shown in FIG. 8, the power conversion device 104 according to the fourth embodiment further includes a plurality of fixing members 70 for fixing the first power conversion unit 11 to the bottom wall portion 20C of the first insulating housing 21.

A first protrusion 20E is formed on the bottom wall 20C of the first insulating housing 21. A first recess 10F is formed on the bottom surface 10C of the first power conversion unit 11. The first protrusion 20E is fitted into the first recess 10F.

The first recess 10F and the first protrusion 20E have, for example, a rail structure. For example, two protrusions are formed on the lower end of the first power conversion unit 11. The first recess 10F is formed between the two protrusions. The two protrusions extend along the extension direction of the first protrusion 20E. The two protrusions are arranged to sandwich the first protrusion 20E in a direction perpendicular to the extension direction of the first protrusion 20E. The bottom surface 10C of the first power conversion unit 11 is formed by the top surfaces of the two protrusions.

Each of the multiple fixing members 70 fixes the first recess 10F of the first power conversion unit 11 to the first convex portion 20E of the first insulating housing 21. Each of the multiple fixing members 70 has, for example, a portion that penetrates one of the two convex portions of the first power conversion unit 11 and a portion that screws into the first convex portion 20E. Each fixing member 70 is, for example, a bolt, and has a male thread portion. The first convex portion 20E has a female thread portion that screws into the male thread portion of each fixing member 70.

Each fixing member 70 has, for example, a head 71, a shaft 72, and a tip 73. The head 71 is in contact with the side of one of the two convex portions of the first power conversion unit 11. The shaft 72 passes through one of the two convex portions of the first power conversion unit 11. The tip 73 is connected to the first convex portion 20E. The tip 73 has a male thread portion. The shaft 72 may also have a male thread portion.

Preferably, the head 71 of each fixing member 70 is disposed inside the outer periphery of the first power conversion unit 11 when viewed from the second direction DR2. The head 71 of each fixing member 70 does not protrude toward the first side wall portion 20A relative to the first side surface 10A of the first power conversion unit 11.

The material constituting the fixing member 70 may be a conductive material.
In the power conversion device 104, fixing members 70 for fixing the first power conversion unit 11 to the first insulating housing 21 are disposed inside the first insulating housing 21. Therefore, in the power conversion device 104, electric field concentration is less likely to occur in each fixing member 70 compared to a case in which each fixing member protrudes outside the above-mentioned space of each insulating housing 20, and the occurrence of dielectric breakdown with each fixing member 70 as the starting point of discharge can be suppressed.

Furthermore, in the power conversion device 104, if the head 71 of each fixing member 70 does not protrude toward the first side wall portion 20A side relative to the first side surface 10A of the first power conversion unit 11, electric field concentration at the head 71 of each fixing member 70 can be suppressed.

<Modifications of the power conversion device 104>
It is sufficient that the power conversion device 104 includes at least one fixing member 70. One fixing member 70 may include, for example, a bolt that passes through each of the two protrusions and the first protrusion 20E, and a nut that is fastened to the bolt.

Power conversion device 104 may have a similar configuration to power conversion device 102 or power conversion device 103, except that it has at least one fixing member 70. Power conversion device 104 can be modified in the same manner as power conversion devices 101 to 103.

Embodiment 5.
Unless otherwise specified, the power conversion device according to the fifth embodiment has the same configuration and the same effects as those of the first embodiment. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

As shown in FIG. 9, in the power conversion device 105 according to the fifth embodiment, the upper wall portion 20D of the first insulating housing 21 is formed with a second convex portion 20F that protrudes outward. The bottom wall portion 20C of the third insulating housing 23 is formed with a second concave portion 20G. The second convex portion 20F is fitted into the second concave portion 20G. The second convex portion 20F and the second concave portion 20G mechanically connect two insulating housings 20 that support two power conversion units 10 that are not electrically connected to each other, among two adjacent insulating housings 20. In other words, the second convex portion 20F and the second concave portion 20G act as a second connecting member 50 made of an electrically insulating material. The power conversion device 105 does not include a second connecting member 50 made of a conductive material.

The power conversion device 105 is made of a conductive material and does not include the second connecting member 50 that penetrates and connects the first insulating housing 21 and the third insulating housing 23, so that the occurrence of insulation breakdown caused by the second connecting member 50 can be suppressed.

<Modification of power conversion device 105>
The second convex portion 20F may be provided so as to screw into the second concave portion 20G. The second convex portion 20F may have a male thread portion, and the second concave portion 20G may have a female thread portion.

As shown in FIG. 10, in the power conversion device 105, the third power conversion unit 13 and the third insulating housing 23 may have the same configuration as, for example, the first power conversion unit 11 and the first insulating housing 21, respectively, in the power conversion device 104. The power conversion device 105 further includes, for example, a plurality of fixing members 70.

The second recess 20G has a protruding portion that protrudes inward from the bottom wall portion 20C of the third insulating housing 23. The protruding portion of the second recess 20G corresponds to the first protruding portion 20E of the power conversion device 104.

The third power conversion unit 13 is formed with a third recess corresponding to the first recess 10F in the power conversion device 104. The protruding portion 20E of the second recess 20G of the third insulating housing 23 is fitted into the third recess 10F of the third power conversion unit 13.

Each of the multiple fixing members 70 fixes the third recess 10F of the third power conversion unit 13 to the protruding portion 20E of the second recess 20G of the third insulating housing 23, and fixes the second recess 20G of the third insulating housing 23 to the second protruding portion 20F of the first insulating housing 21.

Each fixing member 70 has, for example, a portion that penetrates the third power conversion unit 13 and the protruding portion 20E of the second recess 20G of the third insulating housing 23, and a portion that screws into the second protruding portion 20F of the first insulating housing 21.

In the power conversion device 105 shown in FIG. 10, the fixing member 70 can fix the third power conversion unit 13 to the bottom wall portion 20C of the third insulating housing 23, and can also fix the bottom wall portion 20C of the third insulating housing 23 to the upper wall portion 20D of the first insulating housing 21, so that the power conversion device 105 has a higher resistance to vibration than the power conversion device 105 shown in FIG. 9.

The power conversion device 105 may have a configuration similar to any of the power conversion devices 102 to 104, except that a second convex portion 20F is formed on the upper wall portion 20D of the first insulating housing 21, and a second concave portion 20G is formed on the bottom wall portion 20C of the third insulating housing 23. The power conversion device 105 can be modified in the same manner as the power conversion devices 101 to 104.

Embodiment 6.
Unless otherwise specified, the power conversion device according to the sixth embodiment has the same configuration and the same action and effect as those of the first embodiment. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

As shown in FIG. 11, in the power conversion device 106 according to the sixth embodiment, the first direction DR1 is along the Z direction, and the second direction DR2 is along the X direction. In other words, the terminals 30 of two power conversion units 10 adjacent to each other in the Z direction are electrically connected to each other via at least one first connecting member 40.

The upper wall portion 20D of the first insulating housing 21 faces the bottom wall portion 20C of the second insulating housing 22. The upper wall portion 20D of the first insulating housing 21 is in contact with the bottom wall portion 20C of the second insulating housing 22. The upper wall portion 20D of the first insulating housing 21 and the bottom wall portion 20C of the second insulating housing 22 are disposed between the first power conversion unit 11 and the second power conversion unit 12 in the first direction DR1.

The first side wall 20A of the first insulating housing 21 faces the second side wall 20B of the third insulating housing 23. The top wall 20D of the second insulating housing 22 faces the bottom wall 20C of the fourth insulating housing 24.

The second portion 302 extending along the second direction DR2 at the terminal 30 of each power conversion unit 10 is spaced apart from, for example, the bottom wall portion 20C or the top wall portion 20D of the insulating housing 20.

The multiple first connecting members 40 include multiple first connecting members 41 that penetrate the upper wall portion 20D of the first insulating housing 21 and the bottom wall portion 20C of the second insulating housing 22 to connect them, and multiple first connecting members 42 that penetrate the upper wall portion 20D of the second insulating housing 22 and the bottom wall portion 20C of the fourth insulating housing 24 to connect them.

The upper wall portion 20D of the first insulating housing 21 and the bottom wall portion 20C of the second insulating housing 22 each have a plurality of through holes extending in the first direction DR1. Each of the first connecting members 41 is inserted into each of the through holes.

The terminal 31 of the first power conversion unit 11 and the terminal 32A of the second power conversion unit 12 are electrically and mechanically connected to each of the multiple first connecting members 41. The terminal 31 of the first power conversion unit 11 and the terminal 32A of the second power conversion unit 12 are electrically connected to each other via each of the multiple first connecting members 41.

The terminal 32B of the second power conversion unit 12 and the terminal 34 of the fourth power conversion unit 14 are electrically and mechanically connected to each of the multiple first connecting members 42. The terminal 32B of the second power conversion unit 12 and the terminal 34 of the fourth power conversion unit 14 are electrically connected to each other via each of the multiple first connecting members 42.

Even in the power conversion device 106, the structure of each of the multiple first connecting members 41 is not particularly limited.

FIG. 12 shows an example of a power conversion device 106 in which each of the multiple first connecting members 41 has the above-mentioned fastening structure.

Each first connecting member 41 has, for example, a shaft portion 413 having a male thread portion and a female thread portion 414.

The shaft portion 413 has, for example, a third portion 413A and two fourth portions 413B. The third portion 413A is inserted through the through holes formed in the upper wall portion 20D of the first insulating housing 21 and the bottom wall portion 20C of the second insulating housing 22, and through the through holes formed in the second portion 312 of the terminal 31 and the second portion 322 of the terminal 32A. Each of the two fourth portions 413B protrudes outward from the through holes formed in the second portion 312 of the terminal 31 and the second portion 322 of the terminal 32A. One of the two fourth portions 413B is connected to the lower end of the third portion 413A. The other of the two fourth portions 413B is connected to the upper end of the third portion 413A. Each of the two fourth portions 413B is formed as a male screw portion that screws into the female screw portion 414.

The first connecting member 41 allows the relative positions of the first insulating housing 21 and the second insulating housing 22 to be kept constant.

11, each of the first connecting members 40 and a portion of each of the terminals 31, 32A of the first power conversion unit 11 and the second power conversion unit 12 may be disposed outside the first side surface 10A and the second side surface 10B of each of the first power conversion unit 11 and the second power conversion unit 12 when viewed from the Y direction. Preferably, as shown in FIG. 12, each of the first connecting members 40 and each of the terminals 31, 32A of the first power conversion unit 11 and the second power conversion unit 12 are disposed inside the outer periphery of each of the first power conversion unit 11 and the second power conversion unit 12 when viewed from the Y direction. According to such a power conversion device 106, as with the power conversion device 102 according to the second embodiment, the occurrence of dielectric breakdown with each of the terminals 31, 32A and each of the first connecting members 41 as the starting point of discharge can be more effectively suppressed.

The through holes formed in the first side wall portion 20A of the first insulating housing 21 and the second side wall portion 20B of the second insulating housing 22 may be formed as female threads. The third portion 413A of the shaft portion 413 may be configured to screw into the female threads formed in the first side wall portion 20A of the first insulating housing 21 and the second side wall portion 20B of the second insulating housing 22.

<Modifications of the power conversion device 106>
The power converter 106 may have a configuration similar to any of the power converters 102 to 105, except that the first direction DR1 is along the Z direction and the second direction DR2 is along the X direction. The power converter 106 may be modified in the same manner as the power converters 101 to 105.

Embodiment 7.
Unless otherwise specified, the power conversion device according to the seventh embodiment has the same configuration and the same action and effect as those of the sixth embodiment. Therefore, the same components as those of the sixth embodiment are given the same reference numerals and the description thereof will not be repeated.

As shown in FIG. 13, in the power conversion device 107 according to the seventh embodiment, a fourth recess 20H is formed in the first side wall 20A of the first insulating housing 21. A third protrusion 20I is formed in the second side wall 20B of the third insulating housing 23. The third protrusion 20I is fitted into the fourth recess 20H.

The third convex portion 20I is provided to screw into, for example, the fourth recess 20H. The third convex portion 20I has a male thread portion. The fourth recess 20H has a female thread portion. The third convex portion 20I and the fourth recess 20H mechanically connect two adjacent insulating housings 20 that support two power conversion units 10 that are not electrically connected to each other. In other words, the third convex portion 20I and the fourth recess 20H act as a second connecting member 50 made of an electrically insulating material. The power conversion device 107 does not have a second connecting member 50 made of a conductive material.

The power conversion device 107 is made of a conductive material and does not include the second connecting member 50 that penetrates and connects the first insulating housing 21 and the third insulating housing 23, so that the occurrence of insulation breakdown caused by the second connecting member 50 can be suppressed.

<Modification of power conversion device 107>
The third convex portion 20I may be formed on either the first side wall portion 20A of the first insulating housing 21 or the second side wall portion 20B of the third insulating housing 23. The fourth concave portion 20H may be formed on the other of the first side wall portion 20A of the first insulating housing 21 or the second side wall portion 20B of the third insulating housing 23.

Power conversion device 107 may have a configuration similar to any of power conversion devices 102 to 105, except that the first direction DR1 is along the Z direction and the second direction DR2 is along the X direction. Power conversion device 107 can be modified in the same manner as power conversion devices 101 to 105.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

1a, 1b switching elements, 2a, 2b diodes, 3 capacitors, 4a, 4b, 140 connecting wires, 10 power conversion unit, 10A first side, 10B second side, 10C bottom, 10D top, 10E front, 10F first recess, third recess, 11 first power conversion unit, 12 second power conversion unit, 13 third power conversion unit, 14 fourth power conversion unit, 20 insulating housing, 20A first side wall, 20B second side wall, 20C bottom wall, 20D top wall, 20E first convex, protruding portion, 20F second convex, 20G second recess, 20H fourth recess, 20I third convex, 21 first insulating housing, 22 second Insulating housing, 23 third insulating housing, 24 fourth insulating housing, 30, 31, 32A, 32B, 34 terminal, 40, 41, 42 first connecting member, 50 second connecting member, 61 third connecting member, 70 fixing member, 71 head, 72 shaft, 73 tip, 100, 101, 102, 103, 104, 105, 106, 107 power conversion device, 110 upper arm, 120 lower arm, 130 transformer, 301 first part, 302, 312, 322 second part, 411 bolt, 412 nut, 413 shaft, 413A third part, 413B fourth part, 413C fifth part, 414 female thread part, 610 insulating part, 611 through part.

Claims (9)

a plurality of power conversion units including a first power conversion unit and a second power conversion unit adjacent to each other in a first direction;
a plurality of insulating housings each including a first insulating housing and a second insulating housing adjacent to each other in the first direction;
the first power conversion unit is supported by the first insulating housing,
the second power conversion unit is supported by the second insulating housing,
Each of the first power conversion unit and the second power conversion unit has a terminal,
each of the first insulating housing and the second insulating housing has a wall portion disposed between the first power conversion unit and the second power conversion unit in the first direction;
at least one first connecting member penetrating and connecting the wall portions of the first insulating housing and the second insulating housing;
A power conversion device, wherein the terminals of the first power conversion unit and the second power conversion unit are electrically connected to each other via the at least one first connecting member. Each of the plurality of insulating housings has a first side wall portion and a second side wall portion opposed to each other with a gap in the first direction, and a bottom wall portion and a top wall portion opposed to each other with a gap in a second direction perpendicular to the first direction,
Each of the plurality of insulating housings has a space defined by the first side wall portion, the second side wall portion, the bottom wall portion, and the top wall portion,
Each of the plurality of power conversion units is disposed in the space of each of the plurality of insulating housings,
the wall portion of the first insulating housing is the first side wall portion of the first insulating housing,
The power conversion device according to claim 1 , wherein the wall portion of the second insulating housing is the second side wall portion of the second insulating housing adjacent to the first side wall portion of the first insulating housing in the first direction. a first protrusion is formed on the bottom wall of the first insulating housing,
The first power conversion unit has a first recess formed therein,
The first recess is fitted into the first protrusion,
The power conversion device according to claim 2 , further comprising at least one fixing member that fixes the first recess of the first power conversion unit to the first protrusion of the first insulating housing. the plurality of power conversion units further includes a third power conversion unit adjacent to the first power conversion unit in the second direction,
the plurality of insulating housings further includes a third insulating housing adjacent to the first insulating housing in the second direction,
a space defined by the first side wall portion, the second side wall portion, the bottom wall portion, and the top wall portion is formed in the third insulating housing;
the third power conversion unit is disposed in the space of the third insulating housing,
the bottom wall portion of the third insulating housing is in contact with the top wall portion of the first insulating housing,
a second protrusion protruding outward is formed on the upper wall of the first insulating housing,
The power conversion device according to claim 2 , wherein the bottom wall of the third insulating casing has a second recess formed therein and fitted with the second protrusion. the second recess has a protruding portion that protrudes inward from the bottom wall portion of the third insulating housing,
the third power conversion unit is formed with a third recess that is fitted with the protruding portion,
5. The power conversion device according to claim 4, further comprising at least one fixing member that fixes the third recess of the third power conversion unit to the protruding portion of the second recess of the third insulating housing and fixes the second recess of the third insulating housing to the second convex portion of the first insulating housing. The power conversion device according to any one of claims 2 to 5, wherein in the second direction, the at least one first connecting member and the terminals of the first power conversion unit and the second power conversion unit are disposed inside the outer periphery of each of the first power conversion unit and the second power conversion unit. Each of the plurality of insulating housings has a first side wall portion and a second side wall portion opposed to each other with a gap therebetween, a bottom wall portion connected to lower ends of the first side wall portion and the second side wall portion, and an upper wall portion connected to upper ends of the first side wall portion and the second side wall portion,
Each of the plurality of insulating housings has a space defined by the first side wall portion, the second side wall portion, the bottom wall portion, and the top wall portion,
Each of the plurality of power conversion units is disposed in the space of each of the plurality of insulating housings,
the wall portion of the first insulating housing is the upper wall portion of the first insulating housing,
The power conversion device according to claim 1 , wherein the wall portion of the second insulating housing is the bottom wall portion of the second insulating housing adjacent to the top wall portion of the first insulating housing in the first direction. the plurality of power conversion units further includes a third power conversion unit adjacent to the first power conversion unit in a second direction perpendicular to the first direction,
the plurality of insulating housings further includes a third insulating housing adjacent to the first insulating housing in the second direction,
a space defined by the first side wall portion, the second side wall portion, the bottom wall portion, and the top wall portion is formed in the third insulating housing;
the third power conversion unit is disposed in the space of the third insulating housing,
the second side wall portion of the third insulating housing is in contact with the first side wall portion of the first insulating housing,
a third protrusion is formed on either the first side wall of the first insulating housing or the second side wall of the third insulating housing,
8. The power conversion device according to claim 7, wherein the other of the first side wall portion of the first insulating housing and the second side wall portion of the third insulating housing has a fourth recess into which the third protrusion is fitted. at least one third connecting member connecting the wall portions of the first insulating housing and the second insulating housing to each other;
The power conversion device according to any one of claims 1 to 8, wherein the at least one third connecting member has an insulating portion that electrically insulates between the terminal of the first power conversion unit and the terminal of the second power conversion unit.

Images