JP2022107778A - power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power converter capable of suppressing damages or deformations of DC conductors in the event of a short-circuit accident.

SOLUTION: A disclosed power converter has a power line through which a DC power passes. The power line includes a first line part M11 a second line part M12, and a first insulator In1. The first line part M11 and the second line part M12 extend in an X-axis direction. The first insulator In1 is placed between the first line part M11 and the second line part M12. The first line part M11 has a first line conductor 111, a first reinforcement part 112, and a second reinforcement part 113. The first line conductor 111 extends in the X-axis direction. The first reinforcement part 112 and the second reinforcement part 113 extend in the X-axis direction and are fixed along both edges of the first line conductor 111 respectively.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a power converter having a power line through which DC power passes.

Conventionally, a power conversion device having a power line through which DC power passes is known. For example, Japanese Patent Application Laid-Open No. 2015-115975 (Patent Document 1) discloses that a DC capacitor connected in parallel to a plurality of switching elements connected in series is protected from an overvoltage state. An apparatus is disclosed.

JP 2015-115975 A

In the event of a short-circuit accident in which a switching element is short-circuited, DC power is released to the power line from a capacitor connected in parallel with the switching element, causing a larger current than usual to flow through the power line, causing the DC conductor in the power line to break. It can be damaged or deformed. Damaged or deformed DC conductors increase the time required for the power converter to recover from a short circuit fault.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and an object of the present invention is to suppress damage and deformation of a DC conductor when a short-circuit accident occurs.

A power converter according to the present invention has a power line through which DC power passes. The power line includes first and second line sections and a first insulator. The first and second line portions extend in the first direction. The first insulator is arranged between the first line portion and the second line portion. The first line portion has a first line conductor and first and second reinforcing portions. The first line conductor extends in the first direction. The first and second reinforcing parts extend in the first direction and are fixed along both edges of the first line conductor.

According to the power conversion device of the present invention, the strength of the first line conductor is improved by the first and second reinforcing portions fixed along both edges of the first line conductor. Therefore, it is possible to suppress damage and deformation of the first line conductor when a short-circuit accident occurs. As a result, the time required for the power converter to recover from the short circuit accident can be shortened.

1 is a circuit diagram of an inverter as an example of a power conversion device according to Embodiment 1; FIG. FIG. 2 is an external perspective view of a DC conductor included in the power line of the inverter in FIG. 1; It is the figure which planarly viewed the DC conductor of FIG. 2 from the X-axis direction. 4 is an external perspective view of a DC conductor according to a modification of Embodiment 1. FIG. FIG. 8 is an external perspective view of a DC conductor according to Embodiment 2; It is the figure which planarly viewed the DC conductor of FIG. 5 from the X-axis direction. FIG. 10 is an external perspective view of a DC conductor according to a modification of Embodiment 2; FIG. 11 is a circuit diagram of an inverter as an example of a power conversion device according to Embodiment 3;

Hereinafter, embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

[Embodiment 1]
FIG. 1 is a circuit diagram of an inverter 1 that is an example of a power conversion device according to Embodiment 1. As shown in FIG. As shown in FIG. 1, inverter 1 includes terminals P1-P3, switching elements Q1 and Q2, diodes D1 and D2, capacitor C11, and fuses Fs1 and Fs2. Inverter 1 is a two-level inverter.

DC power is input to terminals P1 and P2 from a DC power supply B1. DC power supply B1 may be of any type as long as it outputs DC power, and includes, for example, a generator, a converter, and a storage battery. Capacitor C11 is connected between terminals P1 and P2.

Switching elements Q1 and Q2 are connected in series between terminals P1 and P2. Each of switching elements Q1 and Q2 includes an IGBT (Insulated Gate Bipolar Transistor), for example. The emitter of switching element Q1 and the collector of switching element Q2 are connected at connection point N1. Diodes D1 and D2 are connected in antiparallel to switching elements Q1 and Q2, respectively. The terminal P3 is connected to the connection point N1.

Fuse Fs1 is connected between terminal P1 and the collector of switching element Q1. Fuse Fs2 is connected between terminal P2 and the emitter of switching element Q2.

Inverter 1 has a power line through which DC power from DC power supply B1 passes. The power line includes, for example, a path from terminal P1 to the collector of switching element Q1 and a path from terminal P2 to the emitter of switching element Q2.

FIG. 2 is an external perspective view of DC conductor 100 included in the power line of inverter 1 of FIG. As shown in FIG. 2, DC conductor 100 includes line portions M11 and M12 and insulators In1 to In6. The line portions M11 and M12 extend in the X-axis direction. DC power passes through line portions M11 and M12. Each of the insulators In1 to In6 is arranged between the line portions M11 and M12.

FIG. 3 is a plan view of the DC conductor 100 of FIG. 2 from the X-axis direction. As shown in FIG. 3, the line portion M11 includes a line conductor 111 and reinforcing portions 112 and 113. As shown in FIG. Line conductor 111 and reinforcements 112 and 113 are integrally formed. The line portion M11 is bent at the connecting portion between the line conductor 111 and the reinforcement portion 112 . The line portion M11 is bent at the connecting portion between the line conductor 111 and the reinforcement portion 113 .

The line portion M12 includes a line conductor 121 and reinforcing portions 122 and 123 . Line conductor 121 and reinforcements 122 and 123 are integrally formed. The line portion M12 is bent at the connecting portion between the line conductor 121 and the reinforcement portion 122 . The line portion M12 is bent at the connection portion between the line conductor 121 and the reinforcing portion 123. As shown in FIG.

Referring to FIG. 1 again, when a short-circuit accident occurs in which switching elements Q1 and Q2 are short-circuited, DC power is released from capacitor C11 to the power line, and a current larger than usual flows through the power line. The current blows the fuses Fs1 and Fs2, cutting off the current from the capacitor C11 to the switching elements Q1 and Q2.

During the period from the occurrence of the short-circuit accident until the fuses Fs1 and Fs2 are fused, a current larger than usual flows through the power line, and the DC conductor included in the power line may be damaged or deformed. If the DC conductor is damaged or deformed, it takes longer for the inverter 1 to recover from the short circuit accident.

Referring to FIG. 3 again, according to the DC conductor 100, the strength of the line conductor 111 is improved by the reinforcing portions 112 and 113 fixed along both edges of the line conductor 111, respectively. Further, the strength of the line conductor 121 is improved by the reinforcing portions 122 and 123 fixed along both edges of the line conductor 121 respectively. Therefore, it is possible to suppress damage and deformation of the DC conductor 100 when a short-circuit accident occurs. As a result, the time required for the inverter 1 to recover from the short-circuit accident can be shortened.

[Modification of Embodiment 1]
In Embodiment 1, a case has been described in which two reinforcing portions are fixed to both edges of all line portions included in the DC conductor. The two reinforcing portions may not be fixed to both edges of all the line portions included in the DC conductor. As shown in FIG. 4, the direct-current conductor 100A according to the modification of the first embodiment may include a line portion M92 in which reinforcement portions are not fixed to both edges. Also, the number of line portions included in the DC conductor may be three or more.

As described above, according to the power converter according to the first embodiment and the modified example, it is possible to suppress damage and deformation of the DC conductor when a short-circuit accident occurs. As a result, the time required for the power converter to recover from the short circuit accident can be shortened.

[Embodiment 2]
In Embodiment 1, the case where the line portion included in the DC conductor and the two reinforcing portions fixed to both edges of the line portion are integrally configured has been described. In Embodiment 2, a case where the line portion and the reinforcing portion are formed of different members will be described.

FIG. 5 is an external perspective view of a DC conductor 200 according to Embodiment 2. FIG. The configuration of the DC conductor 200 shown in FIG. 5 is a configuration in which the line portions M11 and M12 of the DC conductor 100 shown in FIG. 2 are replaced with M21 and M22, respectively. Since other configurations are the same, the description will not be repeated.

FIG. 6 is a plan view of the DC conductor 200 of FIG. 5 from the X-axis direction. As shown in FIG. 6, the line portion M21 includes a line conductor 211 and reinforcing portions 212 and 213. As shown in FIG. The reinforcing parts 212 and 213 are fixed to both edges of the line conductor 211 respectively. Reinforcing portions 212 and 213 are made of an insulator.

The line portion M22 includes a line conductor 221 and reinforcing portions 222 and 223 . The reinforcing parts 222 and 223 are fixed to both edges of the line conductor 221, respectively. The reinforcing portions 222 and 223 are made of an insulator.

All of the plurality of line portions included in the DC conductor need not be reinforced with reinforcing portions made of insulators. As in the DC conductor 200A according to the modification of the second embodiment shown in FIG. 7, some line portions have the same configuration as the line portion M21 in FIG. may have the same configuration as that of the line portion M11.

As described above, according to the power converter according to the second embodiment and the modified example, it is possible to suppress damage and deformation of the DC conductor when a short-circuit accident occurs. As a result, the time required for the power converter to recover from the short circuit accident can be shortened.

[Embodiment 3]
In the first and second embodiments, two-level inverters have been described. In the third embodiment, a 3-level inverter will be described.

FIG. 8 is a circuit diagram of the inverter 3, which is an example of the power converter according to the third embodiment. As shown in FIG. 8, inverter 3 includes terminals P31-P34, switching elements Q31-Q34, diodes D31-D36, capacitors C31 and C32, and fuses Fs31-Fs33. Inverter 3 is a three-level inverter.

DC power is input to the terminals P31 and P34 from the DC power supply B31. DC power is input to the terminals P34 and P32 from the DC power supply B32. The DC power sources B31 and B32 may be of any type as long as they output DC power, and include generators, converters, and storage batteries, for example.

Capacitor C31 is connected between terminals P31 and P34. Capacitor C32 is connected between terminals P34 and P32.

Switching elements Q31-Q34 are connected in series between terminals P31 and P32. Each of switching elements Q31-Q34 includes, for example, an IGBT (Insulated Gate Bipolar Transistor). The emitter of switching element Q31 and the collector of switching element Q32 are connected at connection point N31. The terminal P33 is connected to the connection point N31. The emitter of switching element Q33 is connected to the collector of switching element Q31. The collector of switching element Q34 is connected to the emitter of switching element Q32.

Diodes D31-D34 are connected in anti-parallel to switching elements Q31-Q34, respectively. The cathode of diode D35 is connected to the collector of switching element Q31. The anode of diode D35 and the cathode of diode D36 are connected at connection point N32. The anode of diode D36 is connected to the emitter of switching element Q32.

Fuse Fs31 is connected between terminal P31 and the collector of switching element Q33. Fuse Fs32 is connected between terminal P32 and the emitter of switching element Q34. The fuse Fs33 is connected between the terminal P34 and the connection point N32.

Inverter 3 has a power line through which DC power from DC power sources B31 and B32 passes. The power line includes, for example, a path from terminal P31 to the collector of switching element Q33, a path from terminal P32 to the emitter of switching element Q34, and a path from terminal P34 to connection point N32. The power line includes the DC conductors described in the first embodiment, the modification of the first embodiment, and the second embodiment.

As described above, according to the power converter according to Embodiment 3, it is possible to suppress damage and deformation of the DC conductor when a short-circuit accident occurs. As a result, the time required for the power converter to recover from the short circuit accident can be shortened.

In the first to third embodiments, the case where the power conversion device having the power line through which DC power passes is an inverter has been described. The power conversion device according to the embodiment only needs to have a power line through which direct current power passes, and may be, for example, a DC (Direct Current)-DC converter or an AC (Alternating Current)-DC converter. .

It is also planned that the embodiments disclosed this time will be appropriately combined and implemented within a non-contradictory range. It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1, 3 Inverter 100, 100A, 200 DC conductor 111, 121, 211, 221 Line conductor 112, 113, 122, 123, 212, 213, 222, 223 Reinforcement part B1, B31, B32 DC power supply C11 , C31, C32 capacitors, D1, D2, D31 to D36 diodes, Fs1, Fs2, Fs31 to Fs33 fuses, In1 to In6 insulators, M11, M12, M21, M22, M92 lines, P1 to P3, P31 to P34 terminals, Q1, Q2, Q31-Q34 Switching elements.

Claims (4)

A power conversion device having a power line through which DC power passes,
The power line is
a first line portion and a second line portion extending in a first direction and facing each other in a second direction orthogonal to the first direction;
a first insulator disposed between the first line portion and the second line portion;
In the second direction, the thickness of the first insulator is greater than the thickness of the first line portion,
The first line part is
a first line conductor extending in the first direction;
A power converter, comprising: a first reinforcing portion and a second reinforcing portion extending in the first direction and fixed along both edges of the first line conductor. The second line section is
a second line conductor extending in the first direction;
2. The power converter according to claim 1, further comprising a third reinforcing portion and a fourth reinforcing portion extending in said first direction and fixed along both edges of said second line conductor. The first line conductor, the first reinforcing portion, and the second reinforcing portion are integrally formed,
The first line portion is bent at a connecting portion between the first line conductor and the first reinforcing portion, and bent at a connecting portion between the first line conductor and the second reinforcing portion. 3. The power converter according to 1 or 2. 3. The power converter according to claim 1, wherein said first reinforcing portion and said second reinforcing portion are made of a second insulator.

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