JP2021141724A - Power conversion device - Google Patents

Abstract

To provide a power conversion device capable of suppressing vibration of a film capacitor by solving a problem in which the amplitude of vibration due to charging and discharging of the film capacitor is the largest in the direction perpendicular to the winding axis, and therefore, when the direction in which the amplitude is the largest and the bolt insertion direction are different, it is difficult to suppress the vibration in the direction in which the amplitude is the largest.SOLUTION: A power conversion device disclosed herein includes a capacitor unit including a film capacitor, a capacitor case having the film capacitor, and a capacitor terminal that is electrically connected to an external terminal and the film capacitor. The power conversion device further includes a housing that houses the capacitor unit, and a bolt that fastens the external terminal and the capacitor terminal. The capacitor case has a parallel plane parallel to the winding axis of the film capacitor, and the bolt is inserted toward the parallel plane.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a power conversion device that performs power conversion.

Patent Document 1 describes a power conversion device having a capacitor element, a capacitor having a capacitor case for accommodating the capacitor element, and an output terminal block fixed to the capacitor and connected to a terminal of an external device. There is.

Japanese Unexamined Patent Publication No. 2014-23288

The capacitor element vibrates due to charging and discharging. Further, a winding type film capacitor can be considered as one of the capacitor elements, but the amplitude of the vibration of the film capacitor due to charging and discharging is the largest in the direction perpendicular to the winding axis. Here, as an example, consider a case where the insertion direction of the bolt is parallel to the winding axis of the film capacitor when the output terminal block and the terminal of the external device are fastened by inserting the bolt. In this case, the direction in which the amplitude of the film capacitor is the largest is different from the direction in which the bolt is inserted. Therefore, it is difficult to suppress the vibration in the direction in which the amplitude of the film capacitor is the largest.

Based on this circumstance, an object of the present disclosure is to provide a power conversion device capable of suppressing vibration of a capacitor.

The power conversion device in one aspect of the present disclosure for achieving that purpose is:
It is electrically connected to the winding type film capacitor (11), the capacitor case (12) containing the film capacitor, and the external terminal (41) arranged outside the capacitor case, and is also electrically connected to the film capacitor. A capacitor unit (10) having a capacitor terminal (13) connected to the
A housing (30) that houses the capacitor unit and
A bolt (501) for fastening an external terminal and a capacitor terminal is provided.
The capacitor case has a parallel surface (121) parallel to the winding axis of the film capacitor.
Bolts are power converters that are inserted toward parallel planes.

The vibration derived from the charging and discharging of the film capacitor has the largest amplitude in the direction perpendicular to the winding axis. In the present disclosure, the external terminals and the capacitor terminals are fastened with bolts. Then, in the capacitor case, a bolt is inserted toward a parallel surface parallel to the winding axis of the film capacitor. Therefore, the bolt is inserted in the direction in which the amplitude of the film capacitor is the largest. That is, the bolt presses the external terminal toward the capacitor terminal. Therefore, the vibration of the capacitor unit can be further suppressed.

It is a top view which shows typically the positional relationship of the component parts of the power conversion apparatus in 1st Embodiment. It is sectional drawing which shows typically the positional relationship of some component parts of the power conversion apparatus in 1st Embodiment. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 1 is a sectional view taken along line IV-IV of FIG.

Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings. In addition, duplicate description may be omitted by assigning the same reference numerals to the corresponding components in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other parts of the configuration. Further, not only the combination of the configurations specified in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined even if the combination is not specified. Further, an unspecified combination of the configurations described in the plurality of embodiments and modifications is also disclosed by the following description.

(First Embodiment)
The power conversion device 1 will be described with reference to FIGS. 1 to 4. The power conversion device 1 is mounted on a vehicle such as a hybrid vehicle or an electric vehicle, and converts a DC current of an external DC power source (not shown) of the power conversion device 1 into a three-phase AC motor (not shown) as a traveling motor. Generates alternating current (U-phase, V-phase, W-phase) to be energized.

As shown in FIG. 1, the power conversion device 1 includes a capacitor unit 10, a semiconductor module 20, an external terminal fixing portion 40, and a housing 30 for accommodating these.

As shown in FIG. 2, the capacitor unit 10 has a film capacitor 11 which is a winding type capacitor element, and a capacitor case 12 for accommodating the film capacitor 11. Further, the capacitor unit 10 has a capacitor terminal 13 that is electrically connected to the film capacitor 11 and a housing fixing portion 14 for fixing the capacitor case 12 to the housing 30.

The film capacitor 11 is formed by winding and stacking a plurality of capacitors. A plurality of the plurality of film capacitors 11 are housed in the capacitor unit 10 in the capacitor case 12 with the winding shafts 111 in parallel. Hereinafter, the direction in which the plurality of film capacitors 11 are lined up is defined as the X direction, and the axial direction of the winding shaft 111 of the film capacitors 11 is defined as the Y direction.

The film capacitor 11 vibrates as it is charged and discharged. Here, the vibration of the film capacitor 11 is greatest in the direction in which a plurality of capacitors are laminated. That is, the vibration in the direction perpendicular to the winding shaft 111 is the largest.

The capacitor case 12 is made of resin. Further, a plurality of film capacitors 11 are sealed with the resin 124 in the capacitor case 12. Therefore, the capacitor case 12 and the plurality of film capacitors 11 are integrated.

As shown in FIG. 3, the capacitor case 12 has a parallel surface 121 parallel to the winding shaft 111 of the film capacitor 11. The parallel surface 121 is parallel to the Y direction, which is the axial direction of the winding shaft 111, and parallel to the X direction.

As shown in FIG. 1, the capacitor case 12 has a housing fixing portion 14 fixed to the housing 30. The housing fixing portion 14 is arranged outside the case of the capacitor case 12, which is opposite to the inside of the case in which the film capacitor 11 is sealed with the resin 124. In this embodiment, there are four housing fixing portions 14. Further, a bolt hole is formed in the housing fixing portion 14, and the capacitor case 12 is fixed to the housing 30 by inserting the bolt 50.

As shown in FIG. 3, the capacitor terminal 13 is arranged so as to extend from the resin 124. The capacitor terminal 13 has an exposed portion 131 exposed to the outside of the capacitor case 12 and a sealing portion 132 sealed with a resin 124 inside the capacitor case 12. The exposed portion 131 is electrically connected to all of the plurality of film capacitors 11 housed in the capacitor case 12 via the sealing portion 132. In this embodiment, three capacitor terminals 13 are arranged side by side in the X direction.

Hereinafter, the direction perpendicular to the X direction and perpendicular to the Y direction is referred to as the Z direction. The exposed portion 131 and the parallel surface 121 are adjacent to each other in the Z direction.

As shown in FIG. 1, the semiconductor module 20 has a switching element. The switching element is switched on and off by passing an electric current. As a result, the DC current input from the DC power supply is converted into an AC current and output to the three-phase AC motor. The semiconductor module 20 is arranged inside the housing 30 side by side with the capacitor unit 10 in the Y direction.

Further, the power conversion device 1 includes a terminal fastening bolt 501 as a bolt for connecting the external terminal 41 and the capacitor terminal 13. Here, one capacitor terminal 13 is connected to one external terminal 41 by one terminal fastening bolt 501. In the present embodiment, the power conversion device 1 includes three capacitor terminals 13. Therefore, three external terminals 41 and three terminal fastening bolts 501 are also provided.

The external terminal fixing portion 40 fixes the external terminal 41 extending from the external device arranged outside the power conversion device 1 and the housing 30. The external device corresponds to, for example, the above-mentioned DC power supply. The external terminal fixing portion 40 is formed of an insulating member. Specifically, it is formed of resin.

A bolt hole is formed in the external terminal fixing portion 40, and the external terminal fixing portion 40 is fixed to the housing 30 by inserting the bolt 50. Further, as shown in FIG. 3, a part of the external terminal 41 is embedded in the external terminal fixing portion 40. Then, as shown in FIG. 4, the external terminal 41 is fixed to the housing 30 via the external terminal fixing portion 40 by inserting the bolt 50 into the bolt hole. In the present embodiment, all three external terminals 41 are embedded in the external terminal fixing portion 40 side by side in the X direction.

Further, the external terminal fixing portion 40 is formed with a hole portion 401 for inserting a tool for attaching the terminal fastening bolt 501 to the external terminal 41 and the capacitor terminal 13.

The housing 30 is made of metal. Specifically, the housing 30 is formed of aluminum die casting. The housing 30 has a vehicle fixing portion 31 that is fixed to the vehicle. A bolt hole is formed in the vehicle fixing portion 31, and the housing 30 is fixed and mounted on the vehicle by bolting.

Further, the housing 30 has a main body portion 32 that opens in the Z direction and a lid portion 33 that closes the opening of the main body portion 32. The lid portion 33 has a housing hole portion 331 for inserting a tool for attaching the terminal fastening bolt 501 to the capacitor terminal 13 and the external terminal 41.

When the power conversion device 1 is viewed from the Z direction, the capacitor terminal 13, the external terminal 41, the housing hole portion 331, and the hole portion 401 are arranged at overlapping positions. Therefore, the semiconductor module 20 and the capacitor unit 10 can be housed in the main body 32, and the terminal fastening bolt 501 can be attached after the main body 32 is closed by the lid 33.

Further, the insertion direction of the bolt 50 for fixing the vehicle and the housing 30 and the insertion direction of the bolt 50 for fixing the condenser case 12 and the vehicle are the same.

Further, as shown in FIG. 3, the external terminal 41 and the external device are connected by a flexible cable 42. In the present embodiment, one end of the external terminal 41 is connected to the capacitor terminal 13, the other end is connected to the cable 42, and is fixed to the external terminal fixing portion 40 at a position sandwiched between both ends.

The terminal fastening bolt 501 is inserted toward the parallel surface 121 of the capacitor case 12. That is, the terminal fastening bolt 501 is inserted in the Z direction toward the capacitor case 12.

Further, in the present embodiment, the insertion direction of the terminal fastening bolt 501, the insertion direction of the bolt 50 inserted into the vehicle fixing portion 31, the insertion direction of the bolt 50 inserted into the housing fixing portion 14, and the external terminal. The insertion directions of the bolts 50 inserted into the fixing portion 40 are all the same.

Further, the capacitor terminal 13, the external terminal 41, and the terminal fastening bolt 501 exist in the range where the parallel surface 121 is projected in the Z direction.

As shown in FIG. 1, the terminal fastening bolt 501 is arranged in a range perpendicular to the line segment connecting two of the plurality of housing fixing portions 14. Here, the line segment connecting the housing fixing portions 14 to each other is specifically a line segment connecting the centers of the bolt holes formed in the housing fixing portion 14.

In the present embodiment, as an example, among the plurality of housing fixing portions 14, the first fixing portion 141, which is the housing fixing portion 14 having the shortest distance from the terminal fastening bolt 501, and the second fixing portion having the longest distance from the terminal fastening bolt 501, as an example. Consider the line segment connecting 142.

In the present embodiment, all of the plurality of terminal fastening bolts 501 are included in the range perpendicular to the line segment connecting the first fixing portion 141 and the second fixing portion 142.

As shown in FIG. 4, when the capacitor case 12 is viewed from the Z direction, the winding shaft 111 of the film capacitor 11 at one end in the Y direction and the winding shaft of the film capacitor 11 at the other end of the plurality of film capacitors 11 The range between the 111 and the central portion 122 is defined as the central portion 122. The other range is the end 123. In this embodiment, two of the three terminal fastening bolts 501 are arranged at the central portion 122.

The effects of this embodiment are shown below. The vibration derived from the charging and discharging of the film capacitor 11 has the largest amplitude in the direction perpendicular to the winding shaft 111. In this embodiment, the external terminal 41 and the capacitor terminal 13 are fastened by the terminal fastening bolt 501. Then, in the capacitor case 12, the terminal fastening bolt 501 is inserted toward the parallel surface 121 parallel to the winding shaft 111 of the film capacitor 11. Therefore, the terminal fastening bolt 501 is inserted in the direction in which the amplitude of the film capacitor 11 is largest. That is, the terminal fastening bolt 501 presses the external terminal 41 toward the capacitor terminal 13. Therefore, the vibration of the capacitor unit 10 can be further suppressed.

Further, the external terminal 41 is fixed to the housing 30 by the external terminal fixing portion 40. Therefore, when the external terminal 41 and the capacitor terminal 13 are fastened by the terminal fastening bolt 501, the capacitor terminal 13 is fixed to the housing 30 via the external terminal 41 and the external terminal fixing portion 40. Therefore, the vibration of the capacitor unit 10 can be further suppressed via the capacitor terminal 13.

Since the capacitor unit 10 is fixed to the housing 30 by the housing fixing portion 14, vibration derived from the capacitor unit 10 can be suppressed. On the other hand, since the housing 30 is fixed to the vehicle by the vehicle fixing portion 31, the vibration of the vehicle is transmitted to the housing 30. Further, the vibration of the vehicle is transmitted to the capacitor unit 10 via the housing 30. Therefore, for example, in the capacitor unit 10, the portion corresponding to the center point of the line segment connecting two of the plurality of housing fixing portions 14 may be deformed in the Z direction.

In view of these points, in the present embodiment, the terminal fastening bolt 501 is arranged in a range perpendicular to the line segment connecting the first fixing portion 141 and the second fixing portion 142. Here, the capacitor unit 10 is fixed to the housing 30 via the capacitor terminal 13, the external terminal 41, and the external terminal fixing portion 40. Therefore, the fact that the terminal fastening bolt 501 is arranged in the above-mentioned range means that a fixing point between the housing 30 and the capacitor case 12 is formed between the first fixing portion 141 and the second fixing portion 142. Therefore, as compared with the case where the terminal fastening bolt 501 is arranged outside the above range, it is possible to suppress the deformation of the capacitor unit 10 due to the vibration transmitted through the housing 30.

In the present embodiment, a part of the plurality of terminal fastening bolts 501 is included in the above range, but in order to improve the effect of suppressing vibration, the plurality of terminal fastening bolts 501 are included in the above range. It is preferable that all are included.

In this embodiment, the external terminal 41 and the capacitor terminal 13 are fastened by the terminal fastening bolt 501. Then, in the capacitor case 12, the terminal fastening bolt 501 is inserted toward the parallel surface 121 parallel to the winding shaft 111 of the film capacitor 11. Therefore, the vibration of the capacitor unit 10 is suppressed. On the other hand, the vibration of the capacitor unit 10 is easily transmitted to the external device via the external terminal 41. Therefore, in the present disclosure, the external terminal 41 is connected to the flexible cable 42. Therefore, for example, the vibration of the capacitor unit 10 can be further suppressed from being transmitted to the DC power supply as compared with the case where the external terminal 41 is connected to the bus bar having no flexibility.

The film capacitor 11 has the largest vibration immediately above the winding shaft 111. Therefore, the terminal fastening bolt 501 is arranged at the central portion 122. That is, the terminal fastening bolt 501 is arranged in a range where the vibration of the film capacitor 11 is large. Therefore, the vibration of the film capacitor 11 can be further suppressed as compared with the case where the terminal fastening bolt 501 is arranged outside the above range. It is preferable that the central portion 122 includes all of the plurality of terminal fastening bolts 501.

(Other embodiments)
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and the following embodiments are also included in the technical scope of the present disclosure. Various changes can be made within the range that does not deviate.

In the first embodiment, the external terminal fixing portion 40 is arranged, but the external terminal fixing portion 40 may not be arranged. Further, although the external terminal fixing portion 40 is made of resin, it may be made of a material other than resin as long as it is a material having insulating properties.

In the first embodiment, the connection between the external device and the external terminal 41 is via the cable 42, but may be connected via a non-flexible device such as a bus bar.

In the first embodiment, the terminal fastening bolt 501 is arranged in a range perpendicular to the line segment connecting two of the plurality of housing fixing portions 14, but may be arranged outside the above-mentioned range.

In the first embodiment, the first fixing portion 141 and the second fixing portion 142 are selected as two of the plurality of housing fixing portions 14, but any two of the plurality of housing fixing portions 14 are combined. You may.

In the first embodiment, all of the plurality of terminal fastening bolts 501 are arranged in a range perpendicular to the line segment connecting two of the plurality of housing fixing portions 14. However, one or more of the plurality of terminal fastening bolts 501 may be arranged in the above-mentioned range.

In the first embodiment, the terminal fastening bolt 501 is arranged at the central portion 122, but may be arranged at the end portion 123.

In the first embodiment, two of the plurality of terminal fastening bolts 501 are arranged in the central portion 122, but one or more of the terminal fastening bolts 501 may be arranged in the central portion 122.

In the first embodiment, the capacitor unit 10 has four housing fixing portions 14, but any number of housing fixing portions 14 may be provided as long as they are two or more.

In the first embodiment, the film capacitor 11 is sealed by the resin 124 in the capacitor case 12, but it may be sealed by a member other than the resin 124. Further, the film capacitor 11 may be fixed to the capacitor case 12 even if it is not sealed.

In the first embodiment, the capacitor case 12 is made of resin, but may be made of metal. Further, the capacitor case 12 may be formed integrally with the housing 30.

1 ... Power converter,
10 Capacitor unit, 11 Film capacitor, 12 Capacitor case, 121 Parallel plane, 13 Capacitor terminal, 14 Capacitor fixing part, 30 Capacitor, 41 External terminal, 42 Cable, 501 volt.

Claims (5)

The film capacitor is electrically connected to a winding type film capacitor (11), a capacitor case (12) containing the film capacitor, and an external terminal (41) arranged outside the capacitor case. A capacitor unit (10) having a capacitor terminal (13) electrically connected to and
A housing (30) for accommodating the capacitor unit and
A bolt (501) for fastening the external terminal and the capacitor terminal is provided.
The capacitor case has a parallel surface (121) parallel to the winding axis of the film capacitor.
A power conversion device in which the bolt is inserted toward the parallel plane. The power conversion device according to claim 1, further comprising an external terminal fixing portion for fixing the external terminal to the housing. The capacitor unit has a housing fixing portion (14) for fixing the housing and the capacitor case.
The power conversion device according to claim 2, wherein at least one of the plurality of bolts is arranged in a range perpendicular to a line segment connecting two of the plurality of housing fixing portions. With a flexible cable (42)
The power conversion device according to any one of claims 1 to 3, wherein the external terminal is connected to an external device arranged outside the capacitor unit via the cable. The plurality of film capacitors are arranged in the capacitor case in a direction perpendicular to the winding axis with the winding axis parallel to each other.
Assuming that the direction perpendicular to the direction of the winding axis and perpendicular to the direction in which the plurality of the film capacitors are lined up is the Z direction,
When viewed from the Z direction, at least one of the plurality of bolts is the winding shaft of the film capacitor at one end and the winding shaft of the film capacitor at the other end. The power conversion device according to any one of claims 1 to 4, which is arranged between the two.

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