JP2020171097A - Electric power conversion apparatus - Google Patents

Abstract

To provide an electric power conversion apparatus in which transfer of heat from a terminal of a discharge resistor to another electronic component can be suppressed.SOLUTION: An electric power conversion apparatus 1 includes: a discharge resistor 2 electrically connected to a power conversion circuit; a resin-made holder 3 holding the discharge resistor 2; a device case 4 housing the discharge resistor and the holder 3; and an electronic component 5 housed in the device case 4 together with the discharge resistor 2. The discharge resistor 2 has a resistor body portion 21 comprising a resistor body and a terminal 22 protruding from the resistor body portion 21. The holder 3 has a surrounding portion 30 that surrounds at least part of the terminal 22 from an opposite side of the resistor body portion 21, both sides in a first direction orthogonal to a projecting direction Z1 of the terminal 22, and both sides in a second direction Y orthogonal to both the projecting direction Z 1 and the first direction.SELECTED DRAWING: Figure 5

Description

The present invention relates to a power converter having a discharge resistor.

Some power conversion devices such as inverters are provided with a discharge resistor, for example, as described in Patent Document 1. The discharge resistor discharges the electric charge stored in the capacitor or the like in the device. Therefore, when a discharge current flows through the discharge resistor, the discharge resistor generates heat and the temperature rises. In the power conversion device disclosed in Patent Document 1, a discharge resistor is connected to a bus bar having a large heat capacity. This makes it easy to dissipate the heat of the discharge resistor.

Japanese Unexamined Patent Publication No. 5799843

However, in power conversion devices, as the current and voltage increase, the temperature of electronic components that make up the power conversion device, such as capacitors, tends to rise due to the effects of self-heating and heat reception from other components. It tends to be. Therefore, it is desirable to suppress the influence of the heat of the discharge resistor on the surrounding electronic components as much as possible. Since the current is concentrated in the terminal of the discharge resistor, heat is particularly likely to be generated in the terminal portion. Therefore, it is desirable to suppress the transfer of heat from the discharge resistor terminal to the surrounding electronic components.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a power conversion device capable of suppressing heat transfer from a terminal of a discharge resistor to another electronic component.

One aspect of the present invention is a discharge resistor (2) electrically connected to the power conversion circuit (20).
A resin holder (3) that holds the discharge resistance and
The device case (4) that houses the discharge resistor and the holder, and
It has the electronic component (5) housed in the device case together with the discharge resistor.
The discharge resistance has a resistance main body portion (21) provided with a resistor and a terminal (22) protruding from the resistance main body portion.
The holder has at least a part of the terminal on the side opposite to the resistance main body and on both sides in the first direction (X) orthogonal to the protrusion direction (Z1) of the terminal from the resistance main body. It is in a power conversion device (1) having both sides of a second direction (Y) orthogonal to both the protruding direction and the first direction, and a surrounding portion (30) surrounding from.

In the power conversion device, the holder has at least a part of the terminal on the side opposite to the resistance main body and on both sides in the first direction orthogonal to the protruding direction of the terminal from the resistance main body. It has a surrounding portion surrounding from both sides of the second direction orthogonal to both the protruding direction and the first direction. As a result, the movement of heat from the terminal toward the side opposite to the resistance main body in the protruding direction, heat toward both sides in the first direction, and heat toward both sides in the second direction is effectively suppressed. can do.
As a result, it is possible to suppress the transfer of heat from the terminal of the discharge resistor to the electronic component housed in the device case. Therefore, it is possible to suppress the temperature rise of the electronic component due to the heat of the discharge resistor.

As described above, according to the above aspect, it is possible to provide a power conversion device capable of suppressing the transfer of heat from the terminal of the discharge resistor to other electronic components.
The reference numerals in parentheses described in the scope of claims and the means for solving the problem indicate the correspondence with the specific means described in the embodiments described later, and limit the technical scope of the present invention. It's not a thing.

FIG. 5 is a cross-sectional explanatory view of the power conversion device according to the first embodiment. The circuit explanatory diagram of the power conversion apparatus in Embodiment 1. FIG. 5 is a partial cross-sectional explanatory view of a discharge resistor fixed to a holder via a bracket in the first embodiment. FIG. 3 is a cross-sectional view taken along the line IV-IV. FIG. 1 is a cross-sectional view taken along the line VV of FIG. The perspective view of the sub-assy including the discharge resistance in Embodiment 2. Another perspective view of the sub-assy including the discharge resistance in the second embodiment. FIG. 2 is a plan view of the sub-assy including the discharge resistance seen from the Z1 side in the second embodiment. FIG. 2 is a plan view of the sub-assy including the discharge resistance seen from the side opposite to the Z1 side in the second embodiment. The front view of the sub-assy including the discharge resistance in Embodiment 2. The rear view of the subassy including the discharge resistance in Embodiment 2. 2 is a side view of the sub-assy including the discharge resistance seen from the Y direction in the second embodiment. The circuit explanatory view of the power conversion apparatus in Embodiment 2.

(Embodiment 1)
An embodiment of the power conversion device will be described with reference to FIGS. 1 to 5.
As shown in FIG. 1, the power conversion device 1 of the present embodiment includes a discharge resistance 2, a holder 3, a device case 4, and an electronic component 5. As shown in FIG. 2, the discharge resistor 2 is electrically connected to the power conversion circuit 10. The holder 3 is a resin component that holds the discharge resistance 2. As shown in FIG. 1, the device case 4 houses the discharge resistance 2 and the holder 3. The electronic component 5 is housed in the device case 4 together with the discharge resistance 2.

As shown in FIGS. 3 and 4, the discharge resistor 2 has a resistor main body 21 having a resistor and a terminal 22 protruding from the resistor main body 21.
The holder 3 has an enclosing portion 30 that surrounds at least a part of the terminal 22 from the side opposite to the resistance main body portion 21, both sides of the first direction X, and both sides of the second direction Y. Here, the first direction X is a direction orthogonal to the protruding direction Z1 of the terminal 22 from the resistor main body 21. The second direction Y is a direction orthogonal to both the protruding direction Z1 and the first direction X.
In the following, the direction parallel to the protruding direction Z1 of the terminal 22 is appropriately referred to as the Z direction. Further, the first direction X is appropriately referred to as an X direction, and the second direction Y is appropriately referred to as a Y direction.

In this embodiment, the device case 4 is made of a metal having excellent thermal conductivity, such as an aluminum alloy. Then, as shown in FIGS. 1 and 5, a plurality of electronic components 5 are housed inside the device case 4. In the device case 4, a plurality of semiconductor modules 51 constituting the power conversion circuit 10 are arranged together with a cooler 13 for cooling them. The semiconductor module 51 is a part of the plurality of electronic components 5 described above.

As shown in FIG. 1, the cooler 13 has a plurality of cooling pipes 131 laminated together with the plurality of semiconductor modules 51. The laminated body 11 is composed of a plurality of semiconductor modules 51 and a plurality of cooling pipes 131. The stacking direction of the laminated body 11 is the X direction. The cooling pipe 131 has a refrigerant flow path through which the refrigerant flows. The refrigerant flow path is formed along the Y direction. The cooling pipes 131 adjacent to each other in the X direction with the semiconductor module 51 interposed therebetween are connected to each other by the connecting pipes 133 in the vicinity of both ends in the Y direction. The refrigerant introduction pipe 134 for introducing the refrigerant into the cooler 13 and the refrigerant discharge pipe 135 for discharging the refrigerant from the cooler 13 project to the outside of the device case 4.

Further, the device case 4 houses a smoothing capacitor 52 and a current sensor 53 as electronic components 5. The smoothing capacitor 52 smoothes the voltage supplied from the DC power supply BAT to the power conversion circuit 10. The current sensor 53 detects the current flowing between the power conversion circuit 10 and the AC load.

As shown in FIG. 2, the smoothing capacitor 52 is connected so as to be suspended between the upper arm wiring 12H and the lower arm wiring 12L. Further, the discharge resistor 2 is also connected so as to be suspended between the upper arm wiring 12H and the lower arm wiring 12L. The discharge resistor 2 is connected in parallel with the smoothing capacitor 52.

As shown in FIGS. 3 and 4, the discharge resistance 2 is fixed to the holder 3 made of resin via the bracket 61. The resistance body 21 of the discharge resistor 2 is engaged and held by the metal bracket 61. The resin constituting the holder 3 can be, for example, PPS (that is, polyphenylene sulfide) or the like.

The resistor main body 21 is formed by embedding a resistor in cement. The resistor main body 21 has a substantially rectangular parallelepiped shape. Two terminals 22 project from one of the two surfaces of the resistor main body 21 facing opposite sides in the Z direction. The two terminals 22 are each connected to a pair of electrodes of the resistor inside the resistor body 21. In the resistance main body 21, substantially the entire surface of the bottom surface 211, which is the surface opposite to the protruding direction Z1 of the terminal 22, is covered with the bracket 61. The surface of the resistor main body 21 opposite to the bottom surface 211 is referred to as the top surface 212 for convenience.

The bracket 61 has a bottom plate portion 611 that covers the bottom surface 211 of the resistance main body portion 21, and side plate portions 613 that are erected in the Z direction from both ends of the bottom plate portion 611 in the X direction. Then, an engaging claw portion 612 for engaging with the resistance main body portion 21 is formed at the end portion on the Z1 side of the side plate portion. The side plate portion 613 is arranged so as to cover a part of the side surface 213 of the resistance main body portion 21, and the engaging claw portion 612 is bent so as to engage with the upper surface 212 of the resistance main body portion 21.

The bracket 61 is fastened and fixed to the holder 3 at a plurality of fastened portions 614. As a result, the discharge resistance 2 is held by the holder 3 via the bracket 61. In this embodiment, the fastened portions 614 are formed at both ends of the bottom plate portion 611 of the bracket 61 in the Y direction. In these fastened portions 614, the bracket 61 is fastened to the holder 3 by screws 615.

The holder 3 has two first side wall portions 31 arranged so as to face the terminal 22 from both sides in the X direction. Further, the holder 3 has two second side wall portions 32 arranged so as to face the terminal 22 from both sides in the Y direction. Further, the holder 3 has an upper wall portion 33 which is arranged so as to cover the terminal 22 of the discharge resistance 2 from the protruding direction Z1 side.

The upper wall portion 33, the two first side wall portions 31, and the two second side wall portions 32 form a surrounding portion 30 that surrounds the terminal 22 from five directions. Further, the two terminals 22 of the discharge resistance 2 are surrounded by the surrounding portion 30.

As shown in FIG. 5, the discharge resistor 2 is arranged so that the bottom surface 211, which is the surface of the resistor main body 21 opposite to the protruding direction of the terminal 22, faces the inner surface of the device case 4. The discharge resistor 2 has the bottom surface 211 of the resistance main body 21 facing the bottom wall 41 of the device case 4 via the bottom plate 611 of the bracket 61. In addition to the mode in which the bottom surface 211 faces the inner surface of the device case 4, the mode in which the bottom surface 211 faces directly may be a mode in which the bottom surface 211 faces through a member that does not hinder the transfer of heat as in the present embodiment. .. Further, the bottom plate portion 611 of the bracket 61 and the bottom wall portion 41 of the device case 4 are arranged close to each other in the Z direction. The bracket 61 can also be brought into contact with the device case 4.

As shown in FIGS. 1 and 5, the holder 3 is fixed to the device case 4 by the bolt 35 at the flange portion 34 provided on the holder 3. As a result, the discharge resistance 2 held in the holder 3 is fixed in the device case 4. That is, the sub-assy 14 having the discharge resistance 2, the holder 3, and the bracket 61 is fixed to the device case 4 by the bolt 35.

In this embodiment, the holder 3 holding the discharge resistance 2 is arranged at a position facing the cooler 13 in the X direction. Further, the holder 3 holding the discharge resistance 2 is arranged at a position facing the smoothing capacitor 52 in the Y direction.

Next, the action and effect of this embodiment will be described.
In the power conversion device 1, the holder 3 surrounds at least a part of the terminal 22 from the side opposite to the resistor main body 21, both sides of the first direction X, and both sides of the second direction Y. Have. As a result, the heat from the terminal 22 toward the side opposite to the resistance main body 21 in the Z direction, the heat toward both sides of the first direction X, and the heat toward both sides of the second direction Y are transferred. It can be effectively suppressed.
As a result, the transfer of heat from the terminal 22 of the discharge resistance 2 to the electronic component 5 housed in the device case 4 can be suppressed. Therefore, it is possible to suppress the temperature rise of the electronic component 5 due to the heat of the discharge resistance 2.

As the electric power handled by the power conversion device 1 increases in current and voltage, the heat generated by the electronic component 5 (that is, the semiconductor module 51, the smoothing capacitor 52, the current sensor 53, etc.) tends to increase. On the other hand, it is required to extend the life of the electronic component 5. Therefore, it is required for the electronic component 5 to avoid receiving heat from the discharge resistance 2 as much as possible. Since the current is concentrated in the terminal 22 in particular, the discharge resistance 2 tends to generate a large amount of heat from the terminal 22. Therefore, as described above, by providing the holder 3 with the surrounding portion 30 surrounding the terminal 22, the transfer of heat from the terminal 22 to the electronic component 5 can be effectively suppressed.
In particular, in the present embodiment, among the electronic components 5, the temperature rise of the smoothing capacitor 52, the current sensor 53, etc., which is not directly cooled by the cooler 13, can be suppressed, so that the overall life can be extended. Can be planned.

Further, the discharge resistance 2 is arranged so that the bottom surface 211 of the resistance main body 21 faces the inner surface of the device case 4. As a result, the heat of the discharge resistance 2 can be dissipated through the device case 4. That is, as described above, the surrounding portion 30 can suppress the transfer of heat from the terminal 22 of the discharge resistance 2 to the electronic component 5, while dissipating the heat of the discharge resistance 2 to the device case 4. As a result, it is possible to more effectively suppress the influence of the heat of the discharge resistance 2 on the electronic component 5.

As described above, according to the present embodiment, it is possible to provide a power conversion device capable of suppressing the transfer of heat from the terminal of the discharge resistor to other electronic components.

(Embodiment 2)
As shown in FIGS. 6 to 12, this embodiment is a more specific embodiment of a sub-assy 14 having a discharge resistor 2, a holder 3, and a bracket 61.

In this embodiment, the holder 3 holds a grounding capacitor 18 and a bus bar 17 in addition to the discharge resistor 2. As shown in FIG. 10, the grounding capacitor 18 is a capacitor in which one electrode is grounded. The grounding capacitor 18 includes two capacitor elements 82. The two capacitor elements 182 are connected in series with each other. Then, the ground terminal 181 is electrically connected to the wiring between the two capacitor elements 182.

Further, the grounding capacitor 18 is connected in parallel with the smoothing capacitor 52. The grounding capacitor 18 has a function of removing noise current included in the DC power of the DC power supply BAT.

As shown in FIGS. 6 to 12, the grounding capacitor 18 is housed and arranged in a capacitor housing portion 361 provided in a part of the holder 3. That is, the capacitor element 182 is arranged in the capacitor accommodating portion 361 and is sealed with the sealing resin 183. A part of the ground terminal 181 connected to the capacitor element 182 in the sealing resin 183 is exposed from the sealing resin 183 and extends to a part of the flange portion 34 of the holder 3. In the flange portion 34, the ground terminal 181 is fastened to the device case 4 with a bolt 35 and is electrically grounded.

The two bus bars 17 fixed to the holder 3 are arranged parallel to each other. The two bus bars 17 have terminals 171 connected to the two electrodes of the smoothing capacitor 52, respectively. Further, the other terminals 172 of the two bus bars 17 are electrically connected to the external terminals. Further, a part of the bus bar 17 and the terminal 22 of the discharge resistance 2 are electrically connected to each other via the harness 16.

The discharge resistance 2 is fixed to the holder 3 via the bracket 61. The discharge resistor 2 is attached to the holder 3 at a position adjacent to the grounding capacitor 18 in the Y direction. Further, the discharge resistor 2 is attached to the holder 3 at a position adjacent to one bus bar 17 in the Z direction.

The holder 3 has a surrounding portion 30 that surrounds the terminal 22 of the discharge resistance 2 from both sides in the X direction, both sides in the Y direction, and one side in the Z direction, that is, the Z1 side. That is, as shown in FIGS. 6 to 12, the holder 3 has an upper wall portion 33, two first side wall portions 31, and two second side wall portions 32, thereby forming the surrounding portion 30. It is configured. That is, at least a part of the terminal 22 is hidden inside the surrounding portion 30 when viewed from any side in the X direction, from any side in the Y direction, or from the Z1 side in the Z direction. Have been placed. In addition, in FIG. 8, FIGS. 10 to 12, the position of the terminal 22 which is not actually visible in these plane views is shown by a broken line.

A part of the holder 3 is also interposed between the terminal 22 of the discharge resistance 2 and the grounding capacitor 18. This portion also constitutes the first lateral wall portion 31, which is a part of the surrounding portion 30.
Similar to the first embodiment, the sub-assy 14 shown in the present embodiment can also be incorporated in the device case 4 of the power conversion device 1 in the positional relationship as shown in FIG. 1, for example.

In addition, among the codes used in the second and subsequent embodiments, the same codes as those used in the above-described embodiments represent the same components and the like as those in the above-mentioned embodiments, unless otherwise specified.

In the case of this embodiment, since the sub-assy 14 has the grounding capacitor 18 and the bus bar 17, the power conversion device 1 can be easily assembled. Further, since a part of the surrounding portion 30 is interposed between the grounding capacitor 18 and the terminal 22, the temperature rise of the grounding capacitor 18 can be suppressed.
In addition, it has the same effect as that of the first embodiment.

The present invention is not limited to each of the above embodiments, and can be applied to various embodiments without departing from the gist thereof.

1 Power converter 2 Discharge resistance 21 Resistance body 22 Terminal 3 Holder 30 Surrounding part 4 Device case 5 Electronic components

Claims (2)

The discharge resistance (2) electrically connected to the power conversion circuit (20) and
A resin holder (3) that holds the discharge resistance and
The device case (4) that houses the discharge resistor and the holder, and
It has the electronic component (5) housed in the device case together with the discharge resistor.
The discharge resistance has a resistance main body portion (21) provided with a resistor and a terminal (22) protruding from the resistance main body portion.
The holder has at least a part of the terminal on the side opposite to the resistance main body and on both sides in the first direction (X) orthogonal to the protrusion direction (Z1) of the terminal from the resistance main body. A power conversion device (1) having a surrounding portion (30) surrounded by both sides of a second direction (Y) orthogonal to both the protruding direction and the first direction. The discharge resistance according to claim 1, wherein the bottom surface (211), which is a surface of the resistance main body opposite to the protruding direction of the terminal, is arranged so as to face the inner surface of the device case. Power converter.

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