JP2013132136A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion device capable of achieving downsizing in the direction in which a capacitor and a reactor are faced, and capable of sufficiently ensuring insulation properties between components.SOLUTION: A power conversion device 1 includes a main circuit section 2, a bus bar 3, a capacitor 4, and a reactor 6a disposed so as to face the capacitor 4 on a side in which the bus bar 3 is disposed to the main circuit section 2 in a height direction orthogonal to an arrangement direction X of the main circuit section 2 and the capacitor 4. The capacitor 4 is formed by sealing a capacitor element with an insulative sealing material and by housing it in a case 43, and is formed by extracting, to the outside of the case 43, a first terminal 45 to be connected to the bus bar 3 and a second terminal 46 to be connected to the external, and is configured so that the capacitor element is electrically connected to the bus bar 3 via the first terminal 45. A connection portion connecting the first terminal 45 and the second terminal 46 of the capacitor 4 is buried in the sealing material.

Description

  The present invention relates to a power conversion device including a capacitor and a reactor.

Electric vehicles, hybrid vehicles, and the like are equipped with power conversion devices such as inverters and converters. The power conversion device includes, for example, a main circuit unit having a semiconductor module containing a semiconductor element and a cooler that cools the semiconductor module.
Patent Document 1 discloses a power conversion device in which capacitors are stacked on a main circuit portion. Patent Document 2 discloses a power conversion device in which a reactor is arranged so as to be aligned with a main circuit unit.

  Some power converters have a structure including both a capacitor and a reactor. For example, as shown in FIG. 9, the power conversion device 91 having such a structure includes a main circuit unit 92 having a semiconductor module 921 and a cooler 922, and a power terminal 923 that protrudes from the semiconductor module 921 of the main circuit unit 92. And a capacitor 94 electrically connected to the power terminal 923 of the semiconductor module 91 via the bus bar 93. The capacitor 94 is arranged side by side with the main circuit portion 92. A reactor 96 is disposed on the side of the main circuit portion 92 where the bus bar 93 is disposed so as to face the capacitor 94.

  As shown in FIGS. 9 and 10, the capacitor 94 includes a capacitor element 941 sealed with an insulating sealing material 942 and accommodated in a case 943, and a first terminal connected to the bus bar 93. The part 945 is pulled out of the case 943. The capacitor element 941 is connected to the first terminal portion 945 via the capacitor bus bar 944. In addition, a connection bus bar (connecting portion) 95 that connects the first terminal portion 945 and the second terminal portion 946 connected to the outside of the capacitor 94 is disposed.

JP 2011-114966 A JP 2008-220042 A

  However, in the power conversion device 91 having the above structure, the connection bus bar 95 is disposed between the capacitor 94 and the reactor 96 that are disposed to face each other. Therefore, it is necessary to ensure insulation between the connecting bus bar 95 and the reactor 96. For example, it is necessary to increase the distance between the connecting bus bar 95 and the reactor 96 or to dispose an insulator between the connecting bus bar 95 and the reactor 96. As a result, there arises a problem that the power converter 91 becomes larger in the height direction (the direction in which the capacitor 94 and the reactor 96 face each other).

  The present invention has been made in view of such a background, and intends to provide a power conversion device capable of reducing the size in a direction in which a capacitor and a reactor face each other and sufficiently ensuring insulation between components. It is.

One aspect of the present invention is a main circuit unit having a semiconductor module containing a semiconductor element and a cooler for cooling the semiconductor module;
A bus bar connected to a power terminal protruding from the semiconductor module of the main circuit portion;
A capacitor that is arranged side by side with the main circuit portion and electrically connected to the power terminal of the semiconductor module through the bus bar,
A reactor disposed in a height direction perpendicular to the arrangement direction of the main circuit portion and the capacitor, and facing the capacitor on the side where the bus bar is disposed with respect to the main circuit portion; With
The capacitor includes a capacitor element sealed with an insulating sealing material and accommodated in a case, and a first terminal portion connected to the bus bar and a second terminal portion connected to the outside. The capacitor element is drawn out of the case, and the capacitor element is configured to be electrically connected to the bus bar via the first terminal portion.
In the power conversion device, the connection portion that connects the first terminal portion and the second terminal portion in the capacitor is embedded in the sealing material (Claim 1). .

  In the above power converter, the reactor is disposed in a height direction perpendicular to the arrangement direction of the main circuit portion and the capacitor so as to face the capacitor on the side where the bus bar is disposed with respect to the main circuit portion. Has been. And the connection part which connects between the 1st terminal part and 2nd terminal part in a capacitor | condenser is embed | buried under the inside of the insulating sealing material which seals a capacitor | condenser element.

  That is, conventionally, the connecting portion disposed between the capacitor and the reactor outside the capacitor case is embedded in a sealing material housed in the capacitor case. Therefore, the distance between the capacitor and the reactor can be reduced in the height direction in which the capacitor and the reactor face each other. Thereby, size reduction of the said height direction in a power converter device can be achieved.

  Further, as described above, the connection portion that connects the first terminal portion and the second terminal portion in the capacitor is embedded in the insulating sealing material. Therefore, an insulating sealing material is always interposed between the connection portion and the reactor. Thereby, even if it reduces the distance between a capacitor | condenser and a reactor in the said height direction, the insulation between a connection part and a reactor can fully be ensured.

  As described above, it is possible to provide a power converter that can be miniaturized in a direction in which the capacitor and the reactor face each other, and can sufficiently ensure insulation between components.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 3 is an explanatory diagram illustrating a main circuit unit and a capacitor in the first embodiment. FIG. 3 is an explanatory diagram illustrating a capacitor structure in the first embodiment. Explanatory drawing which shows arrangement | positioning of the reactor in Example 1. FIG. FIG. 3 is an explanatory diagram illustrating a power conversion circuit in the first embodiment. FIG. 6 is an explanatory diagram showing a capacitor structure in Example 2. Explanatory drawing which shows the power converter device in Example 3. FIG. Explanatory drawing which shows arrangement | positioning of the reactor in Example 3. FIG. Explanatory drawing which shows the power converter device in background art. Explanatory drawing which shows the structure of a capacitor | condenser in background art.

  In the power conversion device, the capacitor is configured such that the capacitor element is sealed with the insulating sealing material and accommodated in the case as described above. As such a configuration, for example, a configuration in which the capacitor element is potted (casting sealing) with a sealing material in the case, a configuration in which the capacitor element is molded with the sealing material and accommodated in the case, etc. are adopted. Can do.

The reactor may be arranged so as not to overlap the first terminal portion and the second terminal portion of the capacitor in the height direction.
In this case, the distance between the capacitor and the reactor can be reduced in the height direction. Thereby, size reduction of the said height direction in a power converter device can be achieved further.

Further, the reactor is arranged so that at least a part thereof overlaps the main circuit portion in the height direction, and the bus bar has a positive bus bar and a negative bus bar, and at least one of both is It can be set as the structure arrange | positioned so that it may not overlap with the said reactor in the said height direction (Claim 3).
In this case, the distance between the main circuit portion and the reactor can be reduced in the height direction. Thereby, size reduction of the said height direction in a power converter device can be achieved further.

Example 1
The Example concerning a power converter device is described using figures.
As shown in FIGS. 1 to 5, the power conversion device 1 of this example includes a main circuit unit 2 including a semiconductor module 21 including a semiconductor element 211 and a cooler 22 that cools the semiconductor module 21, and a main circuit unit 2. The bus bar 3 (positive side bus bar 3a, negative side bus bar 3b) connected to the power terminal 212 (positive side power terminal 212a, negative side power terminal 212b) protruding from the semiconductor module 21 and the main circuit part 2 And the height direction Z orthogonal to the arrangement direction X of the capacitor 4 electrically connected to the power terminal 212 of the semiconductor module 21 via the bus bar 3 and the main circuit portion 2 and the capacitor 4. In addition, a reactor 6 a disposed to face the capacitor 4 is provided on the side where the bus bar 3 is disposed with respect to the main circuit portion 2.

As shown in the figure, the capacitor 4 includes a capacitor element 41 sealed with an insulating sealing material 42 and accommodated in a case 43, and is connected to a first terminal portion 45 connected to the bus bar 3 and outside. The second terminal portion 46 to be connected is drawn out of the case 43, and the capacitor element 41 is configured to be electrically connected to the bus bar 3 via the first terminal portion 45.
Further, the connection portion 5 that connects between the first terminal portion 45 and the second terminal portion 46 in the capacitor 4 is embedded in the sealing material 42.
This will be described in detail below.

As shown in FIG. 1, the power conversion device 1 constitutes a DC-DC converter mounted on an electric vehicle, a hybrid vehicle, or the like.
The power conversion device 1 includes a main circuit unit 2, a bus bar 3, a capacitor 4, and reactors 6a and 6b that constitute a power conversion circuit 8 (FIG. 5). Moreover, the power converter device 1 accommodates these components in a housing (not shown).

As shown in FIG. 2, the main circuit unit 2 includes a plurality of semiconductor modules 21 including semiconductor elements 211 and a cooler 22 that cools the plurality of semiconductor modules 21. In addition, illustration of the bus bar 3 is abbreviate | omitted in FIG.
As will be described later, each semiconductor module 21 includes a switching element 211a (FIG. 5) made of IGBT (insulated gate bipolar transistor) and the like, and a diode made of FWD (free wheel diode) connected in reverse parallel to the switching element 211a. Two semiconductor elements 211, 211b (FIG. 5), are incorporated.

  As shown in the figure, the cooler 22 has a plurality of cooling pipes 221 for circulating a refrigerant for cooling the semiconductor module 21. The cooling pipes 221 are alternately stacked with the semiconductor modules 21 in the arrangement direction X. That is, the semiconductor module 21 is sandwiched between the cooling pipes 221 from both sides in the arrangement direction X. Two semiconductor modules 21 are arranged side by side between the cooling pipes 221.

  As shown in the figure, the plurality of cooling pipes 221 are connected by connecting pipes 222 that can deform adjacent cooling pipes 221 at both ends in the longitudinal direction (lateral direction Y). In addition, a refrigerant introduction pipe 223 that introduces a refrigerant from outside and a refrigerant discharge pipe 224 that discharges the refrigerant to the outside are disposed at both ends of the cooling pipe 221 disposed at one end in the arrangement direction X among the plurality of cooling pipes 221. And are connected.

  In the cooler 22, the refrigerant introduced from the refrigerant introduction pipe 223 appropriately passes through the connection pipe 222 on the refrigerant introduction pipe 223 side, is distributed to each cooling pipe 221, and flows in the longitudinal direction (lateral direction Y). To do. The refrigerant exchanges heat with the semiconductor module 21 while flowing through the cooling pipes 221. The refrigerant whose temperature has risen due to heat exchange passes through the connecting pipe 222 on the refrigerant discharge pipe 224 side and is discharged from the refrigerant discharge pipe 224 as appropriate.

  Examples of the refrigerant circulating in the cooler 22 include natural refrigerants such as water and ammonia, water mixed with ethylene glycol antifreeze, fluorocarbon refrigerants such as fluorinate, and chlorofluorocarbon refrigerants such as HCFC123 and HFC134a. A refrigerant such as alcohol refrigerant such as methanol or alcohol, or a ketone refrigerant such as acetone can be used.

Further, as shown in the figure, each semiconductor module 21 has a plurality of power terminals 212 protruding on one side in the height direction Z (FIG. 4). Further, in the two semiconductor modules 21 arranged in the horizontal direction Y, the plurality of power terminals 212 are connected to the positive power terminal 212a to which the positive bus bar 3a is connected and the negative bus bar 3b. There is a negative power terminal 212b and an AC power terminal 212c to which an AC bus bar 3c (FIG. 4) is connected. The AC bus bar 3c is not shown in FIGS.
Each semiconductor module 21 has a plurality of control terminals 213 (FIG. 4) protruding on the other side in the height direction Z. The control terminal 213 is connected to a control circuit board (not shown).

  Further, as shown in FIG. 1, the condenser 4 is disposed between the refrigerant introduction pipe 223 and the refrigerant discharge pipe 224 in the cooler 22. The capacitor 4 is arranged side by side with the main circuit unit 2. The arrangement direction X of the main circuit unit 2 and the capacitor 4 is the same as the stacking direction of the semiconductor module 21 and the cooling pipe 221 in the main circuit unit 2. Further, as will be described later, the capacitor 4 has a power terminal 212 (a positive power terminal 212a, a negative power terminal) of the semiconductor module 21 in the main circuit section 2 via a bus bar 3 (a positive bus bar 3a, a negative bus bar 3b). 212b).

As shown in FIG. 3, the capacitor 4 includes a capacitor element 41, an insulating sealing material 42 that seals the capacitor element 41, and a case 43 that houses the capacitor element 41 and the sealing material 42. In FIG. 3, the capacitor element 41 and the case 43 are indicated by dotted lines, and a sealant 42 is provided between them.
In the case 43, three capacitor elements 41 are arranged side by side in the lateral direction Y. The three capacitor elements 41 are potted (casting sealed) with a sealing material 42 in the case 43. The case 43 includes a pair of first terminal portions 45 (45a, 45b) connected to the positive electrode side bus bar 3a and the negative electrode side bus bar 3b, and a pair of second terminal portions 46 (46a) connected to the outside. 46b) are exposed outside.

  Further, as shown in the figure, the capacitor element 41 is connected to a pair of capacitor bus bars 44 (44a, 44b). The pair of capacitor bus bars 44 (44a, 44b) are respectively arranged on both sides in the height direction Z of the three capacitor elements 41, and are potted (casting sealed) with the sealing material 42 together with the three capacitor elements 41. ing. Further, the pair of capacitor bus bars 44 (44a, 44b) is connected to the pair of first terminal portions 45 (45a, 45b), respectively. And the capacitor | condenser element 41 is connected to the positive electrode side bus bar 3a and the negative electrode side bus bar 3b via a pair of 1st terminal part 45 (45a, 45b).

  As shown in FIG. 1, one end of the positive side bus bar 3a and one end of the negative side bus bar 3b are fastened to the pair of first terminal portions 45 (45a, 45b) of the capacitor 4 using bolts (not shown). It is fixed. The other end of the positive bus bar 3 a is welded to the positive power terminal 212 a of the semiconductor module 21 in the main circuit portion 2. The other end of the negative side bus bar 3 b is welded to the negative side power terminal 212 b of the semiconductor module 21 in the main circuit portion 2. Thereby, the capacitor 4 is electrically connected to the power terminals 212 (positive power terminal 212a, negative power terminal 212b) of the semiconductor module 21 in the main circuit section 2 via the bus bar 3 (positive bus bar 3a, negative bus bar 3b). Connected.

  Further, as shown in FIG. 3, the pair of first terminal portions 45 (45a, 45b) and the pair of second terminal portions 46 (46a, 46b) in the capacitor 4 are respectively a pair of connection portions 5 (5a, 5b). Connected by. The pair of connection portions 5 (5a, 5b) is embedded in the sealing material 42 in the case 43. One connecting portion 5a is formed integrally with one capacitor bus bar 44a. The other connecting portion 5b is formed so as to share a part with the other capacitor bus bar 44b.

Moreover, as shown in FIG. 1, the power converter device 1 is provided with the two reactors 6a and 6b.
Reactor 6a is arranged in the height direction Z so as to face capacitor 4 on the side where bus bar 3 is arranged with respect to main circuit portion 2. Reactor 6b is arranged side by side with reactor 6a in arrangement direction X.

  Further, as shown in the figure, the reactor 6 a is arranged so as not to overlap the first terminal portion 45 and the second terminal portion 46 of the capacitor 4 in the height direction Z. Further, the reactor 6 a is arranged so that at least a part thereof overlaps with the main circuit portion 2 in the height direction Z. And among the bus bars 3, the positive electrode side bus bar 3a is arrange | positioned so that it may not overlap with the reactor 6a in the height direction Z (FIG. 4).

Moreover, as shown in FIG. 4, the reactor 6a has the external terminal 61 connected to the exterior. The external terminal 61 is electrically connected to the power terminal 212 (AC power terminal 212c) of the semiconductor module 21 in the main circuit unit 2 through the AC bus bar 3c. Specifically, the external terminal 61 is formed from one side surface in the lateral direction Y of the first reactor 6a toward the main circuit portion 2 side. One end of the AC bus bar 3 c is welded to the AC power terminal 212 c of the semiconductor module 21 in the main circuit unit 2. The external terminal 61 and the other end of the AC bus bar 3 c are fastened and fixed using a bolt 69.
Moreover, the reactor 6b is also connected to the main circuit part 2 similarly to the reactor 6a mentioned above.

Next, as shown in FIG. 5, the power conversion circuit 8 in the power conversion device 1 will be described.
As shown in the figure, the power conversion circuit 8 constitutes a booster circuit that boosts the voltage of the DC power supply 81. The power conversion circuit 8 includes a DC power supply 81, two capacitors (capacitor 4 and capacitor 49), two reactors (reactors 6a and 6b), twelve semiconductor modules 21, and the like.

As shown in the figure, one of the two capacitors 49 is a filter capacitor for smoothing the voltage before boosting. The other capacitor 4 is a smoothing capacitor for smoothing the boosted voltage.
Each semiconductor module 21 includes two semiconductor elements 211. One is a switching element 211a made of IGBT or the like, and the other is a diode 211b made of FWD or the like connected in reverse parallel to the switching element 211a.

  As shown in the figure, twelve semiconductor modules 21 constitute two module modules 20a to 20f in total, with two semiconductor modules 21 as one set. Among these, three module parts 20a-20c are connected to one reactor 6a via the AC bus bar 3c. The remaining three module parts 20d to 20f are connected to the other reactor 6b via the AC bus bar 3c.

Next, the effect of the power converter device 1 of this example is demonstrated.
In the power conversion device 1, the reactor 6 a is in the height direction Z orthogonal to the arrangement direction X of the main circuit unit 2 and the capacitor 4, and on the side where the bus bar 3 is disposed with respect to the main circuit unit 2, It arrange | positions so that the capacitor | condenser 4 may be opposed. The connection portion 5 that connects the first terminal portion 45 and the second terminal portion 46 in the capacitor 4 is embedded in an insulating sealing material 42 that seals the capacitor element 41.

  That is, the connection portion 5 that is conventionally disposed between the capacitor 4 and the reactor 6 a outside the case 43 of the capacitor 4 (see FIGS. 9 and 10) is sealed in the case 43 of the capacitor 4. It is embedded inside the stopper 42. Therefore, in the height direction Z where the capacitor 4 and the reactor 6a face each other, the distance between the two can be reduced. Thereby, size reduction of the height direction Z in the power converter device 1 can be achieved.

  Further, as described above, the connection portion 5 that connects the first terminal portion 45 and the second terminal portion 46 in the capacitor 4 is embedded in the insulating sealing material 42. Therefore, the insulating sealing material 42 is always interposed between the connecting portion 5 and the reactor 6a. Thereby, even if the distance between the capacitor 4 and the reactor 6a is reduced in the height direction Z, the insulation between the connection portion 5 and the reactor 6a can be sufficiently ensured.

  In this example, the reactor 6 a is arranged so as not to overlap the first terminal portion 45 and the second terminal portion 46 of the capacitor 4 in the height direction Z. Therefore, in the height direction Z, the distance between the capacitor 4 and the reactor 6a can be reduced. Thereby, size reduction of the height direction Z in the power converter device 1 can be achieved further.

  The reactor 6a is arranged so that at least a part thereof overlaps the main circuit portion 2 in the height direction Z, and the bus bar 3 includes a positive electrode side bus bar 3a and a negative electrode side bus bar 3b. Are arranged so as not to overlap the reactor 6a in the height direction Z. Therefore, in the height direction Z, the distance between the main circuit unit 2 and the reactor 6a can be reduced. Thereby, size reduction of the height direction Z in the power converter device 1 can be achieved further.

  As described above, according to this example, it is possible to provide the power conversion device 1 that can reduce the size in the direction in which the capacitor 4 and the reactor 6a face each other and sufficiently ensure the insulation between the components.

(Example 2)
In this example, as shown in FIG. 6, the structure of the capacitor 4 is changed.
In this example, as shown in the figure, the pair of capacitor bus bars 44 (44a, 44b) are disposed on both sides in the arrangement direction X of the three capacitor elements 41, and the pair of first terminal portions 45 (45a, 45b).
One connecting portion 5a is formed to share a part with one capacitor bus bar 44a. The other connecting portion 5b is formed so as to share a part with the other capacitor bus bar 44b.
The other configuration is the same as that of the first embodiment, and has the same operation and effect.

(Example 3)
In this example, as shown in FIGS. 7 and 8, the connection structure between the main circuit unit 2 and the reactors 6a and 6b is changed.
In this example, as shown in the figure, the external terminal 61 of the reactor 6a is formed from one side surface in the lateral direction Y of the reactor 6a toward the main circuit portion 2 side. One end of the AC bus bar 3 c is welded to the AC power terminal 212 c of the semiconductor module 21 in the main circuit unit 2. The external terminal 61 and the other end of the AC bus bar 3 c are fastened and fixed using a bolt 69 between the reactor 6 a and the main circuit portion 2.
Moreover, the reactor 6b is also connected to the main circuit part 2 similarly to the reactor 6a mentioned above.
Other configurations are the same as those in the first embodiment.

In the case of this example, in the space between the reactors 6a and 6b arranged in the height direction Z and the main circuit unit 2 and the positive side bus bar 3a and the negative side bus bar 3b are not arranged, The reactors 6a and 6b are connected to the main circuit unit 2. Therefore, size reduction of the horizontal direction Y in the power converter device 1 can be achieved. In addition, a sufficient insulation distance can be ensured between the connection location between the reactors 6a and 6b and the main circuit unit 2 and the housing (not shown) for housing the reactors 6a and 6b, the main circuit unit 2 and the like. .
In addition, the same effects as those of the first embodiment are obtained.

DESCRIPTION OF SYMBOLS 1 Power converter 2 Main circuit part 21 Semiconductor module 211 Semiconductor element 212 Power terminal 22 Cooler 3 Bus bar 4 Capacitor 41 Capacitor element 42 Sealing material 43 Case 45 1st terminal part 46 2nd terminal part 5 Connection part 6a Reactor

Claims (3)

A main circuit unit having a semiconductor module containing a semiconductor element and a cooler for cooling the semiconductor module;
A bus bar connected to a power terminal protruding from the semiconductor module of the main circuit portion;
A capacitor that is arranged side by side with the main circuit portion and electrically connected to the power terminal of the semiconductor module through the bus bar,
A reactor disposed in a height direction perpendicular to the arrangement direction of the main circuit portion and the capacitor, and facing the capacitor on the side where the bus bar is disposed with respect to the main circuit portion; With
The capacitor includes a capacitor element sealed with an insulating sealing material and accommodated in a case, and a first terminal portion connected to the bus bar and a second terminal portion connected to the outside. The capacitor element is drawn out of the case, and the capacitor element is configured to be electrically connected to the bus bar via the first terminal portion.
The power converter according to claim 1, wherein a connection portion that connects the first terminal portion and the second terminal portion in the capacitor is embedded in the sealing material.   2. The power converter according to claim 1, wherein the reactor is arranged so as not to overlap the first terminal portion and the second terminal portion of the capacitor in the height direction. Conversion device.   3. The power conversion device according to claim 1, wherein the reactor is disposed so that at least a part thereof overlaps the main circuit portion in the height direction, and the bus bar includes a positive-side bus bar and a negative-side bus bar. And at least one of them is arranged so as not to overlap the reactor in the height direction.

Images