JP7139603B2 - power converter - Google Patents

Description

The present disclosure relates to power converters.

Patent document 1 discloses a capacitor in which a metal foil protruding from both ends of a capacitor element in which a metal foil and a dielectric are overlapped and wound is sealed with a conductor, and a cooling pipe for flowing a cooling liquid is joined to the sealed conductor. It is

Japanese Patent Application Laid-Open No. 2001-230145

In the technique described in Patent Document 1, the condenser is cooled by connecting the cooling pipe directly to the conductor that seals the metal foil, which may complicate the structure of the condenser.

The present disclosure has been made to solve the above problems, and can be implemented as the following modes.
[Mode 1]
According to one aspect of the present disclosure, power converters (10A, 10B, 10C, 10D) are provided. This power converter includes a capacitor (40) having a first electrode (41) and a second electrode (42), and a plurality of semiconductor modules having a first terminal (21) and a second terminal (22). (20); a conductive first bus bar (50) electrically connecting the plurality of first terminal portions and the first electrodes; and electrically connecting the plurality of second terminal portions and the second electrodes. and a conductive second bus bar (60, 60B) that electrically connects. At least one of the first bus bar and the second bus bar includes a refrigerant supply port (58, 68) and a refrigerant discharge port (59, 69), and the refrigerant supplied inside from the refrigerant supply port is supplied to the plurality of the second bus bars. and a coolant channel (55, 65) for circulating to be discharged from the coolant discharge port via the vicinity of at least one of the one terminal and the plurality of second terminals.
[Mode 2]
According to one aspect of the present disclosure, power converters (10A, 10B, 10C, 10D) are provided. This power converter includes a capacitor (40) having a first electrode (41) and a second electrode (42), and a plurality of semiconductor modules having a first terminal (21) and a second terminal (22). (20); a conductive first bus bar (50) electrically connecting the plurality of first terminal portions and the first electrodes; and electrically connecting the plurality of second terminal portions and the second electrodes. a conductive second bus bar (60, 60B) in direct connection and a current sensor (90). At least one of the first bus bar and the second bus bar includes a refrigerant supply port (58, 68) and a refrigerant discharge port (59, 69), and the refrigerant supplied inside from the refrigerant supply port is supplied to the plurality of the second bus bars. and a coolant channel (55, 65) for circulating to be discharged from the coolant discharge port via the vicinity of at least one of the one terminal and the plurality of second terminals. The current sensor is electrically connected to one of the first bus bar and the second bus bar, which has the refrigerant flow path.

According to one aspect of the present disclosure, power converters (10A, 10B, 10C, 10D) are provided. This power converter includes; a capacitor (40) having a first electrode (41) and a second electrode (42); a semiconductor module (20) having a first terminal (21) and a second terminal (22); ); a conductive first bus bar (50) that electrically connects the first terminal portion and the first electrode; and a conductive bus bar (50) that electrically connects the second terminal portion and the second electrode. and a second bus bar (60, 60B) of; at least one of the first bus bar and the second bus bar has a refrigerant channel (55, 65) in which a refrigerant flows.

According to this aspect, at least one of the first bus bar that connects the first terminal portion and the first electrode and the second bus bar that connects the second terminal portion and the second electrode has a coolant channel inside. , the capacitor and the terminal can be cooled without adopting a complicated structure for the power converter.

1 is a top view of the power converter of the first embodiment; FIG. The figure for demonstrating the cooling structure of the power converter device of 1st Embodiment. The figure which shows about a cooling system provided with a power converter. The top view of the power converter device of 2nd Embodiment. The figure for demonstrating the cooling structure of the power converter device of 2nd Embodiment. The top view of the power converter device of 3rd Embodiment. The figure for demonstrating the cooling structure of the power converter device of 3rd Embodiment. The top view of the power converter device of 4th Embodiment. The figure for demonstrating the cooling structure of the power converter device of 4th Embodiment.

- 1st Embodiment 10 A of power converters of 1st Embodiment are demonstrated using FIG.1 and FIG.2. A cooling system 100 including the power converter 10A and the refrigerant circulation unit 110 will be described with reference to FIG. FIG. 1 shows XYZ axes that are substantially perpendicular to each other. The XYZ axes in FIG. 1 correspond to the XYZ axes in the other figures. The +Z-axis direction is also called "up", and the opposite direction is also called "down". FIG. 1 is a top view of the power conversion device 10A, and FIG. 2 is a diagram for explaining the cooling structure using a simplified sectional view of the power conversion device 10A.

The power conversion device 10A of the present embodiment is an inverter device that converts direct current into multiphase alternating current and outputs it to an external load. The power conversion device 10A is mounted on a vehicle such as an electric vehicle, a hybrid vehicle, or a fuel cell vehicle, and converts a direct current output from a battery (not shown), which is a direct current power supply, into a three-phase alternating current, and supplies it to an external load. It is supplied to a certain three-phase AC motor (not shown). The power converter 10A includes a semiconductor module 20, a capacitor module 30, a first busbar 50, a second busbar 60, and a cooler .

The semiconductor module 20 includes so-called 2-in-1 type semiconductor modules 20u, 20v, and 20w containing a positive-side switching element and a negative-side switching element (not shown). The three semiconductor modules 20u, 20v, and 20w are connected to U-phase, V-phase, and W-phase of external loads, respectively. The switching element on the positive electrode side is connected to the first bus bar 50 via the first terminal portion 21 . The switching element on the negative electrode side is connected to the second bus bar 60 via the second terminal portion 22 . The first terminal portion 21 and the second terminal portion 22 are also called "power terminals".

Cooler 70 contacts the lower surfaces of semiconductor module 20 and capacitor module 30 to cool semiconductor module 20 and capacitor module 30 . A coolant circulates inside the cooler 70 by a circulation pump or the like. In other embodiments, cooler 70 may be a heat sink. In this embodiment, the semiconductor modules 20 and the capacitor modules 30 are stacked so as to fit within the plane of the upper surface of the cooler 70 .

The capacitor module 30 includes a metal capacitor case 31 that accommodates the capacitor 40 , a filling resin 32 , and the capacitor 40 . The filling resin 32 is a resin filled between the capacitor 40 and the capacitor case 31, and for example, an epoxy resin is used. Although the upper sides of the capacitor 40, first bus bar 50, and second bus bar 60 shown in FIG.

The capacitor 40 in this embodiment is a so-called smoothing capacitor that smoothes the direct current that is input to the power converter 10A. Capacitor 40 is configured by winding a metallic film. As shown in FIG. 2, the capacitor 40 has a pair of first electrode 41 and second electrode 42 on both sides in the Z direction, which is the direction of the winding axis. The first electrode 41 is arranged on the upper surface side of the capacitor 40 and the second electrode 42 is arranged on the lower surface side of the capacitor 40 .

The first bus bar 50 is a conductive member that electrically connects the first terminal portion 21, the first electrode 41, and the positive electrode side of the DC power supply. Specifically, the first bus bar 50 includes a semiconductor module connection portion 51 connected to the first terminal portion 21 of the semiconductor module 20, an electrode connection portion 52 connected to the first electrode 41 by welding, and a DC power supply side. and a power supply side connection portion 53 connected to the . The second bus bar 60 is a conductive member that electrically connects the second terminal portion 22, the second electrode 42, and the negative electrode side of the DC power supply. Specifically, the second bus bar 60 includes a semiconductor module connection portion 61 connected to the second terminal portion 22 of the semiconductor module 20, an electrode connection portion 62 connected by welding with the second electrode 42, and a DC power supply side. and a power supply side connection portion 63 connected to the . At least part of the power supply side connection portion 53 and at least part of the power supply side connection portion 63 protrude outside the capacitor case 31 through through holes provided in the capacitor case 31 .

In this embodiment, the first bus bar 50 includes a coolant supply port 58 that is a supply port for supplying coolant into the first bus bar 50 and a coolant discharge port 59 that is a discharge port for discharging the coolant from the first bus bar 50. and a coolant channel 55 through which coolant flows. The coolant channel 55 is provided inside the first bus bar 50 except for the semiconductor module connection portion 51 and the power supply side connection portion 53 . In FIG. 1 , a portion of the inner wall of the first bus bar 50 forming the coolant channel 55 is indicated by a dotted line, and the flow of the coolant through the coolant channel 55 is indicated by a thick arrow. The refrigerant circulates inside the first bus bar 50 by a refrigerant circulation unit 110 connected to the refrigerant supply port 58 and the refrigerant discharge port 59 . As shown in FIG. 3, the refrigerant circulation unit 110 includes a refrigerant discharge pipe 120, a refrigerant supply pipe 130, a radiator 140, a fan 150 for promoting cooling of the refrigerant by blowing air against the radiator 140, and a refrigerant supply pipe. and a circulation pump 160 located at 130 . Coolant discharge pipe 120 connects coolant discharge port 59 and radiator 140 . Coolant supply pipe 130 connects radiator 140 and coolant supply port 58 . The coolant discharged from the coolant discharge port 59 to the coolant discharge pipe 120 is cooled by the radiator 140 and then supplied to the coolant supply port 58 through the coolant supply pipe 130 . The supplied coolant circulates through the coolant channel 55 in the first bus bar 50, cools the first terminal portion 21 and the upper surface side of the capacitor 40, and is discharged from the coolant discharge port 59 (FIG. 1).

In FIG. 2, the state of heat transfer in the power conversion device 10A is indicated by white arrows. Due to the circulation of the coolant, the heat of the first terminal portion 21 and the heat of the upper surface side of the capacitor 40 are transferred to the coolant flowing through the first bus bar 50 . The heat on the bottom side of the condenser 40 moves to the cooler 70 arranged on the bottom side of the condenser 40 . Note that the first terminal portion 21, the second terminal portion 22, and the coolant supply port 58 are not shown in FIG. 2 for convenience of illustration. 2, the semiconductor module connection portion 51 appears above the semiconductor module connection portion 61 for convenience of illustration, but the positions of the semiconductor module connection portion 51 and the semiconductor module connection portion 61 in the Z-axis direction are the same. may

According to this aspect, since the first bus bar 50 connecting the first terminal portion 21 and the first electrode 41 has the coolant flow path 55, the first bus bar 50 can be The upper surface side of the terminal section 21 and the capacitor 40 can be cooled.

According to this aspect, the power conversion device 10A is arranged on the lower surface side of the capacitor 40 and further includes the cooler 70 for cooling the capacitor 40, so that the lower surface side of the capacitor 40 can be cooled by the cooler 70. can.

According to this form, the upper surface side of the capacitor 40, which tends to be heated because it is away from the cooler 70, can be efficiently cooled without adopting a complicated structure for the power converter 10A.

Moreover, according to this embodiment, the cooling of the semiconductor module 20 can be promoted through the first terminal portion 21 .

- 2nd Embodiment The difference from 1st Embodiment is demonstrated using FIG.4 and FIG.5. In the following, the same reference numerals as in the already described embodiments indicate the same configurations, and the preceding description is referred to. In the power converter 10B of the second embodiment, the cooler 70B has a smaller surface along the XY plane than the cooler 70 of the first embodiment. not in contact. In the power converter 10B of the second embodiment, compared to the power converter 10A of the first embodiment, the position of the lower surface of the capacitor module 30B is shifted in the -Z direction by the height of the cooler 70B in the Z direction. are placed.

The second bus bar 60B of the present embodiment differs from the second bus bar 60 of the first embodiment in that, like the first bus bar 50, the second bus bar 60B has a coolant supply port 68, a coolant discharge port 69, It is provided with a coolant channel 65 . The coolant channel 65 is provided inside the second bus bar 60B except for the semiconductor module connection portion 61 and the power supply side connection portion 63 . In FIG. 4 , part of the inner wall of the second bus bar 60B that forms the coolant flow path 65 is indicated by a dotted line, and the flow of the coolant through the coolant flow path 65 is indicated by a thick arrow. there is The coolant is supplied from the coolant supply port 68 by a circulation pump 160 or the like provided outside the power converter 10B. The coolant circulates through the coolant channel 55 in the second bus bar 60 to cool the second terminal portion 22 and the lower surface side of the capacitor 40 , and is discharged from the coolant discharge port 69 . The discharged coolant radiates heat outside the power conversion device 10A and is supplied from the coolant supply port 68 again. As indicated by white arrows in FIG. 5 , the heat of the first terminal portion 21 and the heat of the upper surface side of the capacitor 40 move to the refrigerant flowing through the first bus bar 50 , and the heat of the second terminal portion 22 and the lower surface of the capacitor 40 The side heat is transferred to the coolant flowing through the second bus bar 60 . Although illustration is omitted, the refrigerant discharge port 59 and the refrigerant discharge port 69 are connected to the refrigerant discharge pipe 120 of the refrigerant circulation section 110 in this embodiment. Also, the coolant supply port 58 and the coolant supply port 68 are connected to the coolant supply pipe 130 of the coolant circulation section 110 .

According to this embodiment, the inside of the first bus bar 50 connecting the first terminal portion 21 and the first electrode 41 and the inside of the second bus bar 60B connecting the second terminal portion 22 and the second electrode 42 have , are provided with coolant flow paths 55 and 65, respectively, so that the upper surface side and the lower surface side of the capacitor 40, the first terminal portion 21 and the second terminal portion can be connected without adopting a complicated structure for the power conversion device 10A. 22 and can be efficiently cooled.

According to this embodiment, the lower surface side of the capacitor 40 can be cooled by the second bus bar 60B. The power conversion device 10B can be configured to be small.

According to this aspect, cooling of the semiconductor module 20 can be promoted through the first terminal portion 21 and the second terminal portion 22 .

- 3rd Embodiment The difference from 2nd Embodiment is demonstrated using FIG.6 and FIG.7. The power conversion device 10C of the third embodiment includes a discharge resistor 80 connected in parallel with the capacitor 40 and discharging electric charges accumulated in the capacitor 40 . One end of the discharge resistor 80 is connected to the first terminal portion 21 via a conductive terminal connection portion 83 . The other end of the discharge resistor 80 is connected to the second terminal portion 22 via a conductive terminal connection portion 84 . As indicated by white arrows in FIG. 7, the heat of the discharge resistor 80 is transferred via the terminal connection portions 83 and 84 to the refrigerant flowing through the refrigerant flow path 55 provided in the first bus bar 50 and the second bus bar 60B. The coolant flowing through the coolant channel 65 provided inside moves to.

According to this embodiment, the discharge resistor 80 includes the first terminal portion 21 connected to the first bus bar 50 provided with the coolant channel 55 therein, and the second bus bar provided with the coolant channel 65 therein. It is connected in parallel with the capacitor 40 through the second terminal portion 22 connected to 60B. Therefore, in addition to the effects of the second embodiment, the discharge resistor 80 can be cooled without adopting a complicated structure.

- 4th Embodiment The difference from 1st Embodiment is demonstrated using FIG.8 and FIG.9. The power conversion device 10</b>D includes a current sensor 90 electrically connected to the first busbar 50 . Current sensor 90 measures the direct current flowing through capacitor 40 . The current sensor 90 is connected to the power supply side connection portion 53 of the first bus bar 50 via a conductive sensor connection portion 91 . As indicated by white arrows in FIG. 9, the heat of the first terminal portion 21 and the heat on the upper surface side of the condenser 40 move to the refrigerant flowing through the first bus bar 50, and the heat on the lower surface side of the condenser 40 transfers to the cooler. Move to 70. The heat of current sensor 90 is transferred to the coolant flowing through first bus bar 50 .

According to this embodiment, the current sensor 90 is connected to the first bus bar 50 in which the coolant channel 55 is provided. The current sensor 90 can be cooled to

・Other Embodiment 1
In the power conversion device 10A of the first embodiment, either one of the first busbar 50 and the second busbar 60 may be provided with a coolant channel. That is, the refrigerant flow path 65 may be provided in the second bus bar 60 instead of the first bus bar 50 . According to this aspect, either one of the first terminal portion 21 and the second terminal portion 22 and the capacitor 40 can be efficiently cooled without adopting a complicated structure for the power converter 10A. .

・Other embodiment 2
In each of the above embodiments, the power converters 10A to 10D do not have to include the coolers 70 and 70B. According to this form, the semiconductor module 20 can be cooled through at least one of the first terminal portion 21 and the second terminal portion 22 .

・Other embodiment 3
In the power conversion device 10C of the third embodiment, coolant channels 55 and 65 may be provided in one of the first busbar 50 and the second busbar 60B. According to this embodiment, the discharge resistor 80 is terminal-connected by the coolant flowing through the coolant channel 55 provided in the first bus bar 50 or the coolant flowing through the coolant channel 65 provided in the second bus bar 60B. Cooling can be provided via the portion 83 or the terminal connection portion 84 .

・Other embodiment 4
The current sensor 90 of the fourth embodiment may be connected to one of the first busbar 50 and the second busbar 60 provided with the coolant channel 55 . For example, the current sensor 90 may be connected to the second bus bar 60 when the first bus bar 50 does not have the coolant channel 55 and the second bus bar 60 has the coolant channel 65 . According to this embodiment, the current sensor 90 is connected to the sensor by the coolant flowing through the coolant channel 55 provided in the first bus bar 50 or the coolant flowing through the coolant channel 65 provided in the second bus bar 60. Cooling is possible via the section 91 .

・Other embodiment 5
In the above-described embodiment, the coolant in cooler 70 and cooler 70B may be circulated by coolant circulation unit 110 . According to this form, the structure for circulating the refrigerant in the first bus bar 50, the second bus bar 60B, and the cooler 70 can be shared.

・Another embodiment 6
The configurations of the various embodiments described above may be combined as appropriate. For example, the current sensor 90 may be provided in the power converters 10B and 10C of the second embodiment and the third embodiment.

・Other Embodiment 7
Capacitor 40 is not limited to a smoothing capacitor. Capacitor 40 may be a snubber capacitor for absorbing surge voltages occurring in the switching circuit.

10A, 10B, 10C, 10D power converter, 20 semiconductor module, 21 first terminal portion, 22 second terminal portion, 40 capacitor, 41 first electrode, 42 second electrode, 50 first bus bar, 55 refrigerant channel, 60, 60B Second bus bar

Claims (4)

A power conversion device (10A, 10B, 10C, 10D),
a capacitor (40) comprising a first electrode (41) and a second electrode (42);
a plurality of semiconductor modules (20) each having a first terminal portion (21) and a second terminal portion (22);
A conductive first bus bar (50) electrically connecting the plurality of first terminal portions and the first electrodes, and a conductive portion electrically connecting the plurality of second terminal portions and the second electrodes. sexual second bus bars (60, 60B);
a current sensor (90) ;
At least one of the first busbar and the second busbar,
a coolant supply port (58, 68) and a coolant outlet (59, 69);
A coolant that circulates through the vicinity of at least one of the plurality of first terminal portions and the plurality of second terminal portions so as to be discharged from the coolant discharge port. a channel (55, 65) ;
The current sensor is electrically connected to one of the first bus bar and the second bus bar, which has the refrigerant flow path.
Power converter. The power converter according to claim 1,
In the capacitor, the first electrode is arranged on the upper surface side of the capacitor, and the second electrode is arranged on the lower surface side of the capacitor,
further comprising a cooler (70) arranged on the lower surface side of the condenser for cooling the condenser;
The power conversion device, wherein the first bus bar has the coolant channel. The power converter according to claim 1,
In the capacitor, the first electrode is arranged on the upper surface side of the capacitor, and the second electrode is arranged on the lower surface side of the capacitor,
A power conversion device, wherein the first bus bar and the second bus bar have the refrigerant flow path. The power converter according to any one of claims 1 to 3,
A power conversion device further comprising a discharge resistor (80) connected in parallel with the capacitor via the first terminal and the second terminal.

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