JP2020205703A - In-wheel power conversion device - Google Patents

Abstract

To achieve downsizing of an in-wheel power conversion device.SOLUTION: An in-wheel power conversion device 1 has a shaft housing part 20 forming a housing space of a shaft, a plurality of semiconductor circuit parts 30 having a semiconductor positive electrode terminal 31 and a semiconductor negative electrode terminal 32 respectively, a bus bar 10 connected to the semiconductor circuit part 30 and having the shaft housing part 20, and a smooth capacitor 40 having a plurality of capacitor terminals 41 connected to the bus bar 10. When a plurality of semiconductor circuit parts 30 are seen from an orthogonal direction of a line connecting between the first capacitor terminal and the second capacitor terminal respectively arranged on the farthest positions from the shaft housing part 20 among a plurality of capacitor terminals 41 along a direction of a surface of the bus bar 10, either or both of the semiconductor positive electrode terminal 31 or/and the semiconductor negative electrode terminal 32 is/are arranged on a position overlapping with the line.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power converter with a built-in wheel.

It is desirable that the electric drive system of a hybrid vehicle or an electric vehicle be installed in a wheel in order to expand the passenger compartment space. Therefore, there is a demand for a technology that realizes miniaturization by significantly reducing the smoothing capacitor in the power converter and mounts it in the wheel.

The following Patent Document 1 is known as a background technique of the present invention. In Patent Document 1, n smoothing capacitors corresponding to the power module are placed on the heat sink on the same plane as the power module, between the power modules, and adjacent to the power module located on one end side. Inverters arranged in a distributed manner are described. As a result, the circuit loop related to the voltage fluctuation during switching is reduced and the inductance is suppressed, so that the capacity of the mounted smoothing capacitor can be reduced and the size can be reduced.

Japanese Unexamined Patent Publication No. 2016-226096

In Patent Document 1, since the power module and the smoothing capacitor are arranged adjacent to each other, the smoothing capacitor may be heated due to the loss generated in the power module. In order to avoid this, it is necessary to arrange the smoothing capacitor and the power module at intervals, which poses a problem of limitation in miniaturization.

The power conversion device with a built-in wheel according to the present invention is provided with a shaft storage portion forming a storage space for the shaft and a plurality of semiconductor circuit units each having a positive electrode terminal and a negative electrode terminal, which are provided corresponding to each phase of three-phase AC power. When the bus bar is provided with a bus bar connected to the semiconductor circuit portion and having the shaft accommodating portion and a smoothing capacitor having a plurality of capacitor terminals connected to the bus bar, and the bus bar is viewed from a direction along the shaft. The plurality of semiconductor circuit units are arranged so as to surround two or more sides of a square circumscribing the shaft storage portion, and the plurality of capacitor terminals are arranged at positions farthest from the shaft storage portion. When the plurality of semiconductor circuit units are viewed along the surface direction of the bus bar from the direction perpendicular to the line connecting the first capacitor terminal and the second capacitor terminal, including the first capacitor terminal and the second capacitor terminal. , One or both of the positive electrode terminal and the negative electrode terminal are arranged at positions where they overlap with the line segment.

According to the present invention, the power converter with a built-in wheel can be miniaturized.

It is the schematic of the wheel built-in type power conversion apparatus which concerns on 1st Embodiment of this invention. It is the schematic which shows the arrangement of the electronic component which concerns on embodiment of this invention. It is the schematic of the bus bar which concerns on embodiment of this invention. It is the schematic of the smoothing capacitor which concerns on embodiment of this invention. It is the schematic of the circuit module which concerns on embodiment of this invention. It is a circuit diagram of the power conversion device with a built-in wheel which concerns on embodiment of this invention. It is the schematic of the electric current path example which concerns on embodiment of this invention. It is the schematic of the wheel built-in type power conversion apparatus which concerns on 2nd Embodiment of this invention.

(Structure of power converter with built-in wheel, and first embodiment)
FIG. 1 is a schematic view showing a wheel-embedded power conversion device 1 (hereinafter, simply referred to as a power conversion device 1) according to an embodiment of the present invention. As shown in FIG. 1, the power conversion device 1 includes a bus bar 10, a shaft accommodating portion 20, a plurality of semiconductor circuit portions 30, a plurality of smoothing capacitors 40, and a power supply terminal 50.

The bus bar 10 has a shaft accommodating portion 20, a semiconductor circuit portion 30, and a power supply terminal 50, and has a circular structure. Further, the bus bar 10 includes a plurality of smoothing capacitors 40 on the bus bar 10.

A shaft (not shown) penetrates the shaft accommodating portion 20. This shaft is built in the wheel of the vehicle like the power conversion device 1, and is a rotating shaft of an electric motor with a built-in wheel (not shown) that is rotationally driven by receiving power supply from the power conversion device 1.

The semiconductor circuit unit 30 has a semiconductor positive electrode terminal 31 and a semiconductor negative electrode terminal 32 for electrically connecting to a circuit module 60 described later, and is separately arranged corresponding to the U phase, the V phase, and the W phase. .. Each of the semiconductor circuit units 30 of each phase is combined with the circuit module 60 and electrically connected. The circuit module 60 receives DC power from a battery (not shown) connected to the power supply terminal 50 via the bus bar 10 and converts it into three-phase AC power to be output to the motor.

Further, the semiconductor circuit unit 30 is surrounded by a refrigerant flow path (not shown). The refrigerant flow path is filled with a refrigerant such as water (coolant) or oil. The refrigerant is circulated by a pump (not shown), and is cooled by a radiator (not shown) or the like so that the temperature of the refrigerant is lower than that of the semiconductor circuit unit 30.

The smoothing capacitor 40 is composed of a plurality of capacitor boards 43, a plurality of ceramic capacitors 42 arranged on the plurality of capacitor boards 43, and a plurality of capacitor terminals 41. The capacitor terminal 41 includes two or more pairs of substrate positive electrode terminals 413 and substrate negative electrode terminals 414, each of which is connected to the bus bar 10. By doing so, the inductance per capacitor terminal is reduced. Further, this configuration improves the degree of freedom in the layout of the smoothing capacitor 40 in the circular bus bar 10.

The power supply terminal 50 has a positive electrode power supply terminal 51 and a negative electrode power supply terminal 52. The power supply terminal 50 is connected to a battery (not shown), and the battery supplies electric energy required for driving the electric motor.

FIG. 2 is a schematic view showing the arrangement of electronic components related to the main points of miniaturization of the power conversion device 1. The capacitor board 43 includes a capacitor first board 431 arranged farthest from the shaft storage part 20, and a plurality of capacitor second boards 432 arranged at positions closer to the shaft storage part 20 than the capacitor first board 431. And include. A plurality of capacitor second boards 432 are arranged in the circumferential direction with respect to the capacitor first board 431, and the size of the plurality of capacitor second boards 432 arranged in the circumferential direction is larger than that of the capacitor first board 431. By doing so, the smoothing capacitor 40 can be packed and arranged on the circular end side of the bus bar 10, and the power conversion device 1 can be miniaturized. A plurality of capacitor second substrates 432 may be combined into one substrate and formed so as to be larger in the circumferential direction than the capacitor first substrate 431. Even in this way, the power conversion device 1 can be miniaturized in the same manner as described above.

Here, among the substrate positive electrode terminals 413 included in the plurality of capacitor terminals 41 of the smoothing capacitor 40, the pair of capacitor terminals 41 arranged at the positions farthest from the shaft accommodating portion 20 are the first capacitor terminals 411 and the second capacitor terminals 41. It is defined as a capacitor terminal 412. Further, the first capacitor terminal 411 and the second capacitor terminal 412 are connected to define the line segment 415 of the thick line shown in the figure. When the shaft accommodating portion 20 is viewed in the direction perpendicular to the line segment 415, one or both of the semiconductor positive electrode terminal 31 and the semiconductor negative electrode terminal 32 of the semiconductor circuit unit 30 of each phase overlap with the line segment 415. The portion overlapping the direction perpendicular to the line segment is defined as the terminal arrangement area 16. Further, the smoothing capacitor 40 is arranged apart from the semiconductor circuit unit 30. As a result, a plurality of current paths can be secured between the semiconductor positive electrode terminal 31 and the semiconductor negative electrode terminal 32 of the semiconductor circuit unit 30 of each phase and the plurality of capacitor substrates 43 having the plurality of capacitor terminals 41.

The quadrangle 21 shown in FIG. 2 is an example of a quadrangle circumscribing the shaft storage portion 20. The quadrangle 21 has a pair of sides parallel to the line segment 415. The semiconductor circuit unit 30 is arranged so as to surround two or more sides of the quadrangle 21. The quadrangle circumscribing the shaft storage portion 20 can be defined in addition to the quadrangle 21 in FIG. 2, but in any quadrangle, the semiconductor circuit portion 30 may be arranged so as to surround two or more sides of the quadrangle. it is obvious.

FIG. 3 is a schematic view showing a bus bar 10 according to an embodiment of the present invention, excluding a plurality of smoothing capacitors 40. The upper figure is a front view, and the lower figure is a plan view. The bus bar 10 is composed of a bus bar positive electrode layer 11, a bus bar negative electrode layer 12, and an insulating layer 13. The bus bar positive electrode layer 11 is located on the outermost surface of the bus bar and is made of a copper material. The bus bar negative electrode layer 12 is located on the outermost surface opposite to the bus bar positive electrode layer 11, and is made of a copper material. The insulating layer 13 is located between the bus bar positive electrode layer 11 and the bus bar negative electrode layer 12, and is made of an insulating material such as epoxy resin or paper.

The bus bar positive electrode terminal 14 is located in the bus bar positive electrode layer 11, and the substrate positive electrode terminal 413 is connected to the bus bar positive electrode terminal 14. The bus bar negative electrode terminal 15 is located in the bus bar negative electrode layer 12, and the substrate negative electrode terminal 414 is connected to the bus bar negative electrode terminal 15. The positive electrode power supply terminal 51 is located in the bus bar positive electrode layer 11, and the negative electrode power supply terminal 52 is located in the bus bar negative electrode layer 12.

The bus bar 10 is composed of a first bus bar area 17 and a second bus bar area 18. The first bus bar region 17 is a region formed in a circle having a predetermined first radius from the center of the shaft accommodating portion 20. The second bus bar region 18 is a region within a predetermined second radius larger than the first radius and excluding the first radius. Aiming at miniaturization of the power conversion device 1, if the bus bar 10 is configured only in the first bus bar region 17 and all the components are arranged, the plurality of semiconductor circuit units 30 and the plurality of smoothing capacitors 40 become a short distance. In this case, the plurality of smoothing capacitors 40 may be heated due to the loss generated in the power module of the circuit module 60 connected to the semiconductor circuit unit 30. Therefore, a second bus bar region 18 is provided so that a plurality of smoothing capacitors 40 can be packed and arranged on the circular end side.

FIG. 4 is a schematic view showing a smoothing capacitor 40 according to an embodiment of the present invention. The smoothing capacitor 40 is composed of a capacitor substrate 43, a plurality of ceramic capacitors 42 arranged on the capacitor substrate 43, a substrate positive electrode terminal 413, and a substrate negative electrode terminal 414. Further, the capacitor substrate 43 has a first surface 433 and a second surface 434 on the opposite side thereof, and the ceramic capacitor 42 is arranged on both the first surface and the second surface. By doing so, the number of ceramic capacitors 42 mounted on the capacitor substrate 43 can be increased, and the area of the smoothing capacitor 40 on the bus bar 10 can be reduced, so that the power conversion device 1 can be miniaturized.

FIG. 5 is a schematic view showing a circuit module 60 according to an embodiment of the present invention. The circuit module 60 is composed of a circuit module positive terminal 61, a circuit module negative terminal 62, and a circuit module output terminal 63. The circuit module positive electrode terminal 61 is connected to the semiconductor positive electrode terminal 31 of the semiconductor circuit unit 30, and the circuit module negative electrode terminal 62 is connected to the semiconductor negative electrode terminal 32, respectively. As a result, the electrical energy required to drive the electric motor from the battery is supplied to the circuit module 60.

FIG. 6 is a circuit diagram of a power converter with a built-in wheel according to an embodiment of the present invention. The semiconductor positive electrode terminal 31 is on the side of the bus bar positive electrode terminal 14 located on the bus bar positive electrode layer 11, and the semiconductor negative electrode terminal 32 is on the side of the bus bar negative electrode terminal 15 located on the bus bar negative electrode layer 12. The circuit module 60 has a pair of semiconductor modules 64 on the upper and lower arms, and is divided into U-phase, V-phase, and W-phase. Further, the circuit module positive electrode terminal 61 is electrically connected to the semiconductor positive electrode terminal 31 of the semiconductor circuit unit 30, and the circuit module negative electrode terminal 62 is electrically connected to the semiconductor negative electrode terminal 32, respectively.

The positive electrode power supply terminal 51 and the negative electrode power supply terminal 52 draw energy required for driving the electric motor from a battery (not shown). The power conversion device 1 supplies the electric energy drawn from the battery to the circuit module 60 via the semiconductor positive electrode terminal 31 and the semiconductor negative electrode terminal 32 of the semiconductor circuit unit 30, and the circuit module positive electrode terminal 61 and the circuit module negative electrode terminal 62. To do. Then, the semiconductor module 64 provided in the circuit module 60 controls the AC power output from the circuit module output terminal 63.

FIG. 7 is a schematic view showing an example of a current path according to an embodiment of the present invention. The arrow shown in FIG. 7 is a current path example 70. On the bus bar 10, a semiconductor circuit section 30 of each phase and a smoothing capacitor 40 composed of a plurality of capacitor boards 43 and a plurality of capacitor terminals 41 arranged on the plurality of capacitor boards 43 are provided in the shaft housing section 20. On the other hand, by being dispersedly arranged in the circumferential direction, it is possible to shorten or secure a plurality of current paths coming out of the semiconductor circuit unit 30 of each phase as a whole.

According to the first embodiment of the present invention described above, the following effects are exhibited.

(1) The power conversion device 1 with a built-in wheel is provided with a shaft storage portion 20 forming a storage space for the shaft and corresponding to each phase of three-phase AC power, and has a semiconductor positive electrode terminal 31 and a semiconductor negative electrode terminal 32, respectively. It includes a plurality of semiconductor circuit units 30 having a bus bar 10 connected to the semiconductor circuit unit 30 and having a shaft accommodating portion 20, and a smoothing capacitor 40 having a plurality of capacitor terminals 41 connected to the bus bar 10. When the bus bar 10 is viewed from the direction along the shaft, the plurality of semiconductor circuit units 30 are arranged so as to surround two or more sides of a quadrangle circumscribing the shaft housing unit 20. The plurality of capacitor terminals 41 include a first capacitor terminal 411 and a second capacitor terminal 412, which are arranged at positions farthest from the shaft accommodating portion 20, respectively. When a plurality of semiconductor circuit units 30 are viewed along the plane direction of the bus bar 10 from the direction perpendicular to the line segment 415 connecting the first capacitor terminal 411 and the second capacitor terminal 412, the semiconductor positive electrode terminal 31 and the semiconductor negative electrode terminal 32 One or both are arranged at positions where they overlap with the line segment 415. Since this is done, the power converter 1 with a built-in wheel can be miniaturized.

(2) The smoothing capacitor 40 is composed of a plurality of capacitor boards 43 and a plurality of ceramic capacitors 42 arranged on the plurality of capacitor boards 43. As a result, the degree of freedom in the layout of the smoothing capacitor 40 is improved, so that the power conversion device 1 with a built-in wheel can be further miniaturized.

(3) The plurality of ceramic capacitors 42 are separately arranged on both the first surface 433 of the capacitor substrate 43 and the second surface 434 on the side opposite to the first surface 433. As a result, the area of the smoothing capacitor 40 on the bus bar 10 can be reduced, so that the wheel built-in power converter 1 can be further miniaturized.

(4) The plurality of capacitor substrates 43 are a first substrate 431 arranged farthest from the shaft accommodating portion 20, and a plurality of second substrates arranged at positions closer to the shaft accommodating portion 20 than the first substrate 431. The size of the substrate 432 and the plurality of second substrates 432 arranged in the circumferential direction is larger than that of the first substrate 431. As a result, the smoothing capacitor 40 can be packed and arranged on the circular end side of the bus bar 10, so that the power conversion device 1 with a built-in wheel can be further miniaturized.

(5) Each of the plurality of capacitor substrates 43 has two or more pairs of substrate positive electrode terminals 413 and substrate negative electrode terminals 414 connected to the bus bar 10. As a result, the inductance per terminal can be reduced, so that the heat generation of the smoothing capacitor 40 can be suppressed, and the power conversion device 1 with a built-in wheel can be further miniaturized.

(Second Embodiment)
FIG. 8 is a schematic view showing a wheel-embedded power conversion device according to a second embodiment of the present invention. The power supply terminal 50A has a positive electrode power supply terminal 51A and a negative electrode power supply terminal 52A, and is arranged on the side opposite to the side where the shaft accommodating portion 20 is arranged with the smoothing capacitor 40 as a boundary. FIG. 8 shows the same aspect as that of the first embodiment described above, except for the power supply terminal 50A, the positive electrode power supply terminal 51A, and the negative electrode power supply terminal 52A.

According to the second embodiment of the present invention described above, the following effects are exhibited.

The bus bar 10 on the power converter with a built-in wheel is provided with a power supply terminal 50A that is connected to the battery and transmits DC power from the battery, and the power supply terminal 50A is connected to the shaft housing 20 with a plurality of capacitor terminals 41 as boundaries. Placed on the other side. As a result, the current path between the power supply terminal 50A and each capacitor terminal 41 in the smoothing capacitor 40 is made uniform, and the inductance is suppressed.

The embodiments and various modifications described above are merely examples, and the present invention is not limited to these contents as long as the features of the invention are not impaired. Moreover, although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other aspects conceivable within the scope of the technical idea of the present invention are also included within the scope of the present invention.

1 Wheel built-in power converter 10 Bus bar 11 Bus bar Positive electrode layer 12 Bus bar Negative electrode layer 13 Insulation layer 14 Bus bar Positive electrode terminal 15 Bus bar Negative terminal 16 Terminal arrangement area 17 1st bus bar area 18 2nd bus bar area 20 Shaft storage 21 Square 30 Semiconductor Circuit section 31 Semiconductor positive electrode terminal 32 Semiconductor negative electrode terminal 40 Smoothing capacitor 41 Condenser terminal 411 1st capacitor terminal 412 2nd capacitor terminal 413 Board positive electrode terminal 414 Board negative electrode terminal 415 Line 42 Ceramic capacitor 43 Condenser board 431 Condenser 1st board 432 Condenser 2nd board 433 1st surface 434 2nd surface 50, 50A Power supply terminal 51, 51A Positive power supply terminal 52, 52A Negative power supply terminal 60 Circuit module 61 Circuit module Positive electrode terminal 62 Circuit module Negative electrode terminal 63 Circuit module output terminal 64 Semiconductor module 70 Current path example

Claims (7)

The shaft storage part that forms the shaft storage space and
A plurality of semiconductor circuit units provided corresponding to each phase of three-phase AC power and having positive electrode terminals and negative electrode terminals, respectively.
A bus bar that is connected to the semiconductor circuit section and has the shaft housing section,
A smoothing capacitor having a plurality of capacitor terminals connected to the bus bar, and
When the bus bar is viewed from a direction along the shaft, the plurality of semiconductor circuit portions are arranged so as to surround two or more sides of a quadrangle circumscribing the shaft housing portion.
The plurality of capacitor terminals include a first capacitor terminal and a second capacitor terminal arranged at positions farthest from the shaft housing, respectively.
When the plurality of semiconductor circuit units are viewed along the surface direction of the bus bar from the direction perpendicular to the line segment connecting the first capacitor terminal and the second capacitor terminal, one or both of the positive electrode terminal and the negative electrode terminal. However, a power converter with a built-in wheel is arranged at a position where it overlaps with the line segment. The power conversion device with a built-in wheel according to claim 1.
The busbar comprises a power supply terminal that is connected to the battery and transmits DC power from the battery.
The power supply terminal is a power conversion device with a built-in wheel that is arranged on the side opposite to the shaft housing portion with the plurality of capacitor terminals as boundaries. The power conversion device with a built-in wheel according to claim 1 or 2.
The smoothing capacitor is a power conversion device with a built-in wheel, which is composed of a plurality of substrates and a plurality of ceramic capacitors arranged on the plurality of substrates. The power conversion device with a built-in wheel according to claim 3.
The plurality of ceramic capacitors are wheel-embedded power conversion devices that are separately arranged on both the first surface of the substrate and the second surface on the side opposite to the first surface. The power conversion device with a built-in wheel according to claim 3.
The plurality of substrates include a first substrate arranged farthest from the shaft accommodating portion and a second substrate arranged at a position closer to the shaft accommodating portion than the first substrate.
The second substrate is a power conversion device with a built-in wheel, which is formed larger in the circumferential direction than the first substrate. The power conversion device with a built-in wheel according to claim 3.
The plurality of substrates include a first substrate arranged farthest from the shaft accommodating portion, and a plurality of second substrates arranged closer to the shaft accommodating portion than the first substrate. Have and
The size of the plurality of second substrates arranged in the circumferential direction is larger than that of the first substrate. The power conversion device with a built-in wheel according to claim 3.
Each of the plurality of substrates is a wheel built-in power conversion device having two or more pairs of substrate positive electrode terminals and substrate negative electrode terminals connected to the bus bar.

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