JP7259504B2 - converter unit - Google Patents

Description

The disclosure provided herein relates to a converter unit.

As disclosed in Patent Document 1, a DC-DC converter is known that includes a switching circuit section, a capacitor, and a reactor.

Japanese Patent No. 5483221

In the DC-DC converter described in Patent Document 1, the switching circuit section and the capacitor are arranged in the vertical direction of the reactor and the vehicle. However, depending on how these are arranged, there is a risk that the size of the DC-DC converter (converter unit) in the direction orthogonal to the vertical direction will increase.

Therefore, an object of the disclosure described in this specification is to provide a converter unit in which an increase in physical size is suppressed.

One disclosed is a plurality of reactors (531 to 534) arranged in a row direction,
an element module (549) comprising a plurality of electronic elements (545, 546, 546a);
a capacitor (510, 550);
The element modules and capacitors are aligned in the alignment direction,
Each of the element modules and the capacitors is separated from the multiple reactors in the vertical direction orthogonal to the arrangement direction,
The positions of the element modules and the capacitors in the alignment direction are between the end positions (BL) in the alignment direction of the plurality of reactors.

In this way, in the present disclosure, the element module (549) and the capacitors (510, 550) are positioned between the two end positions (BL) in the arrangement direction of the plurality of reactors (531 to 534). . According to this, at least one of the element module (549) and the capacitors (510, 550) is positioned outside between the end positions (BL) of the plurality of reactors (531 to 534). Compared to the configuration, an increase in physical size in the direction in which the converter units are arranged is suppressed.

Also, the element module (549) and the capacitors (510, 550) are aligned in the alignment direction. Therefore, compared with the configuration in which the element module (549) and the capacitors (510, 550) are arranged in the vertical direction, an increase in the size of the converter unit in the vertical direction is suppressed.

It should be noted that the reference numbers in parentheses above merely indicate the correspondence with the configurations described in the embodiments described later, and do not limit the technical scope in any way.

1 is a circuit diagram showing an in-vehicle system; FIG. 2 is a top view of the power conversion unit according to the first embodiment; FIG. It is a top view which shows the modification of a power conversion unit.

Embodiments will be described below with reference to the drawings.

(First embodiment)
<In-vehicle system>
First, the vehicle-mounted system 100 provided with the power conversion unit 520 will be described based on FIG. This in-vehicle system 100 constitutes a system for an electric vehicle. In-vehicle system 100 has battery 200 , power converter 300 , and motor 400 . The power conversion device 300 includes a power conversion unit 520 .

In-vehicle system 100 also includes a plurality of ECUs (not shown). These multiple ECUs transmit and receive signals to and from each other via bus wiring. A plurality of ECUs cooperate to control the electric vehicle. A plurality of ECUs control regeneration and power running of motor 400 according to the SOC of battery 200 . SOC is an abbreviation for state of charge. ECU is an abbreviation for electronic control unit.

Battery 200 is a fuel cell. However, as the battery 200, a battery stack in which a plurality of secondary batteries are connected in series can also be adopted. A lithium-ion secondary battery, a nickel-hydrogen secondary battery, an organic radical battery, or the like can be used as the secondary battery.

The power conversion device 300 converts power between the battery 200 and the motor 400 . The power conversion device 300 converts the DC power of the battery 200 into AC power having a voltage level suitable for powering the motor 400 .

Motor 400 is connected to an output shaft of an electric vehicle (not shown). The rotational energy of motor 400 is transmitted to the running wheels of the electric vehicle via the output shaft. The motor 400 is driven by AC power supplied from the power converter 300 . This imparts a propulsive force to the running wheels.

<Power converter>
Next, the power conversion device 300 will be described. Power converter 300 includes converter 500 and inverter 600 . Converter 500 boosts the DC power of battery 200 to a voltage level suitable for powering motor 400 . Inverter 600 converts this DC power to AC power. This AC power is supplied to the motor 400 .

As shown in FIG. 1, converter 500 is electrically connected to battery 200 via first power bus bar 301 and second power bus bar 302 . Power conversion unit 520 included in converter 500 is electrically connected to inverter 600 via third power bus bar 303 and fourth power bus bar 304 . Converter 500 will be described in detail later.

Inverter 600 has three or more phase legs connected in parallel between third power bus bar 303 and fourth power bus bar 304 . Each of these three or more phase legs has two switch elements connected in series. A bus bar is connected to the midpoint between these two switch elements. This bus bar is electrically connected to the stator coil of motor 400 . Description and illustration of the configuration of inverter 600 are omitted.

<Converter circuit configuration>
As shown in FIG. 1, converter 500 has first capacitor 510 and power conversion unit 520 . Power conversion unit 520 has reactor 530 , power module 540 , second capacitor 550 , coupling bus bar 560 , P bus bar 571 and N bus bar 572 . Power conversion unit 520 corresponds to a converter unit. Strictly speaking, the second capacitor 550 is a component of the inverter 600 .

As shown in FIG. 1 , one end of first power bus bar 301 is connected to the positive electrode of battery 200 . One end of the second power busbar 302 is connected to the negative electrode of the battery 200 . One of two electrodes of the first capacitor 510 is connected to the first power bus bar 301 . The other of the two electrodes of first capacitor 510 is connected to second power bus bar 302 .

One end of reactor 530 is connected to the other end of first power bus bar 301 . The other end of reactor 530 is connected to power module 540 via coupling bus bar 560 . Thus, the positive electrode of battery 200 and power module 540 are electrically connected via reactor 530 . First capacitor 510 and power module 540 are electrically connected via reactor 530 . In addition, in FIG. 1, the connection part of various busbars is shown by the white circle. These connecting portions are electrically connected by bolts, welding, or the like.

Power module 540 and second capacitor 550 are connected in parallel between P bus bar 571 and N bus bar 572 . Power module 540 and second capacitor 550 are electrically connected without reactor 530 .

The P busbar 571 is connected to the third power busbar 303 . N bus bar 572 is connected to second power bus bar 302 and fourth power bus bar 304 . In FIG. 1, the connection end of the P bus bar 571 with the third power bus bar 303 is denoted by reference numeral 571a. A connection end of the N bus bar 572 with the fourth power bus bar 304 is given a reference numeral 572a. Inverter 600 corresponds to an external device.

As shown in FIG. 1 , the reactor 530 has an A-phase reactor 531 , a B-phase reactor 532 , a C-phase reactor 533 and a D-phase reactor 534 . Accordingly, power module 540 has A-phase leg 541 , B-phase leg 542 , C-phase leg 543 , and D-phase leg 544 . Connection bus bar 560 has A-phase connection bus bar 561 , B-phase connection bus bar 562 , C-phase connection bus bar 563 , and D-phase connection bus bar 564 .

Each of the A-phase leg 541 to D-phase leg 544 has a high-side diode 545, a low-side switch 546, and a freewheeling diode 546a as semiconductor elements. A semiconductor package is constructed by covering and protecting these semiconductor elements with a sealing resin. The high-side diode 545, low-side switch 546, and freewheeling diode 546a correspond to electronic elements.

In this embodiment, a Schottky barrier diode is adopted as the high side diode 545 . An N-channel IGBT is used as the low-side switch 546 .

As shown in FIG. 1, the anode electrode of high side diode 545 is connected to the collector electrode of low side switch 546 . Thereby, the high side diode 545 and the low side switch 546 are connected in series.

A collector electrode of the low-side switch 546 is connected to a cathode electrode of a freewheeling diode 546a. An emitter electrode of the low-side switch 546 is connected to an anode electrode of a freewheeling diode 546a. As a result, the low-side switch 546 is connected to the freewheeling diode 546a in anti-parallel.

Note that each phase leg may have an active element such as an IGBT instead of the high-side diode 545 . The type of switch element provided in each phase leg is not particularly limited, and for example, a MOSFET can be adopted.

Semiconductor elements such as switches and diodes included in each phase leg can be manufactured from semiconductors such as Si and wide-gap semiconductors such as SiC. The constituent material of the semiconductor element is not particularly limited.

Furthermore, the types and constituent materials of the switches possessed by each phase leg may be different. For example, the switches provided in the A-phase leg 541 may be MOSFETs made of SiC, and the switches provided in each of the B-phase legs 542 to 544 may be IGBTs made of Si.

As described above, the high-side diode 545 and low-side switch 546 are covered and protected by the sealing resin. The ends of the terminals connected to the cathode electrode of the high-side diode 545, the midpoint between the high-side diode 545 and the low-side switch 546, and the emitter electrode and gate electrode of the low-side switch 546 are exposed from this sealing resin. there is These terminals are hereinafter referred to as cathode terminal 547a, midpoint terminal 547b, emitter terminal 547c, and gate terminal 547d.

This cathode terminal 547 a is connected to the P bus bar 571 . Emitter terminal 547 c is connected to N bus bar 572 . Thereby, the high side diode 545 and the low side switch 546 are serially connected in order from the P bus bar 571 toward the N bus bar 572 .

Also, the middle point terminal 547 b is connected to the other end of the reactor 530 via the coupling bus bar 560 . Specifically, the midpoint terminal 547 b of the A-phase leg 541 is connected to the A-phase reactor 531 via the A-phase connecting bus bar 561 . A midpoint terminal 547 b of the B-phase leg 542 is connected to the B-phase reactor 532 via a B-phase coupling bus bar 562 . A midpoint terminal 547 b of the C-phase leg 543 is connected to the C-phase reactor 533 via a C-phase coupling bus bar 563 . A midpoint terminal 547 b of the D-phase leg 544 is connected to the D-phase reactor 534 via a D-phase coupling bus bar 564 .

One end of each of the A-phase reactors 531 to D-phase reactors 534 is connected to the first power bus bar 301 as described above. With the electrical connection configuration described above, each phase reactor is connected to the positive electrode of battery 200 and the midpoint terminal 547b of each phase leg. The first capacitor 510 and each phase leg are electrically connected via each phase reactor.

As described above, the converter 500 of this embodiment includes four phase reactors, four phase legs, and four phase connection bus bars. The gate terminal 547d of the low side switch 546 included in each of the four phase legs is connected to the gate driver. The low-side switch 546 is controlled to be opened/closed by the ECU and the gate driver.

The ECU generates control signals and outputs them to the gate drivers. The gate driver amplifies the control signal and outputs it to the gate electrode of the low side switch 546 in the phase leg. Accordingly, the ECU controls opening/closing of low-side switch 546 to boost the voltage level of the DC power input to converter 500 .

The ECU generates pulse signals as control signals. The ECU adjusts the boost level of the DC power by adjusting the on-duty ratio and frequency of this pulse signal. Further, the ECU adjusts the boost level by selecting the number of phase legs to be driven among the four phase legs. This boost level is determined according to the target torque of motor 400 and the SOC of battery 200 .

As described above, converter 500 has a plurality of phase reactors, phase legs, and phase connection busbars. This is to avoid an increase in the temperature of components of converter 500 exceeding the heat-resistant temperature due to an increase in power supplied from battery 200 .

<Configuration of power conversion unit>
Next, the configuration of power conversion unit 520 will be described. Accordingly, the three directions that are orthogonal to each other are hereinafter referred to as the x-direction, the y-direction, and the z-direction. The x direction corresponds to the alignment direction. The vertical direction corresponds to the y direction.

As described above, power conversion unit 520 has reactor 530, power module 540, second capacitor 550, coupling bus bar 560, and P bus bar 571 and N bus bar 572 shown in FIG. In addition to these, the power conversion unit 520 has a case 580 shown in FIG.

The case 580 has a flat support portion 581 with a thin thickness in the z direction, and a frame portion 582 integrally connected to the support portion 581 . A frame portion 582 stands up in the z-direction from a main surface 581a of the support portion 581 facing the z-direction. The frame portion 582 has an annular shape surrounding the main surface 581a.

The frame portion 582 has a first side wall 582a and a second side wall 582b spaced apart in the x direction and facing each other, and a third side wall 582c and a fourth side wall 582d spaced apart in the y direction and facing each other. The first sidewall 582a and the second sidewall 582b extend in the y-direction. The third sidewall 582c and the fourth sidewall 582d extend in the x direction. The first side wall 582a, the third side wall 582c, the second side wall 582b, and the fourth side wall 582d are annularly connected in order in the circumferential direction around the z direction.

As described above, a storage space surrounded by the frame portion 582 is configured above the main surface 581a. A reactor 530, a power module 540, a second capacitor 550, a connecting bus bar 560, and a P bus bar 571 and an N bus bar 572 are stored in this storage space. Note that FIG. 2 partially shows only the connection end 571 a of the P bus bar 571 to the third power bus bar 303 . Only a connection end 572a of the N bus bar 572 with the fourth power bus bar 304 is partially shown.

<Cooler>
As shown in FIG. 2, the power module 540 has, in addition to the A-phase leg 541 to D-phase leg 544, a cooler 548 that accommodates and cools them.

As shown in FIG. 3, the cooler 548 has a supply pipe 548a, an exhaust pipe 548b, and a plurality of relay pipes 548c. The supply pipe 548a and the discharge pipe 548b are connected via a plurality of relay pipes 548c. Refrigerant flows through these three tubes. Refrigerant flows from the supply pipe 548a to the discharge pipe 548b through a plurality of relay pipes 548c.

The supply pipe 548a and the discharge pipe 548b each extend in the x-direction. The supply pipe 548a and the discharge pipe 548b are spaced apart in the y-direction. Each of the plurality of relay pipes 548c extends along the y direction from the supply pipe 548a toward the discharge pipe 548b.

A plurality of relay pipes 548c are spaced apart in the x direction and arranged side by side. A gap is formed between two adjacent relay pipes 548c. A total of four air gaps are configured in the cooler 548 . A-phase leg 541 to D-phase leg 544 constituting a semiconductor package are individually housed in each of these four gaps. As a result, the A-phase leg 541 to D-phase leg 544 are arranged in the x direction via the relay pipe 548c.

The sealing resin of each of the A-phase leg 541 to D-phase leg 544 is in contact with the relay pipe 548c. As a result, the heat generated in the four phase legs can be radiated to the refrigerant through the relay pipe 548c. In the following description, the plurality of relay pipes 548c and the A-phase leg 541 to D-phase leg 544 are collectively referred to as an element module 549 in order to avoid complication of notation.

<Module and second capacitor>
As shown in FIG. 2, the power module 540 is provided on the support portion 581 . The cooler 548 is located on the side of the fourth side wall 582d in the y direction. Similarly, the second capacitor 550 is also located on the side of the fourth side wall 582d in the y direction.

A portion (element module 549) including the phase leg in the power module 540 is located on the side of the first side wall 582a in the x direction. The second capacitor 550 is positioned on the second sidewall 582b side in the x direction. The element module 549 and the second capacitor 550 are arranged facing each other in the x direction.

Also, the second condenser 550 is located between the supply pipe 548a and the discharge pipe 548b in the y-direction. Therefore, the second condenser 550 is surrounded by a supply pipe 548a, a discharge pipe 548b, and a relay pipe 548c through which the refrigerant flows.

<Reactor>
As described above, reactor 530 has A-phase reactor 531 to D-phase reactor 534 . As shown in FIG. 2, these four phase reactors are located on the third side wall 582c side in the y direction. These four phase reactors are arranged in the x direction.

More specifically, A-phase reactor 531, B-phase reactor 532, C-phase reactor 533, and D-phase reactor 534 are arranged in order from the first side wall 582a side toward the second side wall 582b side. Of the four phase reactors aligned in the x direction, the A-phase reactor 531 is positioned closest to the first side wall 582a. The D-phase reactor 534 is positioned closest to the second side wall 582b. A-phase reactor 531 and D-phase reactor 534 are positioned at both ends.

In FIG. 2, two reference lines BL indicating the positions of the ends in the x direction of the four phase reactors arranged in the x direction are indicated by broken lines. One of these two reference lines BL indicates the position of the end of the A-phase reactor 531 on the side of the first side wall 582a in the x direction. The other of the two reference lines BL indicates the position of the end of the D-phase reactor 534 on the side of the second side wall 582b in the x direction.

<Reactor, module, second capacitor>
As shown in FIG. 2, the A-phase reactor 531 is located closer to the first side wall 582a than the element module 549 in the x direction. The D-phase reactor 534 is located closer to the second side wall 582b than the second capacitor 550 in the x direction. Therefore, the element module 549 and the second capacitor 550 are positioned in the x direction between the A-phase reactor 531 and the D-phase reactor 534 positioned at both ends of the four phase reactors arranged in the x direction. In other words, the x-direction positions of the element module 549 and the second capacitor 550 are between the two reference lines BL.

The element module 549 and the second capacitor 550 are separated from the A-phase reactor 531 to the D-phase reactor 534 in the y direction. The element module 549 is arranged so as to face the A-phase reactor 531 to the C-phase reactor 533 in the y direction. The second capacitor 550 is arranged so as to face the C-phase reactor 533 and the D-phase reactor 534 in the y direction. In this manner, the element module 549 and the second capacitor 550 are arranged in a manner facing at least one of the A-phase reactors 531 to D-phase reactors 534 in the y direction.

As described above, the A-phase leg 541 to D-phase leg 544 included in the element module 549 and the A-phase reactor 531 to D-phase reactor 534 are electrically connected via the A-phase connection bus bar 561 to D-phase connection bus bar 564. connected These four phase connection busbars are located between the four phase legs and the four phase reactors in the y-direction. The inter-connection bus bar extends in the x-direction and in the y-direction from the phase leg toward the phase reactor, depending on the positional difference between the two in the x-direction.

Although not shown, the center sides of these four interconnecting bus bars are insert-molded in a terminal block made of an insulating resin material. A current sensor for detecting the current flowing through the phase-connecting busbar is insert-molded in this terminal block.

<Effect>
As described above, the positions of the element module 549 and the second capacitor 550 in the x direction are between the A-phase reactor 531 and the D-phase reactor 534 located at both ends of the four phase reactors arranged in the x direction. there is

According to this, compared to the configuration in which at least one of the element module 549 and the second capacitor 550 is located outside between the A-phase reactor 531 and the D-phase reactor 534, the power conversion unit 520 is suppressed from increasing in size in the x direction.

Also, the element module 549 and the second capacitor 550 are arranged in the x direction. Therefore, compared with the configuration in which the element module 549 and the second capacitor 550 are arranged in the y direction, the increase in size of the power conversion unit 520 in the y direction is suppressed.

Element module 549 and second capacitor 550 each face at least one of A-phase reactor 531 to D-phase reactor 534 in the y direction.

According to this, compared to the configuration in which at least one of the element module 549 and the second capacitor 550 is not opposed to at least one of the four phase reactors in the y direction, the physical size of the power conversion unit 520 in the z direction is reduced. Growth is suppressed.

As described above, the A-phase reactor 531 to D-phase reactor 534 are arranged in the x direction. At the same time, the A-phase leg 541 to D-phase leg 544 are arranged in the x direction. These phase reactors and phase legs are aligned in the y direction.

According to this, extension of the phase connection bus bar which connects a phase reactor and a phase leg is suppressed compared with the structure which several phase legs are located in a line with the y direction, for example. This suppresses an increase in the inductance component of the interconnecting bus bar. An increase in surge voltage caused by a time change in the current flowing through the phase-connecting bus bar and an inductance component is suppressed.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present disclosure.

(First modification)
In this embodiment, an example in which the first capacitor 510 is not included in the power conversion unit 520 is shown. However, for example, as shown in FIG. 3, a configuration in which power conversion unit 520 includes first capacitor 510 can also be adopted. In FIG. 3, the notation of the connection bus bar 560 is omitted in order to avoid complication of the notation.

In the case of the modification shown in FIG. 3, the element module 549 and the second capacitor 550 are arranged side by side in the x direction. According to this, compared to a configuration in which the element module 549 and the second capacitor 550 are arranged in the x-direction via the first capacitor 510, for example, the phase leg included in the element module 549 and the P Extension of the bus bar 571 and the N bus bar 572 is suppressed. Therefore, an increase in the inductance component of the P bus bar 571 and the N bus bar 572 is suppressed. An increase in surge voltage due to time change and inductance component of the current flowing through the P bus bar 571 and the N bus bar 572 is suppressed.

3, the connection end 571a of the P bus bar 571 and the connection end 572b of the N bus bar 572 are connected to the center line CL passing through the center of the element module 549 in the y direction, as indicated by the solid line arrows in FIG. to the second capacitor 550 side. The P busbar 571 and the N busbar 572 correspond to connection busbars.

According to this, the extension of the part which connects the 2nd capacitor|condenser 550 and the inverter 600 in each of the P bus bar 571 and the N bus bar 572 is suppressed. Therefore, an increase in the inductance component of each of the P bus bar 571 and the N bus bar 572 is suppressed. An increase in the surge voltage caused by the time change of the current flowing through these bus bars and the inductance component is suppressed.

Note that FIG. 3 shows an example in which the switch module 549 is positioned between the first capacitor 510 and the second capacitor 550 . However, it is not limited to this, and a configuration in which the second capacitor 550 is positioned between the first capacitor 510 and the switch module 549, for example, can also be adopted.

(Second modification)
In this embodiment, an example is shown in which the battery 200 is a fuel cell. However, as described above, battery 200 may constitute a battery stack in which a plurality of secondary batteries are connected in series. In this case, power converter 300 converts AC power generated by power generation (regeneration) of motor 400 into DC power at a voltage level suitable for charging battery 200 . Therefore, the power conversion device 300 has active elements such as IGBTs and MOSFETs instead of the high-side diodes 545 described above.

(Other modifications)
In this embodiment, an example in which the power conversion unit 520 includes the second capacitor 550 that is a part of the components of the inverter 600 is shown. However, a configuration in which power conversion unit 520 does not include the components of inverter 600 can also be adopted. A configuration in which all the components of inverter 600 are included in power conversion unit 520 may also be employed.

In this embodiment, an example in which the power conversion unit 520 is included in the in-vehicle system 100 for an electric vehicle is shown. However, application of the power conversion unit 520 is not particularly limited to the above example. For example, a configuration in which power conversion unit 520 is included in a hybrid system that includes a motor and an internal combustion engine may be employed. Furthermore, a configuration in which power conversion unit 520 is included in a system other than a vehicle can also be adopted.

In this embodiment, the configuration in which the power conversion device 300 is connected to one motor 400 is shown. However, a configuration in which the power conversion device 300 is connected to two motors 400 can also be adopted. In this case, the power conversion device 300 has two inverters 600 .

DESCRIPTION OF SYMBOLS 100... Vehicle-mounted system, 200... Battery, 300... Power converter, 400... Motor, 500... Converter, 510... 1st capacitor, 520... Power conversion unit, 530... Reactor, 540... Power module, 541... A phase leg, 542... B-phase leg, 543... C-phase leg, 544... D-phase leg, 545... High side diode, 546... Low side switch, 546a... Freewheel diode, 560... Connection bus bar, 561... A phase connection bus bar, 562... B phase Connection bus bar 563...C phase connection bus bar 564...D phase connection bus bar 548...Cooler 549...Element module 550...Second capacitor 571...P bus bar 571a...Connection end 572...N bus bar 572a... Connection end, 600... Inverter

Claims (5)

a plurality of reactors (531 to 534) arranged in the row direction;
an element module (549) comprising a plurality of electronic elements (545, 546, 546a);
a capacitor (510, 550);
the element module and the capacitor are arranged in the arrangement direction;
each of the element modules and the capacitors is separated from the plurality of reactors in a vertical direction perpendicular to the alignment direction;
A converter unit in which the positions of the element modules and the capacitors in the row direction are between both end positions (BL) in the row direction of the plurality of reactors. 2. The converter unit according to claim 1, wherein each of said element module and said capacitor faces at least one of said plurality of reactors in said longitudinal direction. a plurality of the electronic elements are arranged in the arrangement direction in the element module;
3. The converter unit according to claim 1, wherein the plurality of electronic elements and the plurality of reactors are connected via connecting busbars (561 to 564). The capacitor has a first capacitor (510) connected to the electronic element via the reactor and a second capacitor (550) connected to the electronic element,
The converter unit according to any one of claims 1 to 3, wherein the element module and the second capacitor are arranged side by side in the arrangement direction. Connection ends (571a, 572a) of connection busbars (571, 572) connecting the second capacitors and the element modules to the second capacitor side from the element modules in the row direction, and connected to external devices (400, 600). ) is located.

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