JP2020137347A - Voltage conversion device - Google Patents

Abstract

To suppress increase of costs required for configuration.SOLUTION: A voltage conversion device 1 comprises: a first transistor SW1 and second transistor SW2; a first reactor 21 and second reactor 22; and an electronic control unit 15. The first transistor SW1 is connected between a positive electrode bus bar PV and the first reactor 21. The first reactor 21 is connected between the first transistor SW1 and a middle terminal MV. The second transistor SW2 is connected between a negative electrode bus bar NV and the second reactor 22. The second reactor 22 is connected between the second transistor SW2 and the middle terminal MV. The electronic control unit 15 controls switching of the first transistor SW1 and the second transistor SW2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a voltage converter.

Conventionally, there is known a power conversion device that supplies a voltage to two loads while adjusting the voltage (for example, the midpoint voltage) of two loads connected in series (see, for example, Patent Document 1). ). This power conversion device includes a DC / DC converter that divides and supplies the output voltage of the battery to a plurality of loads such as auxiliary machinery mounted on an electric vehicle. A DC / DC converter consists of two switching elements connected in series, two capacitors connected in series, and an inductor connected between the connection point of the two switching elements and the connection point of the two capacitors. , Equipped with. The two loads, the two switching elements, and the two capacitors are connected in parallel between the positive electrode terminal and the negative electrode terminal of the battery.

International Publication No. 2012/017753

By the way, in the power conversion device according to the above-mentioned prior art, when adjusting the midpoint voltage, the output voltage of the battery may be applied to each of the two switching elements connected in series. Therefore, the rated voltage of each switching element needs to be set as high as at least the output voltage of the battery, which causes a problem that the cost required for configuring the power conversion device increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a voltage conversion device capable of suppressing an increase in cost required for configuration.

In order to solve the above problems and achieve the above object, the present invention has adopted the following aspects.
(1) The voltage conversion device according to one aspect of the present invention (for example, the voltage conversion device 1 in the embodiment) is a positive electrode terminal (for example, a positive electrode terminal in the embodiment) of a power supply (for example, a battery 11 in the embodiment). The upper arm element (for example, the first transistor SW1 in the embodiment) connected to the PB) and the lower arm element (for example, the negative electrode terminal NB in the embodiment) connected to the negative electrode terminal of the power supply (for example, the embodiment). The first reactor connected between the second transistor SW2) in the embodiment, the intermediate terminal between the positive electrode terminal and the negative electrode terminal (for example, the intermediate terminal MV in the embodiment), and the upper arm element. (For example, the first reactor 21 in the embodiment), the second reactor connected between the intermediate terminal and the lower arm element (for example, the second reactor 22 in the embodiment), and the upper arm element. And a control unit (for example, the electronic control unit 15 in the embodiment) that controls the switching of the lower arm element.

(2) The voltage conversion device according to (1) above is a first diode connected in parallel with the first reactor between the intermediate terminal and the upper arm element (for example, the first diode in the embodiment). 23) and a second diode (for example, the second diode 24 in the embodiment) connected in parallel with the second reactor between the intermediate terminal and the lower arm element may be provided.

(3) In the voltage conversion device according to (1) or (2) above, the control unit controls switching between the upper arm element and the lower arm element to obtain a voltage output from the intermediate terminal. It may be maintained at a predetermined value.

(4) In the voltage conversion device according to any one of (1) to (3) above, the rated voltage of the upper arm element and the rated voltage of the lower arm element are between the positive electrode terminal and the negative electrode terminal. It may be lower than the applied voltage.

(5) In the voltage conversion device according to (4) above, the difference between the rated voltage of the upper arm element and the rated voltage of the lower arm element may be within a predetermined range.

(6) The voltage conversion device according to any one of (1) to (5) above has a first load (for example, a first load in the embodiment) connected between the positive electrode terminal and the intermediate terminal. A load 25) and a second load (for example, a second load 26 in the embodiment) connected between the intermediate terminal and the negative electrode terminal are provided, and the power consumption of the first load and the second load are provided. The difference from the power consumption of the load may be within a predetermined range.

(7) In the voltage conversion device according to any one of (1) to (6) above, the power storage device (for example, the battery 11 in the embodiment) connected to the positive electrode terminal and the negative electrode terminal, and a motor. (For example, the motor 12 in the embodiment) and the power conversion device (for example, the power module 13 in the embodiment) that transfers power between the motor and the motor are connected via the stator windings of the motor. The charger inlet (for example, the charger inlet 31 in the embodiment) may be provided.

According to the above (1), since the upper arm element and the lower arm element are connected via the first reactor and the second reactor, the voltage between the positive electrode terminal and the negative electrode terminal is divided and the upper arm element is divided. And applied to each of the lower arm elements. As a result, for example, as compared with the case where the voltage between the positive electrode terminal and the negative electrode terminal is concentratedly applied to each of the upper arm element and the lower arm element without being divided, the upper arm element and the lower arm element The withstand voltage of each can be lowered, and an increase in the cost required for the device configuration can be suppressed.

In the case of (2) above, the counter electromotive voltage (surge voltage) generated in each of the first reactor and the second reactor due to the switching of the upper arm element and the lower arm element is sequentially applied to each of the first diode and the second diode. It can be absorbed (consumed) by the current flowing in the direction.

In the case of (3) above, the voltage output from the intermediate terminal can be easily maintained at a predetermined value by switching between the upper arm element and the lower arm element.

In the case of (4) above, for example, the cost required for the device configuration is increased as compared with the case where the rated voltage of each of the upper arm element and the lower arm element is set to be equal to or higher than the voltage between the positive electrode terminal and the negative electrode terminal. It can be suppressed.

In the case of (5) above, the rated voltage of the upper arm element and the rated voltage of the lower arm element can be equalized within a predetermined range. For example, the upper arm element and the lower arm element having different rated voltages beyond the predetermined range can be used. It is possible to suppress an increase in the cost required for the device configuration as compared with the case of providing the device.

In the case of (6) above, the power consumption of the first load and the power consumption of the second load can be equalized within a predetermined range, for example, the first load and the second load having different power consumption beyond the predetermined range It is possible to suppress an increase in the cost required for the device configuration as compared with the case of providing the device.

In the case of (7) above, the voltage input from the charger inlet can be boosted by using the stator winding of the motor and the power conversion device, and the voltage is stored at the rated voltage or higher of the charger connected to the charger inlet. The device can be charged.

It is a figure which shows the structure of a part of the vehicle which carries the voltage conversion apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the current flow when the 2nd transistor is on in the voltage conversion apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the current flow when the 1st transistor is on in the voltage conversion apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the change of the voltage applied between both ends of the positive electrode end and the negative electrode end of a 2nd load with the on / off of a 2nd transistor in the voltage conversion apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the change of the voltage applied between the collector and the emitter of the 2nd transistor with the on / off of the 2nd transistor in the voltage conversion apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of a part of the vehicle which carries the voltage conversion apparatus which concerns on 1st modification of embodiment of this invention. It is a figure which shows the structure of a part of the vehicle which mounts the voltage conversion apparatus which concerns on the 2nd modification of embodiment of this invention.

Hereinafter, an embodiment of the voltage conversion device of the present invention will be described with reference to the accompanying drawings.

The voltage converter according to this embodiment is connected to, for example, a power module that controls power transfer between a motor and a battery. For example, a voltage converter and a power module are mounted on an electric vehicle or the like. The electric vehicle is an electric vehicle, a hybrid vehicle, a fuel cell vehicle, or the like. Electric vehicles are powered by batteries. The hybrid vehicle is driven by a battery and an internal combustion engine as power sources. A fuel cell vehicle is driven by a fuel cell as a power source.

<Vehicle>
FIG. 1 is a diagram showing a partial configuration of a vehicle 10 equipped with a voltage conversion device 1 according to an embodiment of the present invention.
As shown in FIG. 1, in addition to the voltage converter 1, the vehicle 10 includes a battery 11 (BATT), a traveling drive motor 12 (MOT), a power module 13, a current sensor 14, and an electronic control unit. A 15 (MOT ECU) and a gate drive unit 16 (G / D VCU ECU) are provided.

The battery 11 is, for example, a high-voltage battery that is a power source for the vehicle 10. The battery 11 includes a battery case and a plurality of battery modules housed in the battery case. The battery module includes a plurality of battery cells connected in series.
The battery 11 includes a positive electrode terminal PB and a negative electrode terminal NB connected to the DC connector 17a. The positive electrode terminal PB and the negative electrode terminal NB are connected to the positive electrode end and the negative electrode end of a plurality of battery modules connected in series in the battery case.

The motor 12 generates a rotational driving force (power running operation) by the electric power supplied from the battery 11. The motor 12 may generate generated electric power by a rotational driving force input to the rotary shaft. The motor 12 may be configured so that the rotational power of the internal combustion engine can be transmitted. For example, the motor 12 is a three-phase AC brushless DC motor. The three phases are the U phase, the V phase, and the W phase.
The motor 12 includes a rotor having a permanent magnet for a field magnet and a stator having a three-phase stator winding for generating a rotating magnetic field that rotates the rotor. The three-phase stator windings of the motor 12 are connected to the three-phase connector 17b.

The power module 13 is connected to the three-phase stator windings of the motor 12 by, for example, a three-phase connector 13b. The power module 13 converts the DC power input from the battery 11 into three-phase AC power. The power module 13 may convert the three-phase AC power input from the motor 12 into DC power. The DC power converted by the power module 13 can be supplied to the battery 11.

The power module 13 includes a bridge circuit formed by a plurality of switching elements connected by a bridge. For example, the switching element is a transistor such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal Oxide Semi-conductor Field Effect Transistor). For example, in a bridge circuit, a pair of high-side arm and low-side arm U-phase transistors UH and UL, a pair of high-side arm and low-side arm V-phase transistors VH and VL, and a pair of high-side arm and low-side arm. The W-phase transistors WH and WL are bridge-connected, respectively.

In each transistor UH, VH, WH of the high side arm, a collector is connected to the positive electrode bus bar PI to form a high side arm. In each phase, each positive electrode bus bar PI of the high sidearm is connected to the positive electrode bus bar PV of the voltage converter 1.
The emitters of each of the transistors UL, VL, and WL of the low side arm are connected to the negative electrode bus bar NI to form the low side arm. In each phase, each negative electrode bus bar NI of the low side arm is connected to the negative electrode bus bar NV of the voltage converter 1.
The connection between the positive electrode bus bars PI and PV and the connection between the negative electrode bus bars NI and NV are, for example, smaller than bolt fastening and laser welded or clipped so as to suppress thermal damage to the insulated portion. Connection etc. are adopted.

In each phase, the emitters of the high-side arm transistors UH, VH, and WH are connected to the collectors of the low-side arm transistors UL, VL, and WL at the connection point TI.
The input / output bus bar 18 forming the connection point TI in each phase is connected to the input / output terminal Q. The input / output terminal Q is connected to the three-phase connector 17b. The connection point TI of each phase is connected to the stator winding of each phase of the motor 12 via the input / output bus bar 18, the input / output terminal Q, and the three-phase connector 17b.
The bridge circuit includes a diode connected between the collector and the emitter of each transistor UH, UL, VH, VL, WH, and WL so as to be forward from the emitter to the collector.

The power module 13 turns on (conducts) / turns off the transistor pairs of each phase based on the gate signal which is a switching command input from the gate drive unit 16 to the gates of the transistors UH, VH, WH, UL, VL, and WL. (Block) is switched. The power module 13 converts the DC power input from the battery 11 via the voltage converter 1 into three-phase AC power, and sequentially commutates the energization of the three-phase stator windings of the motor 12 to three. Alternating current U-phase current, V-phase current, and W-phase current are applied to the phase stator windings.
The power module 13 is a three-phase AC power output from the three-phase stator windings of the motor 12 by on (conducting) / off (disconnecting) driving of the transistor pairs of each phase synchronized with the rotation of the motor 12. May be converted to DC power. The DC power converted from the three-phase AC power by the power module 13 can be supplied to the battery 11 via the voltage converter 1.

The current sensor 14 is arranged on the input / output bus bar 18 of each phase, for example, and detects the currents of the U phase, the V phase, and the W phase. The current sensor 14 is connected to the electronic control unit 15 by a signal line.

The electronic control unit 15 controls the operation of the motor 12. For example, the electronic control unit 15 is a software function unit that functions by executing a predetermined program by a processor such as a CPU (Central Processing Unit). The software function unit is an ECU (Electronic Control Unit) equipped with a processor such as a CPU, a ROM (Read Only Memory) for storing programs, a RAM (Random Access Memory) for temporarily storing data, and an electronic circuit such as a timer. is there. At least a part of the electronic control unit 15 may be an integrated circuit such as an LSI (Large Scale Integration).

For example, the electronic control unit 15 executes current feedback control using the current detection value of the current sensor 14 and the current target value corresponding to the torque command value for the motor 12, and generates a control signal to be input to the gate drive unit 16. To do. The control signal is a signal indicating the timing for driving each transistor pair of the power module 13 on (conducting) / off (disconnecting). For example, the control signal is a pulse width modulated signal or the like.
Further, the electronic control unit 15 executes current feedback control using the current detection value of the current sensor 14 and the current target value corresponding to the regeneration command value for the motor 12, and generates a control signal to be input to the gate drive unit 16. You may.

The gate drive unit 16 generates a gate signal for actually driving each transistor pair of the power module 13 on (conducting) / off (disconnecting) based on the control signal received from the electronic control unit 15. For example, the gate drive unit 16 amplifies the control signal, shifts the level, and the like to generate the gate signal.
The gate drive unit 16 generates a gate signal for driving the transistors SW1 and SW2 of the voltage converter 1 on (conducting) / off (disconnecting). For example, the gate drive unit 16 generates a gate signal having a duty ratio corresponding to a voltage command at the time of voltage adjustment of the voltage converter 1. The duty ratio is, for example, the ratio of the on-time of each transistor SW1 and SW2.

<Voltage converter>
The voltage converter 1 includes two paired switching elements, a first reactor 21, a second reactor 22, a first diode 23 and a second diode 24, a first capacitor C1a and a second capacitor C1b, and a smoothing capacitor. It includes C2, a first load (Sa) 25, and a second load (Sb) 26.

The two pairing switching elements are, for example, the first transistor SW1 of the high side arm and the second transistor SW2 of the low side arm.
In the first transistor SW1, the collector is connected to the positive electrode bus bar PV to form a high side arm. The positive electrode bus bar PV of the high side arm is connected to the positive electrode terminal PB of the battery 11 and the positive electrode bus bar PI of the power module 13. The emitter of the first transistor SW1 is connected to the first reactor 21.
The emitter of the second transistor SW2 is connected to the negative electrode bus bar NV to form a low side arm. The negative electrode bus bar NV of the low side arm is connected to the negative electrode terminal NB of the battery 11 and the negative electrode bus bar NI of the power module 13. The collector of the second transistor SW2 is connected to the second reactor 22.

The rated voltage of each of the first transistor SW1 and the second transistor SW2 is set lower than the output voltage VB output between the positive electrode terminal PB and the negative electrode terminal NB of the battery 11 applied between the positive electrode bus bar PV and the negative electrode bus bar NV. Has been done.
The difference between the rated voltage of the first transistor SW1 and the rated voltage of the second transistor SW2 is set within a predetermined range. For example, the predetermined range is a range of desired tolerances and the like.

The first reactor 21 and the second reactor 22 are connected to an intermediate terminal MV provided between the positive electrode bus bar PV and the negative electrode bus bar NV. The first reactor 21 is connected between the emitter of the first transistor SW1 and the intermediate terminal MV. The second reactor 22 is connected between the collector of the second transistor SW2 and the intermediate terminal MV.
Each of the first diode 23 and the second diode 24 is connected to each of the first reactor 21 and the second reactor 22. The first diode 23 is connected in parallel with the first diode 23 so as to be in the forward direction from the intermediate terminal MV toward the emitter of the first transistor SW1. The second diode 24 is connected in parallel with the second reactor 22 so as to be in the forward direction from the collector of the second transistor SW2 toward the intermediate terminal MV.

The first capacitor C1a and the second capacitor C1b are connected in series between the positive electrode bus bar PV and the negative electrode bus bar NV. The connection point between the first capacitor C1a and the second capacitor C1b is connected to the intermediate terminal MV. That is, the first capacitor C1a is connected between the positive electrode bus bar PV and the intermediate terminal MV, and the second capacitor C1b is connected between the intermediate terminal MV and the negative electrode bus bar NV. The first capacitor C1a and the second capacitor C1b smooth the voltage fluctuations generated by the on / off switching operation of the first transistor SW1 and the second transistor SW2.

The smoothing capacitor C2 is connected between the positive electrode bus bar PV and the intermediate terminal MV. The smoothing capacitor C2 is connected between the plurality of positive electrode bus bars PI and the negative electrode bus bar NI of the power module 13 via the positive electrode bus bar PV and the negative electrode bus bar NV. The smoothing capacitor C2 smoothes the voltage fluctuation generated by the on / off switching operation of each of the transistors UH, UL, VH, VL, WH, and WL of the power module 13.

The first load (Sa) 25 and the second load (Sb) 26 are, for example, auxiliary equipment such as an air compressor and a DC-DC converter mounted on an electric vehicle, or headlights and wipers mounted on various vehicles. Auxiliary equipment.
The first load (Sa) 25 and the second load (Sb) 26 are connected in series between the positive electrode bus bar PV and the negative electrode bus bar NV. The connection point between the first load 25 and the second load 26 is connected to the intermediate terminal MV. That is, the first load 25 is connected between the positive electrode bus bar PV and the intermediate terminal MV, and the second load 26 is connected between the intermediate terminal MV and the negative electrode bus bar NV.

The voltage conversion device 1 according to the present embodiment has the above configuration, and next, the operation of the voltage conversion device 1 will be described.
The voltage converter 1 switches on (conductivity) / off (disconnection) of a transistor pair based on a gate signal which is a switching command input from the gate drive unit 16 to each gate of the first transistor SW1 and the second transistor SW2. ..
FIG. 2 is a diagram showing an example of current flow when the second transistor SW2 is on in the voltage converter 1 according to the embodiment of the present invention. FIG. 3 is a diagram showing an example of a current flow when the first transistor SW1 is on in the voltage conversion device 1 according to the embodiment of the present invention. FIG. 4 shows a change in the voltage Vsb applied between both ends of the positive electrode end and the negative electrode end of the second load 26 as the second transistor SW2 is turned on / off in the voltage converter 1 according to the embodiment of the present invention. It is a figure which shows an example. FIG. 5 is a diagram showing an example of a change in the voltage Vsw2 applied between the collector and the emitter of the second transistor SW2 as the second transistor SW2 is turned on / off in the voltage converter 1 according to the embodiment of the present invention. Is.

As shown in FIGS. 2 and 3, in the voltage conversion device 1, the first state in which the first transistor SW1 is set to on (conductivity) and the second transistor SW2 is set to off (disconnection), and the first transistor SW1 is off. The voltage output from the intermediate terminal MV is adjusted by alternately switching between (disconnection) and the second state in which the second transistor SW2 is set to ON (conductivity).

As shown in FIG. 2, in the first state, the positive electrode terminal PB of the battery 11, the first load 25, the first transistor SW1, the first reactor 21, the second load 26, and the negative electrode terminal of the battery 11 are sequentially formed. Current flows to NB. The first reactor 21 is DC-excited by the current I1 branched from the output current IB of the battery 11 to the first transistor SW1 side of the first transistor SW1 and the first load 25 to store magnetic energy. In the first state, the power consumption of the second load 26 is relatively larger than that of the first load 25. Further, the counter electromotive voltage (surge voltage) generated in the second reactor 22 is absorbed (consumed) by the current flowing in the forward direction of the second diode 24.

As shown in FIG. 3, in the second state, a current flows sequentially to the positive electrode terminal PB of the battery 11, the first load 25, the second load 26, the second reactor 22, and the second transistor SW2. The second reactor 22 is DC-excited by the current I2 branched from the output current IB of the battery 11 to the second transistor SW2 side of the second transistor SW2 and the second load 26 to store magnetic energy. In the second state, the power consumption of the first load 25 is relatively larger than that of the second load 26. Further, the counter electromotive voltage (surge voltage) generated in the first reactor 21 is absorbed (consumed) by the current flowing in the forward direction of the first diode 23.

The voltage converter 1 maintains the voltage output from the intermediate terminal MV at a predetermined value by switching the first transistor SW1 and the second transistor SW2, for example. For example, the predetermined value is a value (VB / 2) that is 1/2 of the output voltage VB of the battery 11 within a desired tolerance range.
Further, the voltage converter 1 maintains, for example, the difference between the power consumption of the first load 25 and the power consumption of the second load 26 within a predetermined range. For example, the predetermined range is a range of desired tolerances and the like.

In the voltage converter 1, the voltages Vsw1 and Vsw2 applied between the collector and the emitter of the transistors SW1 and SW2 due to the switching of the first transistor SW1 and the second transistor SW2 are the positive ends of the loads 25 and 26 and It is regulated by the respective voltages Vsa and Vsb applied between both ends of the negative electrode end.
For example, as shown in FIGS. 4 and 5, the voltage Vsb applied between both the positive end and the negative end of the second load 26 due to the on (ON) / off (OFF) switching operation of the second transistor SW2. Changes while alternating between a decreasing tendency and an increasing tendency within a predetermined range. The voltage Vsw2 applied between the collector and the emitter of the second transistor SW2 becomes zero when the second transistor SW2 is turned on, and matches the voltage Vsb of the second load 26 when the second transistor SW2 is turned off.
Similarly, the voltage Vsa applied between both ends of the positive electrode end and the negative electrode end of the first load 25 tends to decrease within a predetermined range as the first transistor SW1 is switched on (ON) / off (OFF). And it changes while alternately switching to an increasing tendency. The voltage Vsw1 applied between the collector and the emitter of the first transistor SW1 becomes zero when the first transistor SW1 is turned on, and matches the voltage Vsa of the first load 25 when the first transistor SW1 is turned off.

As described above, according to the voltage conversion device 1 of the present embodiment, the first transistor SW1 of the high side arm and the second transistor SW2 of the low side arm are connected via the first reactor 21 and the second reactor 22. There is. Therefore, the battery voltage VB between the positive electrode bus bar PV and the negative electrode bus bar NV is divided and applied to each of the first transistor SW1 and the second transistor SW2. As a result, each of the first transistor SW1 and the second transistor SW2 is compared with the case where the battery voltage VB between the positive electrode bus bar PV and the negative electrode bus bar NV is applied intensively to each of the first transistor SW1 and the second transistor SW2. It is possible to reduce the withstand voltage of the device and suppress an increase in the cost required for the device configuration.

Further, since the withstand voltage of each of the first transistor SW1 and the second transistor SW2 can be lowered, a switching element such as an FET, which is cheaper and has lower loss than, for example, can be used as compared with an IGBT or the like. As a result, the switching frequency can be increased, the first reactor 21 and the second reactor 22 can be miniaturized, and an increase in the cost required for the device configuration can be suppressed.

Further, the voltage output from the intermediate terminal MV can be easily maintained at a predetermined value by switching the first transistor SW1 and the second transistor SW2.
Further, since the rated voltages of the first transistor SW1 and the second transistor SW2 are lower than the battery voltage VB and are equal to each other within a predetermined range, for example, the first transistor SW1 and the first transistor SW1 having different rated voltages exceeding the predetermined range Compared with the case where the second transistor SW2 is provided, it is possible to suppress an increase in the cost required for the device configuration.

Further, the power consumption of the first load 25 and the power consumption of the second load 26 can be equalized within a predetermined range, and for example, the first load 25 and the second load 26 having different power consumption beyond the predetermined range are provided. Compared with the case, it is possible to suppress an increase in the cost required for the device configuration.
Further, only the difference in power consumption between the first load 25 and the second load 26 appears at the intermediate terminal MV of the voltage conversion device 1, and the voltage conversion device 1 can be miniaturized. Further, by reducing the power passing through the power conversion device 1, the loss in the power conversion device 1 can be reduced, and the energy consumption of the vehicle 10 can be reduced.

Further, the counter electromotive voltage (surge voltage) generated in each of the first reactor 21 and the second reactor 22 due to the switching of the first transistor SW1 and the second transistor SW2 is set in each of the first diode 23 and the second diode 24. It can be absorbed (consumed) by the current flowing in the forward direction.

Hereinafter, a modified example of the embodiment will be described.
In the above-described embodiment, the rated voltages of the first transistor SW1 and the second transistor SW2 are matched within a predetermined range, but the voltage is not limited to this.
The rated voltage of either the first transistor SW1 or the second transistor SW2 is set lower than the output voltage VB of the battery 11, and the rated voltage of the other is the rated voltage of one from the output voltage VB of the battery 11. May be set to the voltage obtained by subtracting.

In the above-described embodiment, the voltage conversion device 1 may include a charger inlet 31 connected via a stator winding 12a of the motor 12. The charger inlet 31 is connected to a charger for charging the battery 11.
FIG. 6 is a diagram showing a partial configuration of a vehicle 10 equipped with a voltage conversion device 1 according to a first modification of the embodiment of the present invention.
As shown in FIG. 6, the voltage conversion device 1 according to the first modification includes, for example, a capacitor C3 and a charger inlet 31. The capacitor C3 is connected, for example, between the neutral point 12b of the three-phase stator winding 12a connected by the star connection in the motor 12 and the negative electrode bus bar NV of the voltage converter 1. The charger inlet 31 is connected in parallel with the capacitor C3 between the neutral point 12b and the negative electrode bus bar NV.

When the voltage converter 1 according to the first modification transforms the output voltage of the charger connected to the charger inlet 31 to charge the battery 11, the stator of at least one of the three phases of the motor 12 is a stator. The high-side arm and low-side arm transistors of the power module 13 corresponding to the winding 12a are simultaneously turned on / off. As a result, the voltage conversion device 1 charges the battery 11 by boosting the voltage supplied to the charger inlet 31 by the boosting action of the inductance of the stator winding 12a while suppressing the rotation of the motor 12.
According to the first modification, the voltage input from the charger inlet 31 can be boosted by using the stator winding 12a of the motor 12 and the power module 13, and the charger connected to the charger inlet 31 can be boosted. The battery 11 can be charged at a voltage equal to or higher than the rated voltage.

In the first modification described above, the inductance of the stator winding 12a of at least one of the three phases of the motor 12 is used, but the present invention is not limited to this. When a parking brake or a clutch is provided as a mechanism for suppressing the transmission of the rotational power of the motor 12 to the drive wheels or the like, for example, the stator winding 12a having only one of the three phases of the motor 12 Inductance of may be used. In this case, when the voltage converter 1 boosts the output voltage of the charger connected to the charger inlet 31 to charge the battery 11, the stator winding 12a of any one of the three phases of the motor 12 is used. The high side arm and low side arm transistors of the corresponding power module 13 are driven on / off at the same time.

In the first modification of the above-described embodiment, the voltage conversion device 1 may further include a pair of switching elements.
FIG. 7 is a diagram showing a partial configuration of a vehicle 10 equipped with a voltage conversion device 1 according to a second modification of the embodiment of the present invention.
As shown in FIG. 7, the voltage conversion device 1 according to the second modification includes, for example, a pair of high-side arm transistors SW3 and low-side arm transistors SW4. The high side arm transistor SW3 and the low side arm transistor SW4 are connected in series. The emitter of the high-side arm transistor SW3 and the collector of the low-side arm transistor SW4 are connected to, for example, the neutral point 12b of the three-phase stator winding 12a connected by the star connection in the motor 12. A capacitor C3 is connected between the collector of the high sidearm transistor SW3 and the emitter of the low sidearm transistor SW4. The charger inlet 31 is connected in parallel with the capacitor C3 between the collector of the high sidearm transistor SW3 and the emitter of the low sidearm transistor SW4. The emitter of the low side arm transistor SW4 is connected to the negative electrode bus bar NV of the voltage converter 1.
The voltage conversion device 1 according to the second modification is provided with a mechanism for suppressing the transmission of the rotational power of the motor 12 to the drive wheels and the like, and the stator has only one of the three phases of the motor 12. The inductance of the winding 12a is used to step down the output voltage of the charger connected to the charger inlet 31 to charge the battery 11.

In the above-described embodiment, the first capacitor C1a and the second capacitor C1b and the smoothing capacitor C2 may form, for example, a capacitor unit including a common positive electrode bus bar and negative electrode bus bar.
In the above-described embodiment, the voltage conversion device 1 is mounted on the vehicle 10, but the present invention is not limited to this, and the voltage conversion device 1 may be mounted on other devices.

The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention as well as the invention described in the claims and the equivalent scope thereof.

1 ... Voltage converter, 10 ... Vehicle, 11 ... Battery (power supply, power storage device), 12 ... Motor, 13 ... Power module (power converter), 15 ... Electronic control unit (control unit), 16 ... Gate drive unit, 21 ... 1st reactor, 22 ... 2nd reactor, 23 ... 1st diode, 24 ... 2nd diode, 25 ... 1st load, 26 ... 2nd load, 31 ... Charger inlet, MV ... Intermediate terminal, NB ... Negative terminal , PB ... Positive electrode terminal, SW1 ... 1st transistor (upper arm element), SW2 ... 2nd transistor (lower arm element)

Claims (7)

The upper arm element connected to the positive electrode terminal of the power supply and
The lower arm element connected to the negative electrode terminal of the power supply and
An intermediate terminal between the positive electrode terminal and the negative electrode terminal, and a first reactor connected between the upper arm element.
A second reactor connected between the intermediate terminal and the lower arm element,
A control unit that controls switching between the upper arm element and the lower arm element,
To prepare
A voltage converter characterized by that. A first diode connected in parallel with the first reactor between the intermediate terminal and the upper arm element,
A second diode connected in parallel with the second reactor between the intermediate terminal and the lower arm element,
To prepare
The voltage conversion device according to claim 1. The control unit
By controlling the switching of the upper arm element and the lower arm element, the voltage output from the intermediate terminal is maintained at a predetermined value.
The voltage conversion device according to claim 1 or 2, wherein the voltage conversion device is characterized by the above. The rated voltage of the upper arm element and the rated voltage of the lower arm element are lower than the voltage applied between the positive electrode terminal and the negative electrode terminal.
The voltage conversion device according to any one of claims 1 to 3, wherein the voltage conversion device is characterized by the above. The difference between the rated voltage of the upper arm element and the rated voltage of the lower arm element is within a predetermined range.
The voltage conversion device according to claim 4. A first load connected between the positive electrode terminal and the intermediate terminal,
A second load connected between the intermediate terminal and the negative electrode terminal,
With
The difference between the power consumption of the first load and the power consumption of the second load is within a predetermined range.
The voltage conversion device according to any one of claims 1 to 5, wherein the voltage conversion device is characterized by the above. A power storage device connected to the positive electrode terminal and the negative electrode terminal,
With the motor
A power converter that transfers power to and from the motor,
With the charger inlet connected via the stator winding of the motor,
The voltage conversion device according to any one of claims 1 to 6, wherein the voltage conversion device is provided.

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