WO2023022107A1

WO2023022107A1 - Power conversion apparatus

Info

Publication number: WO2023022107A1
Application number: PCT/JP2022/030750
Authority: WO
Inventors: セルゲイモイセエフ
Original assignee: 株式会社豊田自動織機
Priority date: 2021-08-20
Filing date: 2022-08-12
Publication date: 2023-02-23
Also published as: JP7563334B2; JP2023029109A

Abstract

According to the present invention, when a reverse voltage (Vd) is to be generated by a change in a first applied electric current (Id1), a first driver circuit (12a) outputs an added voltage obtained by adding a first external commanded voltage and a first feedback voltage to a first switching element (11a), and a second driver circuit (12b) outputs an added voltage obtained by adding a second external commanded voltage and a second feedback voltage to a second switching element (11b). When a reverse voltage (Vd) is to be generated by a change in a second applied electric current (Id2), the first driver circuit (12a) outputs an added voltage obtained by adding the first external commanded voltage and the second feedback voltage to the first switching element (11a), and the second driver circuit (12b) outputs an added voltage obtained by adding the second external commanded voltage and the first feedback voltage to the second switching element (11b).

Description

power converter

The present disclosure relates to power converters.

Patent Document 1 discloses a driver circuit that drives an IGBT (Insulated Gate Bipolar Transistor), which is a switching element. The driver circuit disclosed in Patent Document 1 performs active gate control that feeds back the back electromotive voltage generated by the inductance component of the emitter wiring in order to achieve both reduction of switching loss and reduction of surge voltage or surge current. ing.

JP-A-2004-48843

Here, when performing active gate control, the inductance component must have an inductance value that can generate at least a level of reverse voltage that can be used for active gate control.

In a power conversion device having a plurality of switching elements connected in series with each other, if an inductance component having an inductance value capable of generating a reverse voltage of a level that can be used for active gate control is provided for each switching element, the wiring inductance As a result, the surge voltage and surge current may increase, and the device may become larger.

A power conversion device according to an aspect of the present disclosure is a power conversion device having an inductance component, a first switching element through which a first applied current flows, and a first switching element connected in series to each other, and a second application a second switching element through which a current flows; and configured to convert back electromotive force generated in the inductance component in accordance with a change in the first applied current or a change in the second applied current into a first feedback voltage. a first feedback circuit; a second feedback circuit configured to convert an input voltage to a second feedback voltage; and the first applied current and the second applied current flowing through the second feedback circuit. and a current suppression unit configured to output a voltage based on the back electromotive voltage to the second feedback circuit; and a first external command voltage to drive the first switching element. and a second driver circuit configured to drive the second switching element on the basis of a second external command voltage, wherein the inductance component is the value of the first applied current. When the back electromotive voltage is generated by a change, the first driver circuit obtains an added voltage by adding the first external command voltage and the first feedback voltage, and converts the added voltage to the The second driver circuit obtains an added voltage by adding the second external command voltage and the second feedback voltage, and outputs the added voltage to the second external command voltage. When the inductance component generates the back electromotive force by a change in the second applied current, the first driver circuit outputs the first external command voltage and the second and a feedback voltage to obtain an added voltage and output the added voltage to the first switching element, wherein the second driver circuit includes the second external command voltage and the first A feedback voltage is added to obtain an added voltage, and the added voltage is output to the second switching element.

It is a figure which shows an example of a structure of a power converter device. 2 is a diagram showing details of various connections of the power converter of FIG. 1; FIG. FIG. 10 is a diagram showing another example of various connections; It is a figure which shows an example of a differential amplifier circuit. FIG. 10 is a diagram showing another example of a differential amplifier circuit;

<Embodiment>
[Configuration of power converter 10]
An embodiment of the power converter will be described below. The power conversion device 10 of the present embodiment is mounted on, for example, a vehicle 200 and used to drive an electric motor 201 provided on the vehicle 200 .

Specifically, the electric motor 201 of this embodiment is a running motor for rotating the wheels of the vehicle 200 . The electric motor 201 of this embodiment has three-

phase coils

202u, 202v, and 202w. The three-

phase coils

202u, 202v, and 202w are Y-connected, for example. The electric motor 201 rotates by energizing the three-

phase coils

202u, 202v, and 202w in a predetermined pattern. The connection mode of the three-

phase coils

202u, 202v, and 202w is not limited to Y-connection, and may be delta-connection, for example.

As shown in FIG. 1, vehicle 200 has power storage device 203 . The power conversion device 10 of this embodiment is an inverter device that converts the DC power of the power storage device 203 into AC power that can drive the electric motor 201 . The power conversion device 10 can also be said to be a drive device that drives the electric motor 201 using the power storage device 203 .

The power converter 10 of the present embodiment has configurations related to the three-

phase coils

202u, 202v, and 202w of the electric motor 201, respectively. In the following description, among the various configurations included in the power conversion device 10, the reference numerals for the configurations related to the upper arm are appended with "a", and the reference numerals for the configuration concerning the lower arm are appended with "b". . Further, among the various configurations provided in the power conversion device 10, "u" is added to the end of the reference numerals for the u-phase, "v" is added to the end of the reference numerals for the v-phase, and "v" is attached to the end of the reference numerals for the w-phase. will be described by adding "w" to the end of the reference numerals.

The power converter 10 of this embodiment has a plurality of switching elements 11 . Specifically, the power converter 10 includes an upper arm switching element 11au and a lower arm switching element 11bu corresponding to the u-phase coil 202u, an upper arm switching element 11av and a lower arm switching element 11bv corresponding to the v-phase coil 202v. , an upper arm switching element 11aw and a lower arm switching element 11bw corresponding to the w-phase coil 202w.

In the following description, when the upper arm switching element 11au, upper arm switching element 11av, and upper arm switching element 11aw are not distinguished from each other, they are simply referred to as "upper arm switching element 11a". When the lower arm switching element 11bu, the lower arm switching element 11bv, and the lower arm switching element 11bw are not distinguished from each other, they are simply referred to as "lower arm switching element 11b". The upper arm switching element 11a is an example of a "first switching element". The lower arm switching element 11b is an example of a "second switching element".

Each switching element 11 is, for example, a power switching element, and one example is a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The switching element 11 has a free wheel diode D. Specifically, the upper arm switching element 11au has a freewheeling diode Dau, the upper arm switching element 11av has a freewheeling diode Dav, and the upper arm switching element 11aw has a freewheeling diode Daw. The lower arm switching element 11bu has a freewheeling diode Dbu, the lower arm switching element 11bv has a freewheeling diode Dbv, and the lower arm switching element 11bw has a freewheeling diode Dbw. The anode of the freewheeling diode D is connected to the source terminal of the switching element 11 . A cathode of the freewheeling diode D is connected to a drain terminal of the switching element 11 .

The upper arm switching element 11a and the lower arm switching element 11b are connected in series with each other. Specifically, the source terminal of the upper arm switching element 11au and the drain terminal of the lower arm switching element 11bu are connected via intermediate wirings LC1u and LC2u. The intermediate wiring LC1u and the intermediate wiring LC2u each have a first end and a second end. A first end of the intermediate wiring LC1u is connected to the source terminal of the upper arm switching element 11au. A second end of the intermediate wiring LC2u is connected to the drain terminal of the lower arm switching element 11bu. Intermediate wiring LC3u connected to u-phase coil 202u is connected to intermediate wiring LC2u. A source terminal of the upper arm switching element 11av and a drain terminal of the lower arm switching element 11bv are connected via intermediate wirings LC1v and LC2v. The intermediate line LC1v and the intermediate line LC2v each have a first end and a second end. A first end of the intermediate wiring LC1v is connected to the source terminal of the upper arm switching element 11av. A second end of the intermediate line LC1v and a first end of the intermediate line LC2v are connected. A second end of the intermediate wiring LC2v is connected to the drain terminal of the lower arm switching element 11bv. A connection point between the intermediate wires LC1v and LC2v and the v-phase coil 202v are connected by an intermediate wire LC3v. A source terminal of the upper arm switching element 11aw and a drain terminal of the lower arm switching element 11bw are connected via intermediate wirings LC1w and LC2w. The intermediate wiring LC1w and the intermediate wiring LC2w each have a first end and a second end. A first end of the intermediate wiring LC1w is connected to the source terminal of the upper arm switching element 11aw. A second end of the intermediate wiring LC1w and a first end of the intermediate wiring LC2w are connected. A second end of the intermediate wiring LC2w and a drain terminal of the lower arm switching element 11bw are connected. A connection point between the intermediate wires LC1w and LC2w and the w-phase coil 202w are connected by an intermediate wire LC3w.

In the following description, when the intermediate wiring LC1u, the intermediate wiring LC1v, and the intermediate wiring LC1w are not distinguished from each other, they are simply referred to as "the intermediate wiring LC1." Further, when the intermediate wiring LC2u, the intermediate wiring LC2v, and the intermediate wiring LC2w are not distinguished from each other, they are simply referred to as "the intermediate wiring LC2." Further, when the intermediate wiring LC3u, the intermediate wiring LC3v, and the intermediate wiring LC3w are not distinguished from each other, they are simply referred to as "the intermediate wiring LC3."

The drain terminal of the upper arm switching element 11a is connected to the positive electrode bus LN1. A source terminal of the lower arm switching element 11b is connected to the negative bus line LN2. Positive electrode bus LN1 is connected to a positive electrode terminal (+terminal), which is a high-voltage side terminal of power storage device 203 . Negative bus line LN2 is connected to a negative terminal (− terminal), which is a low-voltage terminal of power storage device 203 . As a result, the DC voltage Vdc of power storage device 203 is applied to the series connection body including upper arm switching element 11a and lower arm switching element 11b.

The power converter 10 includes a driver circuit 12 that drives the switching element 11 . The driver circuit 12 of this embodiment is a so-called gate driver circuit. The power converter 10 of this embodiment has a plurality of driver circuits 12 corresponding to the plurality of switching elements 11 respectively. Specifically, the power converter 10 has a driver circuit 12au corresponding to the upper arm switching element 11au. The power converter 10 has a driver circuit 12bu corresponding to the lower arm switching element 11bu. The power converter 10 has a driver circuit 12av corresponding to the upper arm switching element 11av. The power converter 10 has a driver circuit 12bv corresponding to the lower arm switching element 11bv. The power converter 10 has a driver circuit 12aw corresponding to the upper arm switching element 11aw. The power converter 10 has a driver circuit 12bw corresponding to the lower arm switching element 11bw. In the following description, when the driver circuits 12au, 12av, and 12aw are not distinguished from each other, they are simply described as "upper arm driver circuit 12a." Further, when the driver circuits 12bu, 12bv, and 12bw are not distinguished from each other, they are simply referred to as "lower arm driver circuit 12b". The upper arm driver circuit 12a is an example of a "first driver circuit", and the lower arm driver circuit 12b is an example of a "second driver circuit".

The power conversion device 10 includes a conversion control device 14 that controls each driver circuit 12 . The conversion control device 14 of this embodiment is an inverter control device. The conversion control device 14 determines a target current to flow through the electric motor 201 based on an external command (for example, a required rotation speed), and derives an external command voltage for the target current to flow. The conversion control device 14 then outputs the external command voltage to the driver circuit 12 .

In this embodiment, the conversion control device 14 derives an external command voltage for each driver circuit 12 and outputs the external command voltage to each driver circuit 12 . Thereby, the switching elements 11 are individually controlled. In the following description, the external command voltage output by the conversion control device 14 to the upper arm driver circuit 12a is also referred to as "first external command voltage", and the external command voltage output by the conversion control device 14 to the lower arm driver circuit 12b. is also referred to as "second external command voltage".

The power conversion device 10 includes a first feedback circuit 15 that feedback-controls the upper arm switching element 11a and an inductance component 16 for each phase. Specifically, the power converter 10 includes

first feedback circuits

15u, 15v, 15w and

inductance components

16u, 16v, 16w. In the following description, when the

first feedback circuits

15u, 15v, and 15w are not distinguished from each other, they are simply referred to as "first feedback circuit 15," and when the

inductance components

16u, 16v, and 16w are not distinguished from each other, they are simply referred to as "inductance component 16." ”.

The inductance component 16 generates a back electromotive voltage in response to changes in the applied current flowing through the switching element 11, and has an inductance value that can generate at least a level of reverse voltage that can be used for feedback control. ing. In this embodiment, the inductance component 16 is an inductance component of an inductor.

The power conversion device 10 also includes a current suppressor 17 and a second feedback circuit 18 that feedback-controls the lower arm switching element 11b for each phase. The current suppression unit 17 includes, for example, an inductor 19 magnetically coupled to the inductance component 16 and connection lines LJ3 and LJ4 that connect the inductor 19 to the second feedback circuit 18 . In the inductor 19 , an electromotive voltage Vd′ is generated by a back electromotive voltage Vd generated by a change in the applied current flowing through the inductance component 16 . An electromotive voltage Vd' generated in the inductor 19 is output to the second feedback circuit 18 via the connection lines LJ3 and LJ4. Details of the connection lines LJ3 and LJ4 that connect the inductor 19 to the second feedback circuit 18 will be described later.

The electromotive voltage Vd' generated in the inductor 19 is input to the second feedback circuit 18. The second feedback circuit 18 converts the input electromotive voltage Vd' into a second feedback voltage and outputs the second feedback voltage to the lower arm driver circuit 12b. Specifically, the power converter 10 includes current suppression units 17u, 17v, and 17w. The current suppressor 17u includes an inductor 19u. The current suppressor 17v includes an inductor 19v. The current suppressor 17w includes an inductor 19w. The power converter 10 also includes

second feedback circuits

18u, 18v, and 18w. In the following description, when the current suppressing units 17u, 17v, and 17w are not distinguished from each other, they are simply referred to as "current suppressing unit 17". Moreover, when the

second feedback circuits

18u, 18v, and 18w are not distinguished from each other, they are simply referred to as "the second feedback circuit 18". Moreover, when the

inductors

19u, 19v, and 19w are not distinguished from each other, they are simply referred to as "inductor 19".

[Details of various connections]
Details of connection of the upper arm driver circuit 12a, the lower arm driver circuit 12b, the first feedback circuit 15, the inductance component 16, the current suppressor 17, and the second feedback circuit 18 will be described below with reference to FIG. Since these connections are the same for each phase, the following description will omit the reference numerals at the end corresponding to each phase.

As shown in FIG. 2, the upper arm switching element 11a is a switching element through which the first drain current Id1 flows when in the ON state. The first drain current Id1 is a current flowing between the source and drain of the upper arm switching element 11a. The upper arm switching element 11a includes a gate terminal to which a gate voltage is input, and a drain terminal and a source terminal through which a first drain current Id1 flows when in the ON state.

Also, the lower arm switching element 11b is a switching element through which the second drain current Id2 flows when it is in the ON state. The second drain current Id2 is a current flowing between the source and drain of the lower arm switching element 11b. The lower arm switching element 11b has a gate terminal to which a gate voltage is input, and a drain terminal and a source terminal through which the second drain current Id2 flows when in the ON state.

The upper arm driver circuit 12a and the gate terminal of the upper arm switching element 11a are connected. The upper arm driver circuit 12a outputs a gate voltage to the upper arm switching element 11a based on the first external command voltage to control the upper arm switching element 11a to the ON state or the OFF state. Also, the lower arm driver circuit 12b and the gate terminal of the lower arm switching element 11b are connected. The lower arm driver circuit 12b outputs a gate voltage to the lower arm switching element 11b based on the second external command voltage to control the lower arm switching element 11b to the ON state or the OFF state.

The first feedback circuit 15 and the inductance component 16 are connected. The first feedback circuit 15 has a pair of input terminals and the inductance component 16 has a pair of connection terminals. Specifically, the first feedback circuit 15 has a first input terminal tc1 and a second input terminal tc2. Also, the inductance component 16 has a first connection terminal t1 and a second connection terminal t2. The first input terminal tc1 and the first connection terminal t1 are connected by a connection line LJ1. Also, the second input terminal tc2 and the second connection terminal t2 are connected by a connection line LJ2.

The inductance component 16 is provided between the upper arm switching element 11a and the lower arm switching element 11b so that the first drain current Id1 flows through the inductance component 16. Specifically, the first connection terminal t1 of the inductance component 16 is connected to the source terminal of the upper arm switching element 11a via the first intermediate wiring LC1, and the second connection terminal t2 of the inductance component 16 is connected to the second intermediate wiring LC2. to the drain terminal of the lower arm switching element 11b. The third intermediate wiring LC3 connected to any one of the three-

phase coils

202u, 202v, and 202w is connected to the second intermediate wiring LC2.

The inductance component 16 of this embodiment generates a back electromotive voltage Vd across the connection terminals t1 and t2 according to the change in the first drain current Id1. The change in the first drain current Id1 includes the case where the first drain current Id1 starts flowing through the inductance component 16 and the case where the first drain current Id1 flowing through the inductance component 16 stops. The back electromotive voltage Vd is generated in a direction in which the potential of the first connection terminal t1 becomes higher than the potential of the second connection terminal t2. The first drain current Id1 is an example of the "first applied current".

The input terminals tc1 and tc2 of the first feedback circuit 15 receive the back electromotive voltage Vd generated by the inductance component 16 due to the change in the first drain current Id1. The first feedback circuit 15 and the upper arm driver circuit 12a are connected. The first feedback circuit 15 converts the back electromotive voltage Vd into a first feedback voltage and outputs it to the upper arm driver circuit 12a.

Note that the first feedback circuit 15 may be composed only of wiring. In this case, the first feedback circuit 15 converts the back electromotive voltage Vd into a voltage slightly lower than the back electromotive voltage Vd due to wiring resistance or the like, and outputs the voltage to the upper arm driver circuit 12a.

The upper arm driver circuit 12a of the present embodiment obtains an added voltage by adding the first external command voltage and the first feedback voltage, and outputs the added voltage as a gate voltage to the upper arm switching element 11a. .

Also, the second feedback circuit 18 and the inductor 19 are connected. The second feedback circuit 18 has a pair of input terminals and the inductor 19 has a pair of connection terminals. Specifically, the second feedback circuit 18 has a first input terminal td1 and a second input terminal td2. The inductor 19 also has a first connection terminal t3 and a second connection terminal t4. The first input terminal td1 and the first connection terminal t3 are connected by a connection line LJ3. Also, the second input terminal td2 and the second connection terminal t4 are connected by a connection line LJ4.

In this embodiment, the inductor 19 of the current suppressing section 17 is magnetically coupled with the inductance component 16 as described above. The inductance component 16 and inductor 19 function as an isolation transformer. Therefore, the first drain current Id1 flowing through the inductance component 16 does not flow into the second feedback circuit 18. FIG. That is, it can be said that the current suppression unit 17 blocks the flow of the first drain current Id1 to the second feedback circuit 18 and suppresses the flow of the first drain current Id1 to the second feedback circuit 18 . Also, the inductor 19 generates an electromotive voltage Vd' by the back electromotive voltage Vd generated by the inductance component 16 . The electromotive voltage Vd' is output to the second feedback circuit 18 through connection lines LJ3 and LJ4. That is, it can be said that the current suppression unit 17 outputs a voltage based on the back electromotive force (electromotive voltage Vd′ in the present embodiment) to the second feedback circuit 18 . Note that the electromotive voltage Vd' is generated, for example, in a direction in which the potential of the first connection terminal t3 becomes higher than the potential of the second connection terminal t4.

The number of turns of the inductor 19 in this embodiment is set so that the inductor 19 outputs to the second feedback circuit 18 an electromotive voltage Vd' having a voltage value different from the counter electromotive voltage Vd. can't The number of turns of the inductor 19 may be set such that the inductor 19 outputs to the second feedback circuit 18 an electromotive voltage having the same voltage value as the counter electromotive voltage Vd.

The input terminals tc1 and tc2 of the second feedback circuit 18 receive the electromotive voltage Vd'. The second feedback circuit 18 and the lower arm driver circuit 12b are connected. The second feedback circuit 18 converts the input electromotive voltage Vd' into a second feedback voltage and outputs the second feedback voltage to the lower arm driver circuit 12b. Here, the second feedback voltage may have the same voltage value as the first feedback voltage, or may have a different voltage value.

It should be noted that the second feedback circuit 18 may be composed only of wiring. In this case, the inductor 19 converts the counter electromotive voltage Vd into a voltage slightly higher than the second feedback voltage and outputs it to the second feedback circuit 18 . The second feedback circuit 18 converts a voltage slightly higher than the input second feedback voltage into a second feedback voltage by wiring resistance or the like, and outputs the second feedback voltage to the lower arm driver circuit 12b.

The lower arm driver circuit 12b of this embodiment adds the second external command voltage and the second feedback voltage, and outputs the added voltage as the gate voltage to the lower arm switching element 11b.

[Effect of power conversion device 10]
(1) In the power converter 10, the first feedback circuit 15 converts the back electromotive voltage Vd generated by the inductance component 16 into a first feedback voltage. The current suppressing unit 17 suppresses (more specifically, cuts off) the first drain current Id1 from flowing to the second feedback circuit 18, and suppresses the voltage based on the counter electromotive voltage Vd (electromotive voltage Vd′ in the present embodiment). is output to the second feedback circuit 18 . The second feedback circuit 18 converts the input electromotive voltage Vd' into a second feedback voltage. The upper arm driver circuit 12a obtains an added voltage by adding the first external command voltage and the first feedback voltage, and outputs the added voltage to the upper arm switching element 11a. The lower arm driver circuit 12b obtains an added voltage by adding the second external command voltage and the second feedback voltage, and outputs the added voltage to the lower arm driver circuit 12b.

The feedback control of the first feedback circuit 15 and the feedback control of the second feedback circuit 18 are synchronized. For example, as the first drain current Id1 changes, the first feedback circuit 15 may perform feedback control to lower the gate voltage of the upper arm switching element 11a by a predetermined voltage for a predetermined period. In this case, the second feedback circuit 18 preferably lowers the gate voltage of the lower arm switching element 11b by a predetermined voltage for a predetermined period at the same timing as the first feedback circuit 15 as feedback control. Further, the first feedback circuit 15 may perform feedback control such that the gate voltage of the upper arm switching element 11a is increased by a predetermined voltage for a predetermined period. In this case, it is preferable that the second feedback circuit 18 raises the gate voltage of the lower arm switching element 11b by a predetermined voltage for a predetermined period at the same timing as the first feedback circuit 15 as feedback control.

On the other hand, if the first drain current Id1 is input to the second feedback circuit 18 without being suppressed, the second feedback circuit 18 may be damaged. In the power conversion device 10 of this embodiment, the first feedback circuit 15 converts the back electromotive voltage Vd generated by the inductance component 16 into a first feedback voltage. Further, the current suppressing unit 17 outputs the electromotive voltage Vd' generated in the inductor 19 magnetically coupled with the inductance component 16 to the second feedback circuit 18, and the second feedback circuit 18 outputs the input electromotive voltage Vd'. Convert to a second feedback voltage. As a result, the power converter 10 uses the common inductance component 16 to synchronize the upper arm switching element 11a and the lower arm switching element 11b that are connected in series with each other based on changes in the back electromotive force Vd. feedback control can be performed.

In addition, the upper arm switching element 11a has an inductance component having an inductance value that generates a reverse voltage level that can be used for feedback control, and the lower arm switching element 11b has an inductance value that generates a reverse voltage level that can be used for feedback control. The wiring inductance of the power conversion device 10 can be reduced as compared with the case where the power conversion device 10 includes an inductance component and an inductance component. Therefore, the power conversion device 10 can achieve both reduction of switching loss and reduction of surge voltage or surge current as compared with the case where each switching element 11 has an inductance component.

(2) An inductance component having an inductance value that generates a reverse voltage level that can be used for feedback control in the upper arm switching element 11a, and an inductance value that generates a reverse voltage level that can be used for feedback control in the lower arm switching element 11b. The power conversion device 10 can be downsized as compared with the case where the power conversion device 10 includes each of the inductance components.

Each of the above embodiments may be modified as follows. Note that the above embodiment and each of the following examples may be combined with each other within a technically consistent range.
○In the above-described embodiment, the case where the inductance component 16 generates the back electromotive voltage Vd due to the change in the first drain current Id1 has been described, but the present invention is not limited to this. The inductance component 16 may, for example, generate a back electromotive force Vd by changing the second drain current Id2.

As shown in FIG. 3, in this case, the first connection terminal t1 of the inductance component 16 is connected to the source terminal of the lower arm switching element 11b. A second connection terminal t2 of the inductance component 16 is connected to the negative electrode bus LN2. The inductance component 16 generates a back electromotive voltage Vd across the connection terminals t1 and t2 according to the change in the second drain current Id2. The change in the second drain current Id2 includes the case where the second drain current Id2 starts flowing through the inductance component 16 and the case where the second drain current Id2 flowing through the inductance component 16 stops. The second drain current Id2 is an example of the "second applied current".

Also, in this case, the lower arm driver circuit 12 b is connected to the first feedback circuit 15 . The upper arm driver circuit 12 a is connected to the second feedback circuit 18 and the current suppressing section 17 . The upper arm driver circuit 12a obtains an added voltage by adding the first external command voltage and the second feedback voltage, and outputs the added voltage as a gate voltage to the upper arm switching element 11a. Further, the lower arm driver circuit 12b obtains an added voltage by adding the second external command voltage and the first feedback voltage, and outputs the added voltage to the lower arm driver circuit 12b. According to such a configuration, the power converter 10 can obtain the same effects as (1) and (2).

O Although the said embodiment demonstrated the case where the current suppression part 17 was equipped with the inductor 19, it is not restricted to this. The current suppressor 17 may include a differential amplifier circuit 20 .
As shown in FIG. 4, the differential amplifier circuit 20 has a pair of input terminals. Specifically, the differential amplifier circuit 20 has a first input terminal te1 and a second input terminal te2. The first input terminal te1 is connected to the first connection terminal t1. The second input terminal te2 is connected to the second connection terminal t2. The differential amplifier circuit 20 includes

voltage dividing resistors

21 , 22 , 23 and 24 and an operational amplifier 25 . The

voltage dividing resistors

21 and 22 are connected in series with each other. The

voltage dividing resistors

23 and 24 are connected in series with each other. The voltage dividing resistor 23 has a first end connected to the voltage dividing resistor 24 and a second end connected to the first input terminal te1. Also, the voltage dividing resistor 21 has a first end connected to the voltage dividing resistor 22 and a second end connected to the second input terminal te2. Voltage dividing resistor 22 has a first end connected to voltage dividing resistor 21 and a second end connected to voltage dividing resistor 24 . Voltage dividing resistor 24 has a first end connected to voltage dividing resistor 23 and a second end connected to voltage dividing resistor 22 . A connection point between the voltage dividing resistor 22 and the voltage dividing resistor 24 is connected to the second input terminal td2.

A connection point between the voltage dividing resistor 21 and the voltage dividing resistor 22 is connected to the + terminal of the operational amplifier 25 . A connection point between the

voltage dividing resistors

23 and 24 is connected to the negative terminal of the operational amplifier 25 . An output terminal of the operational amplifier 25 is connected to the first input terminal td1.

With this configuration, the back electromotive voltage Vd is input to the pair of input terminals te1 and te2 of the differential amplifier circuit 20, and the differential amplifier circuit 20 amplifies the voltage Vd between the pair of input terminals te1 and te2. '' is output from the output terminal. Here, the resistance values of the

voltage dividing resistors

21 and 23 match, and the resistance values of the

voltage dividing resistors

22 and 24 match. That is, the voltage dividing ratio of the

voltage dividing resistors

21 and 22 and the voltage dividing ratio of the

voltage dividing resistors

23 and 24 match.

The voltage dividing ratio of the

voltage dividing resistors

21 and 22, the voltage dividing ratio of the

voltage dividing resistors

23 and 24, and the operational amplifier 25 amplification factor are the voltage Vd which is the potential difference between the output terminal of the operational amplifier 25 and the second input terminal td2. '' may be set to a voltage division ratio and amplification factor that match the back electromotive voltage Vd, or the potential Vd'' is set to a voltage division ratio and amplification factor that are different from the back electromotive voltage Vd. may have been

According to this configuration, the current suppressing section 17a suppresses the first drain current Id1 from flowing to the second feedback circuit 18, and suppresses the voltage based on the counter electromotive voltage Vd generated by the inductance component 16 (in this embodiment, the potential difference Vd″) to the second feedback circuit 18 . Thereby, the power converter 10 can obtain the same effect as (1).

In the example shown in FIG. 4, the inductance component 16 may generate the back electromotive voltage Vd by, for example, changing the second drain current Id2. In this case, the first connection terminal t1 of the inductance component 16 is connected to the source terminal of the lower arm switching element 11b. A second connection terminal t2 of the inductance component 16 is connected to the negative electrode bus LN2. Also, the upper arm driver circuit 12 a is connected to a current suppressor 17 a having a second feedback circuit 18 and a differential amplifier circuit 20 . The lower arm driver circuit 12b is connected to the first feedback circuit 15a. Since the operation of the power conversion device 10 in this configuration is the same as that of the above-described embodiment and modification, description thereof will be omitted.

(circle) the differential amplifier circuit 20 may be replaced with the differential amplifier circuit 20a which detects the back electromotive force Vd more accurately.
As shown in FIG. 5 , the differential amplifier circuit 20 a includes

voltage dividing resistors

21 , 22 , 23 , 24 , 28 and 29 and

operational amplifiers

26 , 27 and 30 . The connection of the

voltage dividing resistors

21, 22, 23, and 24 is the same as in the case of FIG. 4 described above, so the description is omitted.

A connection point between the voltage dividing resistor 21 and the voltage dividing resistor 22 is connected to the + terminal of the operational amplifier 27 . The - terminal of the operational amplifier 27 is connected to the output terminal of the operational amplifier 27 . A connection point between the

voltage dividing resistors

23 and 24 is connected to the + terminal of the operational amplifier 26 . The - terminal of the operational amplifier 26 is connected to the output terminal of the operational amplifier 26 . Thereby, the

operational amplifiers

26 and 27 operate as voltage follower circuits.

Also, the output terminal of the operational amplifier 26 is connected to the - terminal of the operational amplifier 30 . The output terminal of operational amplifier 27 is connected to the first end of voltage dividing resistor 28 . A second end of voltage dividing resistor 28 is connected to a first end of voltage dividing resistor 29 . A second end of the voltage dividing resistor 29 is connected to the second input terminal td2. That is, the voltage dividing resistor 28 and the voltage dividing resistor 29 are connected in series between the output terminal of the operational amplifier 27 and the second input terminal td2. A connection point between the

voltage dividing resistors

28 and 29 is connected to the + terminal of the operational amplifier 30 . An output terminal of the operational amplifier 30 is connected to the first input terminal td1.

With this configuration, the back electromotive voltage Vd is input to the pair of input terminals te1 and te2 of the differential amplifier circuit 20a, and the differential amplifier circuit 20a amplifies the voltage Vd between the pair of input terminals te1 and te2. ' is output from the output terminal.

The voltage dividing ratio of the

voltage dividing resistors

21 and 22, the voltage dividing ratio of the

voltage dividing resistors

23 and 24, the voltage dividing ratio of the

voltage dividing resistors

28 and 29, and the amplification factor of the operational amplifier 30 are determined by the output terminal of the operational amplifier 30 and the second input. The voltage division ratio and the amplification factor may be set so that the voltage Vd', which is the potential difference from the terminal td2, matches the back electromotive voltage Vd, or the voltage Vd' may be set to a voltage dividing ratio different from the back electromotive voltage Vd. It may be set to a pressure ratio and an amplification factor.

As described above, the

operational amplifiers

26 and 27 operate as voltage follower circuits. Therefore, no input bias voltage flows to the input terminals of the

operational amplifiers

26, 27 and 30. FIG. Therefore, the voltages input to the input terminals of the

operational amplifiers

26, 27 and 30 do not have an offset voltage drop due to the input bias current. Therefore, the differential amplifier circuit 20a can detect the back electromotive force Vd with higher accuracy than the differential amplifier circuit 20 can.

With this configuration, the differential amplifier circuit 20a can propagate the back electromotive voltage Vd to the operational amplifier 30 with higher accuracy. Thereby, the power converter 10 can obtain the same effect as (1).

Note that in the example shown in FIG. 5, the inductance component 16 may generate the back electromotive voltage Vd by, for example, a change in the second drain current Id2. In this case, the first connection terminal t1 of the inductance component 16 is connected to the source terminal of the lower arm switching element 11b. A second connection terminal t2 of the inductance component 16 is connected to the negative electrode bus LN2. Also, the upper arm driver circuit 12a is connected to a current suppression section 17b having a second feedback circuit 18 and a differential amplifier circuit 20a. The lower arm driver circuit 12b is connected to the first feedback circuit 15a. Since the operation of the power conversion device 10 in this configuration is the same as that of the above-described embodiment and modification, description thereof will be omitted.

○ The switching element 11 is not limited to a MOSFET, and may be an IGBT, for example. In this case, the gate terminal of the switching element 11 corresponds to the "control terminal". Also, the collector current flowing between the collector and the emitter of the upper arm switching element 11a corresponds to the "first applied current". Also, the collector current flowing between the collector and the emitter of the lower arm switching element 11b corresponds to the "second applied current".

When the inductance component 16 is provided between the upper arm switching element 11a and the lower arm switching element 11b, that is, when the first drain current Id1 flowing through the upper arm switching element 11a flows through the inductance component 16, the intermediate wiring LC3 is , to the portion between the ends of the inductance component 16 . Specifically, when the inductance component 16 is an inductor having the first connection terminal t1 and the second connection terminal t2 as in the above-described embodiment, the intermediate wiring LC3 has the first connection terminal t1 and the second connection terminal t2. connected to the part between When the inductance component 16 is a parasitic inductance, the intermediate wiring LC3 has a first end connected to the upper arm switching element 11a in the intermediate wiring LC1 and a second end connected to the lower arm switching element 11b in the intermediate wiring LC2. connected to the part between the ends.

Since it is necessary to connect the intermediate wiring LC to one of the three-

phase coils

202u, 202v, and 202w, it is necessary to separate the upper arm switching element 11a and the lower arm switching element 11b sufficiently apart. Therefore, the length of the intermediate wiring LC provided between the upper arm switching element 11a and the lower arm switching element 11b also increases. Therefore, by connecting the wiring connected to any one of the three-

phase coils

202u, 202v, and 202w among the intermediate wirings LC to the portion between both ends of the inductance component 16, the upper arm switching element 11a and the lower arm switching element 11a are connected. It is possible to suppress lengthening of the intermediate wiring LC provided between the element 11b.

○ The inductor 19 may generate an electromotive voltage Vd' having a polarity opposite to the back electromotive voltage Vd. In this case, the second feedback circuit 18 inverts and amplifies the electromotive voltage Vd′ and outputs it to the driver circuit 12 .

○The combination of the

voltage dividing resistors

21, 22, 23, 24, 28, 29, the amplification factor of the operational amplifier 25, and the amplification factor of the operational amplifier 30 affects the conversion loss, the driver circuit 12, the second feedback circuit 18, the

operational amplifiers

25, 26, 27, 30, etc., may be taken into account. Specifically, the combination of the

voltage dividing resistors

21, 22, 23, 24, 28, 29, the amplification factor of the operational amplifier 25, and the amplification factor of the operational amplifier 30 is the driver circuit 12, the second feedback circuit 18, the

operational amplifiers

25, 26, 27. , 30 may be an amplification factor for amplifying the back electromotive force Vd' so as to recover the voltage drop or the like.

○ Each switching element 11 constitutes an inverter, but it is not limited to this, and is optional. That is, the power conversion device 10 is not limited to an inverter, and may be any DC/DC converter, AC/AC converter, AC/DC inverter, or the like. In other words, the power converter 10 may convert DC power or AC power into DC power or AC power.

○ The load is not limited to the electric motor 201, but is arbitrary.
(circle) the power converter device 10 may be mounted in other than the vehicle 200. FIG. That is, the power conversion device 10 may drive a load other than the load provided on the vehicle 200 .

○ The inductance component 16 may be realized by the parasitic inductance of the wiring on which the inductance component 16 is provided. That is, the inductance component 16 may be a parasitic inductance component present in the wiring. In this case, the inductance component 16 has no connection terminals. According to such a configuration, the power conversion device 10 can be made smaller by using the parasitic inductance compared to the case where the inductance is provided separately.

o The first feedback circuit 15 and the second feedback circuit 18 may have the same configuration or different configurations.

Claims

A power conversion device having an inductance component,
a first switching element through which the first applied current flows;
a second switching element connected in series with the first switching element and through which a second applied current flows;
a first feedback circuit configured to convert back electromotive force generated in the inductance component into a first feedback voltage in accordance with a change in the first applied current or a change in the second applied current;
a second feedback circuit configured to convert the input voltage to a second feedback voltage;
a current suppressing unit configured to suppress the first applied current and the second applied current from flowing to the second feedback circuit, and to output a voltage based on the back electromotive force to the second feedback circuit; ,
a first driver circuit configured to drive the first switching element based on a first external command voltage;
a second driver circuit configured to drive the second switching element based on a second external command voltage;
When the inductance component generates the counter-electromotive voltage due to a change in the first applied current,
The first driver circuit is configured to obtain an added voltage by adding the first external command voltage and the first feedback voltage, and output the added voltage to the first switching element,
The second driver circuit is configured to obtain an added voltage by adding the second external command voltage and the second feedback voltage, and output the added voltage to the second switching element,
When the inductance component generates the counter-electromotive force due to a change in the second applied current,
The first driver circuit is configured to obtain an added voltage by adding the first external command voltage and the second feedback voltage, and output the added voltage to the first switching element,
The second driver circuit is configured to obtain an added voltage by adding the second external command voltage and the first feedback voltage, and output the added voltage to the second switching element. ,
Power converter.
The inductance component is realized by a parasitic inductance of wiring connected to the first switching element and/or the second switching element,
The power converter according to claim 1.
The current suppression unit includes an inductor magnetically coupled with the inductance component,
The inductor generates an electromotive voltage by the back electromotive voltage generated by the inductance component,
The second feedback circuit is configured to convert the electromotive voltage generated by the inductor into the second feedback voltage.
The power converter according to claim 1 or 2.
The current suppression unit includes a differential amplifier circuit having a pair of input terminals to which the back electromotive force is input,
The differential amplifier circuit is configured to amplify and output a potential difference between the pair of input terminals when the back electromotive voltage is input to the pair of input terminals,
The second feedback circuit is configured to convert the voltage output by the differential amplifier circuit into the second feedback voltage.
The power converter according to claim 1 or 2.