JP2022076710A - Power conversion device - Google Patents

Abstract

To provide a power conversion device in which both suppression of a surge and reduction of loss can be preferably achieved.SOLUTION: A power conversion device 10 includes a switching element 11, a driver circuit 12 that drives the switching element 11, a drive line LNx through which an inverter current Iv flows, and a first inductance component L1 disposed on the drive line LNx. The power conversion device 10 includes a ground wire LNy for connecting a source terminal of the switching element 11 and a reference potential V0' of the driver circuit 12, and a second inductance component L2 disposed on the ground wire LNy. The second inductance component L2 generates a negative feedback voltage Vfb when the inverter current Iv is increasing, and generates a positive feedback voltage Vfb when the inverter current Iv is decreasing.SELECTED DRAWING: Figure 3

Description

The present invention relates to a power conversion device.

For example, Patent Document 1 describes a driver circuit that drives an IGBT as a switching element. The driver circuit described in Patent Document 1 feeds back the induced voltage induced from the inductance component of the emitter wiring through which the collector current flows as the applied current in order to achieve both reduction of switching loss and reduction of surge voltage or surge current. Active gate control is performed. The induced voltage is induced by changing the collector current.

Japanese Unexamined Patent Publication No. 2004-48843

Here, there is still room for improvement in order to achieve both suppression of surge and reduction of loss.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power conversion device capable of suitably achieving both suppression of surge and reduction of loss.

The power conversion device that achieves the above object is a switching element having a control terminal, a first application terminal and a second application terminal through which an applied current flows, a driver circuit for driving the switching element, and a drive through which the applied current flows. To connect the line, the first inductance component provided on the drive line, the control line connecting the driver circuit and the control terminal, and the second application terminal and the reference potential of the driver circuit. The ground wiring includes a second inductance component provided on the ground wiring at a position where the magnetic flux generated from the first inductance component penetrates, and the second inductance component includes a case where the applied current increases. While generating a negative feedback voltage, a positive feedback voltage is generated when the applied current decreases, and the driver circuit is connected to the ground wiring and the feedback voltage is input to the driver circuit. By converting the feedback input terminal, the external input terminal into which the external command voltage is input, the conversion command voltage obtained by converting the external command voltage or the external command voltage, and the feedback voltage or the feedback voltage. It is characterized by including an adder circuit that adds the obtained conversion feedback voltage and outputs the added added voltage toward the control terminal.

According to such a configuration, the feedback voltage is generated from the second inductance component by changing the magnetic flux with the change of the drain current flowing through the first inductance component. Then, the feedback voltage or the conversion feedback voltage obtained by converting the feedback voltage is fed back to the adder circuit, and the added voltage is input to the control terminal. As a result, it is possible to suppress a surge at the time of turn-on or turn-off of the switching element.

In particular, according to this configuration, the feedback voltage becomes negative when the applied current increases, while it becomes positive when the applied current decreases. As a result, it is not necessary to invert the feedback voltage and input it to the adder circuit. Therefore, the configuration related to inversion can be omitted.

For the power conversion device, the inductance of the second inductance component may be larger than the inductance of the first inductance component.
According to such a configuration, the feedback voltage can be increased, so that the feedback effect can be improved.

For the power conversion device, the drive line has a first inductance portion provided with the first inductance component, the ground wiring is arranged next to the first inductance portion, and the second inductance component is provided. The second inductance portion has a second inductance portion provided with the above, and the second inductance portion has a direction toward the driver circuit from the second application terminal in the ground wiring and a direction of the applied current flowing through the first inductance portion. It is preferable that they extend along the first inductance portion so that they are the same.

According to this configuration, since the first inductance portion is arranged next to the second inductance portion, the separation distance between the two tends to be short. As a result, an interaction is likely to occur between the two inductance components. Therefore, the feedback voltage can be increased.

Further, since the second inductance portion extends along the first inductance portion so that the direction from the second application terminal in the ground wiring toward the driver circuit and the direction of the applied current flowing through the first inductance portion are the same. The feedback voltage becomes negative when the applied current increases, while it becomes positive when the applied current decreases. Thereby, the above-mentioned effect can be obtained with a relatively simple configuration.

The power conversion device may have an upper arm switching element and a lower arm switching element connected in series with each other by an intermediate wiring, and the switching element may be the lower arm switching element.

According to such a configuration, it is possible to preferably achieve both suppression of surge and reduction of loss in the lower arm switching element.
The power conversion device includes a capacitor, and the drive line includes a positive electrode bus to which the upper arm switching element is connected, a negative electrode bus to which the lower arm switching element is connected, an intermediate wiring, and a positive electrode bus. The second inductance component includes the first capacitor connecting wire connecting the capacitor and the second capacitor connecting wire connecting the negative electrode bus and the capacitor, and the second inductance component is the positive positive bus, the negative negative bus, and the intermediate. It is preferable that the capacitor is provided at a position where the magnetic flux generated from the parasitic inductance included in at least one of the wiring, the first capacitor connection line and the second capacitor connection line penetrates.

According to such a configuration, the feedback voltage can be generated by using the parasitic inductance contained in at least one of the positive electrode bus, the negative electrode bus, the intermediate wiring, the first capacitor connection line, and the second capacitor connection line.

According to the present invention, it is possible to preferably achieve both suppression of surge and reduction of loss.

A circuit diagram showing an outline of the electrical configuration of a power converter. The front view schematically shows the switching element, the driver circuit, the drive line, etc. mounted on the drive board. A circuit diagram schematically showing a switching element and a driver circuit. The graph which shows the inverter current, the source-drain voltage, the feedback voltage and the addition voltage at the time of turn-on under the condition that there is no feedback by a feedback voltage. A graph showing the inverter current, source-drain voltage, feedback voltage, and additional voltage at turn-on under certain conditions of feedback by the feedback voltage. The graph which shows the inverter current, the source-drain voltage, the feedback voltage and the addition voltage which the resistance value of a gate resistance was adjusted so that the surge equivalent to the case where there is no feedback occurs under the condition which there is feedback by a feedback voltage. The graph which shows the inverter current, the source-drain voltage, the feedback voltage and the addition voltage at the time of turn-off under the condition that there is no feedback by a feedback voltage. A graph showing the inverter current, source-drain voltage, feedback voltage, and additional voltage at turn-off under certain conditions of feedback by the feedback voltage. The graph which shows the inverter current, the source-drain voltage, the feedback voltage and the addition voltage which the resistance value of a gate resistance was adjusted so that the surge equivalent to the case where there is no feedback occurs under the condition which there is feedback by a feedback voltage.

Hereinafter, an embodiment of the power conversion device will be described. The following description shows an example of the power conversion device, and the power conversion device is not limited to the contents of the present embodiment.

The power conversion device 10 of the present embodiment is mounted on the vehicle 200, for example, and is used to drive the electric motor 201 provided on the vehicle 200.
The electric motor 201 of the present embodiment is a traveling motor for rotating the wheels of the vehicle 200. The electric motor 201 of this embodiment has three-phase coils 202u, 202v, 202w. The three-phase coils 202u, 202v, 202w are, for example, Y-connected. The electric motor 201 rotates when the three-phase coils 202u, 202v, 202w are energized in a predetermined pattern. The connection mode of the three-phase coils 202u, 202v, 202w is not limited to Y connection, and may be arbitrary, for example, delta connection.

As shown in FIG. 1, the vehicle 200 has a power storage device 203. The power conversion device 10 of the present embodiment includes input terminals 10a and 10b, and the power storage device 203 is connected to the input terminals 10a and 10b. Specifically, the first input terminal 10a is connected to the positive electrode terminal (+ terminal) on the high voltage side of the power storage device 203, and the second input terminal 10b is the negative electrode terminal (-) on the low voltage side of the power storage device 203. It is connected to the terminal). As a result, the DC power of the power storage device 203 is input to the power conversion device 10.

The power conversion device 10 is an inverter device that converts the DC power of the power storage device 203 input to the input terminals 10a and 10b into AC power that can be driven by the electric motor 201. In other words, the power conversion device 10 can be said to be a drive device for driving the electric motor 201 by using the power storage device 203. The voltage of the power storage device 203 is defined as the power supply voltage Vdc.

The power conversion device 10 has a positive electrode bus LN1 connected to the first input terminal 10a, a negative electrode bus LN2 connected to the second input terminal 10b, and a switching element 11. The positive electrode bus LN1 is connected to the positive electrode terminal of the power storage device 203 via the first input terminal 10a, and the negative electrode bus LN2 is connected to the negative electrode terminal of the power storage device 203 via the second input terminal 10b.

The power conversion device 10 of the present embodiment has a plurality of switching elements 11, and more specifically, u-phase switching elements 11u1 and 11u2 corresponding to the u-phase coil 202u and v-phase switching corresponding to the v-phase coil 202v. The elements 11v1, 11v2 and the w-phase switching elements 11w1, 11w2 corresponding to the w-phase coil 202w are provided.

Each switching element 11u1, 11u2, 11v1, 11v2, 11w1, 11w2 (hereinafter referred to as "each switching element 11u1 to 11w2") is, for example, a power switching element, and an example is a MOSFET. Each switching element 11u1 to 11w2 corresponds to a "switching element". The switching elements 11u1 to 11w2 have return diodes (body diodes) Du1 to Dw2.

The u-phase switching elements 11u1 and 11u2 are connected in series with each other. Specifically, the u-phase upper arm switching element 11u1 and the u-phase lower arm switching element 11u2 are connected via the u-phase intermediate wiring LNu, and the u-phase intermediate wiring LNu is connected to the u-phase coil 202u. .. The u-phase upper arm switching element 11u1 is connected to the positive electrode bus LN1, and the u-phase lower arm switching element 11u2 is connected to the negative electrode bus LN2. As a result, the DC power of the power storage device 203 is input to the series connection of the u-phase switching elements 11u1 and 11u2. The negative electrode bus LN2 is connected to the reference potential V0 via the second input terminal 10b.

The connection mode of the other switching elements 11v1, 11v2, 11w1, 11w2 is the same as that of the u-phase switching elements 11u1, 11u2, except that the corresponding coils are different. Specifically, the v-phase upper arm switching element 11v1 and the v-phase lower arm switching element 11v2 are connected via the v-phase intermediate wiring LNv, and the v-phase intermediate wiring LNv is connected to the v-phase coil 202v. .. The w-phase upper arm switching element 11w1 and the w-phase lower arm switching element 11w2 are connected via the w-phase intermediate wiring LNw, and the w-phase intermediate wiring LNw is connected to the w-phase coil 202w.

The power conversion device 10 of the present embodiment includes a capacitor C0, a first capacitor connection line LNc1 connecting the capacitor C0 and the positive electrode bus LN1, and a second capacitor connection line LNc2 connecting the capacitor C0 and the negative electrode bus LN2. It is equipped with. As a result, the capacitor C0 is connected to the power storage device 203 and also to the switching elements 11u1 to 11w2.

As shown in FIGS. 1 and 2, the power conversion device 10 includes a driver circuit 12 for driving the switching element 11 and a drive board 13 on which the switching element 11 is mounted. In this embodiment, the driver circuit 12 is mounted on the drive board 13. The drive board 13 of this embodiment is, for example, a multilayer board. However, the present invention is not limited to this, and the specific configuration of the drive board 13 is arbitrary.

The driver circuit 12 of this embodiment is a so-called gate driver circuit. The power conversion device 10 of the present embodiment has a plurality of driver circuits 12 corresponding to a plurality of switching elements 11. Specifically, the power conversion device 10 has a plurality of driver circuits 12u1 to 12w2 corresponding to the plurality of switching elements 11u1 to 11w2. The driver circuits 12u1 to 12w2 are connected to the gates of the switching elements 11u1 to 11w2, and the switching elements 11u1 to 11w2 are turned ON / OFF by controlling the gate voltage.

As shown in FIG. 1, the power conversion device 10 includes a conversion control device 14 that controls the driver circuit 12. The conversion control device 14 of the present embodiment is an inverter control device. The conversion control device 14 determines a target current flowing through the electric motor 201 based on an external command (for example, a required rotation speed), and derives an external command voltage Vp for the target current to flow. Then, the conversion control device 14 outputs the external command voltage Vp toward the driver circuit 12.

In the present embodiment, the conversion control device 14 derives the external command voltage Vp for each of the switching elements 11u1 to 11w2, and outputs the external command voltage Vp to each driver circuit 12u1 to 12w2. As a result, each switching element 11u1 to 11w2 is individually controlled.

The external command voltage Vp is a pulse voltage having a predetermined pulse width. For example, the external command voltage Vp switches from LOW to HI, maintains the HI state for a certain period of time, and then switches from HI to LOW. In the following description, the switching from LOW to HI is referred to as "rising", and the switching from HI to LOW is referred to as "falling".

The conversion control device 14 of the present embodiment is mounted on the drive board 13. However, the present invention is not limited to this, and the conversion control device 14 may be mounted on a board different from the drive board 13.

The driver circuits 12u1 to 12w2 apply a gate voltage to the switching elements 11u1 to 11w2 based on the external command voltage Vp individually input. As a result, the switching elements 11u1 to 11w2 are periodically turned ON / OFF, and the DC power of the power storage device 203 is converted into three-phase AC power and supplied to the electric motor 201. That is, the conversion control device 14 PWM controls the switching elements 11u1 to 11w2.

Here, the conversion control device 14 includes at least one of the upper arm switching elements 11u1, 11v1, 11w1 and each lower arm switching element within a range in which the upper arm switching element and the lower arm switching element of the same phase are not turned on at the same time. Turn on at least one of 11u2, 11v2, 11w2. As a result, the inverter current Iv flows through the positive electrode bus LN1 and the negative electrode bus LN2, at least one of the intermediate wirings LNu, LNv, and LNw, and at least one of the coils 202u to 202w. Further, the inverter current Iv also flows through the first capacitor connection line LNc1 and the second capacitor connection line LNc2.

In the present embodiment, the positive electrode bus LN1, the negative electrode bus LN2, the intermediate wiring LNu, LNv, LNw and both capacitor connecting lines LNc1 and LNc2 correspond to the drive line LNx through which the inverter current Iv as the applied current flows.

Next, the switching elements 11u1 to 11w2 and the driver circuits 12u1 to 12w2 will be described in detail.
Here, the switching elements 11u1 to 11w2 have basically the same configuration, and the driver circuits 12u1 to 12w2 have basically the same configuration. Therefore, in the following, one of the switching elements 11u1 to 11w2, the switching element 11 (u-phase lower arm switching element 11u2) and the corresponding driver circuit 12 (lower arm u-phase driver circuit 12u2) will be mainly described. do.

As shown in FIG. 2, the switching element 11 includes an element main body 20, a gate terminal 21, a drain terminal 22, and a source terminal 23 attached to the element main body 20.
The element body 20 has, for example, a rectangular parallelepiped shape. The element main body 20 has a first side surface 20a and a second side surface 20b which are both end faces in the X direction orthogonal to the thickness direction of the drive substrate 13. The second side surface 20b is a side surface opposite to the first side surface 20a. It can be said that the X direction intersects the both side surfaces 20a and 20b (orthogonally in the present embodiment).

The drain terminal 22 is provided on the first side surface 20a. In the present embodiment, the drain terminal 22 is one, and is formed in a tab shape in one direction of the first side surface 20a, specifically in the Y direction. The Y direction is a direction orthogonal to both the thickness direction and the X direction of the drive substrate 13.

In this embodiment, a plurality of source terminals 23 are provided. The gate terminal 21 and the plurality of source terminals 23 are provided on a portion of the switching element 11 opposite to the drain terminal 22. Specifically, the gate terminal 21 and the plurality of source terminals 23 are provided on the second side surface 20b. In this case, it can be said that the gate terminal 21 and the plurality of source terminals 23 face the drain terminal 22 in the X direction via the element main body 20. That is, it can be said that the X direction is the opposite direction between the drain terminal 22 and the source terminal 23.

The gate terminal 21 and the plurality of source terminals 23 are arranged in the Y direction at a predetermined pitch on the second side surface 20b. In other words, the Y direction can be said to be the arrangement direction of the plurality of source terminals 23.

When a gate voltage equal to or higher than a predetermined threshold is applied to the gate terminal 21, an inverter current Iv flows between the source and drain of the switching element 11. That is, the inverter current Iv of this embodiment can be said to be a drain current flowing through the drain terminal 22 and the plurality of source terminals 23.

In the present embodiment, the inverter current Iv flows from the drain terminal 22 through the element main body 20 toward the plurality of source terminals 23. Therefore, the inverter current Iv flows in the switching element 11 in the X direction. That is, the X direction can be said to be the direction of the current flowing in the switching element 11. The number of source terminals 23 is arbitrary. In this embodiment, the gate terminal 21 corresponds to the "control terminal".

Here, a source-drain voltage Vds, which is a voltage for passing an inverter current Iv through the switching element 11, is applied between the source and drain of the switching element 11. The source-drain voltage Vds of the present embodiment is the power supply voltage Vdc when the switching element 11 is in the OFF state, and is 0V when the switching element 11 is in the ON state.

As shown in FIG. 2, in the present embodiment, the u-phase upper arm switching element 11u1 and the u-phase lower arm switching element 11u2 are arranged apart from each other in the X direction. The X direction can be said to be the arrangement direction of the u-phase upper arm switching element 11u1 and the u-phase lower arm switching element 11u2, and the Y direction is the arrangement direction of both u-phase switching elements 11u1 and 11u2 and the thickness direction of the drive substrate 13. It can be said that the directions are orthogonal to both.

The same applies to the v-phase upper arm switching element 11v1 and the v-phase lower arm switching element 11v2, and the w-phase upper arm switching element 11w1 and the w-phase lower arm switching element 11w2.

In the present embodiment, the positive electrode bus LN1, the negative electrode bus LN2, the intermediate wirings LNu, LNv, LNw, and both capacitor connection lines LNc1 and LNc2 are configured by a wiring pattern formed on the drive board 13. The positive electrode bus LN1, the negative electrode bus LN2, the intermediate wirings LNu, LNv, LNw and both capacitor connection lines LNc1 and LNc2 include parasitic inductances.

The positive electrode bus LN1 is arranged on both sides of the u-phase upper arm switching element 11u1 in the X direction where the drain terminal 22 is located, and is specifically formed on the side of the first side surface 20a of the drive substrate 13. .. The drain terminal 22 of the u-phase upper arm switching element 11u1 is connected to the positive electrode bus LN1.

The u-phase intermediate wiring LNu connecting the u-phase upper arm switching element 11u1 and the u-phase lower arm switching element 11u2 is arranged on both sides of the u-phase upper arm switching element 11u1 in the X direction where a plurality of source terminals 23 are present. In detail, it is formed on the side of the second side surface 20b of the drive substrate 13. A part of the u-phase intermediate wiring LNu is arranged between the u-phase upper arm switching element 11u1 and the u-phase lower arm switching element 11u2. A plurality of source terminals 23 of the u-phase upper arm switching element 11u1 are connected to the u-phase intermediate wiring LNu, and a drain terminal 22 of the u-phase lower arm switching element 11u2 is connected to the u-phase intermediate wiring LNu. Further, the u-phase intermediate wiring LNu is connected to the electric motor 201 (specifically, the u-phase coil 202u).

The negative electrode bus LN2 is arranged on both sides of the u-phase lower arm switching element 11u2 in the X direction where a plurality of source terminals 23 are located, and is specifically formed on the side of the second side surface 20b of the drive substrate 13. ing. The plurality of source terminals 23 of the u-phase lower arm switching element 11u2 are connected to the negative electrode bus LN2.

According to this configuration, when the u-phase upper arm switching element 11u1 is in the ON state, an inverter current Iv flows from the positive electrode bus LN1 to the u-phase intermediate wiring LNu via the u-phase upper arm switching element 11u1. Further, when the u-phase lower arm switching element 11u2 is in the ON state, an inverter current Iv flows from the u-phase intermediate wiring LNu toward the negative electrode bus LN2 via the u-phase lower arm switching element 11u2.

As shown in FIG. 2, the first capacitor connection line LNc1 is connected to the positive electrode bus LN1 and extends in the X direction from the positive electrode bus LN1 toward the negative electrode bus LN2.
The second capacitor connection line LNc2 is connected to the negative electrode bus LN2 and extends in the X direction from the negative electrode bus LN2 toward the positive electrode bus LN1. The first capacitor connection line LNc1 and the second capacitor connection line LNc2 are arranged so as to be separated from each other in the Y direction. The second capacitor connection line LNc2 is arranged on the side opposite to the u-phase intermediate wiring LNu with respect to the first capacitor connection line LNc1.

The capacitor C0 of the present embodiment is arranged so as to straddle both capacitor connection lines LNc1 and LNc2, and is connected to both capacitor connection lines LNc1 and LNc2. As a result, the inverter current Iv flows through the capacitors C0 through both capacitor connection lines LNc1 and LNc2.

As shown in FIGS. 2 and 3, the power conversion device 10 includes a gate wiring LNg as a control line formed on the drive board 13. The gate wiring LNg is formed, for example, in the surface layer and the intermediate layer of the drive board 13, and connects the driver circuit 12 and the gate terminal 21 through below the second capacitor connection line LNc2.

The power conversion device 10 includes a ground wiring LNy for connecting the source terminal 23 and the reference potential V0'of the driver circuit 12. The ground wiring LNy connects the negative electrode bus LN2 to which the source terminal 23 is connected and the driver circuit 12, and is connected to the reference potential V0'of the driver circuit 12 in the driver circuit 12. As a result, the reference potential V0'can be applied to the source terminal 23.

Here, as shown in FIG. 3, the power conversion device 10 includes, for example, a gate-source resistor R1 and a gate-source capacitor C1 connected to the gate wiring LNg and the negative electrode bus LN2. The gate-source resistor R1 and the gate-source capacitor C1 are connected to the gate terminal 21 and the source terminal 23 via the gate wiring LNg and the negative electrode bus LN2. Further, the gate-source resistor R1 and the gate-source capacitor C1 are connected to the reference potential V0'of the driver circuit 12 via the negative electrode bus LN2 and the ground wiring LNy.

The gate-source resistor R1 and the gate-source capacitor C1 are mounted on, for example, a drive board 13. However, the present invention is not limited to this, and it may be mounted in the driver circuit 12. For convenience of illustration, the gate-source resistor R1 and the gate-source capacitor C1 are omitted in FIG.

As shown in FIGS. 2 and 3, the power conversion device 10 includes a first inductance component L1 and a second inductance component L2.
The first inductance component L1 is provided on the drive line LNx through which the inverter current Iv flows, and in the present embodiment, it is provided on the second capacitor connection line LNc2 of the drive line LNx. In the present embodiment, the first inductance component L1 is composed of the parasitic inductance contained in the second capacitor connection line LNc2.

The second inductance component L2 is provided at a position where the magnetic flux generated from the first inductance component L1 penetrates. The second inductance component L2 generates a feedback voltage Vfb by a change in the magnetic flux accompanying a change in the inverter current Iv. The feedback voltage Vfb is a positive voltage when the inverter current Iv increases, and is a negative voltage when the inverter current Iv decreases. It can be said that the second inductance component L2 is magnetically coupled to the first inductance component L1 and can be said to form a transformer in cooperation with the first inductance component L1.

In the present embodiment, the ground wiring LNy has an extension portion 30 extending along the second capacitor connection line LNc2. The extension portion 30 is arranged next to the second capacitor connection line LNc2. Specifically, the extension portion 30 is arranged next to the second capacitor connection line LNc2 in the Y direction and extends in the X direction. That is, the second capacitor connection line LNc2 and the extension portion 30 are arranged side by side in the Y direction.

The second inductance component L2 is provided in the extension portion 30. Specifically, the second inductance component L2 is composed of the parasitic inductance contained in the extension portion 30. In the present embodiment, the extension portion 30 corresponds to the “second inductance portion”.

The extension portion 30 is provided along the second capacitor connection line LNc2 so that the direction from the source terminal 23 in the ground wiring LNy toward the driver circuit 12 and the direction of the inverter current Iv flowing through the second capacitor connection line LNc2 are the same. It is extended. Specifically, in the second capacitor connection line LNc2, the extension portion 30 is displaced in the Y direction with respect to the second capacitor connection line LNc2 in correspondence with the inverter current Iv flowing from the negative electrode bus LN2 toward the capacitor C0. At this position, it extends from the negative electrode bus LN2 toward the capacitor C0. As a result, the second inductance component L2 generates a negative feedback voltage Vfb when the inverter current Iv increases, while it generates a positive feedback voltage Vfb when the inverter current Iv decreases.

In the present embodiment, the inductance of the second inductance component L2 is larger than the inductance of the first inductance component L1. Specifically, the width W1 of the extension portion 30 is narrower than the width W2 of the second capacitor connection line LNc2, and the parasitic inductance included in the extension portion 30 of the ground wiring LNy becomes the second capacitor connection line LNc2. It is larger than the parasitic inductance included. As a result, the feedback voltage Vfb is larger than the voltage generated by the first inductance component L1.

According to this configuration, when the switching element 11 is turned on and the inverter current Iv flows, magnetic flux is generated from the first inductance component L1. In the present embodiment, since the first inductance component L1 is composed of the parasitic inductance of the second capacitor connection line LNc2, a magnetic flux is generated around the second capacitor connection line LNc2. The magnetic flux changes as the inverter current Iv changes. As a result, the feedback voltage Vfb is generated from the second inductance component L2. As a reminder, the current flowing through the ground wiring LNy is sufficiently smaller than the current flowing through the drive line LNx.

Next, the driver circuit 12 will be described.
As shown in FIG. 3, the driver circuit 12 includes an external input terminal 51, an output terminal 52, and a feedback input terminal 53.

The external input terminal 51 is electrically connected to the conversion control device 14. The external command voltage Vp from the conversion control device 14 is input to the external input terminal 51.
The output terminal 52 is a terminal for outputting a gate voltage (in other words, a gate current) from the driver circuit 12. The output terminal 52 and the gate terminal 21 are electrically connected by the gate wiring LNg, and the gate voltage output from the output terminal 52 is input to the gate terminal 21 via the gate wiring LNg.

The feedback input terminal 53 is a terminal to which the feedback voltage Vfb is input. The feedback input terminal 53 is connected to the ground wiring LNy. As a result, the feedback voltage Vfb generated by the second inductance component L2 provided on the ground wiring LNy is applied to the feedback input terminal 53. The feedback input terminal 53 is connected to the reference potential V0'in the driver circuit 12.

The driver circuit 12 generates an additional voltage Vad based on the external command voltage Vp input from the external input terminal 51 and the feedback voltage Vfb input to the feedback input terminal 53, and the added voltage Vad is used as the gate voltage. It is configured to output from the output terminal 52.

An example of the driver circuit 12 that outputs the added voltage Vad will be described below.
The driver circuit 12 of the present embodiment includes a command conversion circuit 55 that converts an external command voltage Vp into a conversion command voltage Vpt, and an addition circuit 57 that adds a conversion command voltage Vpt and a feedback voltage Vfb.

The command conversion circuit 55 converts the external command voltage Vp into a conversion command voltage Vpt by amplifying the external command voltage Vp at a predetermined amplification factor while reducing the noise contained in the external command voltage Vp input from the external input terminal 51. Convert to. Then, the command conversion circuit 55 outputs the conversion command voltage Vpt toward the addition circuit 57. The amplification factor includes "1". The specific configuration of the command conversion circuit 55 is arbitrary, and may be, for example, a non-inverting amplifier circuit having an operational amplifier.

The adder circuit 57 is connected to the command conversion circuit 55 and the feedback input terminal 53, and is also connected to the output terminal 52. The conversion command voltage Vpt and the feedback voltage Vfb are input to the adder circuit 57. The adder circuit 57 adds the conversion command voltage Vpt and the feedback voltage Vfb, and outputs the added added voltage Vad toward the output terminal 52. As a result, the added voltage Vad as the gate voltage is input to the gate terminal 21.

The specific configuration of the adder circuit 57 is arbitrary. For example, the adder circuit 57 may be configured to connect a line through which the conversion command voltage Vpt is transmitted and a line through which the feedback voltage Vfb is transmitted. Further, the addition circuit 57 may have a voltage amplification circuit that generates an addition voltage Vad by amplifying a voltage obtained by combining the conversion command voltage Vpt and the feedback voltage Vfb.

The adder circuit 57 may have a current amplifier circuit for supplying the required current to the gate terminal 21 while maintaining the adder voltage Vad.
As shown in FIG. 3, the driver circuit 12 includes a gate resistor Rg provided between the adder circuit 57 and the output terminal 52. The slope of the rise / fall of the switching element 11 changes according to the resistance value of the gate resistance Rg.

Incidentally, the same applies to the u-phase upper arm switching element 11u1 and the u-phase upper arm driver circuit 12u1. In this case, for example, the ground wiring LNy connects the u-phase intermediate wiring LNu and the u-phase upper arm driver circuit 12u1. Further, at least a part of the ground wiring LNy is provided at a position where the magnetic flux generated from the parasitic inductance included in the first capacitor connection line LNc1 penetrates, or a position where the magnetic flux generated from the parasitic inductance contained in the positive electrode bus LN1 penetrates. It is good to have. For example, the ground wiring LNy may have a portion that is arranged next to the first capacitor connection line LNc1 or the positive electrode bus LN1 and extends along the wiring. Alternatively, at least a part of the ground wiring LNy may be provided at a position where the magnetic flux generated from the parasitic inductance included in the u-phase intermediate wiring LNu penetrates.

Next, the operation of the present embodiment will be described with reference to FIGS. 4 to 9.
FIG. 4 is a graph showing the inverter current Iv, the source-drain voltage Vds, the feedback voltage Vfb, and the added voltage Vad at the time of turn-on under the condition that there is no feedback by the feedback voltage Vfb. FIG. 5 is a graph showing the inverter current Iv, the source-drain voltage Vds, the feedback voltage Vfb, and the added voltage Vad at the time of turn-on under the condition that the feedback by the feedback voltage Vfb is present. FIG. 6 shows an inverter current Iv, a source-drain voltage Vds, and a feedback voltage Vfb in which the resistance value of the gate resistance Rg is adjusted so that a surge equivalent to that in the case of no feedback occurs under the condition of feedback by the feedback voltage Vfb. It is a graph which shows the addition voltage Vad.

FIG. 7 is a graph showing the inverter current Iv, the source-drain voltage Vds, the feedback voltage Vfb, and the added voltage Vad at the time of turn-off under the condition that there is no feedback due to the feedback voltage Vfb. FIG. 8 is a graph showing the inverter current Iv, the source-drain voltage Vds, the feedback voltage Vfb, and the added voltage Vad at turn-off under certain conditions of feedback by the feedback voltage Vfb. FIG. 9 shows an inverter current Iv, a source-drain voltage Vds, and a feedback voltage Vfb in which the resistance value of the gate resistance Rg is adjusted so that a surge equivalent to the case without feedback occurs under the condition of feedback by the feedback voltage Vfb. It is a graph which shows the addition voltage Vad.

In FIGS. 4 to 9, the inverter current Iv is indicated by a solid line, the source-drain voltage Vds is indicated by a broken line, the feedback voltage Vfb is indicated by a two-dot chain line, and the added voltage Vad is indicated by a one-dot chain line.

First, the turn-on time of the switching element 11 will be described with reference to FIGS. 4 to 6.
As shown in FIGS. 4 and 5, as the added voltage Vad rises, the source-drain voltage Vds begins to fall, while the inverter current Iv (drain current) begins to flow. In this case, as shown in FIG. 4, when there is no feedback due to the feedback voltage Vfb, a surge occurs when the inverter current Iv rises.

On the other hand, when there is feedback due to the feedback voltage Vfb, the magnetic flux generated from the first inductance component L1 changes due to the change (specifically, increase) in the inverter current Iv. As a result, as shown by the alternate long and short dash line in FIG. 5, the feedback voltage Vfb is generated from the second inductance component L2. In this case, the feedback voltage Vfb is a negative voltage.

Then, the conversion command voltage Vpt and the feedback voltage Vfb are added, and the added voltage Vad is input to the gate terminal 21 of the switching element 11. In this case, since the negative feedback voltage Vfb is added, the added voltage Vad becomes small. As a result, the slope of the rise from LOW to HI in the added voltage Vad becomes gentle. As a result, as shown by the solid line in FIG. 5, the surge when the inverter current Iv rises is suppressed.

Further, as shown in FIG. 6, when the resistance value of the gate resistance Rg is adjusted so that a surge equivalent to that in the case without feedback occurs, the slope of the rising edge of the inverter current Iv becomes larger than in the case without feedback. be able to. This reduces the loss at turn-on.

Next, the turn-off time of the switching element 11 will be described with reference to FIGS. 7 to 9.
As shown in FIGS. 7 and 8, as the added voltage Vad falls, the source-drain voltage Vds starts to rise, while the inverter current Iv (drain current) starts to decrease. In this case, as shown by the broken line in FIG. 7, when there is no feedback by the feedback voltage Vfb, a surge occurs when the source-drain voltage Vds rises.

On the other hand, when there is feedback by the feedback voltage Vfb, the magnetic flux generated in the first inductance component L1 changes as the inverter current Iv becomes smaller. As a result, as shown by the two-dot chain line in FIG. 8, the feedback voltage Vfb is generated from the second inductance component L2. In this case, the feedback voltage Vfb is a positive voltage.

Then, the conversion command voltage Vpt and the feedback voltage Vfb are added, and the added voltage Vad is input to the gate terminal 21 of the switching element 11. In this case, since the positive feedback voltage Vfb is added, the added voltage Vad becomes large. As a result, as shown by the alternate long and short dash line in FIG. 8, the slope of the fall from HI to LOW at the added voltage Vad becomes gentle. As a result, as shown by the broken line in FIG. 8, the surge when the source-drain voltage Vds rises is suppressed.

Further, as shown in FIG. 9, when the resistance value of the gate resistance Rg is adjusted so that a surge equivalent to that in the case without feedback occurs, the slope of the fall of the inverter current Iv becomes larger than in the case without feedback. can do. This reduces the loss.

According to the present embodiment described in detail above, the following effects are obtained.
(1) The power conversion device 10 includes a switching element 11 and a driver circuit 12 for driving the switching element 11. The switching element 11 includes a drain terminal 22 and a source terminal 23 through which an inverter current Iv as an applied current flows, and a gate terminal 21 as a control terminal.

The power conversion device 10 includes a drive line LNx through which an inverter current Iv flows, a first inductance component L1 provided on the drive line LNx, and a gate wiring LNg as a control line connecting the driver circuit 12 and the gate terminal 21. , Is equipped. The power conversion device 10 includes a ground wiring LNy for connecting the source terminal 23 and the reference potential V0'of the driver circuit 12, and a second inductance component L2 provided on the ground wiring LNy.

The second inductance component L2 is provided at a position where the magnetic flux generated from the first inductance component L1 penetrates. The second inductance component L2 generates a negative feedback voltage Vfb when the inverter current Iv increases, while it generates a positive feedback voltage Vfb when the inverter current Iv decreases.

The driver circuit 12 includes an external input terminal 51 to which an external command voltage Vp is input, and a feedback input terminal 53 to which a feedback voltage Vfb is input. The driver circuit 12 adds the conversion command voltage Vpt obtained by converting the external command voltage Vp and the feedback voltage Vfb, and outputs the added added voltage Vad toward the gate terminal 21. I have.

According to this configuration, the feedback voltage Vfb is induced from the second inductance component L2 by changing the magnetic flux with the change of the inverter current Iv flowing through the first inductance component L1. Then, the feedback voltage Vfb is added to the conversion command voltage Vpt, and the added added voltage Vad is input to the gate terminal 21. As a result, it is possible to suppress a surge at the time of turn-on or turn-off of the switching element 11.

Further, by adjusting the resistance value of the gate resistance Rg, the slope of the rise of the inverter current Iv at the time of turn-on or the rise of the source-drain voltage Vds at the time of turn-off within the range where the surge is within the allowable range. The tilt can be increased. This makes it possible to reduce the loss. Therefore, it is possible to preferably achieve both suppression of surge and reduction of loss.

In particular, according to this configuration, the feedback voltage Vfb becomes negative when the inverter current Iv increases, and becomes positive when the inverter current Iv decreases. As a result, it is not necessary to invert the feedback voltage Vfb and input it to the adder circuit 57. Therefore, the configuration related to inversion can be omitted.

Further, in the configuration in which the counter electromotive force generated by the first inductance component L1 is fed back, for example, when the first inductance component L1 is small, the counter electromotive force is also small, so that the feedback effect (specifically, the surge suppression effect) is small. , The desired feedback effect may not be obtained. However, since the inverter current Iv flows through the first inductance component L1, if the first inductance component L1 is increased in an attempt to increase the counter electromotive force, the loss and surge increase.

In this respect, according to this configuration, since the feedback voltage Vfb depends on the second inductance component L2, a desired feedback voltage Vfb can be obtained by adjusting the second inductance component L2. Further, since the inverter current Iv does not flow through the second inductance component L2, the loss caused by the second inductance component L2 can be small. This makes it possible to obtain a desired feedback effect while suppressing loss.

(2) The second inductance component L2 is larger than the first inductance component L1. According to such a configuration, the feedback voltage Vfb can be increased, and the feedback effect can be improved.

To elaborate on the above effect, for example, when the first inductance component L1 is small, the back electromotive force is also small, so that the feedback effect (specifically, the surge suppression effect) is small, and the desired feedback effect may not be obtained. obtain. However, since the inverter current Iv flows through the first inductance component L1, if the first inductance component L1 is increased in an attempt to increase the counter electromotive force, the loss and surge increase.

In this respect, according to this configuration, since the feedback voltage Vfb depends on the second inductance component L2, a desired feedback voltage Vfb can be obtained by adjusting the second inductance component L2. Further, since the inverter current Iv does not flow through the second inductance component L2, the loss caused by the second inductance component L2 can be small. This makes it possible to obtain a desired feedback effect while suppressing loss.

(3) The drive line LNx has a second capacitor connection line LNc2 as a first inductance portion provided with a first inductance component L1. The ground wiring LNy has an extension portion 30 as a second inductance portion provided with the second inductance component L2. The extension portion 30 is arranged next to the second capacitor connection line LNc2. The extension portion 30 is provided along the second capacitor connection line LNc2 so that the direction from the source terminal 23 in the ground wiring LNy toward the driver circuit 12 and the direction of the inverter current Iv flowing through the second capacitor connection line LNc2 are the same. It is extended.

According to this configuration, the extension portion 30 provided with the second inductance component L2 is arranged next to the second capacitor connection line LNc2 provided with the first inductance component L1, so that the separation distance between the two is increased. It tends to be short. As a result, an interaction is likely to occur between the two inductance components L1 and L2. Therefore, the feedback voltage Vfb can be increased. Further, the feedback voltage Vfb becomes negative when the inverter current Iv increases, and becomes positive when the inverter current Iv decreases. As a result, the effects such as (1) can be obtained with a relatively simple configuration.

(4) The power conversion device 10 includes a drive board 13 on which a switching element 11 is mounted. The extension portion 30 and the second capacitor connection line LNc2 are configured by a wiring pattern formed on the drive board 13. In such a configuration, the first inductance component L1 is composed of the parasitic inductance contained in the second capacitor connection line LNc2, and the second inductance component L2 is composed of the parasitic inductance contained in the extension portion 30. The width W1 of the extension portion 30 is narrower than the width W2 of the second capacitor connection line LNc2. As a result, the second inductance component L2 can be made larger than the first inductance component L1.

(5) The power conversion device 10 includes upper arm switching elements 11u1, 11v1, 11w1 and lower arm switching elements 11u2, 11v2, 11w2 connected in series by intermediate wirings LNu, LNv, LNw, and a capacitor C0. ing.

The drive line LNx includes a positive electrode bus LN1 to which the upper arm switching elements 11u1, 11v1, 11w1 are connected, and a negative electrode bus LN2 to which the lower arm switching elements 11u2, 11v2, 11w2 are connected. The drive line LNx includes intermediate wiring LNu, LNv, LNw, a first capacitor connection line LNc1 connecting the positive electrode bus LN1 and the capacitor C0, and a second capacitor connection line LNc2 connecting the negative electrode bus LN2 and the capacitor C0. including.

The second inductance component L2 is at least one of the positive electrode bus LN1, the negative electrode bus LN2, the intermediate wiring LNu, LNv, LNw, the first capacitor connection line LNc1 and the second capacitor connection line LNc2 (in this embodiment, the second capacitor connection). It is provided at a position where the magnetic flux generated from the parasitic inductance of the wire LNc2) penetrates.

According to such a configuration, the feedback voltage Vfb can be generated by using the parasitic inductance contained in at least one of the positive electrode bus LN1, the negative electrode bus LN2, the intermediate wiring LNu, LNv, LNw and both capacitor connection lines LNc1 and LNc2. can.

The above embodiment may be changed as follows. Further, the above-described embodiment and the following alternative examples may be appropriately combined within a range that does not cause a technical contradiction.
○ The first inductance component L1 is composed of the parasitic inductance contained in the second capacitor connection line LNc2, but is not limited to this, and is composed of, for example, a dedicated coil provided on the second capacitor connection line LNc2. You may.

○ The first inductance component L1 may be composed of the parasitic inductance contained in the negative electrode bus LN2, or may be composed of the parasitic inductance contained in any of the intermediate wirings LNu, LNv, and LNw.

○ The specific position of the second inductance component L2 is arbitrary as long as it is provided at a position where the magnetic flux generated from the first inductance component L1 penetrates. For example, the second inductance component L2 may be arranged next to the negative electrode bus LN2. In this case, the magnetic flux generated from the parasitic inductance contained in the negative electrode bus LN2 penetrates the second inductance component L2. That is, the second inductance component L2 is generated from the parasitic inductance contained in at least one of the positive electrode bus LN1, the negative electrode bus LN2, the intermediate wiring LNu, LNv, LNw, the first capacitor connection line LNc1 and the second capacitor connection line LNc2. It suffices if it is provided at a position where the magnetic flux penetrates.

○ When the second inductance component L2 is composed of the parasitic inductance contained in the ground wiring LNy, the ground wiring LNy is spirally or zigzag next to the second capacitor connection line LNc2 in order to increase the parasitic inductance. It may be formed. Further, a part of the ground wiring LNy may be locally formed to be narrow.

○ What constitutes the second inductance component L2 is not limited to the parasitic inductance of the wiring pattern formed on the drive board 13, and is arbitrary as long as it has an inductance. For example, the second inductance component L2 may be composed of a dedicated coil mounted on the drive board 13.

○ The driver circuit 12 may have a feedback conversion circuit that converts the feedback voltage Vfb into a conversion feedback voltage Vft and outputs the converted conversion feedback voltage Vft toward the addition circuit 57. In this case, the adder circuit 57 may add the conversion command voltage Vpt and the conversion feedback voltage Vft.

○ The command conversion circuit 55 may be omitted. In this case, the external command voltage Vp is input to the adder circuit 57. The addition circuit 57 may add the external command voltage Vp and the conversion feedback voltage Vft obtained by converting the feedback voltage Vfb or the feedback voltage Vfb.

That is, in the adder circuit 57, either one of the external command voltage Vp or the conversion command voltage Vpt and either the feedback voltage Vfb or the conversion feedback voltage Vft may be input. That is, the adder circuit 57 may add the external command voltage Vp or the conversion command voltage Vpt and the feedback voltage Vfb or the conversion feedback voltage Vft.

○ The magnitude relationship between the inductance of the first inductance component L1 and the inductance of the second inductance component L2 is arbitrary. For example, both inductances may be the same, or the inductance of the first inductance component L1 may be larger than the inductance of the second inductance component L2.

○ The switching element 11 is not limited to the MOSFET but may be arbitrary, and may be, for example, an IGBT. In this case, the gate terminal of the switching element 11 corresponds to the "control terminal", the collector current flowing between the collector and the emitter of the switching element 11 corresponds to the "applied current", and the collector terminal and the emitter terminal correspond to the "applied terminal". handle.

○ Each switching element 11u1 to 11w2 has configured an inverter, but is not limited to this, and is optional. For example, a DC / DC converter that converts the DC power of the power storage device 203 into a DC power of a different voltage may be configured. good. That is, the power conversion device 10 is not limited to the inverter, but may be a DC / DC converter, an AC / AC converter, an AC / DC inverter, or the like. In other words, the power conversion device 10 may convert DC power or AC power into DC power or AC power.

○ In the embodiment, the feedback voltage Vfb is fed back to all the switching elements 11u1 to 11w2, but the present invention is not limited to this. For example, the feedback voltage Vfb may be fed back to the lower arm switching elements 11u2, 11v2, 11w2, while the upper arm switching elements 11u1, 11v1, 11w1 may not be fed back, or vice versa.

○ The load is not limited to the electric motor 201 and is arbitrary.
○ The power conversion device 10 may be mounted on a vehicle other than the vehicle 200. That is, the power conversion device 10 may drive a load other than the load provided on the vehicle 200.

10 ... Power converter, 11 (11u1 to 11w2) ... Switching element, 12 (12u1 to 12w2) ... Driver circuit, 13 ... Drive board, 21 ... Gate terminal (control terminal), 22 ... Drain terminal (first application terminal) , 23 ... source terminal (second application terminal), 30 ... extension, 51 ... external input terminal, 52 ... output terminal, 53 ... feedback input terminal, 55 ... command conversion circuit, 56 ... feedback conversion circuit, 57 ... addition Circuit, 200 ... Vehicle, 201 ... Electric motor (load), 203 ... Power storage device, LNx ... Drive line, LN1 ... Positive voltage bus, LN2 ... Negative voltage bus, LNu, LNv, LNw ... Intermediate wiring, C0 ... Condenser, LNc1 ... 1 capacitor connection line, LNc2 ... second capacitor connection line, LNy ... ground wiring, Vp ... external command voltage, Vpt ... conversion command voltage, Vf ... feedback voltage, Vad ... additional voltage, V0 ... reference potential, V0'... driver circuit Reference potential, L1 ... 1st inductance component, L2 ... 2nd inductance component, Iv ... Inverter current (applied current).

Claims (5)

A switching element having a control terminal and a first application terminal and a second application terminal through which an applied current flows, and
The driver circuit that drives the switching element and
The drive line through which the applied current flows and
The first inductance component provided on the drive line and
A control line connecting the driver circuit and the control terminal,
The ground wiring for connecting the second application terminal and the reference potential of the driver circuit, and
A second inductance component provided on the ground wiring at a position where the magnetic flux generated from the first inductance component penetrates,
Equipped with
The second inductance component generates a negative feedback voltage when the applied current increases, and generates a positive feedback voltage when the applied current decreases.
The driver circuit is
The feedback input terminal to which the ground wiring is connected and the feedback voltage is input,
An external input terminal to which an external command voltage is input, and
The conversion command voltage obtained by converting the external command voltage or the external command voltage is added to the feedback voltage or the conversion feedback voltage obtained by converting the feedback voltage, and the added added voltage is added. An adder circuit that outputs to the control terminal and
A power conversion device characterized by being equipped with. The power conversion device according to claim 1, wherein the inductance of the second inductance component is larger than the inductance of the first inductance component. The drive line has a first inductance portion provided with the first inductance component.
The ground wiring has a second inductance portion that is arranged next to the first inductance portion and is provided with the second inductance component.
The second inductance portion is along the first inductance portion so that the direction from the second application terminal in the ground wiring toward the driver circuit and the direction of the applied current flowing through the first inductance portion are the same. The power conversion device according to claim 1 or claim 2. It has an upper arm switching element and a lower arm switching element connected in series with each other by intermediate wiring.
The power conversion device according to any one of claims 1 to 3, wherein the switching element is the lower arm switching element. Equipped with a capacitor
The drive line is
The positive electrode bus to which the upper arm switching element is connected and
The negative electrode bus to which the lower arm switching element is connected and
With the above intermediate wiring
A first capacitor connection line connecting the positive electrode bus and the capacitor,
A second capacitor connection line connecting the negative electrode bus and the capacitor,
Including
The second inductance component is located at a position where the magnetic flux generated from the parasitic inductance contained in at least one of the positive electrode bus, the negative electrode bus, the intermediate wiring, the first capacitor connection line, and the second capacitor connection line penetrates. The power conversion device according to claim 4, which is provided.

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