JP6946971B2 - Power converter - Google Patents

Description

The present invention relates to a power conversion device, and in particular, connects to a connection point between a first element and a second element composed of a diode or a switching element and a connection point between a third element and a fourth element composed of a switching element. The present invention relates to a power conversion device including a diode.

Conventionally, a power conversion device including a capacitor connected to a connection point between a first element and a second element composed of a diode or a switching element and a connection point between a third element and a fourth element composed of a switching element has been used. It is known (see, for example, Patent Document 1).

Patent Document 1 discloses a DC-DC converter including a switch circuit unit including a first switching element, a second switching element, a third switching element, and a fourth switching element, which are connected in series with each other. In this DC-DC converter, a capacitor (flying capacitor) connected to a connection point between the first switching element and the second switching element and a connection point between the third switching element and the fourth switching element is provided. Further, one end of the chopper reactor is connected between the second switching element and the third switching element. Further, a smoothing capacitor is connected in parallel to the switch circuit section.

In the DC-DC converter described in Patent Document 1, the chopper reactor and the third switching are turned on by turning off the second switching element and the fourth switching element and turning on the first switching element and the third switching element. A current flows through a path (hereinafter referred to as path 1) via the element, the flying capacitor, and the first switching element. Further, when the second switching element and the fourth switching element are turned on and the first switching element and the third switching element are turned off, the chopper reactor, the second switching element, the flying capacitor, and the fourth switching element are turned on. A current flows through the path (hereinafter referred to as path 2) via the.

Japanese Unexamined Patent Publication No. 2013-192383

However, in the conventional DC-DC converter as described in Patent Document 1, parasitic capacitance may occur in the first switching element and the second switching element that are turned off. In this case, for example, when the first switching element and the third switching element are turned on (path 1), a path through which a current flows through the parasitic capacitances of the third switching element, the flying capacitor, and the second switching element (path 1). Hereinafter, the route 3) occurs. When the second switching element and the fourth switching element are turned on (path 2), a path through which the current flows through the parasitic capacitance of the first switching element, the flying capacitor, the fourth switching element, and the smoothing capacitor (path 2). Hereinafter referred to as path 4) occurs. Since this path 4 is relatively long (longer than the path 3), there is a problem that the radiation noise generated by the current flowing through the path 4 becomes relatively large.

The present invention has been made to solve the above problems, and one object of the present invention is to provide a power conversion device capable of reducing radiation noise.

In order to achieve the above object, the power conversion device according to one aspect of the present invention is composed of a DC power supply and a first element, a diode or a switching element, which is connected in series with each other and is composed of a diode or a switching element. A switching circuit unit including a second element, a third element composed of a switching element, and a fourth element composed of a switching element is connected to a DC power supply at one end, and the second element and the third element are connected to each other. A reactor whose other end is connected to a point, a first capacitor connected to a connection point of the first element and the second element, and a connection point of the third element and the fourth element, and parallel to the switching circuit section. The second capacitor is provided with a second capacitor to be connected and a wiring for connecting the components constituting each of the first element, the second element, the third element, the fourth element, the first capacitor, and the second capacitor. The components constituting the first element, the first capacitor, and the fourth element are arranged so as to be adjacent to each other, and between adjacent components and between the components and the wiring adjacent to the components. At least one of them is arranged so that the directions of the flowing currents are substantially opposite to each other.

In the power conversion device according to one aspect of the present invention, as described above, the components constituting each of the second capacitor, the first element, the first capacitor, and the fourth element are arranged so as to be adjacent to each other. , The directions of the flowing currents are arranged so as to be substantially opposite between the adjacent parts and at least one of the parts and the wiring adjacent to the parts. As a result, the radiation noise (magnetic flux) generated by the current (current flowing in one direction) flowing in one of the adjacent parts (or the wiring adjacent to the parts) and the current flowing in the other (one direction). The radiation noise (magnetic flux) generated by the current flowing in substantially opposite directions cancels each other out. As a result, radiation noise can be reduced. As a result, it is possible to suppress malfunction of the component itself (second capacitor, first element, first capacitor and fourth element) and malfunction of the component (equipment) arranged around the component.

In the power conversion device according to the above one aspect, preferably, the components constituting each of the second capacitor, the first element, the first capacitor, and the fourth element are arranged so as to be adjacent to each other along a predetermined direction. Has been done. With this configuration, all the components constituting each of the second capacitor, the first element, the first capacitor, and the fourth element are adjacent to each other in a state of being arranged along a predetermined direction, so that they are adjacent to each other. It is possible to easily reverse the directions of the flowing currents between the components and at least one of the components and the wiring adjacent to the components.

In the power conversion device according to the above one aspect, preferably, the first element, the second element, the third element, the fourth element, the first capacitor and the second capacitor are provided in the first layer of the multilayer substrate. The wiring is provided in the first layer of the multilayer substrate, and includes a first wiring that connects the second capacitor, the first element, the first capacitor, and the fourth element in this order. With this configuration, the components and wiring are arranged on the same plane (first layer of the multilayer board), so that the radiation noise (magnetic flux) cancels each other on the same plane (first layer of the multilayer board). be able to.

In this case, preferably, in a plan view, the first wiring has a meandering shape, and the components constituting each of the second capacitor, the first element, the first capacitor, and the fourth element have a meandering shape. They are connected to each other by the first wiring. With this configuration, the directions of the currents flowing between adjacent parts in the first wiring having a meandering shape are substantially opposite to each other, so that wiring between adjacent parts and between parts and parts adjacent to each other can be easily performed. The direction of the current flowing in at least one of the and can be made substantially opposite.

In the power conversion device including the second wiring, preferably, the wiring is provided in the second layer of the multilayer substrate so as to overlap the first wiring in a plan view, and the fourth element and the second capacitor are electrically connected. Further includes a second wiring in which a current flows in a direction substantially opposite to the direction of the current flowing in the first wiring. With this configuration, the direction of the current flowing through the second wiring is substantially opposite to the direction of the current flowing through the first wiring, so that radiation noise (magnetic flux) is generated between the first wiring and the second wiring. Can cancel each other out. Thereby, the radiation noise can be further reduced.

In this case, preferably, in a plan view, the second wiring is provided in the second layer of the multilayer substrate so as to have a path substantially along the path of the first wiring. With this configuration, the radiation noise (magnetic flux) can be effectively canceled between the first wiring and the second wiring.

In the power conversion device according to the above one aspect, preferably, the first capacitor includes a first capacitor on one side and a first capacitor on the other side connected in parallel with each other, and a second capacitor, a first element, and a first capacitor on one side. The parts that make up each of the 1st capacitor, the 4th element, the 1st capacitor on the other side, the 3rd element, and the 2nd element are arranged so as to be adjacent to each other, and are placed between adjacent parts and between parts. At least one of the adjacent wirings is arranged so that the directions of the flowing currents are substantially opposite to each other. With this configuration, even if the radiated noise generated in the series circuit including the first capacitor, the third element, and the second element on the other side becomes large, the first capacitor on the other side, the third element, and the second element Since the directions of the currents flowing are substantially opposite between the components constituting each component and at least one of the components and the wiring adjacent to the components, the radiated noise generated in the series circuit is also reduced. be able to. Further, unlike the case where one relatively large first capacitor is arranged, the relatively small one-sided first capacitor and the other-sided first capacitor divided into two can be easily arranged.

In the power conversion device according to the above one aspect, preferably, at least one of the first element, the second element, the third element, and the fourth element is composed of a wide bandgap semiconductor. Here, since the wide bandgap semiconductor can be switched at high speed (that is, the switching frequency is high), the energy of radiated noise becomes relatively large. Therefore, when at least one of the first element, the second element, the third element, and the fourth element is composed of a wide bandgap semiconductor, wiring between adjacent parts and between parts and adjacent parts. Arranging the components so that the directions of the currents flowing in at least one of the components are substantially opposite to each other is particularly effective in reducing radiated noise. Further, the radiation noise due to the wide bandgap semiconductor having a relatively large radiation noise can be reduced without separately providing a component for noise countermeasures. As a result, it is possible to reduce the radiation noise while suppressing the increase in size of the power conversion device.

According to the present invention, radiation noise can be reduced as described above.

It is a circuit diagram which shows the whole structure of the power conversion apparatus by 1st Embodiment. It is a circuit diagram (1) for demonstrating operation of a power conversion apparatus. It is a circuit diagram (2) for demonstrating operation of a power conversion apparatus. It is a circuit diagram (3) for demonstrating operation of a power conversion apparatus. It is a circuit diagram (4) for demonstrating operation of a power conversion apparatus. It is a figure which shows the arrangement of the component of the power conversion apparatus by 1st Embodiment (the 1st layer of a multilayer board). It is the figure which rewrote the circuit diagram of FIG. 1 according to the arrangement of parts. It is a figure which shows the multilayer substrate by 1st Embodiment. It is a figure which shows the 2nd layer of the multilayer substrate by 1st Embodiment. It is a circuit diagram which shows the whole structure of the power conversion apparatus by 2nd Embodiment. It is a figure which shows the arrangement of the component of the power conversion apparatus (the first layer of a multilayer board) by 2nd Embodiment. It is the figure which rewrote the circuit diagram of FIG. 10 according to the arrangement of parts. It is a circuit diagram which shows the whole structure of the power conversion apparatus by a modification.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

[First Embodiment]
The configuration of the power conversion device 100 according to the first embodiment will be described with reference to FIGS. 1 to 9.

(Configuration of power converter)
As shown in FIG. 1, the power conversion device 100 is configured to convert the voltage Vin of the DC power supply 1 and supply it to the load 101. For example, the power converter 100 is configured as a so-called boost chopper.

Further, the power conversion device 100 is provided with a reactor 2 (chopper reactor). One end of the reactor 2 is connected to the DC power supply 1. Further, the other end of the reactor 2 is connected to a connection point A1 between the diode D2 and the switching element Q1, which will be described later.

Further, the power conversion device 100 is provided with a switching circuit unit 3. The switching circuit unit 3 includes a diode D1, a diode D2, a switching element Q1, and a switching element Q2. The diode D1, the diode D2, the switching element Q1, and the switching element Q2 are connected in series with each other in this order. Specifically, the source of the switching element Q1 is connected to the drain of the switching element Q2. Further, the anode of the diode D2 is connected to the drain of the switching element Q1. Further, the anode of the diode D1 is connected to the cathode of the diode D2. The diode D1 and the diode D2 are examples of the "first element" and the "second element" in the claims, respectively. Further, the switching element Q1 and the switching element Q2 are examples of the "third element" and the "fourth element" in the claims, respectively.

Here, in the first embodiment, the diode D1 and the diode D2 are composed of a Schottky barrier diode formed of a wide bandgap semiconductor (for example, SiC).

Further, the switching element Q1 and the switching element Q2 are composed of, for example, a MOSFET (Metal-Oxide-Semicondutor Field-Effective Transistor), an IGBT (Insulated Gate Bipolar Transistor), and the like. In the first embodiment, the switching element Q1 and the switching element Q2 are composed of a wide bandgap semiconductor (for example, SiC).

Further, the power conversion device 100 is provided with a capacitor Cf. The capacitor Cf is connected to the connection point A2 between the diode D1 and the diode D2 and the connection point A3 between the switching element Q1 and the switching element Q2. The capacitor Cf is called a flying capacitor. Further, the capacitor Cf is an example of the "first capacitor" in the claims.

Further, the power conversion device 100 is provided with a capacitor Cd (DC capacitor) connected in parallel to the switching circuit unit 3. Specifically, the positive potential side of the capacitor Cd is connected to the cathode of the diode D1, and the negative potential side of the capacitor Cd is connected to the source of the switching element Q2. A flying capacitor type chopper is composed of a reactor 2, a diode D1, a diode D2, a switching element Q1, a switching element Q2, a capacitor Cf, and a capacitor Cd. The capacitor Cd is an example of the "second capacitor" in the claims.

(Operation of power converter)
Next, the operation of the power conversion device 100 will be described with reference to FIGS. 2 to 5. In the following description, the forward voltage drop of the diode D1, the diode D2, the switching element Q1 and the switching element Q2 is ignored. Further, in FIGS. 2 to 5, the voltage of the capacitor Cf is held at substantially E / 2 during the operation of the power conversion device 100. This makes it possible to suppress the application of an overvoltage to the switching element Q2 when the diode D1 and the diode D2 are conducting.

As shown in FIG. 2, both the switching element Q1 and the switching element Q2 are turned on. As a result, the voltage value of the voltage Vr is substantially 0, and no current flows through the capacitor Cf.

Further, as shown in FIG. 3, the switching element Q1 is turned off and the switching element Q2 is turned on. As a result, the voltage value of the voltage Vr is approximately E / 2, and a current flows through the capacitor Cf. As a result, the capacitor Cf is charged. Here, the parasitic capacitance Cs1 is generated in the diode D1. Therefore, a path B1 (see the dotted line in FIG. 3) for charging the parasitic capacitance Cs1 via the diode D1, the capacitor Cf, the switching element Q2, and the capacitor Cd is generated. The length of the route B1 is longer than that of the route B2 (see the dotted line in FIG. 4) described later. Therefore, when the switching element Q2 is turned on, a relatively large radiation noise (magnetic flux) is generated due to the current flowing through the path B1.

Further, as shown in FIG. 4, the switching element Q1 is turned on and the switching element Q2 is turned off. As a result, the voltage value of the voltage Vr is approximately E / 2, and the capacitor Cf is discharged. It is assumed that the capacitance of the capacitor Cf is sufficiently large for the amount of one charge and the amount of one discharge. Further, the voltage fluctuation due to charging / discharging is small (for example, 10% or less of E / 2). Here, the parasitic capacitance Cs2 is generated in the diode D2. Therefore, a path B2 (see the dotted line in FIG. 4) for charging the parasitic capacitance Cs2 via the diode D2, the switching element Q1 and the capacitor Cf is generated. Since the length of the path B2 is shorter than that of the path B1 (see the dotted line in FIG. 3), the radiated noise (magnetic flux) generated is relatively small.

Further, as shown in FIG. 5, the switching element Q1 is turned off and the switching element Q2 is turned off. As a result, the voltage value of the voltage Vr becomes E, and no current flows through the capacitor Cf.

(Specific structure of power converter)
Next, the specific structure of the power conversion device 100 will be described.

As shown in FIG. 6, the power conversion device 100 is connected to the components 4 (components 4a to 4f) constituting each of the diode D1, the diode D2, the switching element Q1, the switching element Q2, the capacitor Cf, and the capacitor Cd. The wiring 5 is provided. The components 4a to 4f mean the capacitor Cd, the diode D1, the capacitor Cf, the switching element Q2, the diode D2, and the switching element Q1, respectively. Further, the wiring 5 is composed of a wiring pattern (a flat wiring 5 having a width relatively wide with respect to the thickness). This makes it possible to easily overlap (overlap) the first wiring 51 and the second wiring 52, which will be described later, in a plan view.

Further, FIG. 7 is a rewrite of the circuit diagram of FIG. 1 so as to follow the arrangement of the component 4 of FIG. That is, the arrangement of the components 4 in FIG. 6 and the electrical connection between the components 4 are the same as those in the circuit section of FIG.

Here, in the first embodiment, as shown in FIG. 6, the capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 (components 4a, 4b, 4c, and 4d constituting these) are adjacent to each other. It is arranged like this. The capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 (the components 4a, 4b, 4c, and 4d constituting these) are located between the adjacent components 4 and adjacent to the components 4 and 4. At least one of the wiring 5 and the wiring 5 are arranged so that the directions of the flowing currents are substantially opposite to each other. Hereinafter, a specific description will be given.

Specifically, in the first embodiment, the capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 (components 4a, 4b, 4c, and 4d constituting these) are connected to each other along the X direction. They are arranged next to each other. Further, the capacitor Cd, the diode D1, the capacitor Cf and the switching element Q2 are arranged in this order from the X1 direction side to the X2 direction side. The X direction is an example of the "predetermined direction" of the claims. Further, the expression "arranged along the X direction" includes the case where the capacitor Cd, the diode D1, the capacitor Cf and the switching element Q2 are slightly deviated from each other in the Y direction. The extent to which this deviation is allowed is within a distance at which the radiation noise described later can cancel each other out. Further, the diode D2 and the switching element Q1 are displaced in the Y1 direction side and the Y2 direction side with respect to the capacitor Cd, the diode D1, the capacitor Cf and the switching element Q2 arranged along the X direction, respectively. Have been placed.

Further, it is desirable to make the distance between the capacitors Cd, the diode D1, the capacitor Cf, and the switching element Q2 adjacent to each other as small as possible (the shortest distance). This makes it possible to reduce the size of the power conversion device 100 and further reduce the radiation noise described later.

In the first embodiment, the diode D1, the diode D2, the switching element Q1, the switching element Q2, the capacitor Cf, and the capacitor Cd are provided on the first layer 6a of the multilayer board 6. The wiring 5 is provided on the first layer 6a of the multilayer board 6, and includes a first wiring 51 that connects the capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 in this order. Further, in a plan view, the first wiring 51 has a meandering shape. The capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 (components 4a, 4b, 4c, and 4d constituting these) are connected to each other by a first wiring 51 having a meandering shape.

Specifically, the negative potential side of the capacitor Cd is connected to the first wiring portion 51a having a substantially linear shape. Further, the positive potential side of the capacitor Cd and the cathode of the diode D1 are connected by a first wiring portion 51b having a substantially U-shape. Further, the anode of the diode D1 and the positive potential side of the capacitor Cf are connected by a first wiring portion 51c having a substantially S-shape. Further, the negative potential side of the capacitor Cf and the drain of the switching element Q2 are connected by a first wiring portion 51d having a substantially S-shape. Further, the source of the switching element Q2 is connected to the first wiring portion 51e having a substantially linear shape. The diode D2 is electrically connected to the first wiring portion 51c, and the switching element Q1 is electrically connected to the first wiring portion 51d.

Then, as described above, by providing the capacitor Cd, the diode D1, the capacitor Cf, the switching element Q2, and the first wiring 51, the switching elements Q2 are adjacent to each other in the on state (path B1, see FIG. 3). In the arranged capacitor Cd and the diode D1, the direction of the current flowing through the capacitor Cd is the Y1 direction, while the direction of the current flowing through the diode D1 is the Y2 direction (the direction opposite to the Y1 direction). Further, in the diode D1 and the first wiring portion 51c arranged so as to be adjacent to each other, the direction of the current flowing through the diode D1 is in the Y2 direction, while the direction of the current flowing through the first wiring portion 51c is in the Y1 direction. be.

Further, in the first wiring portion 51c and the capacitor Cf arranged so as to be adjacent to each other, the direction of the current flowing through the first wiring portion 51c is in the Y1 direction, while the direction of the current flowing through the capacitor Cf is in the Y2 direction. be. Further, in the capacitors Cf and the first wiring portion 51d arranged adjacent to each other, the direction of the current flowing through the capacitor Cf is in the Y2 direction, while the direction of the current flowing through the first wiring portion 51d is in the Y1 direction. be. Further, in the first wiring portion 51d and the switching element Q2 arranged so as to be adjacent to each other, the direction of the current flowing through the first wiring portion 51d is the Y1 direction, while the direction of the current flowing through the switching element Q2 is Y2. The direction. As a result, between the capacitor Cd and the diode D1, between the diode D1 and the first wiring portion 51c, between the first wiring portion 51c and the capacitor Cf, between the capacitor Cf and the first wiring portion 51d, the first Radiation noise (capacitor) is reduced (cancelled) between the wiring portion 51d and the switching element Q2.

Further, in the first embodiment, as shown in FIGS. 8 and 9, the wiring 5 is provided on the second layer 6b of the multilayer board 6 so as to overlap the first wiring 51 in a plan view, and the switching element Q2 Includes a second wire 52 that electrically connects the capacitor Cd and the capacitor Cd. Then, as shown in FIG. 9, the second wiring 52 is configured so that the current flows in a direction substantially opposite to the direction of the current flowing through the first wiring 51. Specifically, in a plan view, the second wiring 52 is provided on the second layer 6b of the multilayer substrate 6 so as to have a path substantially along the path of the first wiring 51. That is, the second wiring 52 has a meandering shape like the first wiring 51.

Specifically, the second wiring 52 has the same shape as the first wiring portion 51a to the first wiring portion 51e of the first wiring 51. Then, in a plan view, the first wiring 51 and the second wiring 52 substantially overlap (overlap). Further, the first wiring 51 and the second wiring 52 are connected by a via 53 (see FIG. 8). Then, the current flowing from the positive potential side of the capacitor Cd flows to the negative potential side of the capacitor Cd via the diode D1, the capacitor Cf, the switching element Q2, the via 53, the second wiring 52, and the via 53. As a result, the radiation noise (magnetic flux) generated by the current flowing through the capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 is reduced (offset) by the radiation noise (magnetic flux) generated by the current flowing through the second wiring 52. ..

[Effect of the first embodiment]
In the first embodiment, the following effects can be obtained.

In the first embodiment, as described above, the capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 (components 4a, 4b, 4c, and 4d constituting these) are arranged so as to be adjacent to each other. At least one of the adjacent components 4 and the wiring 5 adjacent to the component 4 and the component 4 are arranged so that the directions of the flowing currents are substantially opposite to each other. As a result, the radiation noise (magnetic flux) generated by the current (current flowing in one direction) flowing in one of the adjacent parts 4 (or the wiring 5 adjacent to the parts 4 and the parts 4) and the current flowing in the other. Radiation noise (magnetic flux) generated by (current flowing in a direction substantially opposite to one direction) cancels each other out. As a result, radiation noise can be reduced. As a result, it is possible to suppress malfunction of the component 4 itself (capacitor Cd, diode D1, capacitor Cf and switching element Q2) and malfunction of components (equipment) arranged around the component 4.

Further, in the first embodiment, as described above, the capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 (components 4a, 4b, 4c, and 4d constituting these) are aligned in the X direction. , Are arranged next to each other. As a result, all of the components 4 constituting each of the capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 are adjacent to each other in a state of being arranged along the X direction. At least one of the component 4 and the wiring 5 adjacent to the component 4 can easily have the directions of the flowing currents substantially opposite.

Further, in the first embodiment, as described above, the wiring 5 is provided in the first layer 6a of the multilayer board 6, and the capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 are connected in this order. Includes wiring 51. As a result, the component 4 and the wiring 5 are arranged on the same plane (first layer 6a of the multilayer board 6), so that radiation noise (magnetic flux) is generated on the same plane (first layer 6a of the multilayer board 6). You can cancel each other out.

Further, in the first embodiment, as described above, in the plan view, the components 4 constituting each of the capacitor Cd, the diode D1, the capacitor Cf and the switching element Q2 are connected to each other by the first wiring 51 having a meandering shape. Has been done. As a result, the directions of the currents flowing between the adjacent parts 4 in the first wiring 51 having a meandering shape are substantially opposite to each other, so that the directions of the currents flowing between the adjacent parts 4 are easily opposite to each other, and the parts 4 and the parts 4 are adjacent to each other easily. The direction of the current flowing in at least one of the wiring 5 can be made substantially opposite.

Further, in the first embodiment, as described above, the wiring 5 is provided on the second layer 6b of the multilayer substrate 6 so as to overlap the first wiring 51 in a plan view, and the switching element Q2 and the capacitor Cd are connected. Includes a second wiring 52 that is electrically connected and has a current flowing in a direction substantially opposite to the direction of the current flowing through the first wiring 51. As a result, the direction of the current flowing through the second wiring 52 is substantially opposite to the direction of the current flowing through the first wiring 51, so that radiation noise (magnetic flux) is generated between the first wiring 51 and the second wiring 52. Can cancel each other out. Thereby, the radiation noise can be further reduced.

Further, in the first embodiment, as described above, the second wiring 52 is provided on the second layer 6b of the multilayer substrate 6 so as to have a path substantially along the path of the first wiring 51 in a plan view. Has been done. Thereby, the radiation noise (magnetic flux) can be effectively canceled between the first wiring 51 and the second wiring 52.

Further, in the first embodiment, as described above, the diode D1, the diode D2, the switching element Q1 and the switching element Q2 are composed of the wide bandgap semiconductor. Here, since the wide bandgap semiconductor can be switched at high speed (that is, the switching frequency is high), the energy of radiated noise becomes relatively large. Therefore, when the diode D1, the diode D2, the switching element Q1 and the switching element Q2 are composed of a wide bandgap semiconductor, between the adjacent components 4 and between the component 4 and the wiring 5 adjacent to the component 4. Arranging the component 4 so that the directions of the currents flowing in at least one of the components 4 are substantially opposite to each other is particularly effective in reducing radiation noise. Further, the radiation noise due to the wide bandgap semiconductor having a relatively large radiation noise can be reduced without separately providing a component for noise countermeasures. As a result, radiation noise can be reduced while suppressing the increase in size of the power conversion device 100.

[Second Embodiment]
Next, the configuration of the power conversion device 200 according to the second embodiment will be described with reference to FIGS. 10 to 12. In the second embodiment, the capacitor Cf1 and the capacitor Cf2, which are flying capacitors, are connected in parallel with each other. The capacitor Cf1 and the capacitor Cf2 are examples of the "first capacitor on one side" and the "first capacitor on the other side" in the claims, respectively.

As shown in FIG. 10, in the power conversion device 200, the capacitors Cf1 and the capacitors Cf2 are connected in parallel with each other. Note that, in FIG. 10, the configuration on the circuit diagram other than the point where the capacitor Cf1 and the capacitor Cf2 are connected in parallel with each other is the same as the circuit diagram of the power conversion device 100 of the first embodiment shown in FIG. be.

Here, in the second embodiment, as shown in FIGS. 11 and 12, in the power conversion device 200, the capacitor Cd, the diode D1, the capacitor Cf1, the switching element Q2, the capacitor Cf2, the switching element Q1 and the diode D2 (these are used). The constituent parts 4a, 4b, 41c, 4d, 42c, 4f, and 4e) are arranged so as to be adjacent to each other. Further, they are arranged so that the directions of the flowing currents are substantially opposite between the adjacent components 4 and the wiring 105 adjacent to the component 4 and the component 4.

The capacitor Cd, the diode D1, the capacitor Cf1, the switching element Q2, the capacitor Cf2, the switching element Q1 and the diode D2 are connected to each other by a wiring 105 made of a pattern wiring. Here, the configuration of the capacitor Cd, the diode D1, the capacitor Cf1 and the switching element Q2 is the same as the configuration in which the capacitor Cf of the power conversion device 100 of the first embodiment is replaced with the capacitor Cf1.

Further, the positive potential side of the capacitor Cf2 and the diode D2 are connected by a first wiring portion 105a having a substantially U-shape. Further, the diode D2 and the switching element Q1 are connected by a first wiring portion 105b having a substantially S-shape. Further, the switching element Q1 and the negative potential side of the capacitor Cf2 are connected by a first wiring portion 105c having a substantially U-shape. The first wiring portions 105a, 105b and 105c for connecting the capacitor Cf2, the switching element Q1 and the diode D2 are provided on the first layer 6a of the multilayer board 6, and the second layer 6b has the capacitor Cf2. No wiring is provided to connect the switching element Q1 and the diode D2.

Then, the directions of the currents flowing between the adjacent capacitors Cf2 and the switching element Q1 are substantially opposite to each other. Further, the directions of the flowing currents are substantially opposite between the adjacent diodes D2 and the first wiring portion 105b. Further, the directions of the flowing currents are substantially opposite between the adjacent first wiring portion 105b and the switching element Q1. This makes it possible to reduce (cancel) radiation noise (magnetic flux) between adjacent components 4 or between adjacent components 4 and the wiring 105. That is, when the radiation noise in the series circuit including the switching element Q1, the diode D2 and the capacitor Cf (switching element Q1 is on, see FIG. 4) becomes relatively large, the capacitor Cf (first embodiment) is changed to the capacitor Cf1. By replacing the capacitor Cf2 with the capacitor Cf2 in parallel (second embodiment), it is possible to reduce the radiation noise of the series circuit described above.

[Effect of the second embodiment]
In the second embodiment, the following effects can be obtained.

In the second embodiment, as described above, the capacitor Cd, the diode D1, the capacitor Cf1, the switching element Q2, the capacitor Cf2, the switching element Q1 and the diode D2 (components 4a, 4b, 41c, 4d, which constitute these). The component 42c, the component 4f, and the component 4e) are arranged so as to be adjacent to each other, and at least one of the adjacent components 4 and the wiring 105 adjacent to the component 4 and the component 4 is adjacent to each other. In, the directions of the flowing currents are arranged so as to be substantially opposite to each other. As a result, even when the radiation noise generated in the series circuit including the capacitor Cf2, the switching element Q1 and the diode D2 becomes large, between the components 4 constituting each of the capacitor Cf2, the switching element Q1 and the diode D2, and Since the directions of the currents flowing in at least one of the component 4 and the wiring 105 adjacent to the component 4 are substantially opposite, the radiation noise generated in the series circuit can also be reduced. Further, unlike the case where one relatively large capacitor Cf is arranged, the arrangement of the relatively small capacitor Cf1 and the capacitor Cf2 divided into two can be easily performed.

[Modification example]
It should be noted that the embodiments disclosed this time are exemplary in all respects and are not considered to be restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the above-described embodiment, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims.

For example, in the first and second embodiments, the directions of the flowing currents are substantially opposite both between adjacent parts and between the parts and the wiring adjacent to the parts. The present invention is not limited to this. For example, the directions of the currents flowing may be substantially opposite between the adjacent parts and only one of the parts and the wiring adjacent to the parts. That is, the capacitor Cd, the diode D1, the capacitor Cf, and the switching element Q2 may be arranged so as to be adjacent to each other so that the directions of the currents flowing between the adjacent components are substantially opposite to each other.

Further, in the first and second embodiments, an example is shown in which the present invention is applied to a power conversion device in which a diode D1, a diode D2, a switching element Q1 and a switching element Q2 are connected in series, but the present invention presents the present invention. Not limited to this. For example, as shown in FIG. 13, the present invention can be applied to a power conversion device 300 according to a modified example in which a switching element Q11 and a switching element Q12 are provided instead of the diode D1 and the diode D2.

Further, in the first and second embodiments, the example in which the capacitor Cd, the diode D1, the capacitor Cf and the switching element Q2 are arranged along the X direction is shown, but the present invention is not limited to this. .. For example, the capacitor Cd and the diode D1 are arranged along the X direction so that the directions of the flowing currents are opposite to each other, and the capacitor Cf and the switching element Q2 are along the Y direction so that the directions of the flowing currents are opposite to each other. It may be arranged so as to.

Further, in the first and second embodiments, an example is shown in which the wiring includes the first wiring provided in the first layer of the multilayer board and the second wiring provided in the second layer of the multilayer board. , The present invention is not limited to this. For example, the wiring may be composed only of the first wiring provided in the first layer of the multilayer board.

Further, in the first and second embodiments, the example in which the second wiring has a meandering shape similar to that of the first wiring is shown, but the present invention is not limited to this. For example, the second wiring may be configured to linearly connect the switching element Q2 and the negative potential side of the capacitor Cd.

Further, in the first and second embodiments, an example is shown in which the diode D1, the diode D2, the switching element Q1 and the switching element Q2 are all composed of a wide bandgap semiconductor, but the present invention is limited to this. No. For example, only one of the diode D1, the diode D2, the switching element Q1 and the switching element Q2 may be composed of the wide bandgap semiconductor.

1 DC power supply 2 Reactors 4, 4a to 4f, 41c, 42c Parts 5, 105 Wiring 6 Multilayer board 6a First layer 6b Second layer 51 First wiring 52 Second wiring 100, 200, 300 Power converter A1, A2, A3 connection point Cd capacitor (second capacitor)
Cf capacitor (first capacitor)
Cf1 capacitor (first capacitor on one side)
Cf2 capacitor (first capacitor on the other side)
D1 diode (first element)
D2 diode (second element)
Q1 Switching element (3rd element)
Q2 switching element (4th element)

Claims (8)

DC power supply and
It is composed of a first element composed of a diode or a switching element connected in series with each other, a second element composed of the diode or the switching element, a third element composed of the switching element, and the switching element. Switching circuit section including the 4th element
A reactor in which one end is connected to the DC power supply and the other end is connected to the connection point between the second element and the third element.
A first capacitor connected to a connection point between the first element and the second element and a connection point between the third element and the fourth element.
A second capacitor connected in parallel to the switching circuit section,
The first element, the second element, the third element, the fourth element, the first capacitor, and the wiring for connecting the components constituting each of the second capacitor are provided.
The parts constituting each of the second capacitor, the first element, the first capacitor, and the fourth element are arranged so as to be adjacent to each other, and are placed between the adjacent parts and the parts. A power conversion device arranged so that the directions of flowing currents are substantially opposite to each other at at least one of the wiring between the component and the wiring adjacent to the component. The first aspect of the present invention, wherein the parts constituting each of the second capacitor, the first element, the first capacitor, and the fourth element are arranged so as to be adjacent to each other along a predetermined direction. The power converter described. The first element, the second element, the third element, the fourth element, the first capacitor, and the second capacitor are provided in the first layer of the multilayer substrate.
The wiring is provided in the first layer of the multilayer substrate, and includes a first wiring that connects the second capacitor, the first element, the first capacitor, and the fourth element in this order. The power conversion device according to 1 or 2. In a plan view, the first wiring has a meandering shape.
The third aspect of the present invention, wherein the components constituting each of the second capacitor, the first element, the first capacitor, and the fourth element are connected to each other by the first wiring having a meandering shape. Power converter. The wiring is provided in the second layer of the multilayer substrate so as to overlap the first wiring in a plan view, electrically connects the fourth element and the second capacitor, and is connected to the first wiring. The power conversion device according to claim 3 or 4, further comprising a second wiring in which a current flows in a direction substantially opposite to the direction of the flowing current. The power conversion device according to claim 5, wherein the second wiring is provided in the second layer of the multilayer substrate so as to have a path substantially along the path of the first wiring in a plan view. .. The first capacitor includes a first capacitor on one side and a first capacitor on the other side connected in parallel with each other.
The components constituting each of the second capacitor, the first element, the first capacitor on one side, the fourth element, the first capacitor on the other side, the third element, and the second element are adjacent to each other. And at least one of the adjacent parts and the wiring between the parts and the wiring adjacent to the parts, the directions of the currents flowing are substantially opposite to each other. The power conversion device according to any one of claims 1 to 6. The electric power according to any one of claims 1 to 7, wherein at least one of the first element, the second element, the third element, and the fourth element is composed of a wide bandgap semiconductor. Conversion device.

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