JP6673741B2 - Full bridge circuit and power converter - Google Patents

Description

  The present invention relates to a full bridge circuit and a power conversion device.

  2. Description of the Related Art Conventionally, there is known a half-bridge inverter in which electrodes of heat radiating portions of a high side arm and a low side arm of a switching element are different from each other and connected to the same heat sink without insulating a heat radiating plate (for example, Patent Document 1).

JP 2010-148229 A

  However, in the technology described in Patent Literature 1, since the electrodes of the heat radiating section are of different types, the switching element of the high side arm and the switching element of the low side arm are separate components, and the types of components increase and the cost increases.

  An object of the present invention, which has been made in view of such circumstances, is to reduce the cost of components, and to realize a printed circuit and a switching element on a substrate that are short and have good routing and are capable of realizing an arrangement of switching elements. Is to provide.

  A full bridge circuit according to one embodiment of the present invention includes a circuit board having an opening, and a plurality of switching elements of the same type arranged in the opening in a plan view of the circuit board. The first phase high side arm, the first phase low side arm, the second phase high side arm and the second phase low side arm. The high-side arm and the low-side arm of the second phase are a line segment connecting the high-side arm of the first phase and the high-side arm of the second phase in plan view of the circuit board. The low-side arm of the first phase and the line connecting the low-side arm of the second phase are arranged in the opening so as to intersect with each other.

  A power converter according to one embodiment of the present invention is a power converter including a full-bridge circuit, wherein the full-bridge circuit has a circuit board having an opening, and the circuit board has an opening in a plan view of the circuit board. A plurality of switching elements of the same type arranged, wherein the plurality of switching elements are a first phase high side arm, a first phase low side arm, a second phase high side arm, and a second phase high side arm. A low-side arm of two phases, wherein the high-side arm of the second phase and the low-side arm of the second phase are connected to the high-side arm of the first phase in plan view of the circuit board. The opening is formed in a positional relationship where a line connecting the high-side arm of the second phase and a line connecting the low-side arm of the first phase and the low-side arm of the second phase intersect. It is placed in.

  According to the full-bridge circuit and the power converter according to the embodiment of the present invention, it is possible to reduce the cost of components and realize the shortest arrangement of the printed pattern and the switching elements on the board with good routing.

FIG. 1 is a diagram illustrating a power converter including a full bridge circuit according to an embodiment of the present invention. It is a top view of the circuit board concerning one embodiment of the present invention. It is AA sectional drawing of FIG. It is a top view of the circuit board concerning one embodiment of the present invention. FIG. 5 is a composite diagram of FIG. 2 and FIG. 4. It is a top view of a circuit board concerning other embodiments of the present invention.

  The power conversion device 90 according to the embodiment of the present invention illustrated in FIG. 1 includes at least a full bridge circuit 80 and cooperates with a power system. The full bridge circuit 80 is applied to, for example, an inverter of the power converter 90, but may be applied to a DC / DC converter. The power conversion device 90 may include, for example, a voltage measurement unit, a system interconnection switch, and the like in addition to those illustrated in FIG. In the present embodiment, a case where the full bridge circuit 80 is applied to a single-phase three-wire system will be described. However, as an alternative example, the full-bridge circuit 80 may be applied to a single-phase two-wire system or a three-phase three-wire system.

  The full bridge circuit 80 includes a plurality of switching elements of the same type. The plurality of switching elements of the present embodiment include a high-side arm S1 of a first phase, a low-side arm S2 of a second phase, a low-side arm S3 of a first phase, and a high-side arm S4 of a second phase. Arms S1 to S4 collectively). In the present embodiment, the first phase is the U phase of the system and the second phase is the W phase of the system. However, as an alternative, the second phase may be a V phase. Each of the arms S1 to S4 is, for example, an IGBT (Insulated Gate Bipolar Transistor). As an alternative example, each of the arms S1 to S4 may be an FET (Field Effect Transistor). When each of the arms S1 to S4 is an IGBT, the IGBT may be provided in a single package with a freewheeling diode connected between the collector and the emitter of the IGBT.

  The collector terminal of the high-side arm S1 of the first phase and the collector terminal of the high-side arm S4 of the second phase are connected to the DC bus 12a. The emitter terminal of the low-side arm S3 of the first phase and the emitter terminal of the low-side arm S2 of the second phase are connected to the DC bus 12b.

  Snubber capacitors 4a to 4c are connected between the DC bus 12a and the DC bus 12b. The capacitors 4a to 4c are, for example, film capacitors. Alternatively, the number of capacitors connected between the DC bus 12a and the DC bus 12b may be 0 to 2 or 4 or more.

  FIG. 2 is a diagram illustrating an A-side pattern when the full bridge circuit 80 according to the embodiment of the present invention is viewed from one side (hereinafter, referred to as an A-side) of the circuit board 1. The full bridge circuit 80 has at least a circuit board 1 made of an arbitrary resin, a DC bus 12b1, and capacitors 4a to 4c. The full bridge circuit 80 may have other elements such as a capacitor and a diode, but the description is omitted in this embodiment. The presence or absence of the temperature sensor 3 and the number of capacitors are arbitrary.

  The circuit board 1 has an opening 11. The shape of the opening 11 is an N-sided polygon (N is an even number) or a circle, but the opening 11 of the present embodiment is a quadrilateral. In the present embodiment, for convenience of description, one of the four sides of the opening 11 on the left side in FIG. Note that the side 11a may be another side. In the present embodiment, a side opposite to the side 11a is a side 11b.

  A heat sink 2 is provided on the back side of the A side of the circuit board 1. The heat sink 2 contacts the arms S1 to S4 and cools the arms S1 to S4. For example, the arms S1 to S4 are screwed to the heat sink 2. As shown in FIG. 2, the area of the heat sink 2 in plan view of the circuit board 1 is slightly smaller than the area of the circuit board 1, but the area of the heat sink 2 is arbitrary. The area of the heat sink 2 may be, for example, equal to the area of the opening 11 or may be equal to the circuit board 1.

  At least a part of the arms S <b> 1 to S <b> 4 is arranged in the opening 11 in a plan view of the circuit board 1. That is, at least a part of the arms S <b> 1 to S <b> 4 is visible through the opening 11 in a plan view of the circuit board 1.

  The opening 11 has a first region R1 and a second region R2. The first region R1 is a region along the side 11a of the opening 11, and the second region R2 is a region along the side 11b of the opening 11. A first-phase high-side arm S1 and a first-phase low-side arm S3 are arranged in a first region R1, and a second-phase high-side arm S4 and a second-phase high-side arm S4 are arranged in a second region R2. Is disposed.

  Line segment L1 is a line segment connecting the reference point of high-side arm S1 of the first phase and the reference point of high-side arm S4 of the second phase, and line segment L2 is the line segment of low-side arm S3 of the first phase. This is a line segment connecting the reference point and the reference point of the low-side arm S2 of the second phase. The reference point may be, for example, a screw hole for fixing each of the arms S1 to S4 to the heat sink 2. The high-side arm S4 of the second phase and the low-side arm S2 of the second phase are arranged in the opening 11 in a positional relationship where the line segment L1 and the line segment L2 intersect in a plan view of the circuit board 1.

  As shown in FIG. 2, in plan view of the circuit board 1, the high-side arm S4 of the second phase and the low-side arm S2 of the second phase are connected to the high-side arm S1 of the first phase and the high-side arm S1 of the first phase. It may be arranged on the side 11b in such a positional relationship as to be point-symmetric with the low side arm S3. In other words, in the full bridge circuit 80, the pair of the high-side arm and the low-side arm of the same phase are arranged on the same side, and the high-side arm and the low-side arm are in a point-symmetrical relationship. May be arranged. To be arranged on the side includes not only being directly connected to the side but also being arranged within a predetermined distance from the side. The center of point symmetry is, for example, the intersection of two diagonal lines of the opening 11. The positional relationship that is point-symmetric includes not only a positional relationship that is exactly point-symmetric but also a positional relationship that is substantially point-symmetric.

  In a plan view of the circuit board 1, a temperature sensor 3 is provided at a position that is equidistant from each of the arms S1 to S4. The position that is equidistant from each of the arms S1 to S4 means that the position is equidistant from each of the reference points of the arms S1 to S4 (for example, the point closest to the temperature sensor 3 in each of the arms S1 to S4). Position. The equidistant position includes not only a positional relationship of exactly equidistant but also a position of approximately equidistant including an error within a predetermined value.

  FIG. 3 is a sectional view taken along line AA of FIG. As shown in FIG. 3, capacitors 4a to 4c are provided on the circuit board 1. A plurality of arms S1 to S4 are arranged below the circuit board 1 in FIG.

  The arms S1 to S4 are provided so as to contact the heat sink 2. Therefore, the arms S1 to S4 dissipate heat via the heat sink 2. Further, in the present embodiment, the temperature sensor 3 is provided on the heat sink 2, but the temperature sensor 3 can be installed at any position as long as the position is equidistant from each of the arms S1 to S4.

  FIG. 4 is a diagram showing a pattern on a surface B opposite to the surface A when the circuit board 1 is viewed from the same direction as in FIG. FIG. 4 shows the B-side pattern with the A-side pattern omitted. When the circuit board 1 is viewed from the same direction as in FIG. 1, the B-side pattern is not actually visible. However, for convenience of description in FIG. 5 described below, a B-side pattern when viewed from the same direction as in FIG. 1 will be described. In FIG. 4, the description of the elements described in FIG. 2 is omitted.

  As shown in FIG. 4, the collector terminal of the high-side arm S1 of the first phase and the collector terminal of the high-side arm S4 of the second phase are connected to the DC bus 12a. The emitter terminal of the low-side arm S2 of the second phase is connected to the DC bus 12b, and the emitter terminal of the low-side arm S3 of the first phase is connected to the DC bus 12b2.

  FIG. 5 shows a combination of the A-side pattern shown in FIG. 2 and the B-side pattern shown in FIG. 4 when the circuit board 1 is viewed from the same direction as in FIG. In FIG. 5, the description of the elements performed in FIG. 2 or FIG. 4 is omitted. As shown in FIG. 5, the DC bus 12b on the side B to which the low-side arm S2 of the second phase is connected and the DC bus 12b2 on the side B to which the low-side arm S3 of the first phase are connected are A They are connected via the DC bus 12b1 on the surface side. The DC bus 12b1 connects the DC bus 12b and the DC bus 12b2 via, for example, through holes.

  According to the present embodiment, since the plurality of switching elements are of the same type, the cost of the arms S1 to S4 can be reduced. In addition, since the arms S1 to S4 can be visually recognized through the opening 11, maintenance such as arm replacement and screwing is easy, and maintenance is good. In addition, it is possible to realize a printed pattern and an arrangement of switching elements on a substrate which is short and has good routing properties while reducing costs.

  The circuit board 1 has an opening 11 through which the arms S1 to S4 are visible. Therefore, since the heat sink 2 is not disposed outside the circuit board 1 in plan view of the circuit board 1, the overall structure can be made compact.

  Further, a line segment L1 connecting the high-side arm S1 of the first phase and the high-side arm S4 of the second phase, and a line segment connecting the low-side arm S2 of the second phase and the low-side arm S3 of the first phase. Crosses L2. For this reason, the connection between the high side arm and the low side arm when configuring the bridge becomes easy. Specifically, the configuration required for connecting the high side arm and the low side arm can be shortened. Thus, the area of the power line, which requires a relatively large area, on the circuit board 1 can be reduced. In addition, the layout of the pattern on the circuit board 1 becomes easy as a whole.

  According to the present embodiment, each of the plurality of switching elements is formed of an IGBT, and the IGBT and the freewheeling diode connected between the collector and the emitter of the IGBT are provided in one package. Here, in general, when a plurality of switching elements are formed of IGBTs, a freewheeling diode is required. In the case where a freewheeling diode is connected to the full bridge circuit 80 of the power conversion device 90 according to the present embodiment as an external component, a freewheeling diode having a large capacity and a large size is required to cope with relatively large power. If such a freewheel diode is to be arranged on the circuit board 1, the arrangement of other elements is restricted, and it is difficult to arrange the arms S1 to S4 in a point-symmetric positional relationship. Therefore, by providing the IGBT and the freewheeling diode connected between the collector and the emitter of the IGBT in one package as in the present embodiment, the above-described positional relationship having the point symmetry can be realized.

  According to the present embodiment, the full bridge circuit 80 further includes the temperature sensor 3 disposed at a position equidistant from each of the plurality of switching elements. The reason that the temperature sensor 3 can be arranged at a position equidistant from each of the plurality of switching elements is because the arms S1 to S4 are arranged in a positional relationship that is point-symmetric. Therefore, whether or not a plurality of switching elements are at abnormal temperatures can be monitored without bias by a single sensor, so that the cost of the temperature sensor 3 can be reduced.

  According to the present embodiment, the high-side arm S1 of the first phase and the low-side arm S3 of the first phase are connected to the low-side arm S2 of the second phase and the high-side arm S4 of the second phase, respectively. A snubber capacitor is connected between the DC buses. For this reason, the snubber capacitor can be arranged at a distance as short as possible ideally for one set of the high-side arm and the low-side arm, so that the snubber effect can be enhanced and noise can be greatly reduced. .

  FIG. 6 is a diagram illustrating a full bridge circuit 80 according to another embodiment. Another embodiment is different from the above embodiment in the arrangement of the DC bus 12a and the DC bus 12b. In other embodiments, descriptions similar to those described in the above embodiment will be omitted.

  In FIG. 6, the circuit board 1 is a board having two or more layers having an insulating layer. As shown in FIG. 6, the DC bus 12a to which the collector terminals of the high-side arm S1 of the first phase and the high-side arm S4 of the second phase are connected is provided on the front surface of the circuit board 1 of FIG. Can be The DC bus 12b to which the emitter terminals of the low-side arm S2 of the second phase and the low-side arm S3 of the first phase are connected is provided on the back surface of the circuit board 1 in FIG.

  At least a portion of the DC bus 12a and the DC bus 12b extend on the same line with the insulating layer of the circuit board 1 interposed therebetween. Specifically, the DC bus 12a and the DC bus 12b extend so as to overlap in the region R3 with the insulating layer interposed therebetween in plan view of the circuit board 1.

  As shown in FIG. 6, the circuit board 1 is provided with snubber capacitors 4a and 4c. However, another capacitor may be provided on the circuit board 1, or the capacitor 4a and the capacitor 4c may not be provided.

  According to another embodiment, at least a portion of the DC bus 12a and the DC bus 12b extend on the same line with the insulating layer interposed therebetween. For this reason, the inductance of the DC bus 12a and the DC bus 12b through which a large current flows can be greatly reduced, thereby reducing noise.

  Although the present invention has been described with reference to the drawings and embodiments, it should be noted that those skilled in the art can easily make various changes and modifications based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, functions included in each member, each unit, each step, and the like can be rearranged so as not to be logically inconsistent. Also, when the present invention is implemented as a method invention, a plurality of units, steps, and the like can be combined into one or divided.

REFERENCE SIGNS LIST 1 Circuit board 2 Heat sink S1 First phase high side arm S2 Second phase low side arm S3 First phase low side arm S4 Second phase high side arm 11 Opening 11a Side 11b Side 3 Temperature sensor 4a Capacitor 4b Capacitor 4c Capacitor 12a DC bus 12b DC bus 12b1 DC bus 12b2 DC bus 80 Full bridge circuit 90 Power converter L1, L2 Line segment R1, R2, R3 area

Claims (7)

A circuit board having an opening;
A plurality of switching elements of the same type arranged in the opening in plan view of the circuit board,
Has,
The plurality of switching elements constitute a first phase high side arm, a first phase low side arm, a second phase high side arm, and a second phase low side arm,
The high-side arm of the second phase and the low-side arm of the second phase connect the high-side arm of the first phase and the high-side arm of the second phase in plan view of the circuit board. A line segment and a line segment connecting the low-side arm of the first phase and the low-side arm of the second phase are disposed in the opening in a positional relationship to intersect;
Full bridge circuit. The full bridge circuit according to claim 1, wherein
The opening includes a first region in which the high-side arm of the first phase and the low-side arm of the first phase are arranged, and a high-side arm of the second phase and a low-side arm of the second phase. A second area on which the arm is arranged,
The opening has an N-sided shape (N is an even number),
The first region is a region along one side of the opening,
The second region is a region along a side opposite to the one side,
The high-side arm of the second phase and the low-side arm of the second phase are point-symmetric with the high-side arm of the first phase and the low-side arm of the first phase in plan view of the circuit board. Placed in such a positional relationship,
Full bridge circuit. The full bridge circuit according to claim 1 or 2,
A full bridge circuit, wherein each of the plurality of switching elements is formed of an IGBT, and the IGBT and a freewheeling diode connected between a collector and an emitter of the IGBT are provided in one package. The full bridge circuit according to claim 1, wherein:
A full-bridge circuit further comprising a temperature sensor disposed at a position equidistant from each of the plurality of switching elements. A full bridge circuit according to any one of claims 1 to 4, wherein
The high-side arm of the first phase and the low-side arm of the first phase are connected between DC buses to which the high-side arm of the second phase and the low-side arm of the second phase are respectively connected. A full-bridge circuit further comprising a snubber capacitor. The full bridge circuit according to claim 1, wherein:
The circuit board is a board of two or more layers having an insulating layer,
At least a DC bus to which each high-side arm of the first phase and the second phase is connected and a DC bus to which each low-side arm of the first phase and the second phase are connected A part is a full bridge circuit extending on the same line with the insulating layer interposed therebetween. A power converter including a full bridge circuit,
The full bridge circuit,
A circuit board having an opening;
A plurality of switching elements of the same type arranged in the opening in plan view of the circuit board,
Has,
The plurality of switching elements constitute a first phase high side arm, a first phase low side arm, a second phase high side arm, and a second phase low side arm,
The high-side arm of the second phase and the low-side arm of the second phase connect the high-side arm of the first phase and the high-side arm of the second phase in plan view of the circuit board. A line segment and a line segment connecting the low-side arm of the first phase and the low-side arm of the second phase are disposed in the opening in a positional relationship to intersect;
Power converter.

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