JP2005065414A - Inverter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter device which has a conductor device with lower inductance. <P>SOLUTION: This inverter device is of laminate structure where an anode conductor 1, an insulating sheet 3, and a cathode conductor 4 are arranged in this order, and an insulating gap 2, which has a flange part 10 for gaining a creeping distance and barrier parts 11 and 12 for securing spatial distances, is arranged between the anode conductor 1 and the insulating sheet 3. Since only the round holes 9 and 17 of indispensable minimum size to only pass and arrange the barrier part 12 of the insulating gap 2, as for the anode conductor 1, and the barrier part 11, as for the cathode conductor 4, are opened, this inverter can enlarge the reduction effect of the inductance being obtained by approximating counter currents to each other, whereby this can suppress the surge voltage, thus it becomes possible to omit a fuse and a snubber circuit. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an inverter device, and more particularly to an inverter device that enables high-speed switching by connecting a smoothing capacitor and a semiconductor switching element with a low-inductance conductor device having a laminated structure.

  The inverter device includes a plurality of smoothing capacitors serving as a power source, a plurality of semiconductor switching elements, and a snubber circuit connected to each semiconductor switching element, and the smoothing capacitor and the semiconductor switching element are connected by a conductor device. This conductor device is known to have a laminate structure comprising a plate-like anode conductor constituting an anode electrode, a plate-like cathode conductor constituting a cathode electrode, and an insulating sheet sandwiched therebetween (for example, , See Patent Document 1).

  4 is a developed perspective view showing a conventional conductor device, FIG. 5 is a completed perspective view showing the conventional conductor device, FIG. 6 is a plan view showing conductors constituting the conventional conductor device, and FIG. A conductor (B) represents a cathode conductor.

  The conventional conductor device includes a plate-like anode conductor 101, an insulating sheet 102, and a plate-like cathode conductor 103. The anode conductor 101 has an anode power input terminal 104, an anode power output terminal 105 connected to the semiconductor switching element, and an anode terminal connection portion 106 connected to the anode terminal of the smoothing capacitor. The anode terminal connecting portion 106 is formed with a notch 107 around it, and is stepped so as to be at the same level as the cathode conductor 103 when the conductor device is completed, and the cathode terminal of the smoothing capacitor cathode terminal. The insulation distance is secured.

  The cathode conductor 103 has a cathode power source input terminal 108, a cathode power source output terminal 109 connected to the semiconductor switching element, and a cathode terminal connection portion 110 connected to the cathode terminal of the smoothing capacitor. A notch 111 is formed adjacent to 110 to ensure an insulation distance from the anode terminal of the smoothing capacitor.

  When the insulating sheet 102 is sandwiched between the anode conductor 101 and the cathode conductor 103, a notch 112 is formed at a portion corresponding to the anode terminal connection portion 106 of the anode conductor 101 and the cathode terminal connection portion 110 of the cathode conductor 103. Have.

As described above, the conductor device that electrically connects the smoothing capacitor and the semiconductor switching element has a laminated configuration, so that the opposing currents flowing through the anode conductor 101 and the cathode conductor 103 become close to each other. The inductance is offset and the wiring inductance can be reduced. By reducing the inductance of the conductor device, the surge voltage applied to the semiconductor switching element during switching is reduced, and the capacity of the snubber capacitor can be reduced or omitted.
JP-A-9-117126 (paragraph numbers [0007] to [0008], [0012], FIG. 2)

  However, the conductor device used in the conventional inverter device is a laminate configuration in which the anode conductor and the cathode conductor from the semiconductor switching element to the smoothing capacitor are stacked in a plane, and only the insulating sheet is interposed between the conductor phases. In order to secure the insulation distance of the connection part to the terminal of each smoothing capacitor, the anode conductor and the cathode conductor need to be largely cut out around each terminal connection part, and there is a range that is not laminated, There was a problem that it became a bottleneck for inductance reduction. In particular, when an IGBT (insulated gate bipolar transistor) element is used as the semiconductor switching element of the large-capacity inverter device, it is necessary to further reduce the wiring inductance in order to suppress the surge voltage below the element breakdown voltage.

  This invention is made | formed in view of such a point, and it aims at providing the inverter apparatus which has a conductor apparatus made into low inductance.

  In the present invention, in order to solve the above-described problem, a smoothed conductor device in which an insulating sheet is sandwiched between a first conductor constituting the first electrode and a second conductor constituting the second electrode is used. In the inverter device for connecting a capacitor and a semiconductor switching element, the second conductor is arranged between the first conductor and the second conductor and connected to one of the terminal connection portions of the smoothing capacitor. A cylindrical first barrier portion extending through the first conductor so as to surround a screw to be engaged with a first flange portion having a peripheral edge portion separated from the periphery of the first barrier portion by a predetermined distance. A first insulating cap having the first conductor, and a screw disposed between the first conductor and the second conductor to connect the first conductor to the other of the terminal connection portions of the smoothing capacitor. Said first conductor A cylindrical second barrier portion extending through the second conductor and a peripheral portion of the second barrier portion so as to surround a round step portion provided with a step having a substantially plate thickness in the direction of the conductor of the second barrier portion. And a second insulating cap having a second flange portion separated by a predetermined distance from the surroundings, and the first conductor is simply disposed through the first barrier portion of the first insulating cap. A first round hole and a second round hole provided in the center of the stepped portion, and the second conductor is disposed through the second barrier portion of the second insulating cap. There is provided an inverter device characterized by having a third round hole to be allowed to pass and a fourth round hole through which the screw is passed.

  According to such an inverter device, the first and second conductors constituting the laminate-structured conductor device are provided only by the first and second barrier portions of the first and second insulating caps. Since only the first and third round holes are opened, the area overlapped in the plane can be maximized, and thereby the inductance obtained by bringing the opposing currents flowing through the first and second conductors close to each other. As a result, the surge voltage applied to the semiconductor switching element during switching can be suppressed, and the fuse and the snubber circuit can be omitted.

  In the inverter device of the present invention, since the inductance of the conductor device connecting the smoothing capacitor and the semiconductor switching element is reduced, the surge voltage applied to the semiconductor switching element at the time of switching can be suppressed below the element breakdown voltage. In this case, not only the snubber circuit can be omitted, but also a normally provided fuse can be omitted, so that there is an advantage that the cost of the inverter device can be reduced.

Hereinafter, a case where the embodiment of the present invention is applied to a three-phase AC output inverter device will be described in detail with reference to the drawings.
1 is a developed perspective view showing a conductor device of an inverter device according to the present invention, FIG. 2 is a completed perspective view showing a conductor device of the inverter device according to the present invention, and FIG. 3 shows conductors constituting the conductor device of the inverter device according to the present invention. It is the top view shown, Comprising: (A) has shown the anode conductor, (B) has shown the cathode conductor.

  The conductor device of the inverter device according to the present invention includes a plate-like anode conductor 1, an insulation cap 2 in which first and second insulation caps are integrally formed by resin molding, an insulation sheet 3, and a plate-like cathode conductor 4. And. The anode conductor 1 has a shape in which two opposite sides of a substantially rectangular conductor plate are bent in opposite directions, and an anode power input terminal 5 is integrally formed on one of the bent pieces, and the other bent piece has The anode power supply output terminal 6 connected to the semiconductor switching element is integrally formed. In the inverter device of this example, three sets of semiconductor switching elements are provided in order to obtain a three-phase alternating current output, so three anode power supply output terminals 6 are provided. The anode conductor 1 also has an anode terminal connection portion 7 connected to the anode terminal of the smoothing capacitor. The anode terminal connecting portion 7 is provided with a concave portion having a step corresponding to the plate thickness in the anode conductor 1, and a round hole for inserting a screw 8 screwed to the anode terminal of the smoothing capacitor is formed in the center thereof. It is formed by being installed. In this example, four anode terminal connection portions 7 are provided at positions corresponding to the anode terminals in order to connect four smoothing capacitors to the anode conductor 1 in parallel. A round hole 9 for inserting a screw 8 screwed to the cathode terminal of the smoothing capacitor adjacent to the anode terminal connecting portion 7 is also formed in the anode conductor 1.

  The insulating cap 2 has a thin flange portion 10 for increasing a creepage distance, and cylindrical barrier portions 11 and 12 extending in opposite directions from the surface of the flange portion 10 to ensure a spatial distance. The flange portion 10 and the barrier portions 11 and 12 are integrally molded with an insulating resin. The flange portion 10 has a peripheral edge portion that is separated from the periphery of the barrier portions 11 and 12 by a certain distance. The large-diameter barrier portion 11 of the insulating cap 2 has a through hole that does not interfere with the stepped portion of the anode terminal connecting portion 7, and the small-diameter barrier portion 12 has a through hole through which the screw 8 can pass. The barrier portion 12 is inserted into the round hole 9 of the anode conductor 1 when the conductor device is assembled.

  The insulating sheet 3 has a shape in which two opposing sides of a substantially rectangular sheet are bent in opposite directions, and a large-diameter circle into which the large-diameter barrier portion 11 of the insulating cap 2 is inserted when the conductor device is assembled. Four sets of holes 13 and round holes 14 having the same diameter as the round holes 9 of the anode conductor 1 are provided.

  The cathode conductor 4 has a shape in which two opposite sides of a substantially rectangular conductor plate are bent in opposite directions, and a cathode power input terminal 15 is integrally formed on one of the bent pieces, and the other bent piece has The four cathode power output terminals 16 connected to the semiconductor switching element are integrally formed. The cathode conductor 4 is also screwed into the large-diameter round hole 17 having the same diameter as the round hole 13 of the insulating sheet 3 through which the large-diameter barrier portion 11 of the insulating cap 2 is inserted, and the cathode terminal of the smoothing capacitor. And a round hole 18 through which the screw 8 is inserted.

  The conductor device has a laminated structure in which the anode conductor 1, the insulating sheet 3, and the cathode conductor 4 are arranged in this order, the insulating cap 2 is between the anode conductor 1 and the insulating sheet 3, and the barrier portion 11 is a round of the insulating sheet 3. By arranging the hole 13 and the round hole 17 of the cathode conductor 4 so that the barrier portion 12 penetrates the round hole 9 of the anode conductor 1, it is configured as shown in FIG. 2. In the anode conductor 1 and the cathode conductor 4 around each connection portion by the screw 8, only the necessary minimum round holes 9 and 17 for escaping the shape of the insulating cap 2 are formed.

  Therefore, by using the insulating sheet 3 and the insulating cap 2 to maximize the area where the anode conductor 1 and the cathode conductor 4 can be overlapped on a plane, it is possible to laminate portions that could not be laminated conventionally. Thus, the effect of reducing the inductance obtained by bringing the opposing currents flowing through the anode conductor 1 and the cathode conductor 4 close to each other can be further increased. By reducing the wiring inductance, the surge voltage applied to the semiconductor switching element during switching can be further suppressed. Therefore, under the operating conditions where the surge voltage is kept below the element breakdown voltage, it is possible not only to omit the fuse and snubber circuit, which have been necessary in the past, but also to greatly reduce the capacity of the snubber circuit capacitor. It is possible to employ an IGBT whose withstand voltage of the element is severe as a semiconductor switching element.

  In the above embodiment, one insulating cap 2 is used for one smoothing capacitor. However, if the smoothing capacitor has a large inter-terminal distance or does not require a long creepage distance, a smoothing capacitor is used. One may be used for each capacitor terminal.

It is an expansion | deployment perspective view which shows the conductor apparatus of the inverter apparatus by this invention. It is a completion perspective view which shows the conductor apparatus of the inverter apparatus by this invention. It is a top view which shows the conductor which comprises the conductor apparatus of the inverter apparatus by this invention, Comprising: (A) has shown the anode conductor, (B) has shown the cathode conductor. It is an expansion | deployment perspective view which shows the conventional conductor apparatus. It is a completion perspective view which shows the conventional conductor apparatus. It is a top view which shows the conductor which comprises the conventional conductor apparatus, Comprising: (A) has shown the anode conductor, (B) has shown the cathode conductor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anode conductor 2 Insulation cap 3 Insulation sheet 4 Cathode conductor 5 Anode power supply input terminal 6 Anode power output terminal 7 Anode terminal connection part 8 Screw 9 Round hole 10 Flange part 11,12 Barrier part 13,14 Round hole 15 Cathode power supply input terminal 16 Cathode power output terminal 17, 18 Round hole

Claims (2)

A smoothing capacitor and a semiconductor switching element are connected by a laminated conductor device in which an insulating sheet is sandwiched between a first conductor constituting the first electrode and a second conductor constituting the second electrode. In the inverter device,
The first conductor is inserted between the first conductor and the second conductor so as to surround a screw that connects the second conductor to one of the terminal connection portions of the smoothing capacitor. A first insulating cap having an extending cylindrical first barrier portion and a first flange portion whose peripheral edge portion is separated from the periphery of the first barrier portion by a predetermined distance; the first conductor; A plate approximately in the direction of the second conductor to the first conductor to seat a screw disposed between the second conductor and connecting the first conductor to the other terminal connection of the smoothing capacitor. A cylindrical second barrier portion extending through the second conductor and a peripheral portion are separated from the periphery of the second barrier portion by a predetermined distance so as to surround a round step portion provided with a thickness step. And a second insulating cap having a second flange portion,
The first conductor has a first round hole that only allows the first barrier portion of the first insulating cap to pass through, and a second round hole provided in the center of the stepped portion. And
The second conductor has a third round hole that only allows the second barrier portion of the second insulating cap to pass therethrough, and a fourth round hole that passes the screw.
An inverter device characterized by that.   2. The inverter device according to claim 1, wherein the first and second insulating caps are integrally formed by resin molding.

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