JP2005166867A - Conductor structure for power conversion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the weight and cost of a power conversion apparatus by decreasing the amount of copper materials used as conductors in the power conversion apparatus. <P>SOLUTION: A first conductor 17a for connecting power semiconductor elements 15a-15c and the first potential of DC smoothing capacitors 3a-3d is shaped into a sheet, and part of the sheet is cut away. A second conductor 18a for connecting the elements 15a-15c and the second potential of the capacitors 3a-3d is also shaped into a sheet, and the two conductors 17a and 18b are arranged to be adjacent to each other. Specifically, the size of the second conductor 18a is made to be such that it fits in the space created by the partial removal of the first conductor 17a, and this contributes to weight reduction, shape simplification, and cost reduction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a conductor structure of a power conversion device using a power semiconductor module.

  FIG. 3 shows a main circuit diagram of an inverter that converts from direct current to alternating current, which is a typical example of a power converter. In the figure, reference numeral 1 is an AC power source, 2 is a rectifying unit for converting AC to DC, 3 is a DC smoothing capacitor, and a large-capacity electrolytic capacitor is usually used. 4 is a load such as a motor, and 5 is an inverter unit for converting from direct current to alternating current. The rectifying unit 2 and the inverter unit 5 are composed of a plurality of power semiconductors. Reference numeral 6 of the inverter unit 5 is an IGBT (Insulated Gate Bipolar Transistor), 7 is a diode connected in antiparallel with the IGBT, and these are composed of 6 circuits. Moreover, although the rectifier 2 is a diode rectifier circuit, it may have a circuit configuration similar to that of the inverter 5.

  The power semiconductor module usually has two elements for the upper and lower arms as one set, or six elements as one set. When a normal converter or inverter is configured, when the elements are not connected in parallel, 2 Three modules with elements are connected in parallel, or one with six elements is used as it is. The fuse 8 is connected to prevent secondary damage when the power semiconductor element of the electrolytic capacitor 3, the rectifying unit 2 or the inverter unit 5 fails and an overcurrent flows, as shown in the figure. Inserted between the negative potential side of the electrolytic capacitor 3 and the direct current n line 16 (may be inserted between the positive potential side of the electrolytic capacitor 3 and the direct current p line 17 but is functionally the same. Therefore, explanation is omitted).

FIG. 4 shows an external view of a two-element power semiconductor module.
11 is a positive side DC output terminal (P terminal), 12 is a negative side DC output terminal (N terminal), and 13 is a load output terminal (U terminal). In FIG. 3, reference numeral 14 denotes a snubber circuit, which prevents an overvoltage generated at the time of IGBT switching. When a module with two elements is used, a C snubber circuit having only a capacitor as shown in FIG. In general, an RCD snubber circuit composed of a capacitor, a diode, and a resistor as shown in FIG. 5B is connected between each element PN terminal.

  FIG. 6 shows a stack structure diagram in which a plurality of electrolytic capacitors (4 parallel), a power semiconductor module for three phases (three modules with two elements) and a fuse are connected, and FIG. 7 is a circuit diagram corresponding to FIG. Indicates. 3a to 3d are four electrolytic capacitors connected in parallel, 14a to 14c are snubber capacitors, 8 is a fuse, and 15a to 15c are two-element IGBT modules installed on the radiator 20. Also, 16 is an N-line conductor, 17 is a P-line conductor, 18 is a conductor connecting the fuse 8 and the negative potential side terminal of the four parallel electrolytic capacitors 3, and 19a to 19c are three-phase output conductors. .

Usually, in order to suppress the surge voltage when switching the IGBT and reduce the snubber capacitor capacity, it is necessary to reduce the wiring inductance between the electrolytic capacitor 3 and the IGBT module 15, and as shown in FIG. In general, the P-line conductor 17 and the N-line conductor 16 and the P-line conductor 17 and the conductor 18 have a laminated structure (parallel plate structure) sandwiching an insulating material (not shown). The stack structure as described above is disclosed in, for example, Non-Patent Document 1 and Patent Document 1.
Fuji Electric product catalog “All-IGBT UPS6000D series Fuji large-capacity UPS 100-1500KVA” JP-A-11-098815 (page 3, FIG. 1)

As shown in FIG. 6, in the case of a stack in which the conductor has a laminated structure, there is an effect of reducing the inductance of the conductor portion, but on the other hand, there is a problem that the cost increases and the weight increases due to the increase in the copper material. Furthermore, since an insulating material is required between the conductors, there is a problem that the cost increases accordingly. In addition, when the electrolytic capacitor is connected to the conductor 17 and the conductor 18, the conductor 17 and the conductor 18 are not on the same plane, so that the conductor structure of the connection portion with the electrolytic capacitor becomes complicated, or the positive side of the electrolytic capacitor. Since measures such as changing the height of the electrode and the negative electrode are required, there is a problem that the cost is increased accordingly.
Accordingly, an object of the present invention is to achieve a reduction in cost by simplifying and reducing the weight of the conductor structure.

  In order to solve such a problem, in the invention of claim 1, in the conductor structure of the power converter for connecting the DC smoothing capacitor and the fuse of the DC part to the power semiconductor element of the power converter. The first conductor connecting the power semiconductor element and the first potential of the DC smoothing capacitor is formed in a plate shape with a part cut out, and the second potential of the DC smoothing capacitor and the fuse are The second conductor to be connected is plate-shaped, and the second conductor is disposed in the cut-out portion of the first conductor in the vicinity of the first conductor.

  In the first aspect of the invention, the second conductor can be made smaller than the cut-out portion of the first conductor (the second aspect of the invention). In the invention of the first or second aspect, The second conductor can be embedded in the cut-out portion of the first conductor, and the first and second conductors can be arranged so as to be substantially in the same plane (invention of claim 3). In the first aspect of the present invention, the second conductor can be made larger than the cut-out portion of the first conductor, and can be arranged in parallel and in close proximity to the first conductor. invention).

  According to the present invention, while suppressing an increase in the wiring inductance value of the conductor portion, the copper material and the number of manufacturing steps can be reduced as compared with the conventional laminated structure conductor, so that the weight of the device and the manufacturing can be simplified. Cost reduction can be realized.

FIG. 1 is a block diagram showing a first embodiment of the present invention.
In contrast to the conventional example shown in FIG. 6, a part of the P-line conductor 17 is cut into a rectangular shape (17a), and the conductor connecting the fuse 8 and the negative potential side terminal of the electrolytic capacitor 3 is The area is smaller than the cut shape (18a), the conductor 18a is inserted into the cut portion of the conductor 17a, and the electrolytic capacitors 3a to 3d are connected between the conductors 17a and 18a.

  With the above-described configuration, the conductor 18a can be manufactured using a copper material cut out when the conductor 17a is manufactured, so that the cost can be reduced. In addition, since the conductors 17a and 18a can be installed on the same plane, it is not necessary to use special processing of the conductors or electrolytic capacitors whose electrode shapes are special specifications when connecting each conductor and the electrolytic capacitor. Cost reduction is also possible from the viewpoint.

  Further, the inductance value of the conductor increases because the conductors 17a and 18a are not laminated as in the conventional case. However, when the configuration shown in FIG. 1 is used, most of the currents ip and in shown in FIG. , That is, in flows along the right and left ends (in1, in2) of the conductor 18a, and ip1 and ip2 concentrate in the vicinity where in1 and in2 are flowing, respectively. The generated magnetic fields cancel each other, and the inductance value becomes small.

FIG. 2 shows a second embodiment.
As is apparent from the figure, the conductor 17a in FIG. 1 has a “B” shape, whereas it has a “U” shape (17b). The principle and effect are the same as in FIG.
The conductors 18a and 18b in FIGS. 1 and 2 are manufactured (appropriated) using a copper material obtained by cutting out the conductors 17a and 17b for cost reduction, and both conductors are assumed to be arranged in substantially the same plane. However, it is not always necessary to do this, and not only another copper material is used, but the size is larger than the cut-out part, and a certain insulation distance (step) is provided between the two conductors. It may be made to do.

The block diagram which shows 1st Embodiment of this invention The block diagram which shows 2nd Embodiment of this invention Circuit diagram showing a general example of an inverter main circuit External view of module with two elements Circuit diagram showing a typical example of a snubber circuit Configuration diagram showing a conventional stack structure example of a power converter Circuit diagram showing the main circuit of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... AC power source, 2 ... Rectification part, 3, 3a-3d ... DC smoothing capacitor, 4 ... Load (motor), 5 ... Inverter part, 6 ... IGBT, 7 ... Diode, 8 ... Fuse, 11 ... Positive side direct current Output terminal, 12 ... negative DC output terminal, 13 ... load output terminal, 14a-14d ... snubber capacitor, 15a-15d ... IGBT module, 16 ... N line conductor, 17, 17a ... P line conductor, 18 ... conductor , 19a to 19d ... three-phase output conductors, 20 ... radiators.

Claims (4)

In the conductor structure of the power converter for connecting the DC smoothing capacitor and the fuse of the DC part to the power semiconductor element of the power converter,
The first conductor connecting the power semiconductor element and the first potential of the DC smoothing capacitor is formed in a plate shape with a part cut out, and the second potential of the DC smoothing capacitor and the fuse are connected. A conductor structure for a power converter, wherein the second conductor is formed in a plate shape, and the second conductor is arranged in the cut-out portion of the first conductor in proximity to the first conductor.   The conductor structure of the power conversion device according to claim 1, wherein the second conductor has a shape smaller than a cut-out portion of the first conductor.   3. The conductor structure of the power conversion device according to claim 2, wherein the second conductor is embedded in a cut-out portion of the first conductor, and the first and second conductors are arranged in substantially the same plane. . The conductor structure of the power conversion device according to claim 1, wherein the second conductor has a shape larger than the cut-out portion of the first conductor, and is disposed in parallel with the first conductor in proximity to the first conductor.

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