JP2000060126A - Main circuit structure for power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the effects of multiphase switching and irregularities in a current with a simple constitution by constituting each conductor connecting a main circuit as a flat plate, and installing a slit between each of phases. SOLUTION: A positive side conductor 1 is arranged as the lowermost layer and is fastened to a collector terminal of an IGBT 49 by using a terminal spacer 149 formed of conductor and a bolt 139. On the conductor 1, an AC side conductor 2c is arranged. A negative side conductor 3 is arranged as the uppermost layer. The conductors 2c, 3 are connected with terminals of the positive side IGBT 49 or a negative side IGBT 59, by using terminal spacers 249, 269, 349 and bolts 239, 259, 339. A terminal hole 101 is bored in the conductor 1. The IGBT of each layer is provided with terminal holes 111-113, connected with the collector terminal of the IGBT of an U-phase. Between the U-phase and its right V-phase, a slit 11 is formed. The U-phase and the V-phase are connected with each other via a constriction part in the upper part of conductor. In the V-phase part, terminal holes 114-116 connected with the IGBT are bored. In the right part of the holes, a slit 12 is formed. The V-phase part is connected with a W-phase part via a constricted part 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure of a main circuit of a power converter in general, such as a power converter for a railway vehicle.

[0002]

2. Description of the Related Art Conventionally, wiring of a power converter is disclosed in
Elongated conductor bars and electric wires as shown in JP-A-160373 have been used. In such a configuration, since the inductance of the wiring is large, there is a problem that a large jump of current or voltage occurs when the semiconductor element is turned on and off.
In order to protect the semiconductor element, it is necessary to connect a snubber circuit or the like having a large capacity, which has been an obstacle to miniaturization of the device. By the way, it is known that the inductance can be reduced by making the conductor that is the current path as flat as possible and by setting the conductors on the outward path and the return path as close as possible, that is, in a so-called parallel plate shape. . This is because the changes in the magnetic flux created by the forward path and the return path cancel each other, and the change in the magnetic flux apparently hardly occurs. A wiring method using such a principle is disclosed in Japanese Unexamined Patent Publication No. 6-3850.
7, JP-A-6-225545, JP-A-6-225545
327266, JP-A-7-131981,
Techniques described in JP-A-9-47036, JP-A-9-70184, and the like can be mentioned. In each of these, as described above, parallel-plate-like wiring in which plate-like conductors are arranged close to each other with an insulating layer or the like interposed therebetween is used to realize a reduction in inductance. However, the connection between the phases is not particularly described. In Japanese Unexamined Patent Publication No. 7-245951, each phase is directly connected by a flat conductor.
With such a connection, the fact that there is little inductance between the phases backfires, and a voltage surge at the time of switching of one phase may adversely affect other phases. When elements are connected in parallel in each phase, a difference in inductance due to a slight difference in the path from the filter capacitor has a large effect, and the current flowing through each element varies. For this reason, in an element in which a large current flows, the element is destroyed by a peak current, or the amount of generated heat increases, leading to destruction. The power converter may be destroyed.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the influence of multi-phase switching with a simple structure and a reduced main circuit inductance. The object is to minimize these current variations.

[0004]

In order to solve the above-mentioned problems, each conductor for connecting the main circuit is formed in a flat plate shape, and a slit is provided between each phase. Alternatively, when the main circuit conductor is divided into a part for connecting the semiconductor element and a part for connecting the filter capacitor, the semiconductor element part is separately installed for each phase, and the phases for connecting the filter capacitors are connected to each other. .

The present invention reduces the effect of a switching waveform of one phase on another phase. When a plurality of terminals or elements are connected in parallel, variation in current between the terminals or elements is reduced.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a representative embodiment of the present invention. It is an example of a three-phase two-level power converter using an IGBT. For simplicity, only conductors and insulating plates are described, and other components such as semiconductor elements and bolts are omitted. 1 is a positive conductor, 2a
Ｃc is an AC-side conductor of each phase, and 3 is a negative-side conductor. Also,
61 and 62 are insulating plates.

FIG. 2 is a view of the embodiment of FIG. 1 as viewed from the side (the right side of FIG. 1). For convenience, IGBTs 49 and 5
The conductor closer to 9 will be referred to as a lower layer, and the conductor farther away will be referred to as an upper layer. The positive conductor 1 is arranged in the lowermost layer, and is fastened to the collector terminal of the IGBT 49 by a terminal spacer 149 made of a conductor and a bolt 139. The AC conductor 2c
Is further disposed on the uppermost layer, and the terminal spacers 249, 269, 349 and the bolts 239, 259,
339, the positive IGBT 49 or the negative IGBT 5
9 to the corresponding terminal. The insulating plates 61 and 62 are provided between these conductors. However, if the distance between the conductor and other conductors or conductors such as bolts is sufficiently large from the viewpoint of ensuring insulation, these may be omitted.

FIGS. 3 to 5 show the conductors 1, 2 of the embodiment of FIG.
Each of a to c and 3 is shown alone. Conductor 1
Terminal hole 1 connected to the positive terminal of the filter capacitor at the top
01 is opened. Although the IGBTs of each phase are arranged in three parallel in this example, the terminal holes 111 and 11 connected to the collector terminals of the U-phase IGBTs 41 to 43 (see FIG. 6).
2 and 113 are opened side by side. A slit 11 is provided between the V phase and the right side thereof, and the U phase and the V phase are connected via a constricted portion 13 at the upper part of the conductor. IGBT for V-phase part
Terminal holes 114-1 to be connected to 44-46 (see FIG. 6)
Open 16. Similarly, a slit 12 is provided on the right side, and the slit 12 is connected to the W-phase via the constricted portion 14. Terminal holes 117 to 119 for connection to IGBTs 47 to 49 (see FIG. 6) are formed in the W-phase portion. Since the AC-side conductors 2a to 2c have different potentials, they are not connected and are separate conductors.
Terminal holes 201 to 203 for AC output are respectively formed, and electric wires and the like connected to a load such as a motor are connected here. IG
Terminal holes 211 to 219 and 221 to 229 connected to BT
Can be opened in the same way. The shape of the conductor 3 is similar to the conductor 1. Negative terminal holes 301 of the filter capacitor, terminal holes 311 to 319 to be connected to the IGBT,
32, constrictions 33 and 34 are provided between each phase.

FIG. 6 is a circuit diagram corresponding to this embodiment, in which conductors 1, 2a to 3c, IGBTs 41 to 49, 51
59 shows the connection relationship of the filter capacitor 7. In addition, each terminal hole 101, 111 to 119, 201 to 20
3, 211-219, 221-229, 301, 311
319 electrical positions are also shown.

FIG. 7 is a conceptual diagram showing the effect of providing slits 11, 12, 31, 32 between the phases of conductors 1 and 3. In the case of FIG. 7A without a slit,
The variation of the current path length from the terminal hole 101 of the filter capacitor to the terminal holes 117 to 119 of the IGBT connected in parallel is large. This difference is unchanged from 101 to 117-
Each IGBT is reflected in the difference in inductance to 119
Current will vary. For this reason, the IGBT through which a large current flows may be destroyed first by the large current, or the loss of the IGBT through which a large current flows steadily may be larger than that of other parts, resulting in thermal breakdown. In any case, there is a problem that the power converter must be operated with a smaller current value as a whole as compared with the case where the power converter flows evenly in each IGBT. Furthermore, since the inductance with the other phase is small, when switching is performed in a certain phase, a spike-like voltage or current is generated in the other phase due to the effect, which may adversely affect the IGBT. On the other hand, in FIG. 7B, a slit 12 is provided between other phases (illustration of the slits 11, 31, and 32 is omitted). As a result, the respective current paths from the terminal 101 to the terminals 117 to 119 follow almost the same path up to the constricted portion 14, so that the variation in the current path length is smaller than in the case of FIG. On the other hand, a variation remains in the current path length from the constricted portion 14 to each terminal. However, since the remaining variation slightly increases the inductance at the constricted portion 14, the variation with respect to the total inductance is reduced, and the current is equalized. In addition, since the inductance between the other phases is increased, the influence of the switching of the other phases is reduced. With such a configuration, in the present embodiment, the IGBT currents connected in parallel can be equalized, and the influence of switching of other phases can be reduced.
A power converter that makes full use of the capabilities of the GBT can be realized.

FIG. 8 shows another embodiment of the present invention. In order to obtain the same effect as in FIG. 1, it is one method to provide a slit between the phases, but the point is to connect the phases as far as possible from the IGBT of each phase. In FIG. 8, the current path length is increased by newly providing the negative side conductor 8 to connect the phases (for example, the terminal hole 317-conductor 3c-terminal hole 32).
3- Negative conductor 8-Terminal hole 322-Conductor 3b-Terminal hole 31
6). Therefore, in FIG. 8, the bus conductor is divided into 1a to c, 2a to c, 3a to c connecting the IGBT, and the positive conductor 9 and the negative conductor 8 on the filter capacitor side. This is because, depending on the configuration of the main circuit, the division of the conductor in this way may improve handling convenience. FIG.
Although the shapes of the AC-side conductors 2a to 2c do not change as compared with the embodiment, the positive-side and negative-side conductors are divided for each phase.
Connection terminal hole 12 to filter capacitor side conductor
Connected to the conductors 8 and 9 via 1-123 and 321-323. The connections between the three phases are also made here. An insulating plate 63 is inserted between the conductors 8 and 9 as needed. The negative conductor 8, the positive conductor 9, and the terminal holes 321, 322, 323 are
In FIG. 6, the circuits corresponding to the present embodiment are shown in parentheses (8), (9), (321), (322), and (323).
Indicated. By adopting such a configuration, in the present embodiment, as in FIG. 1, it is possible to equalize the sharing of the IGBTs connected in parallel and reduce the influence of switching of other phases.

Each of the above-described embodiments has shown the case of a three-phase power converter and two-level converters of three phases in parallel. As a matter of course, the same configuration can be applied to general other-phase, multi-parallel, and multi-level converters. In addition, there is an advantage that the influence of the other-phase switching can be reduced even when the parallel connection is not performed. Further, in the above-described embodiment, the description has been given as the element parallel, but naturally, the case where one module has a plurality of sets of terminals is also included.

[0013]

As described above, according to the present invention,
Since it is possible to prevent the adverse effect due to the switching of a certain phase from affecting the other phases, it is possible to prevent the destruction of the semiconductor element. In addition, since the current balance of the semiconductor elements connected in parallel can be improved, the performance of each element can be fully utilized. Therefore, with this mounting structure, a high-performance and highly-reliable power converter can be realized at relatively low cost and small size.

[Brief description of the drawings]

FIG. 1 is a representative embodiment of the present invention.

FIG. 2 is a side view of the embodiment of FIG. 1;

FIG. 3 is a diagram showing a positive conductor of the embodiment of FIG. 1;

FIG. 4 is a diagram showing an AC-side conductor of the embodiment of FIG. 1;

FIG. 5 is a diagram showing a negative conductor of the embodiment of FIG. 1;

FIG. 6 is a circuit diagram corresponding to the embodiment of FIG. 1;

FIG. 7 is a conceptual diagram showing an advantage of providing a slit between phases.

FIG. 8 shows another embodiment of the present invention.

[Explanation of symbols]

1, 1a-c: positive side conductor, 2a-c: AC side conductor, 3,
3a to c: negative side conductor, 41 to 49: positive side IGBT element,
51 to 59: negative IGBT element, 61, 62, 63: insulating plate, 7: filter capacitor, 8: filter capacitor side negative conductor, 9: filter capacitor side positive conductor, 1
1, 12, 31, 32 ... conductor slits, 13, 14,
33, 34: Constricted portion of conductor, 101: Filter capacitor positive terminal hole, 102: Filter capacitor negative terminal hole, 111 to 119, 211 to 219, 221 to 22
9, 311 to 319 IGBT terminal holes, 121 to 12
3, 321 to 323... Terminal holes connecting the IGBT-side conductor and the filter capacitor-side conductor, 139, 239, 259, 3
39: bolt, 149, 259, 269, 349: terminal spacer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Asako Koyanagi 7-2-1, Omika-cho, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Power and Electricity Development Division (72) Inventor Akira Mishima Omika-cho, Hitachi City, Ibaraki Prefecture No. 7-2-1 F-term (Reference) 5H006 AA01 AA05 CA01 CA13 HA08 HA83 5H007 AA01 AA06 CA01 CC07 HA03 HA04 5H740 AA05 BA11 BB02 MM10 PP01 PP03

Claims (4)

[Claims] 1. A main circuit structure of a power converter, wherein a slit is provided between each phase of a positive side conductor and a negative side conductor in a multi-phase power conversion device using parallel plate-shaped conductors. 2. A multi-phase power converter using parallel plate-shaped conductors, wherein said conductor is divided into a portion connecting a terminal of a semiconductor element and a portion connecting a filter capacitor terminal, and A main circuit structure of a power converter, wherein a conductor connecting elements is divided for each phase. 3. A main circuit structure of a power converter, wherein a constricted portion is provided between each phase of a positive side conductor and a negative side conductor in a multi-phase power conversion device using parallel plate-shaped conductors. 4. The main circuit structure of a power converter according to claim 1, wherein a terminal portion connected to a main circuit component or a conductor of the power converter has an elongated shape.