JP4567570B2 - Power converter - Google Patents

Description

  The present invention relates to a power converter, and more particularly to a power converter having a relatively large capacity, and more particularly to a power converter used in a hybrid vehicle or an electric vehicle.

  Hybrid vehicles that assist the engine with a motor and electric vehicles that run only with the output of the motor using hydrogen as an energy source have the advantages of high fuel efficiency and reduced environmental impact. It is what has been.

  When hybrid vehicles were put into practical use, the motor output was lower than that of engine vehicles, and there was a problem that the strength of the vehicle as seen in acceleration performance was weak. By improving this, the output of the motor was increased, and it became possible to obtain a strength comparable to that of a conventional engine car. Currently, since a motor for traveling is being mounted on a vehicle that requires higher output such as SUV (Sport Utility Vehicle), it can be seen that further increase in the output of the motor for traveling is required in the future.

  An automobile equipped with a motor rotates the motor with electric power charged in a vehicle-mounted battery. In order to obtain high fuel efficiency, it is necessary to adjust the motor torque and rotation speed according to the driving situation. By converting the DC power of the battery to AC power according to the driving situation, the torque and rotation speed of the motor The adjustment is realized. It is an in-vehicle inverter (hereinafter referred to as a power converter) that plays a role of converting the direct current power of the battery into alternating current power. With the increase in the output of the motor described above, there is a need to increase the power consumption of the in-vehicle power converter.

  For example, Patent Document 1 discloses a power conversion device having a configuration using a semiconductor module as an in-vehicle power conversion device. This example is an example in which two power converters are mounted. However, in one power converter, a configuration using three semiconductor modules in which switching elements responsible for one phase of three-phase outputs are sealed is disclosed. Has been.

JP 2004-254358 A (page 3-4, FIG. 2)

  In order to increase the power consumption of an in-vehicle power conversion device, a method of increasing the power of individual semiconductor modules can be considered. However, since there is a limit to increasing the power of semiconductor elements, a plurality of semiconductor modules are electrically connected. It will be connected in parallel to increase power.

  In order to connect the semiconductor modules in parallel, it is necessary to connect the main terminals having the same polarity of the semiconductor modules connected in parallel. Therefore, a bus bar for connecting the main terminals is required, and there is a problem that the volume of the power conversion device increases because the bus bar is arranged.

  The present invention has been made in view of such problems, and provides a power conversion device that can be made compact even when a plurality of semiconductor modules are connected in parallel in a power conversion device that requires high power. It is aimed.

The power conversion device according to the present invention is a power conversion device in which each phase in the power conversion circuit is formed by electrically connecting a plurality of semiconductor modules in parallel.
Each of the semiconductor modules has a switching element and a plurality of main terminals to which the switching element is connected by wiring,
Main terminals of the same polarity between the semiconductor modules are connected in direct contact with each other.

  According to the power conversion device of the present invention, a compact power conversion device can be provided even when a plurality of semiconductor modules are connected in parallel and used in a power conversion device that requires high power.

Embodiment 1 FIG.
FIG. 1 is a plan view for explaining a first embodiment of a power conversion device according to the present invention. FIG. 2A is a plan view of the semiconductor module, and FIG. 2B is a circuit diagram corresponding to the semiconductor module of FIG.

  As shown in FIG. 2, the semiconductor module 1a includes an AC output terminal (hereinafter referred to as AC terminal) 2a, an anode DC input terminal (hereinafter referred to as P terminal) 2b, and a cathode input terminal (hereinafter referred to as N terminal). ) 2c, an upper arm side IGBT 3a, a lower arm side IGBT 3b, an upper arm side FWD 4a, a lower arm side FWD 4b, a heat spreader 6, and the IGBT 3a, the FWD 4a and the AC terminal 2a, and the IGBT 3b, the FWD 4b and the N terminal 2c are electrically connected by the wire bond 5, respectively. Connected to each other and molded by the mold resin 8. The circuit in FIG. 2B is a switching element corresponding to one phase of a typical power converter. The power converter is equipped with switching elements for three phases, the positive terminal and negative terminal of the battery are connected to the P terminal 2b and N terminal 2c, respectively, and the AC terminal 2a of each phase is connected to a load (in the case of a hybrid vehicle, a motor) Connected. Then, each switching element is opened and closed at a high speed, and the timing is controlled to supply desired AC power to the load.

  FIG. 1 is a diagram in which two semiconductor modules described in FIG. 2 are connected in parallel. Two semiconductor modules 1a and 1b form a circuit for one phase. As shown in the figure, a pair of main terminals (P terminal 2b, N terminal 2c, and AC terminal 2a) with respect to the mirror symmetry plane 7 is shown. The main terminals of the same polarity of) have a mirror surface relationship. By adopting such a structure, the main terminals having the same polarity of the set of main terminals (P terminal 2b, N terminal 2c and AC terminal 2a) are directly connected to each other, so that a bus bar is provided to connect the main terminals. This eliminates the necessity, and the power conversion device having a large capacity by connecting the semiconductor modules 1a and 1b in parallel can be made compact.

  Furthermore, since the wiring of the power part is in a mirror surface relationship with respect to the mirror plane 7, the wiring can be shortened.

Embodiment 2. FIG.
3 to 5 are plan views for explaining Embodiment 2 of the power conversion device according to the present invention. As shown in FIG. 3 (a), two sets of main terminals (P terminal 2b, N terminal 2c and AC terminal 2a) are provided from one semiconductor module 1, and these are shown in FIG. 2 (b). As shown, the same-polarity main terminals are arranged so as to be mirror surfaces, and are connected in direct contact with each other. As a result, a plurality of semiconductor modules can be connected in parallel without using a bus bar, and the power converter having a large capacity can be made compact.

  In the second embodiment, as shown in FIG. 3 and FIG. 4, two sets of main terminals are provided in the semiconductor module 1 having a rectangular shape, a square shape, a fan shape, etc. Variations are also conceivable that are arranged in such a way that they are directly connected and connected.

  In the description of the second embodiment, the case where there are two sets of main terminals has been described. However, the number of sets of main terminals is not limited to this. Various shapes and arrangements of semiconductor modules are possible depending on the number of sets of main terminals.

Embodiment 3 FIG.
FIG. 6: is the side view (a) and front view (b) explaining Embodiment 3 of the power converter device which concerns on this invention. As shown in FIG. 6A, the main terminal 2 protruding from the semiconductor module 1 is bent at a right angle in the vicinity of the semiconductor module, and welding is started at multiple points as shown in FIG. 6B above the semiconductor module. They are connected by a metal joint 9.

  In the first and second embodiments, the connection between the main terminals is usually performed by mechanical fastening. However, as in the third embodiment, the connection by the metal joint 9 is used to connect the machine. Compared with the case of fastening, the screw space and the like are omitted, so that the volume of the power converter can be further reduced.

  6 shows an example of a shape in which the main terminal 2 protruding from the semiconductor module 1 is bent at a right angle in the vicinity of the semiconductor module, the shape of the main terminal of the present invention is the shape of the main terminal in FIG. It is not limited.

  The power converter according to the present invention can be effectively used for a power converter having a relatively large capacity, particularly a power converter used in a hybrid vehicle or an electric vehicle.

It is a top view for demonstrating Embodiment 1 of the power converter device which concerns on this invention. It is the top view (a) of a semiconductor module, and the circuit diagram (b) corresponding to a semiconductor module. It is a top view explaining Embodiment 2 of the power converter device which concerns on this invention. It is a top view explaining the modification of Embodiment 2 of the power converter device which concerns on this invention. It is a top view explaining the modification of Embodiment 2 of the power converter device which concerns on this invention. It is the side view (a) and front view (b) explaining Embodiment 3 of the power converter device which concerns on this invention.

Explanation of symbols

1, 1a, 1b semiconductor module, 2a AC terminal (main terminal),
2b P terminal (main terminal), 2c N terminal (main terminal), 3a Upper arm side IGBT,
3b Lower arm side IGBT, 4a Upper arm side FWD, 4b Lower arm side FWD,
5 Wire bond, 7 Mirror plane, 8 Mold resin, 9 Welded part.

Claims (3)

In the power conversion device in which each phase in the power conversion circuit is formed by electrically connecting a plurality of semiconductor modules in parallel,
Each of the semiconductor modules has a switching element and a plurality of main terminals to which the switching element is connected by wiring,
A power conversion device, wherein the main terminals of the same polarity of the semiconductor modules are connected in direct contact with each other. 2. The power conversion device according to claim 1 , wherein each of the semiconductor modules has a plurality of sets of the main terminals, and the main terminals of the same polarity of the semiconductor modules are arranged in a mirror surface. . The power converter according to claim 1 or 2 , wherein the main terminals having the same polarity are connected by metal bonding .

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