JP2003209978A - Power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a conventional power converter that power loss is generated by a radiation field generated around a bus bar. <P>SOLUTION: Bus bars 72 and 74 connect the P terminal of an inverter 40 and the P terminal of a smoothing capacitor 40 in parallel. Bus bars 82 and 84 connect the N terminal of the inverter 40 and the N terminal of the smoothing capacitor 40 in parallel. The bus bar 84 connecting the N terminals is superposed on the bus bar 72 connecting the P terminals in a specified region including an A-A' line. The bus bar 74 connecting the P terminals is superposed on the bus bar 82 connecting the N terminals in a specified region including the A-A' line. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter including a converter, a capacitor, and an inverter, wherein a low-inductance conductor is used for connecting the capacitor and the inverter. 2. Description of the Related Art Generally, a power converter obtains a DC current smoothed by a capacitor on a converter output side, converts the DC current into an AC voltage having a predetermined frequency by an inverter based on the DC current, and supplies the AC voltage to a load. . A bus bar made of a low-inductance conductive member is used for the wiring connecting the capacitor and the inverter, and the wiring impedance is reduced. [0003] In such a power converter, when a large current flows between the capacitor and the inverter, a radiated magnetic field is generated around the bus bar. For this reason, there is a problem that an eddy current is generated in a conductor around the wiring, which causes a power loss. In order to solve this problem, for example, see
In Japanese Patent Application Publication No. 000-102260, two P-side wirings connecting a capacitor and a P terminal of an inverter and an N-side wiring connecting N terminals are arranged in the order of P-side wiring-N-side wiring-P-side wiring. By doing so, a technique for reducing inductance is described. [0005] FIG. 6 is a schematic diagram of Japanese Unexamined Patent Application Publication No. 2000-2000.
It is sectional drawing of the bus bar described in -102260. A current flows in the same direction in the bus bar 200 and the bus bar 220, and the bus bars 210 and 22
A current in a direction opposite to 0 flows. Therefore, the bus bar 2
The magnetic flux between 00 and busbar 210 is in the same direction (arrow 2).
30) and strengthen each other. The magnetic flux between the bus bar 210 and the bus bar 220 is in the same direction (arrow 240), and reinforces each other. As described above, the radiated magnetic field generated between the bus bars exists while being strengthened, and this adversely affects the surroundings. [0007] Therefore, an object of the present invention is to provide a power conversion device capable of solving the above-mentioned problem that can suppress a radiation magnetic field generated around a bus bar. That is, the present invention provides an inverter for converting a DC voltage to supply an AC voltage to a load,
In a power converter including a converter for converting a power supply voltage into a voltage for inputting the voltage to an inverter, and a smoothing capacitor provided between the converter and the inverter, a power converter including the inverter and the positive terminal of the smoothing capacitor in parallel. A first and a second conductive member for connecting the first and second conductive members, and a third and a fourth conductive member for connecting the negative terminal of the inverter and the smoothing capacitor in parallel. 2 x 2
The books are arranged in a matrix, and the first and second conductive members and the third and fourth conductive members are provided so as to cross each other. The present invention will be described below through embodiments of the present invention. FIG. 1 shows a power converter 1 according to an embodiment.
0 is a circuit configuration diagram of FIG. The power converter 10 includes a battery 20, a DC / DC converter 30, and a smoothing capacitor 4.
0, an inverter 50, and a three-phase AC motor 60 as a load. The DC / DC converter 30 includes a pair of transistors 31 and 32 connected in series in a forward direction between DC terminals of an inverter 50, feedback diodes 33 and 34 connected in anti-parallel to each transistor, and a It includes a reactor 35 connected to the connection point.
The DC / DC converter 30 boosts the power of the battery 20, and the boosted power is stored in the smoothing capacitor 40 connected between the DC terminals of the inverter 50. The inverter 50 has a plurality of switching elements, converts a DC current sent from the smoothing capacitor 40 into a three-phase AC current, and supplies it to a three-phase AC motor 60. The P terminal of the inverter 50 and the P terminal of the smoothing capacitor 40 are connected by a wiring 70. The N terminal of the inverter 50 and the smoothing capacitor 4
0 is connected to the N terminal by a wiring 80. FIG. 2 is a plan view showing a specific configuration of the wirings 70 and 80. The wiring 70 specifically includes a bus bar (a low-inductance conductive plate material) 72 and a bus bar 74. The bus bar 72 and the bus bar 74 connect the P terminal of the inverter 50 and the P terminal of the smoothing capacitor 40 in parallel. The wiring 80 is, specifically,
A bus bar 82 and a bus bar 84 are provided. Bus bar 8
2 and the bus bar 84 connect the N terminal of the inverter 50 and the N terminal of the smoothing capacitor 40 in parallel. The bus bar 72 connecting the P terminals and the bus bar 84 connecting the N terminals overlap each other in a predetermined area including the line AA 'with the bus bar 84 facing upward. Further, the bus bar 74 connecting between the P terminals and the bus bar 82 connecting between the N terminals overlap with each other in a predetermined area including the line AA ′ with the bus bar 74 facing upward. FIG. 3 shows the inverter 50 of the wirings 70 and 80.
It is a perspective view which shows the connection in a part. The end of the bus bar 74 is shaped to connect to the P terminal of the inverter 50. The ends of the busbars 82 and 84 are formed so as to be connected to the N terminal of the inverter 50. Insulating films 90 and 92 are provided between the bus bar 72 and the bus bar 84 and between the bus bar 74 and the bus bar 82, respectively, to keep the insulation therebetween (see FIG. 4). FIG. 5 is a sectional view taken along line AA 'of FIG.
The bus bars 72, 74, 82, 84 are arranged in two rows and columns. The directions of the currents flowing through the bus bars 72 and 74 and the bus bars 82 and 84 are reversed. Therefore, the magnetic flux between the bus bar 72 and the bus bar 84 is in the direction of the arrow 100. On the other hand, the magnetic flux between the bus bar 74 and the bus bar 82 is in the direction of the arrow 102,
The direction is opposite to 00. Therefore, the bus bar 7
The magnetic flux between the bus bar 2 and the bus bar 84 and the magnetic flux between the bus bar 74 and the bus bar 82 have a mutually canceling (cancelling) relationship. The magnetic flux between the bus bar 72 and the bus bar 82 is in the direction of arrow 104. On the other hand, the magnetic flux between the bus bar 74 and the bus bar 84 is in the direction of the arrow 106, which is opposite to the direction of the arrow 104. Therefore, the magnetic flux generated between the bus bar 72 and the bus bar 82 and the magnetic flux generated between the bus bar 74 and the bus bar 84 are in a mutually canceling (cancelling) relationship. As described above, the bus bars between the P terminals and the N terminals are respectively arranged in parallel, and the bus bars between the P terminals and the N terminals are wired in two rows and columns in a crosswise positional relationship. The magnetic flux generated therebetween can be canceled out and weakened. As a result, the influence of the radiation magnetic field on the surroundings can be reduced, and the power efficiency can be improved. As is apparent from the above description, according to the present invention, the magnetic flux generated between the bus bars can be canceled out, and the radiated magnetic field can be weakened.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit configuration diagram of a power conversion device 10 according to an embodiment. FIG. 2 is a plan view showing a specific configuration of wirings 70 and 80. FIG. 3 is a perspective view showing connections of wirings 70 and 80 at an inverter 50 part. FIG. 4 shows an insulating film 90 provided between bus bars.
FIG. FIG. 5 is a sectional view taken along line AA ′ of FIG. 2; FIG. 6 is a cross-sectional view of a bus bar described in JP-A-2000-102260. [Description of Signs] 10 power conversion device, 20 battery, 30 DC / D
C converter, 40 smoothing capacitor, 50 inverter, 60 3-phase AC motor, 70, 80 wiring, 72,
74, 82, 84 bus bar, 90, 92 insulating film.

   ────────────────────────────────────────────────── ─── Continuation of front page    F-term (reference) 5H007 AA01 AA07 BB06 CC12 HA03                       HA07                 5H740 BB09 BB10 PP02 PP03

Claims (1)

Claims 1. An inverter for converting a DC voltage to supply an AC voltage to a load, a converter for converting a power supply voltage into a voltage for input to the inverter, and between the converter and the inverter. And a first and a second conductive member that connect in parallel the positive terminal of the inverter and the positive terminal of the smoothing capacitor; and the negative terminal of the inverter and the negative terminal of the smoothing capacitor. And a fourth and a fourth conductive member for connecting the first and fourth conductive members in parallel, the first to fourth conductive members are arranged in a matrix of 2 × 2, and the first and second conductive members are arranged in a matrix of 2 × 2. A power converter, wherein a conductive member and the third and fourth conductive members are provided so as to have a crosswise relationship with each other.