JP2004096887A - Conductor structure of bulk power conversion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid unbalance among currents passed through smoothing capacitors and switch units in a bulk power conversion device with a large number of parallel switch units, and simplify the wiring between the smoothing capacitors and the switch units for the reduction of wiring space. <P>SOLUTION: The distances are set larger between the switch units connected with positive-pole and negative-pole conductor plates 21 and 31 and positive-pole and negative-pole conductor terminals 22 and 32. The positive-pole and the negative-pole conductor plates or their positive-pole and the negative-pole conductor terminals are bent to reduce the air clearances between the switch units and the positive-pole and the negative-pole conductor terminals. Positive-pole and the negative-pole conductor plates 24 and 34 provided with slits are provided with notches 25 and 35 between the switch units and the positive-pole and the negative-pole conductor terminals 22 and 32. The dimensions of the notches are set such that their length is substantially half the left-right dimension of the positive-pole and the negative-pole conductor plates 24 and 34 provided with slits, and their width is such that the influences of interaction of currents can be reduced. The positive-pole and the negative-pole conductor plates provided with slits are bent to reduce the air clearances between the switch units and the positive-pole and the negative-pole conductor terminals. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductor structure of a large-capacity power converter that avoids unbalanced current flowing in a semiconductor switching element when performing power conversion by connecting a large number of semiconductor switching elements in parallel.
[0002]
[Prior art]
Hereinafter, the present invention will be described in detail by taking an inverter device that converts DC power into AC power as an example of a power converter.
The inverter device includes, for example, two sets of an IGBT (insulated gate bipolar transistor) as a semiconductor switch element and an anti-parallel connection circuit of a diode connected in series and inserted between the positive and negative electrodes of a DC circuit. DC power is converted to AC power by sequentially turning on and off the IGBTs. Recently, these two IGBTs and two diodes have been packaged together in a package to form a switch unit. Are used in a number corresponding to the number of phases, thereby simplifying the configuration of the device. If the capacity of the inverter increases, the capacity of the IGBT and the diode also increases, but if the capacity still cannot be satisfied, a plurality of switch units are connected in parallel and used. At this time, the smoothing capacitor is also connected between the positive and negative electrodes. However, since the smoothing capacitor also needs to have a large capacity, a plurality of capacitors are connected in parallel and used like the switch unit.
[0003]
Since the current flowing through a large-capacity inverter is large, a sandwich structure is used in which a plate-shaped insulator is sandwiched between a plate-shaped positive conductor and a negative conductor to reduce the resistance and inductance of the conductor. However, it is necessary to devise to connect a large number of switch units in parallel with this sandwich-structured conductor.
FIG. 7 is a structural diagram showing a situation where a plurality of switch units are connected in parallel by a conductor having a sandwich structure. In FIG. 7, a positive terminal P, a negative terminal N, and an AC terminal W are provided on the upper surface of the switch unit 15A. A positive terminal connection hole 16P provided in the positive conductor plate 16 and a positive terminal P of the switch unit 15A are provided. Are connected by screwing. Similarly, by screwing the negative terminal connection hole 17N provided in the negative conductor plate 17 and the negative terminal N of the switch unit 15A, the two are connected. At this time, a conductor having a sandwich structure is formed by interposing the insulating plate 18 between the positive conductor plate 16 and the negative conductor plate 17. The positive electrode conductor plate 16, the negative electrode conductor plate 17, and the insulating plate 18 are provided with similar openings for connecting other switch units (not shown). Can be connected in parallel.
[0004]
FIG. 8 is a structural view showing a conventional example of a positive electrode conductor plate in which the positive terminals of a plurality of switch units are connected in parallel for a large-capacity inverter. A three-phase inverter is formed by a total of 12 switch units 15A arranged in three stages. In order to connect these switch units 15A in parallel, the positive electrode conductor plate 16 has an opening at a position corresponding to each switch unit 15A, and a positive terminal connection hole 16P for connecting the positive terminal P to this opening. Is provided. There is a positive conductor terminal 16T on the lower left side of the positive conductor plate 16 for connecting the positive terminals of a plurality of smoothing capacitors (not shown) arranged in a row below the switch unit 15A in parallel. Are connected to the positive conductor terminal 16T.
[0005]
FIG. 9 is a structural view showing a conventional example of a negative electrode conductor plate in which the negative terminals of a plurality of switch units are connected in parallel for a large-capacity inverter, and corresponds to each switch unit 15A similarly to the positive electrode conductor plate 16 described above. There is an opening at a position where the negative electrode terminal N is connected, and a negative electrode terminal connection hole 17N for connecting the negative electrode terminal N is provided in this opening. A negative conductor terminal 17T is provided on the lower right side of the lower end of the negative conductor plate 17, and a conductor for connecting the negative terminals of the plurality of smoothing capacitors in parallel to each other is connected to the negative conductor terminal 17T.
[0006]
[Problems to be solved by the invention]
In the conventional example of the positive electrode conductor plate shown in FIG. 8 described above, for example, the difference between the distance from the lowermost leftmost switch unit to the positive electrode conductor terminal 16T and the distance from the rightmost switch unit to the positive electrode conductor terminal 16T even at the same lowermost stage. Is big. This difference in distance causes a difference between the resistance and the inductance of the conductor, and this difference causes an imbalance in the current flowing through each switch unit. If the positive conductor terminal 16A is pulled out from the center portion of the positive conductor plate 16 and the negative conductor terminal 17T is pulled out from the center portion of the negative conductor plate 17, the unbalance of resistance and inductance from each switch unit to the positive and negative bipolar conductor terminals is reduced. However, it is possible to reduce the current imbalance, but since the connection between the switch unit and the plurality of smoothing capacitors is indispensable in the inverter device, the positive conductor terminal 16T is provided at the left end, and the positive side of the smoothing capacitor is By connecting to the terminal and connecting to the negative electrode side terminal of the smoothing capacitor from the negative electrode conductor terminal 17T provided at the right end, it is possible to suppress the occurrence of unbalance in the current of each of the smoothing capacitors connected in parallel.
[0007]
In other words, when the conductor terminals are drawn out from the center of the positive and negative bipolar conductor plates to suppress the current imbalance of each switch unit, there arises a disadvantage that the current imbalance occurs in each smoothing capacitor. Therefore, if the positive and negative bipolar conductor terminals are pulled out from the center and the current of each smoothing capacitor is to be balanced, the conductor arrangement between the positive and negative bipolar conductors and the smoothing capacitor becomes complicated, and the assembling work is troublesome. However, since a large space is required between the positive and negative bipolar conductors and the smoothing capacitor, there is also a disadvantage that the entire device is enlarged.
[0008]
In the invention described in Japanese Patent Application Laid-Open No. 2000-350475, a positive terminal is pulled out rightward from a vertical center of a plurality of arranged switch units, and a negative terminal is drawn left. Therefore, when a power conversion device such as an inverter is configured by connecting to a smoothing capacitor as described above, there is a disadvantage that a conductor connection that does not generate an unbalanced current requires a large space and labor, and a switch unit. Since an even number of switches must be used, an extra switch unit may be used, resulting in a problem that the size of the device is increased and the cost is increased.
[0009]
Therefore, an object of the present invention is to avoid imbalance between currents flowing through each smoothing capacitor and each switch unit in a large-capacity power converter having a large number of parallel switch units, and to simplify wiring between the smoothing capacitor and the switch unit. To reduce wiring space.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a conductor structure of a large-capacity power conversion device according to the present invention is configured such that one phase of a switch unit formed by connecting two sets of an anti-parallel circuit of a semiconductor switch element and a diode in series is connected. When arranged in a line in the left and right direction, the required number of phases are all arranged on the same plane in the up and down direction, a plurality of smoothing capacitors are arranged in the left and right direction, and when covering the surfaces of the switch units arranged vertically and horizontally with a positive electrode conductor plate, The position corresponding to the negative electrode terminal and the AC terminal of each switch unit is an opening, and each positive electrode terminal is connected to the corresponding positive electrode conductor plate. An opening is formed at a position corresponding to the positive terminal and the AC terminal of the unit, and each negative terminal is connected to the negative conductive plate, and the smoothing capacitor is connected to one of right and left ends of the positive conductive plate. Comprising a cathode conductor terminal to be connected, in conductor structure of the negative electrode conductor plate the opposite large capacity power conversion apparatus comprising an anode conductor terminal for connecting the smoothing capacitor on the end of,
The distance from the switch unit connected to the positive conductor plate to the positive conductor terminal and the distance from the switch unit connected to the negative conductor plate to the negative conductor terminal are increased.
[0011]
The positive / negative bipolar conductor plate or its positive / negative bipolar conductor terminal is bent to reduce the spatial distance from the switch unit to the positive / negative bipolar conductor terminal.
The positive electrode conductor plate is a slit-containing positive electrode conductor plate provided with a cutout portion having a length of substantially half the left-right dimension of the positive electrode conductor plate between the switch unit and the positive electrode conductor terminal, the negative electrode conductor plate, A negative electrode conductor plate with a slit is provided between the switch unit and the negative electrode conductor terminal, with a cutout having a length substantially half of the left-right dimension of the negative electrode conductor plate.
[0012]
The positive and negative bipolar conductor plates with slits or the positive and negative bipolar conductor terminals are bent to reduce the spatial distance from the switch unit to the positive and negative bipolar conductor terminals.
The width of the notch provided in the positive and negative bipolar conductor plate with a slit is set to a size that can reduce the influence of the interaction of the current flowing through one edge and the other edge of the notch.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a structural diagram of a positive electrode conductor plate showing a first embodiment of the present invention. The structure of the positive electrode conductor plate 21 is such that the distance L from the switch unit to the positive electrode conductor terminal 22 is the same as that described in FIG. Is different from that of the conventional example described above, but all other configurations are the same. By increasing the dimension L, it is possible to reduce the difference between the wiring resistance and the inductance of the switch unit at a position close to the positive electrode conductor terminal 22 and the switch unit at a position far from the positive electrode conductor terminal 22 in the same phase as compared with the related art.
[0014]
FIG. 2 is a structural view of the negative electrode conductor plate showing the first embodiment of the present invention. The structure of the negative electrode conductor plate 31 is such that the distance L from the switch unit to the negative electrode conductor terminal 32 is shown in FIG. As in the first embodiment, the difference between the wiring resistance and the inductance between the switch unit in the same phase and the switch unit at a position far from the negative electrode terminal 32 is smaller than that of the conventional switch unit.
[0015]
FIG. 3 is a structural view of a negative electrode conductor plate according to a second embodiment of the present invention, in which a negative electrode conductor plate 33 is bent between a switch unit and a negative electrode conductor terminal 32. By this bending process, the smoothing capacitor and the switch unit can be mounted close to each other, so that the length L from the switch unit to the negative electrode conductor terminal 32 is secured as in the first embodiment described above with reference to FIG. However, the entire device can be downsized. Although not shown, the positive electrode conductor plate is also subjected to the same bending.
[0016]
FIG. 4 is a structural view of a positive electrode conductor plate according to a third embodiment of the present invention, which comprises a positive electrode conductor plate 24 having a slit 25 having a notch 25 and a positive electrode terminal 22. Due to the cutout portion 25, the length of the current path from the leftmost switch unit to the positive electrode conductor terminal 22 and the length of the current path from the rightmost switch unit of the same phase to the positive electrode conductor terminal 22 are made substantially the same. For this purpose, the cutout 25 is cut roughly to half the width of the slitted positive electrode conductor plate 24.
[0017]
From the left end switch unit, a current flows to the positive electrode conductor terminal 22 through a path indicated by an arrow A and a path indicated by an arrow B. However, if the width dimension B of the notch 25 is small, the current of the path A and the path B Current flows close to each other to reduce the wiring inductance, so that even if the notch 25 is provided, the effect of correcting the current imbalance is reduced. Since the wiring inductance changes with the square of the width B, the value of the width B is determined so that the decrease in the wiring inductance can be ignored.
[0018]
FIG. 5 is a structural view of a negative electrode conductor plate according to a third embodiment of the present invention, which is composed of a positive electrode conductor plate 34 with a slit provided with a notch 35 and a negative electrode conductor terminal 32. Is the same as the case of the positive electrode conductor plate with slits 24 described above with reference to FIG. 4, and the description thereof will be omitted.
FIG. 6 is a structural view of a negative electrode conductor plate with a slit, showing a fourth embodiment of the present invention. The negative electrode conductor plate with a slit 36 is bent between the switch unit and the negative electrode terminal 32. By this bending, the smoothing capacitor and the switch unit can be mounted close to each other, so that the length from the switch unit to the negative electrode conductor terminal 32 is secured as in the third embodiment already described with reference to FIG. However, the entire device can be downsized. Although not shown, the positive electrode conductor plate is also subjected to the same bending.
[0019]
【The invention's effect】
In a conventional large-capacity power converter in which a large number of switch units must be connected in parallel, if there is a difference in resistance or inductance of a conductor connecting each switch unit to another device (for example, a smoothing capacitor). Care must be taken in laying conductors so that there will be no difference in resistance or inductance because the current flowing will be unbalanced.However, when the current of the switch unit is balanced, the current of the smoothing capacitor will be It has been difficult to lay conductors that do not cause imbalance when the number of parallel circuits is large, such as unbalance. In the present invention, in order to facilitate connection with the smoothing capacitor, the distance from the positive and negative bipolar conductor plates to which the switch units are connected in parallel to the positive and negative bipolar conductor terminals is extended, a notch is provided in the middle between the two, and bending is performed. By performing processing, it is possible to obtain an effect of facilitating connection with other devices such as a smoothing capacitor and suppressing an unbalance of current flowing through each switch unit without requiring an extra wiring space.
[Brief description of the drawings]
FIG. 1 is a structural diagram of a positive electrode conductor plate showing a first embodiment of the present invention; FIG. 2 is a structural diagram of a negative electrode conductor plate showing a first embodiment of the present invention; FIG. 3 is a second embodiment of the present invention; FIG. 4 is a structural diagram of a negative electrode conductor plate according to a third embodiment of the present invention. FIG. 5 is a structural diagram of a negative electrode conductor plate according to a third embodiment of the present invention. FIG. 6 is a structural diagram of a negative electrode conductor plate with slits showing a fourth embodiment of the present invention. FIG. 7 is a structural diagram showing a situation in which a plurality of switch units are connected in parallel by a sandwich-structured conductor. FIG. 9 is a structural view showing a conventional example of a positive conductor plate in which the positive terminals of a plurality of switch units are connected in parallel for a capacity inverter. FIG. 9 is a diagram of a negative conductor plate in which the negative terminals of a plurality of switch units are connected in parallel for a large capacity inverter. Structural diagram showing a conventional example [Description of reference numerals]
15A Switch unit 16 Positive conductor plate 16P Positive terminal connection hole 16T Positive conductor terminal 17 Negative conductor plate 17N Negative terminal connection hole 17T Negative conductor terminal 18 Insulating plate 21 Positive conductor plate 22 Positive conductor terminal 24 Slit positive conductor plate 25, 35 cut Notches 31, 33 Negative conductor plate 32 Negative conductor terminals 34, 36 Negative conductor plate with slit

Claims (5)

A plurality of switch units formed by connecting two sets of an anti-parallel circuit of a semiconductor switch element and a diode in series are arranged in a line in the left-right direction to form one phase, and the required number of phases are all set in the vertical direction. Arrange on the same plane,
Arrange multiple smoothing capacitors in the horizontal direction,
When covering the surfaces of the switch units arranged vertically and horizontally with a positive electrode conductor plate, the positions corresponding to the negative electrode terminal and the AC terminal of each switch unit are opened and connected to each positive electrode terminal with the corresponding positive electrode conductor plate,
The positive electrode conductor plate and the negative electrode conductor plate that are overlapped with an insulating sheet interposed therebetween have openings corresponding to the positive terminal and the AC terminal of each switch unit and connect each negative electrode terminal to the negative electrode conductor plate,
A positive conductor terminal for connecting the smoothing capacitor to one of right and left ends of the positive conductor plate,
In the conductor structure of the large-capacity power converter, comprising a negative conductor terminal for connecting the smoothing capacitor to an end of the negative conductor plate opposite to the end,
A conductor structure for a large-capacity power converter, wherein a distance from a switch unit connected to the positive conductor plate to a positive conductor terminal and a distance from a switch unit connected to the negative conductor plate to a negative conductor terminal are increased. The conductor structure of the large-capacity power converter according to claim 1,
A conductor structure for a large-capacity power converter, wherein the positive / negative bipolar conductor plate or its positive / negative bipolar conductor terminal is bent to reduce a spatial distance from the switch unit to the positive / negative bipolar conductor terminal. A plurality of switch units formed by connecting two sets of an anti-parallel circuit of a semiconductor switch element and a diode in series are arranged in a line in the left-right direction to form one phase, and the required number of phases are all set in the vertical direction. Arrange on the same plane,
Arrange multiple smoothing capacitors in the horizontal direction,
When covering the surfaces of the switch units arranged vertically and horizontally with a positive electrode conductor plate, the positions corresponding to the negative electrode terminal and the AC terminal of each switch unit are opened and connected to each positive electrode terminal with the corresponding positive electrode conductor plate,
The positive electrode conductor plate and the negative electrode conductor plate that are overlapped with an insulating sheet interposed therebetween have openings corresponding to the positive terminal and the AC terminal of each switch unit and connect each negative electrode terminal to the negative electrode conductor plate,
A positive conductor terminal for connecting the smoothing capacitor to one of right and left ends of the positive conductor plate,
In the conductor structure of a large-capacity power conversion device including a negative conductor terminal for connecting the smoothing capacitor to an end of the negative conductor plate opposite to the end,
The positive electrode conductor plate is a slit-containing positive electrode conductor plate provided with a cutout portion having a length of substantially half the left-right dimension of the positive electrode conductor plate between the switch unit and the positive electrode terminal,
The negative electrode conductor plate may be a slit-type negative electrode conductor plate provided with a cutout portion having a length substantially half the left-right dimension of the negative electrode conductor plate between the switch unit and the negative electrode terminal. Conductor structure of capacitive power converter. The conductor structure of the large-capacity power converter according to claim 3,
A conductor structure for a large-capacity power converter, wherein the positive / negative bipolar conductor plate with a slit or its positive / negative bipolar conductor terminal is bent to reduce a spatial distance from the switch unit to the positive / negative bipolar conductor terminal. The conductor structure of the large-capacity power converter according to claim 3 or 4,
The width dimension of the notch provided in the positive / negative bipolar conductor plate with a slit is set to a dimension that can reduce the influence of the interaction of the current flowing through one edge and the other edge of the notch. Conductor structure of the large-capacity power converter.

Images