JP2005237118A - Bus bar structure and power converting apparatus utilizing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problem that currents flowing bus bars in opposite directions do not match each other in a bus bar structure with a pair of plate bus bars in which the currents flow in the opposite directions. <P>SOLUTION: A positive bus bar 54 is provided with a positive terminal 64 connected to the high potential side (+) of a power supply, and has positive conductor posts 22, 32 and 42 extending from the positive bus bar 54 and electrically connected to the positive side of a module. A negative bus bar 52 is provided with a negative terminal 62 connected to the low potential side (-) of the power supply, and has negative conductor posts 24, 34 and 44 extending from the negative bus bar 52 and electrically connected to the negative side of a module. Narrowed regions 83a, 83b are formed in at least a part of the positive and negative bus bars 54, 52 so as to maintain a position relationship for matching the regions in the opposite directions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a bus bar structure used for supplying current from a power source to a module (typically a circuit such as an inverter or a converter) provided with a switching element such as an IGBT or a MOSFET. . More specifically, the present invention relates to a bus bar structure including a pair of plate-like bus bars through which currents in opposite directions flow.

In recent years, for example, with the increase in current of motors and actuators for electric vehicles, there is an increasing demand for handling inverter circuits and the like provided in the equipment with a large current. In order to meet this type of demand, the above circuit tends to increase in size in consideration of parallel use of switching elements and heat dissipation. For this reason, a large wiring portion (bus bar or the like) of this type of circuit has been used.
Generally, when a switching element provided in this type of circuit is switched, a spike-like surge voltage may be generated. This is because the parasitic inductance of the wiring portion is multiplied by the current change during switching. As described above, when the wiring portion becomes larger, the parasitic inductance of the wiring portion also increases. Therefore, in recent years, it has become more important to take some measures against the parasitic inductance of the wiring portion.
Patent Document 1 discloses a technique for reducing mutual inductance between bus bars by disposing a pair of plate-like bus bars through which currents flowing in opposite directions flow and canceling out magnetic fluxes from the currents flowing through the respective bus bars. Has been described.
JP 2002-44960 A (refer to FIG. 1 of that publication)

First, before describing a pair of plate-shaped bus bars, a three-phase inverter circuit is illustrated as an example in which this type of bus bar structure is used. FIG. 5 shows an equivalent circuit of a three-phase inverter circuit.
In the three-phase inverter circuit shown in FIG. 5, the positive side (+) of the power source and the transistors Tr1 to Tr3 are connected in parallel via the connection points 122, 132, 142, and the upper side is connected by these three transistors Tr1 to Tr3. Forming part. On the other hand, the negative side (−) of the power source and the transistors Tr4 to Tr6 are connected in parallel via connection points 124, 134, and 144, and the transistors Tr4 to Tr6 form a low side portion. Diodes D1 to D6 are connected in parallel to the transistors Tr1 to Tr6, and play a role of bypassing reverse recovery current at the time of switching. The U-phase, V-phase, and W-phase are output to a load (not shown) from locations where the upper side transistors Tr1 to Tr3 and the low side transistors Tr4 to Tr6 are connected. As the current increases in recent years, there are cases where, for example, three transistors Tr1 corresponding to the U phase are configured in parallel instead of one, and this type of circuit tends to increase in size. is there.

FIG. 6 shows an example of a bus bar structure used in this type of inverter circuit using a perspective view.
This bus bar structure includes a pair of positive side bus bars 154 and negative side bus bars 152 through which currents in opposite directions flow. The positive side bus bar 154 is connected to the high-order side (+) of the power source via the positive terminal 164. Extending from the positive bus bar 154, positive side conductor pillars 222, 232, and 242 that can electrically connect the upper side portion of the three-phase inverter and the positive bus bar 154 are formed. The phase conductor column is connected to the upper side connection point 122, and the positive side V phase conductor column in FIG. 232 is connected to the upper side connection point 132, and the positive side W phase conductor column in FIG. Is connected to a connection point 142 on the upper side. This bus bar structure has a symmetrical structure on the left and right sides of the drawing, and the three-phase inverter circuit shown in FIG. 5 is arranged on the right side of the drawing, and a separate three-phase inverter circuit is further formed on the left side of the drawing. . Therefore, this bus bar structure is a bus bar structure that can simultaneously supply current from the power source to the two three-phase inverter circuits arranged on the left and right.
The negative bus bar 152 formed so as to face the positive bus bar 154 is connected to the lower power source (−) via the negative terminal 162. Extending from the negative side bus bar 152, negative side conductor columns 224, 234, 244 that can electrically connect the low side portion of the three-phase inverter circuit and the negative side bus bar 152 are formed. The U-phase conductor column is connected to the low-side connection point 124, the negative-side V-phase conductor column in FIG. 234 is connected to the low-side connection point 134, and the negative-side W-phase conductor in FIG. The column is connected to a connection point 144 on the low side.
The positive terminal 164 and the negative terminal 162 of this bus bar structure are not in contact with each other by being aligned on the same plane and offset in the horizontal direction. This is offset in the horizontal direction in this way because of the ease of connection and assembly with other parts.

  The supply current supplied from the positive side (+) of the power supply passes through the positive side bus bar 154 from the positive terminal 164, passes through the positive side conductor column connected to the transistor turned on at the upper side, and is not shown in the figure. Supplied to the load. The feedback current fed back from the load passes through the transistor that is turned on at the low side, passes through the negative conductor column connected to the transistor and the negative bus bar 152, and from the negative terminal 162 to the negative side (− ). Therefore, the supply current flowing in the positive bus bar 154 and the feedback current flowing in the negative bus bar 152 flow in opposite directions, thereby canceling the reverse magnetic flux generated by each current. The mutual inductance of is reduced.

However, as a result of studies by the present inventors, it has been found that the current distribution of the supply current and the feedback current flowing through each bus bar is unevenly distributed based on the shape of the bus bar. In particular, the current distribution of bus bars, which have been increasing in size in recent years, has become more uneven, and there is a situation where the current distribution of the supply current and the current distribution of the feedback current do not match in the opposite direction. It turns out. Therefore, the present inventors have recognized that the magnetic flux generated from each current is not sufficiently canceled out and the mutual inductance cannot be sufficiently reduced. This phenomenon will be briefly described with reference to FIG.
FIG. 7 schematically shows a plan view of the bus bar structure shown in FIG. 6 and a conduction path of a current flowing through the bus bar. FIG. 7A shows the positive bus bar 154, and FIG. ) Is the negative bus bar 152, and FIG. 7C is a plan view in which the positive bus bar 154 and the negative bus bar 152 are overlapped. 7A shows the conduction path of the supply current in the positive bus bar 154, and FIG. 7B shows the conduction path of the feedback current in the negative bus bar 152 using a solid line. In this example, only the supply current to the W phase and the feedback current from the W phase are shown. Actually, it is necessary to consider all combinations of the supply current and the feedback current conducted between each terminal and each conductor column, but in this example, only the supply current and the feedback current corresponding to the W phase are considered for convenience.

As shown in FIGS. 7A and 7B, the supply current and the feedback current tend to flow along the shortest path connecting the terminal and the conductor column.
Accordingly, as shown in FIG. 7C, it can be seen that the conduction path of the supply current flowing through the positive bus bar 154 and the feedback current flowing through the negative bus bar 152 do not coincide with each other in the facing direction. In the study by the present inventors, it has been confirmed that this tendency is noticeable when the width of the bus bar exceeds 20 mm (even if the width is less than this, there is a bias in the conduction path, which is caused by the surge voltage. It will be a problem if it affects.) Therefore, the magnetic flux generated by the supply current and the feedback current is not sufficiently canceled, and as a result, the problem that the surge voltage cannot be sufficiently reduced occurs.
The object of the present invention is to match the current distribution of the supply current and the feedback current flowing through the positive bus bar and the negative bus bar in the opposite direction of the bus bar (the current when the positive bus bar and the negative bus bar are overlapped). An object of the present invention is to provide a bus bar structure in which mutual inductance is reduced by canceling out magnetic fluxes generated by respective currents, and thus a surge voltage is suppressed.

The present invention is embodied in a bus bar structure including a pair of plate-like bus bars through which currents in opposite directions flow.
The bus bar structure according to the present invention includes a positive bus bar including a positive terminal connected to the higher power supply side. A positive-side conductor column that extends from the positive-side bus bar and that can electrically connect the positive side of the module and the positive-side bus bar is provided. Thereby, the supply current supplied from the higher power supply side is supplied from the terminal to the module via the positive bus bar and the positive conductor column.
The bus bar structure of the present invention includes a negative bus bar that is formed in a positional relationship facing the positive bus bar and has a negative terminal connected to the lower power supply side. A negative conductor pillar is provided that extends from the negative bus bar and can electrically connect the negative side of the module to the negative bus bar. Thereby, the feedback current returning from the module flows to the lower side of the power source via the negative side conductor column, the negative side bus bar, and the negative terminal. Therefore, the supply current flowing in the positive bus bar and the feedback current flowing in the negative bus bar flow in opposite directions.
A constriction region is formed in at least a part of the positive bus bar and the negative bus bar. The narrowed region is formed in a positional relationship that coincides with the opposing direction. That is, when the positive side bus bar and the negative side bus bar are overlapped, the narrowed regions are formed in a positional relationship.

According to the bus bar structure described above, the constricted regions are formed in the positive bus bar and the negative bus bar, and the constricted regions coincide with each other in the opposing direction. Since the supply current flowing through the positive bus bar and the feedback current flowing through the negative bus bar pass through the respective constricted regions, the supply current and the feedback current flow in the constricted region in the opposite direction of the bus bar. Since each current conduction path flowing through the constriction region to the terminal or the conductor column is once converged in this constriction region, it flows relatively in the opposite direction in the other bus bars. It will be. Therefore, the reverse magnetic fluxes generated from the respective currents are canceled out, the mutual inductance is reduced, and the surge voltage is suppressed.
Note that Patent Document 1 described in the background art describes a technique for forming a slit (notch) in a bus bar to balance the distribution of current flowing in the opposite bus bar. However, the slit described in Patent Document 1 is a slit formed for the purpose of aligning the shapes of the opposing bus bars, and can be said to be a technique for balancing the current distribution more roughly. On the other hand, the constriction region of the present invention is a technique for further matching the current distribution in the bus bar with the opposite bus bar, and the technical ideas of both are different.

The constriction region is preferably formed in the vicinity of the terminal.
Since the positive terminal and the negative terminal are offset in the horizontal direction so as to be aligned on the same plane, the conduction path between the supply current and the feedback current in the vicinity of the terminal is greatly biased in the direction opposite to the bus bar. Therefore, if a constriction region is formed in the vicinity of this terminal, the current is focused at that point, so that the supply current and the feedback current can be made to coincide with each other in the opposing direction of the bus bar. Furthermore, the conduction paths of the supply current and the feedback current flowing through the bus bar through the constricted area flow in the same direction in the opposite direction of the bus bar, so the magnetic flux generated from each current is offset. The effect to do is extremely great. As a result, the mutual inductance is reduced, and the surge voltage is suppressed.

It is preferable that the constriction region is formed in the vicinity of the connection portion between the bus bar and the conductor column.
Both the positive and negative conductor columns are formed to extend toward the module, and the positions of the connecting portions of the bus bars and the conductor columns are offset so that the respective conductor columns are not overlapped. Therefore, in the vicinity of the connecting portion, the conduction path between the supply current and the feedback current is greatly biased in the direction in which the bus bar faces. For this reason, the supply current and the feedback current can be converged by forming the constriction region in the vicinity of the connecting portion. As a result, the reverse magnetic flux generated from each current is canceled out, the mutual inductance is reduced, and the surge voltage is suppressed.

A power converter that uses the bus bar structure in a module having a three-phase inverter circuit is preferable.
In this case, a U-phase switching element and a V-phase switching element in which a positive U-phase conductor column, a positive V-phase conductor column, and a positive W-phase conductor column extending from the positive bus bar are formed on the upper side of the three-phase inverter circuit. And connected to the positive side of the W-phase switching element. A negative U-phase conductor column, a negative V-phase conductor column, and a negative W-phase conductor column extending from the negative bus bar are formed on the low side of the three-phase inverter circuit. It is connected to the negative side of the switching element.
The three-phase inverter circuit has been increased in size with an increase in current, and a bus bar having a large width used for the three-phase inverter circuit is used following the increase in size. Therefore, in the three-phase inverter circuit, the generation of a surge voltage due to the parasitic inductance caused by the bus bar is a big problem.
When the bus bar of the present invention is used for this three-phase inverter circuit, the effect of reducing the surge voltage is sufficiently exhibited, which is preferable.
It is particularly preferred to use the present invention when the bus bar width exceeds 20 mm. When the width of the bus bar exceeds 20 mm, the current flowing in the bus bar tends to be distributed, and according to the present invention, such current distribution can be matched in the direction in which the bus bars face each other.

  According to the present invention, the supply current that flows through the positive bus bar and the feedback current that flows through the negative bus bar flow in opposite directions, and the current distribution matches in the opposite direction. Are offset, the mutual inductance is reduced, and consequently the surge voltage is reduced.

First, the main features of the embodiment are listed.
First Embodiment A module, a positive bus bar, and a negative bus bar are formed in parallel. Conductor columns extending from the positive bus bar and the negative bus bar are formed to extend in a direction perpendicular to the parallel plane. As a result, the current flowing in the conductor column and the current flowing in each bus bar and module are orthogonal to each other, and no mutual inductance is generated between them.
(Second Embodiment) In order to reduce the mutual inductance between the current flowing in the module and the current flowing in the bus bar, the bus bar in which the current in the direction opposite to the direction of the current flowing in the module is provided in the module. Place on the near side. For example, if the supply current flows in the opposite direction to the direction of the current flowing in the module, the module, the positive bus bar, and the negative bus bar are arranged in this order.

Embodiments will be described in detail below with reference to the drawings.
First Example FIG. 1 is a schematic perspective view of a bus bar structure according to a first example. Note that the difference between the bus bar structure of this embodiment can be clearly understood by comparing with the conventional bus bar structure shown in FIG. Further, the bus bar structure of the present embodiment is connected to the three-phase inverter circuit shown in FIG. 5, and the description of the three-phase inverter circuit is omitted here.
The bus bar structure shown in FIG. 1 includes a pair of positive bus bars 54 and a negative bus bar 52 through which currents flowing in opposite directions flow. The positive side bus bar 54 and the negative side bus bar 52 may be opposed to each other via an insulating film (not shown), or may be insulated from each other by a predetermined distance. The positive side bus bar 54 and the negative side bus bar 52 have a substantially rectangular shape, and the shapes thereof are substantially the same.
The positive-side bus bar 54 is connected to the high-order side (+) of the power source via the positive terminal 64. Extending from the side surface of the positive side bus bar 54 in the long side direction, positive side conductor columns 22, 32, 42 that can electrically connect the upper side portion of the three-phase inverter and the positive side bus bar 54 are formed. The positive side conductor columns 22, 32 and 42 extend in a direction perpendicular to the positive side bus bar 54.
22 is connected to a transistor corresponding to the U phase on the upper side, and the positive V phase conductor column in FIG. 32 is connected to a transistor corresponding to the V phase on the upper side. The positive-side W-phase conductor column shown in FIG. 42 is connected to a transistor corresponding to the W-phase on the upper side. This bus bar structure has a symmetrical structure on the left and right sides of the drawing, and a three-phase inverter circuit is arranged on each of the left and right sides. This bus bar structure can simultaneously supply current from the power source to the two three-phase inverter circuits.

The negative bus bar 52 formed in a positional relationship facing the positive bus bar 54 is connected to the lower power supply side (−) via the negative terminal 62. Negative side conductor columns 24, 34, and 44 are formed that extend from the side surface of the negative side bus bar 52 in the long side direction and can electrically connect the low side portion of the three-phase inverter circuit and the negative side bus bar 52. . The negative side conductor columns 24, 34, 44 extend in a direction perpendicular to the negative side bus bar 52.
The negative U-phase conductor column in FIG. 24 is connected to the low-side transistor, and the negative V-phase conductor column in FIG. 34 is connected to the low-side transistor. The conductor column is connected to the transistor on the low side.
The positive terminal 64 and the negative terminal 62 of this bus bar structure are aligned in the same plane and formed at a position offset in the horizontal direction, and in the vicinity of the positive terminal 64 of the positive bus bar 54, A notch 82 a is formed, and a negative terminal side notch 82 b is formed in the vicinity of the negative terminal 62 of the negative bus bar 52. Narrow regions 81a and 81b are formed in the vicinity of the terminals of the bus bars by the terminal-side cutouts 82a and 82b. The narrowed area 81a of the positive bus bar 54 and the narrowed area 81b of the negative bus bar 52 are formed in a positional relationship that coincides with the opposing direction of the bus bar.

The supply current supplied from the positive side (+) of the power supply passes through the positive side conductor bar connected to the transistor which is turned on at the upper side via the positive side bus bar 54 from the positive terminal 64 and a load (not shown). (Typically a motor). The feedback current fed back from the load passes through the transistor that is turned on at the low side, passes through the negative conductor column connected to the transistor and the negative bus bar 52, and from the negative terminal 62 to the negative side (− ).
This bus bar structure is characterized in that since each conductor column and each bus bar are formed in an orthogonal positional relationship, no mutual inductance occurs between them. In addition, the positive and negative conductor columns are formed almost in parallel, and the current flowing through each conductor column flows in the opposite direction, so that the magnetic flux generated between them is offset and the mutual inductance is reduced. The effect that it is done can be expected. In addition, this bus bar structure can supply or return current to the transistors of each phase of the two three-phase inverter circuits by one bus bar, and its three-dimensional structure is extremely simplified, and the size of the device can be reduced. It is also very effective for conversion.

  FIG. 2 schematically shows a plan view of the bus bar shown in FIG. 1 and a conduction path of current flowing through the bus bar. 2A is the positive bus bar 54, FIG. 2B is the negative bus bar 52, and FIG. 2C is a diagram in which the positive bus bar 54 and the negative bus bar 52 are overlapped. 2A shows the conduction path of the supply current in the positive bus bar 54, and FIG. 2B shows the conduction path of the feedback current in the negative bus bar 52 using a solid line. In this example, only the supply current to the W phase and the feedback current from the W phase are shown. Actually, it is necessary to consider all combinations of the supply current and the feedback current conducted between each terminal and each conductor column, but in this example, the supply current and the feedback current are examined only in the W phase. In this embodiment, the W phase is disposed at the position farthest from the terminal, and therefore the conduction path between them is the longest, and the parasitic inductance component between them is the largest. For this reason, limiting the conduction path between them is most effective in reducing the parasitic inductance.

As shown in FIG. 2A, the supply current supplied from the positive terminal 64 is converged in the constricted region 81a and flows toward the positive W-phase conductor column 42 after passing through the constricted region 81a.
As shown in FIG. 2B, the feedback current returning from the negative side W-phase conductor column 44 flows toward the constricted region 81b, and after being focused in the constricted region 81b, flows into the negative terminal 62.
As shown in FIG. 2 (c), since the supply current and the feedback current are both concentrated in the constricted regions 81a and 81b, the conduction paths in each bus bar should be in good agreement in the opposite direction of the bus bar. become. Therefore, the magnetic flux generated by each current is canceled out, the mutual inductance of the bus bar is reduced, and the surge voltage is suppressed.

(Second Embodiment) FIG. 3 schematically shows a plan view of a bus bar according to a second embodiment and a conduction path of a current flowing in the bus bar. In addition, the same code | symbol is attached | subjected to the substantially identical component of 1st Example, and the description is abbreviate | omitted. Further, the bus bar structure of the present embodiment is connected to a three-phase inverter circuit, and the three-phase inverter circuit includes three transistors in parallel in each of the upper side portion and the low side portion. It is a parallel operation inverter circuit. Therefore, operation with a large current is possible.
The positive side bus bar 54 and the negative side bus bar 52 of this embodiment are opposed to each other with an insulating material therebetween, and the facing distance is 2 mm. The width (L1) in the short side direction of the positive side bus bar 54 and the negative side bus bar 52 is 40 mm. Notches are formed at two locations on the long side of each bus bar, and partition the conductor columns connected to the U phase, V phase, and W phase. The short side width (L2) corresponding to this notch is 20 mm. This notch is formed from the advantage of the configuration of the apparatus, and also has a function of limiting a current conduction path by the notch.

A positive W-phase notch portion 84a is formed in the vicinity of the connecting portion with the positive W-phase conductor column 42 connected to the W phase of the positive bus bar 54 of this embodiment, thereby forming a constricted region 83a. Has been. A negative side W-phase notch 84b is formed in the vicinity of the connecting portion of the negative side bus bar 52 to the negative side W-phase conductor column 44 connected to the W phase, thereby forming a constricted region 83b. The narrowed region 83a of the positive bus bar 54 and the narrowed region 83b of the negative bus bar 52 are formed to coincide with each other in the facing direction of the bus bar.
As shown in FIG. 3A, the conduction path of the supply current supplied from the positive terminal 64 of the positive bus bar 54 is focused by the constriction region 83a. As a result, this conduction path is bent by the constriction region 83 a and flows into the positive W-phase conductor column 42 along the side surface of the positive bus bar 54.
On the other hand, as shown in FIG. 3B, the feedback current returning from the negative side W-phase conductor column 44 is focused on the conduction path by the constricted region 83b. Flows along the side surface of the negative bus bar 52 and flows toward the negative terminal 62 after passing through the constriction region 83b.
As shown in FIG. 3C, the conduction paths of the supply current and the feedback current both flow along the side surfaces of the bus bars in the vicinity of the constricted regions 83a and 83b. It matches well in the opposite direction. As described above, once the conduction path is focused in the vicinity of the W phase that is farthest from the terminal, the conduction paths are well matched over the entire area in the bus bar, and the mutual inductance is reduced. The effect of reducing is great.
The total inductance corresponding to this W-phase conduction path was 50 nH. The total inductance when the W-phase notches 84a and 84b are not formed is 60 nH, and the effect of reducing the mutual inductance has been demonstrated.
Note that the bus bar of this embodiment has notches formed at two locations on the long side, and the current conduction path via the U phase and the V phase can be controlled by the notches. Therefore, this notch is effective in reducing parasitic inductance.

(Third Embodiment) FIG. 4 shows a plan view of a bus bar structure according to a third embodiment and a conduction path of a current flowing through the bus bar. In addition, this example is an example in which a notch is formed in the vicinity of the terminal in addition to the bus bar structure of the second example.
As shown in FIG. 4A, the positive terminal side notch 82 a is formed in the vicinity of the positive terminal 64, thereby forming a constricted region 81 a in the vicinity of the positive terminal 64. Therefore, the conduction path of the supply current supplied from the positive terminal 64 is focused in the vicinity of the positive terminal 64.
On the other hand, as shown in FIG. 4B, the negative terminal side notch 82 b is formed in the vicinity of the negative terminal 62, thereby forming a constricted region 81 b in the vicinity of the negative terminal 62. Therefore, the conduction path of the feedback current returning from the W-phase side is focused by this constriction region 81b.
Further, in this embodiment, the vertical arrangement of the positive bus bar 54 and the negative bus bar 52 is opposite to the arrangement of the second embodiment. The positive bus bar 54 is on the lower side, and the negative bus bar 52 is on the upper side. This is because the current flowing in the three-phase inverter circuit flows in the opposite direction to the supply current flowing in the positive bus bar 54. Thus, the mutual inductance between them can be reduced by arranging the bus bar on the side flowing in the opposite direction to the direction of the current flowing in the three-phase inverter circuit.
As shown in FIG. 4 (c), looking at the conduction path corresponding to the W phase, both the supply current and the feedback current are converged in the vicinity of both ends of the bus bar. The conduction paths are well matched in the opposite direction.
The total inductance corresponding to this W-phase conduction path was 40 nH. It has been demonstrated that the mutual inductance is extremely reduced by forming both the W-phase notches 84a and 84b and the terminal-side notches 82a and 82b.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

The perspective view of the bus-bar structure of 1st Example is shown. (a) The top view of the positive side bus bar of 1st Example is shown. (b) The top view of the negative side bus bar of 1st Example is shown. (c) The top view which piled up the positive side bus bar and the negative side bus bar is shown. (a) The top view of the positive side bus bar of 2nd Example is shown. (b) The top view of the negative side bus bar of 2nd Example is shown. (c) The top view which piled up the positive side bus bar and the negative side bus bar is shown. (a) The top view of the positive side bus bar of 3rd Example is shown. (b) The top view of the negative side bus bar of 3rd Example is shown. (c) The top view which piled up the positive side bus bar and the negative side bus bar is shown. The equivalent circuit of a three-phase inverter circuit is shown. The perspective view of the conventional bus-bar structure is shown. (a) The top view of the conventional positive side bus bar is shown. (b) The top view of the conventional negative side bus bar is shown. (c) The top view which piled up the positive side bus bar and the negative side bus bar is shown.

Explanation of symbols

22, 32, 42: Positive side conductor columns 24, 34, 44: Negative side conductor columns 52: Negative side bus bar 54: Positive side bus bar 62: Negative terminal 64: Positive terminals 81a, 81b: Terminal side constricted regions 82a, 82b: Terminal-side notches 83a and 83b: W-phase side constricted portions 84a and 84b: W-phase side notches

Claims (4)

In a bus bar structure including a pair of plate-like bus bars in which currents in opposite directions flow,
A positive bus bar with a positive terminal connected to the higher side of the power supply;
A positive conductor pillar extending from the positive bus bar and electrically connecting the positive side of the module and the positive bus bar;
A negative bus bar that is formed in a positional relationship facing the positive bus bar and has a negative terminal connected to the lower side of the power source,
The negative side bus bar extends from the negative side bus bar, and the negative side of the module and the negative side conductor bar capable of electrically connecting the negative side bus bar are provided.
A bus bar structure, wherein a stenosis region is formed in at least a part of a positive bus bar and a negative bus bar, and the stenosis region is formed in a positional relationship that coincides with a facing direction.   The bus bar structure according to claim 1, wherein the narrowed region is formed in the vicinity of the terminal.   3. The bus bar structure according to claim 2, wherein the narrowed region is formed in the vicinity of a connecting portion between the bus bar and the conductor pillar. A power conversion device comprising the bus bar structure according to any one of claims 1 to 3 and a three-phase inverter circuit,
A U-phase switching element, a V-phase switching element, and a W-phase, in which a positive U-phase conductor pillar, a positive V-phase conductor pillar, and a positive W-phase conductor pillar extending from the positive bus bar are formed on the upper side of the three-phase inverter circuit. Connected to the positive side of the switching element,
A negative U-phase conductor column, a negative V-phase conductor column, and a negative W-phase conductor column extending from the negative bus bar are formed on the low side of the three-phase inverter circuit. It is connected to the negative side of a switching element, The power converter device characterized by the above-mentioned.

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