JP2001352767A - Power unit for power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable power unit for power converter having a low wiring inductance in which compaction of the unit is achieved. SOLUTION: The power unit for power converter comprises a smoothing capacitor (9), a power module (1) including a switching chip (2a), a cooler (7), and pattern conductors (15c-15g) for electrical connection fixed onto a high current wiring board (15). The power module (1) is fixed to an insulation board (3) and the power module (1) and the cooler (7) fixed to the insulation board (3) are fixed to the high current wiring board (15) under pressure contact state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a power unit for a power converter.

[0002]

2. Description of the Related Art A motor drive for driving an AC motor at a variable speed by using a DC voltage supplied from a storage battery or a DC voltage obtained by rectifying an AC voltage as a power source to obtain an AC voltage having a variable frequency by an inverter. The system has recently been used for vehicles driven at variable speeds, such as electric vehicles, due to the development of semiconductor devices and control technologies. The present invention relates to a power unit for a power converter used for driving such an AC motor at a variable speed.

FIG. 12 shows a typical main circuit configuration of a motor drive device having a voltage type three-phase inverter device. A smoothing capacitor 9 is connected between a pair of input terminals including a positive DC terminal 10ap and a negative DC terminal 10an, and a DC input terminal of the three-phase inverter, that is, the power module 1 is connected. Power module 1
That is, each arm of the inverter includes a switching chip and a freewheeling diode chip connected in anti-parallel to the switching chip. If this is illustrated for the U phase, the positive side arm is composed of a switching chip 2a and a diode chip 2c, and the negative side arm is composed of a switching chip 2b and a diode chip 2d. As a switching chip, IGBT (gate insulated bipolar transistor)
However, this may be another type of switching element as long as it is a self-extinguishing type switching element, for example,
A MOS FET can also be used. A three-phase output terminal of the power module 1 is connected to a three-phase output terminal 10b via a current detector 11 provided for each phase for current control.
u, 10bv, 10bw. The power unit 20 is constituted by the smoothing capacitor 9, the power module 1, and the current detector 11. Power unit 2
0 output terminal is an AC motor (MOT) 1 to be driven.
2. For example, a permanent magnet type synchronous motor is connected. In addition,
In the following description, both DC terminals 10ap, 10an
Are collectively referred to as a DC input terminal 10a, and a three-phase output terminal 10a.
bu, 10bv, and 10bw may be collectively referred to as an AC output terminal 10b.

FIG. 13 is a perspective view showing the structure of a power unit 20 corresponding to the main circuit shown in FIG. The power unit 20 shown in FIG. 13 is housed in the housing 13 as a whole. In the housing 13, the metal base 5 is mounted on the cooler 7 by mounting screws 6, and the power module 1 including the switching chip 2 a and the diode chip 2 c is mounted on the metal base 5 via the insulating substrate 3. Are located. The switching chip 2a and the diode chip 2c are connected via the solder 4 patterned on the insulating substrate 3. The output terminal of the power module 1 is connected to the AC output terminal 10b of the terminal block 8 via the current detector 11. The smoothing capacitor 9 is connected to the DC input terminal 10a of the terminal block 8 via the connection conductor 10. A gate circuit unit 14 that controls on / off of the power module 1, that is, the switching chip 2 a, is arranged near the power module 1.

FIG. 14 shows a main circuit configuration of a system in which a two-winding type AC motor 12a is driven by a power unit 22 of a double multiplex system which is frequently used as a measure for reducing harmonics. Here, two sets of power modules 1 having the same configuration
a, 1b are provided, their DC input terminals are connected in parallel to the DC input terminals 10ap, 10an, and the AC output terminals are led to the output terminals 10b, 10c of the power unit 22 via the current detectors 11a, 11b, respectively. . Output terminals 10b and 10c are connected to separate stator windings of AC motor 12a. In this case, the power module 1
a and 1b generate outputs whose phases are shifted by a predetermined angle according to a known method to reduce harmonics.
a to two sets of windings.

[0006]

Briefly speaking, the conventional power units 20 and 22 of this kind simply include juxtaposition of existing modular switching chips and general-purpose circuit components.
Or, they are merely stacks, and little consideration is given to issues such as downsizing the unit and reducing the wiring inductance.Therefore, the wiring inductance becomes unbalanced, causing malfunctions or increasing the size. I was

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a power unit for a power converter which achieves a compact unit and has a small wiring inductance and high reliability.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a smoothing capacitor, a power module including a switching chip, a cooler, and a pattern conductor for electrical connection are provided with a large current wiring. In the power unit for a power converter mounted on a substrate, the power module is mounted on an insulating substrate, and the power module and the cooler mounted on the insulating substrate are mounted in a pressurized contact state with a large-current wiring substrate. And

According to a second aspect of the present invention, in the power unit for a power converter according to the second aspect, the switching modules included in the two sets of power modules are entirely divided into a positive switching module and a negative switching module, The positive-side power module and the negative-side power module are distributed on the front side and the back side of the large current wiring board.

According to a third aspect of the present invention, in the power unit for a power converter according to the second aspect, the switching modules included in the two sets of power modules are divided into a positive switching module and a negative switching module as a whole. One of the positive side power module and the negative side power module is disposed on the front side of the large current wiring board, and the other is disposed on the rear side of the large current wiring board.

The invention according to claim 4 is the invention according to claims 1 to 3
In the power unit for a power converter according to any one of the above, the cooler is a water-cooled cooler.

According to a fifth aspect of the present invention, in the power unit for a power converter according to the fourth aspect, the insulating substrate is formed of a flexible insulating sheet, and a contact conductor is inserted between the switching module and the insulating sheet. And
A metal block for connection is arranged between the switching module and the large current wiring board.

The invention according to claim 6 is the invention according to claims 1 to 5
In the power unit for a power converter according to any one of the above, the smoothing capacitor is composed of a number of unit capacitors, the pattern conductor for connecting the unit capacitors,
A slit for equalizing the wiring inductance of each unit capacitor is formed.

The invention according to claim 7 is the invention according to claims 3 to 5
In the power unit for a power converter according to any one of the above, the smoothing capacitor is composed of a large number of unit capacitors, and these unit capacitors are almost equally divided into two into a first and a second unit capacitor group. Second
Are characterized by being arranged on both sides of a switching module on a large current wiring board with a switching module interposed therebetween.

According to an eighth aspect of the present invention, in the power converter power unit according to the first or second aspect, the cooler is an air-cooled cooler.

According to a ninth aspect of the present invention, in the power unit for a power converter according to the eighth aspect, a cooler is provided for each arm of an inverter constituted by the power unit.

According to a tenth aspect of the present invention, in the power converter power unit according to any one of the first to ninth aspects, a heat pipe type cooler is provided on the large current wiring board. .

According to an eleventh aspect of the present invention, in the power unit for a power converter according to any one of the first to ninth aspects, a metal plate is provided instead of the cooler, and the metal plate and the high-current wiring board are heated. A pipe-type cooler is provided.

[0019]

(Embodiment 1) FIGS. 1 and 2 show Embodiment 1 of the present invention. FIG. 1 shows the overall configuration of the power unit, and FIG. 2 shows an electric connection pattern conductor combined with the large current wiring board 15.

The power unit shown in FIG. 1 corresponds to the main circuit shown in FIG. 12, and is roughly divided into a structural portion arranged on the large current wiring board 15 and a structural portion centered on the cooler 7. It consists of The cooler 7 is a water-cooled type having cooling water outlets 7a and 7b, and an insulating substrate 3 having a wiring pattern, on which a switching chip 2a and a diode chip 2c are mounted.
Is arranged. The insulating substrate 3 projects the contact electrode 16 upward for gate control of the switching chip 2a.

As shown in FIG. 2, the large current wiring board 15 has a positive input terminal 10ap and a pattern contact portion 15bp.
P-type conductor 15c having a negative input terminal 10a
N and a pattern conductor 15d having a pattern contact portion 15bn, a U-phase pattern conductor 15e having a U-phase output terminal 10bu, a V-phase pattern conductor 15f having a V-phase output terminal 10bv, and a W having a W-phase output terminal 10bw. It consists of a phase pattern conductor 15g. The P-pattern conductor 15c is connected from the positive input terminal 10ap to each unit capacitor 9
A positive current circuit is formed to reach the positive terminal of u and the positive terminal of the three-phase positive arm of the power module 1. Similarly,
The N pattern conductor 15d is connected from the negative input terminal 10an to the negative terminal of each unit capacitor 9u and the power module 1
The negative side current circuit reaching the negative side terminal of the three-phase negative side arm is formed. The phase pattern conductors 15e, 15f, and 15g connect the AC output terminals of each phase of the power module 1 to the AC output terminals 10bu, 10bv, and 10b of the power unit 20, respectively.
An alternating current circuit leading to w is formed.

On the large current wiring board 15, the smoothing capacitor 9, divided into a number of unit capacitors 9u, input terminals 10ap and 10an, output terminal 10b, current detector 11, and gate circuit section 14 are arranged. ing. A pressure tongue piece 15a is provided on the lower surface of the large current wiring board 15, and the contact electrode 15b projects downward so as to face the contact electrode 16. Large current wiring board 15
The insulating substrate 3 on which the respective chips are arranged below the gate circuit portion 14 so as to be vertically arranged with the gate circuit portion 14 is screwed with the mounting screws 6 to thereby comprise the switching chip 2a, the diode chip 2c and the like attached to the insulating substrate 3. The power module and the cooler 7 are attached to the large current wiring board 15 in a pressure contact state. Here, the pressurized contact state does not mean a particularly large pressurized state, but refers to a state of being tightened with a tightening force in normal screwing, for example, a tightening force of at most about 10 kg per square cm. Shall mean.

According to this embodiment, the workability and the cooling efficiency are improved by dividing the smoothing capacitor 9 into a number of unit capacitors 9u, thereby achieving the downsizing of the cooler 7 and the downsizing of the unit. In addition, it is possible to provide a highly reliable power unit for a power converter having a small wiring inductance. In addition, since almost no solder is used, the life with respect to the temperature cycle becomes longer,
Further improvement in reliability can be achieved.

(Embodiment 2) FIGS. 3 and 4 show a power unit according to Embodiment 2. FIG. In this embodiment, as shown in FIG.
1 shows an embodiment corresponding to a two-multiplex inverter including a and 1b. Here, the power module 1a
And 1b are not directly configured as independent structures, but are connected to the positive DC terminal 10
a positive-side module including a positive-side switching chip 2a and a positive-side diode chip 2c connected to ap, and a negative-side switching chip 2b and a negative-side diode chip 2d connected to a negative-side DC terminal 10an. The positive switching module is combined with the first cooler 7a, and the negative switching module is combined with the second cooler 7b. The first cooler 7a is arranged, for example, on the front side of the large current wiring board 15, and the second cooler 7b is arranged on the back side of the large current wiring board 15.

A P-pattern conductor 15c is led out from the positive switching module via a pattern contact portion 15b that contacts the contact electrode 16, and an N-pattern conductor 15d is led out from the negative switching module. Then, for each phase from the common connection point of both switching modules, for example, from the U-phase common connection point to the U-phase pattern conductor 15e
Is derived.

The unit capacitors constituting the smoothing capacitor are also composed of the first capacitor group 9a and the second capacitor group 9
b, the first capacitor group 9a is arranged on the front side of the large current wiring board 15, and the second capacitor group 9b is arranged at a corresponding position on the back side. Each cooler 7a,
Gate circuit sections 14a and 14b for gate-controlling the switching modules disposed on the switching module 7b are also arranged in a form corresponding to each switching module and are divided into two at corresponding positions on both surfaces of the large current wiring board 15. I have. The input / output terminals 10a and 10b may be provided only on one surface of the large current wiring board 15, for example, only on the surface as shown in the figure.

With the above arrangement, the wiring length can be shortened, the cooling efficiency can be improved, and the same effect as that of the first embodiment can be obtained, even though the inverter is a two-multiplex inverter.

(Embodiment 3) FIG. 5 shows a power unit according to Embodiment 3 of the present invention. This embodiment corresponds to a modification of the first embodiment, and includes a capacitor 9, input terminals 10ap and 10an, and an output terminal 1
Ob and the gate circuit unit 14 are arranged on the front surface of the large current wiring board 15, and the cooler 7, the insulating plate 30, the switching chip 2 a, the diode chip 2 c, etc. are arranged on the back surface of the large current wiring board 15. . Insulation plate 3
Reference numeral 0 denotes an electrically insulating rubber-like heat conductive sheet, for example, a silicon sheet.

The feature of this embodiment is that when the cooler 7 on which various components are arranged is mounted on the back surface of the large current wiring board 15, a metal block 17 is inserted for electrical connection of each chip. is there. That is, the insulating plate 3 (common to each arm) and the contact conductor 18 for collector wiring (for each arm of the power unit 1 in FIG. 12) are placed on the cooler 7, and the switching chip 2a and the diode are placed on the contact conductor 18. The chips 2c are juxtaposed, a metal block 17 is arranged on each chip as an emitter-side connection conductor, and the cooler 7 is attached to the large current wiring board 15 by the mounting screws 6.
The chip 2a, 2c is electrically connected to the pattern contact portion 15b on the large current wiring board 15 side. In that case, the contact conductor 18 and the chips 2a, 2
The workability is improved if the chips c and the chips 2a and 2c are integrated with the metal block 17 in advance by soldering or the like. The metal block 17 is made of a material having a similar linear expansion coefficient to the chips 2a and 2c made of silicon or the like, for example, molybdenum.

According to this embodiment, in addition to the functions and effects obtained by the first embodiment, it is possible to provide a power unit having good electrical connection and workability.

(Embodiment 4) FIG. 6 shows a P-pattern conductor 15c and an N-pattern conductor 15d according to a fourth embodiment. The feature of the sixth embodiment is that slits 15h and 15i are formed in the P-pattern conductor 15c and the N-pattern conductor 15d, respectively, so that the wiring lengths of a large number of unit capacitors constituting the capacitor 9 are as uniform as possible. . In the P pattern conductor 15c, the input terminal 10ap passes through the relatively narrow input side entrance 15j to each unit capacitor without directly reaching each unit capacitor from the positive input terminal 10ap through the outer edge. In the pattern conductor 15d, the outlet 15 is set on the opposite side to the inlet 15j without reaching the negative input terminal 10an through the shortest distance from each unit capacitor on the outlet side.
k to the input terminal 10an, exit 15k
A connection portion 15m extending from the first pattern conductor 15d to the negative input terminal 10an juxtaposed to the positive input terminal 10ap is formed, and a slit 15i is formed between the original pattern conductor 15d and the connection portion 15m.

According to this embodiment, the positive input terminal 1
The wiring length of each unit capacitor connected between 0 ap and the negative input terminal 10an can be equalized as much as possible with a simple structure, thereby increasing the wiring inductance of each unit capacitor. And the circuit operation can be balanced, and the reliability as a power converter can be improved.

(Fifth Embodiment) FIG. 7 shows a power unit according to a fifth embodiment. The feature of the fifth embodiment is that a smoothing capacitor 9 composed of many unit capacitors is used.
For the first capacitor group 9a and the second capacitor group 9b.
And the insulating substrate 3 and the chips 2a and 2c
The cooler 7 in which the components are arranged is arranged at the center of the back surface of the large current wiring board 15, the gate circuit unit 14 is arranged at the center of the surface of the large current wiring board 15, and the first capacitor group 9a
And the second capacitor group 9b is arranged on both sides of the large current wiring board 15 so as to sandwich the gate circuit section 14 on the front side thereof. The input terminal 10a and the output terminal 10b are provided before and after one capacitor group, for example, the first capacitor group 9a.

According to this embodiment, the balance state of weight, heat, current, etc. can be further improved, and the reliability of the device can be further improved.

(Embodiment 6) FIG. 8 shows a power unit according to Embodiment 6. The feature of this embodiment is that an air-cooled cooler 70 having a large number of cooling fins 71 is provided in place of the water-cooled cooler 7 in FIG. Others are the same as those in FIG.

This embodiment can be suitably applied to a case where the cooling performance does not require the use of a water-cooled cooler or a case where it is difficult to use a water-cooled cooler. This is advantageous in terms of maintainability because water is not handled.

(Embodiment 7) FIG. 9 shows a power unit according to Embodiment 7 of the present invention. The feature of this embodiment is that a total of six sets of air-cooled coolers 72 separated for each arm of the three-phase inverter (see FIG. 12) are used instead of the common air-cooled cooler 70 in FIG. It is in. Others are the same as those in FIG.

According to this embodiment, the individual coolers 7
2 is small in size, easy to handle, easy to attach, and small in warpage of parts.

(Eighth Embodiment) FIG. 10 shows a power unit according to an eighth embodiment. The feature of the eighth embodiment is that the heat pipe type cooler 19 is provided for the large current wiring board 15 in addition to the water-cooled type cooler 7 as a cooling means based on the embodiment shown in FIG. It is a feature.

According to this embodiment, it is possible to further improve the cooling efficiency of the device, cope with a severer load, or use a chip having a relatively small capacity.

Ninth Embodiment FIG. 11 shows a power unit according to a ninth embodiment. A feature of the ninth embodiment is that a metal plate 7c is provided instead of the water-cooled cooler 7 or the air-cooled coolers 70 and 72, and the large-current wiring board 15
A heat pipe type cooler 19 is provided for the metal plate 7c.

According to this embodiment, as in the embodiment shown in FIG. 1, a compact unit can be achieved, and a highly reliable power converter power unit having a small wiring inductance can be provided.

[0043]

According to the present invention, it is possible to provide a high-reliability power unit for a power converter having improved cooling efficiency, achieving a compact unit, and having a small wiring inductance.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a power unit according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of various pattern conductors combined with the large current wiring board in FIG. 1;

FIG. 3 is a partially exploded perspective view of a power unit according to a second embodiment of the present invention.

FIG. 4 is a side sectional view of a main part in FIG. 3;

FIG. 5 is an exploded perspective view of a power unit according to a third embodiment of the present invention.

FIG. 6 is a perspective view of a P-pattern conductor and an N-pattern conductor according to a fourth embodiment of the present invention.

FIG. 7 is an exploded perspective view of a power unit according to a fifth embodiment of the present invention.

FIG. 8 is an exploded perspective view of a power unit according to a sixth embodiment of the present invention.

FIG. 9 is an exploded perspective view of a power unit according to a seventh embodiment of the present invention.

FIG. 10 is an exploded perspective view of a power unit according to an eighth embodiment of the present invention.

FIG. 11 is a perspective view of a power unit according to a ninth embodiment of the present invention.

FIG. 12 is a connection diagram showing a main circuit configuration of a known power unit.

FIG. 13 is a perspective view of a conventional unit showing a state in which the power unit shown in FIG. 12 is housed in a housing, with a part of the housing cut away.

FIG. 14 is a connection diagram illustrating a main circuit configuration of a known power unit in a two-multiplex system.

[Explanation of symbols]

 1, 1a, 1b Power module 2a P-side switching chip 2b N-side switching chip 2c P-side diode chip 2d N-side diode chip 3 Insulating substrate 6 Mounting screw 7 Water-cooled cooler 8 Terminal block 9, 9a, 9b Smoothing capacitor 9u Unit Capacitor 10a DC input terminal 10ap Positive DC terminal 10an Negative DC terminal 10b AC output terminal 10bu U-phase output terminal 10bv V-phase output terminal 10bw W-phase output terminal 11 Current detector 12 AC motor 14, 14a, 14b Gate circuit section 15 Large current wiring board 15a Pressing tongue piece 15b Pattern contact portion 15c P pattern conductor 15d N pattern conductor 15e U phase pattern conductor 15f V phase pattern conductor 15g W phase pattern conductor 15h, 15i Slit 16 Contact electrode 17 Metal block 1 8 Contact conductor 19 Heat pipe type cooler 30 Insulation plate 70, 72 Air-cooled type cooler 71 Cooling fin

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H007 AA06 BB06 CA01 CB05 CC03 DC05 HA03 HA06 HA07 5H740 BA11 BB05 BB08 BB10 PP02 PP03 PP06

Claims (11)

[Claims] 1. A power unit for a power converter in which a smoothing capacitor, a power module including a switching chip, a cooler, and a pattern conductor for electrical connection are mounted on a high-current wiring board, wherein the power module is mounted on an insulating substrate. A power unit for a power converter, wherein the power module and the cooler attached to the insulating substrate are attached to the large-current wiring board in a pressurized contact state. 2. The power unit for a power converter according to claim 1, further comprising two sets of power modules constituting a double multiplex inverter. 3. The power unit for a power converter according to claim 2, wherein the switching modules included in said two sets of power modules are divided into a positive switching module and a negative switching module as a whole, and said positive power module is provided. A power unit for a power converter, wherein one of the negative power module and the negative power module is disposed on the front side of the large current wiring board, and the other is disposed on the rear side of the large current wiring board. 4. The power unit for a power converter according to claim 1, wherein the cooler is a water-cooled cooler. 5. The power converter power unit according to claim 4, wherein the insulating substrate is formed of a flexible insulating sheet, and a contact conductor is inserted between the switching module and the insulating sheet. A power unit for a power converter, wherein a connecting metal block is arranged between a switching module and the high-current wiring board. 6. The power unit for a power converter according to claim 1, wherein said smoothing capacitor comprises a plurality of unit capacitors, and said pattern conductor for connecting said unit capacitors is each unit capacitor. Characterized by forming a slit for equalizing the wiring inductance of the power converter. 7. The power unit for a power converter according to claim 3, wherein said smoothing capacitor includes a plurality of unit capacitors, and said unit capacitors are included in first and second unit capacitor groups. The power unit for a power converter, wherein the first and second unit capacitor groups are substantially equally divided into two, and the first and second unit capacitor groups are arranged on both sides of the switching module on the large current wiring board. 8. The power unit for a power converter according to claim 1, wherein the cooler is an air-cooled cooler. 9. The power unit for a power converter according to claim 8, wherein the cooler is provided for each arm of an inverter constituted by the power unit. 10. The power unit for a power converter according to claim 1, wherein a heat pipe type cooler is provided on the large current wiring board. 11. The power unit for a power converter according to claim 1, wherein a metal plate is provided in place of said cooler, and said metal plate and said high-current wiring board are heat pipe-type cooled. A power unit for a power converter, wherein a power unit is provided.