JP3300566B2 - Power module and power converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced air cooling type power converter, and more particularly to a power module and a power converter applied to a neutral point clamp type inverter.

[0002]

2. Description of the Related Art A power converter is constituted by using a large number of power semiconductor elements, and a cooling structure by forced air cooling is generally used. In addition, power semiconductor devices have become faster (higher frequency) and larger in capacity, the packaging density has been increased, the size of power converters has been reduced, and cooling air passages and pressure losses have been increasingly reduced. It's getting harder. In addition, there is a demand for a structure for performing maintenance from the front side (hereinafter referred to as front maintenance) in order to reduce the maintenance space of the power conversion device, and the cooling structure is becoming complicated. In order to satisfy these demands, it is an important theme to efficiently and radiate heat generated from power semiconductor elements and other electric appliances in a well-balanced manner and to have a simple structure.

FIG. 11 shows a part (for two arms) of a main circuit of a general power converter, wherein 1 is a power semiconductor element (hereinafter referred to as a semiconductor element), 2 is a capacitor, and 3 is a diode. 4 and 4 are resistors. Two semiconductor elements 1 are connected in series between a positive pole P and a negative pole N of a DC voltage to form a bridge circuit, and an intermediate point thereof is connected to an AC output terminal U. The snubber circuit including the capacitor 2, the diode 3, and the resistor 4 is for suppressing a surge voltage generated when the semiconductor element 1 is turned off. A plurality of such unit circuits are connected in parallel according to a required output current, and are configured as a power module functioning as one bridge circuit. A plurality of such power modules are provided according to the required number of AC output phases. For example, in the case of three-phase AC output, three sets of power modules are provided. 5 is a filter capacitor for smoothing the DC voltage.

FIG. 12 shows a front-rear-maintenance type power converter equipped with a power module having the above-described bridge circuit mounted thereon, and FIG. 13 shows a front-rear-maintenance type power converter. In each figure, (a) is a perspective view and (b) is a side view.

[0005] As shown in FIG.
A cooler 7 having a heat pipe structure is used. The cooler 7 is composed of a vertically long flat plate-shaped cooling block 7a made of a metal having good thermal conductivity and cooling fins 7b.
A heat pipe is vertically inserted into the inside of the cooling block 7a, and a cooling fin 7b for passing cooling air in a horizontal direction is attached to the heat pipe protruding above the cooling block 7a. A plurality of semiconductor elements 1 are mounted on the front and rear surfaces of the cooling block 7a, and are connected in parallel by a power board 6 on which conductors of a positive pole P and a negative pole N of DC voltage are arranged. A condenser 2, a diode 3 and a resistor 4 are mounted on the front side of the power board 6, and a filter condenser 5 is mounted below the cooler 7.

Most of the heat energy generated from the semiconductor element 1 is conducted from the mounting surface to the cooling block 7a.
Heat is transported to the upper cooling fins 7b through the coolant liquid of the heat pipe inserted therein, and the heat energy transmitted to the cooling fins 7b is transferred to the cooling air 12b and released.
The refrigerant liquid whose temperature has decreased due to the release of thermal energy descends to the lower part and circulates inside the heat pipe.

In the case of the front and rear maintenance type, as shown in FIG. 12, a cooling fan 8 is provided at the rear of the cooling fin 7b,
Cooling air 12b is sucked in from the upper opening 9b on the front of the device through the ventilation duct 11, blows through the cooling fins 7b, and is discharged from the upper opening on the back of the device through the cooling fan 8.

In the case of the front maintenance type, as shown in FIG. 13, a cooling fan 8 is installed at the uppermost part (ceiling side) of the apparatus, and through a ventilation duct 11, an upper opening 9b at the front of the apparatus.
After the cooling air 12b is sucked in and blows through the cooling fins 7b, the cooling air 12b is introduced to the uppermost portion through the ventilation duct 11, and is discharged from the opening of the ceiling through the cooling fan 8.

In the case of the front and rear maintenance type, as shown in FIG. 10, the filter condenser 5 attached to the lower part of the power module is cooled by cooling air 12 sucked from openings 9, 9a on the front and rear sides of the lower part of the apparatus. In the case of the front maintenance type, as shown in FIG. 11, the apparatus is cooled by cooling air 12 sucked through an opening 9 in the front of the lower part of the apparatus.

The thermal energy emitted from the surface of the semiconductor element 1 and the thermal energy emitted from the capacitor 2, the diode 3, the resistor 4, and the power board 6 generate heat in the cooling air 12a rising inside the device. Transmitted and released. The rising cooling air 12a passes through the ventilation holes provided in the ventilation plate 10 and is taken from the upper opening 9b.
Merges with 12a and is discharged outside the device.

[0011]

The above-mentioned conventional device has a general main circuit configuration and cannot be directly applied to a neutral point clamp type inverter. In addition, in the conventional cooling structure, since a heat pipe structure cooler is used, the cooling fins need a predetermined dimension in the vertical direction, and the cooling air flows in the horizontal direction, so that the size of the device can be reduced. Be restricted. In addition, when the front maintenance type is used, there is a problem that the pressure loss of the cooling air is increased, a cooling fan having a large capacity is required, the size is increased, and noise is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to be applicable to a neutral-point-clamped inverter. It is an object of the present invention to provide a power module having a large capacity, a small size, and excellent cooling efficiency, and a front maintenance type power conversion device that can be easily maintained using the power module.

[0013]

SUMMARY OF THE INVENTION A power module according to the present invention comprises a flat plate-shaped metal having a predetermined thickness and good heat conductivity, and has a hollow portion in which a refrigerant liquid for boiling cooling is filled. A cooling block installed so that a surface is vertical, and a hollow portion attached to an upper portion of the cooling block and continuous with a hollow portion of the cooling block, and heat energy of the cooling block is transmitted through the coolant liquid. And a plurality of semiconductor elements mounted on the flat surface of the cooling block, and the four semiconductor elements are arranged side by side in the horizontal direction on the flat surface of the cooling block and in the vertical direction. And a stacked conductor for connecting the semiconductor elements arranged in the vertical direction in parallel and connecting the semiconductor elements arranged in the horizontal direction in series.
(Claim 1) Further, the heat radiating portion is a flat metal block having a hollow portion continuous with the cooling block and having good heat conduction, and is perpendicular to a surface of the metal block so that cooling air flows in a vertical direction. And a plurality of cooling fins provided on both sides of the metal block and having a hollow portion continuous with the hollow portion of the metal block, so that cooling air flows in a vertical direction. (Claim 2) Further, of the plurality of semiconductor elements mounted on the flat surface of the cooling block, at least two semiconductor elements mounted horizontally at the lowermost portion are neutral point clamp diodes, and the laminated conductor is: A first conductor connecting one end of a semiconductor element arranged at both ends to a positive or negative electrode of a DC voltage, and a semiconductor element arranged at both ends of four semiconductor elements arranged in a horizontal direction on the flat surface of the cooling block. The other end of the semiconductor element to be connected and one end of the semiconductor element disposed inside are constituted by a second conductor connected to one end of the neutral point clamp diode, and the other end of the semiconductor element disposed inside is connected to an AC output terminal. And a fourth conductor for connecting the other end of the neutral point clamp diode to the neutral point of the DC voltage, and a bridge for one phase of the neutral point clamp type inverter circuit. Configure the circuit. (Claim 3) Further, the first, second, and third conductors have a plurality of connection terminals formed of a metal collar having a vertically long flat plate shape and having through holes vertically protruding in front of and behind the flat plate surface. The first conductor has a vertically long and wide flat plate shape so as to cover the width of the second conductor, and has a hole through which a connection terminal of the second conductor penetrates; And the third conductor is disposed at the center of the laminated conductor disposed on both sides. (Claim 4) Further, the first, second and third conductors are connected to the terminals of the respective semiconductor elements by fastening screws passing through the through holes of the metal collars of the connection terminals, and the semiconductor elements are arranged at both ends. A first tightening screw connecting one end of the semiconductor element to the first conductor, a second tightening screw connecting the other end of the semiconductor element disposed inside to the third conductor, and a semiconductor element disposed at both ends. A snubber circuit component comprising a diode and a capacitor is tightened and connected by a third tightening screw connecting one end of the semiconductor element disposed at the end or inside to the second conductor. (Claim 5) Further, the snubber circuit article is composed of two snubber diodes and two snubber capacitors housed in one container and connected in series, and is disposed adjacent to an upper portion of the container. First terminals and one second terminal disposed below the container, one end of the snubber capacitor is connected to the first terminal of the container, and the other end of the snubber capacitor is first tightened. The second terminal of the container is tightened and connected with the third tightening screw by a screw and a second tightening screw. (Claim 6) Further, the snubber circuit article is composed of two snubber diodes and two snubber capacitors housed in one container and connected in series, and is disposed adjacent to an upper portion of the container. A first fifth terminal and a second terminal disposed at a lower portion of the container, and a vertically long fifth conductor which is tightened and connected by the third tightening screw and is disposed on the first conductor. A second terminal of the container is tightened and connected to the fifth conductor, one end of the snubber capacitor is connected to a first terminal of the container, and the other end of the snubber capacitor is connected to the first and second tightening screws. Tighten and connect. (Claim 7) Further, a sixth conductor which is connected to the third conductor at one end and has a connector for automatic connection at the other end and which is disposed in parallel with the flat surface of the cooling block, is provided. To the AC output terminal via (Claim 8) Further, the plurality of semiconductor elements mounted on the flat surface of the cooling block are symmetrically mounted on both surfaces, and an L-shaped connection portion is provided below the first conductor at the same position on both surfaces,
A seventh conductor for connecting the connecting portions is provided, and an eighth conductor having an end for leading the potential of the seventh conductor to the front side is provided. The fourth conductor is attached to both surfaces of the cooling block. A U-shaped connecting the other end of the point clamp diode is connected to the fourth conductor.
A ninth conductor having an end flush with the end of the conductor is provided, and is connected to a DC voltage having a neutral potential through the ends of the eighth conductor and the ninth conductor. (Claim 9) The power converter of the present invention connects the power module to a capacitor unit containing a plurality of capacitors connected to a positive electrode and a negative electrode of a DC voltage having a neutral point and a neutral point. A neutral point-clamped inverter that forms a main circuit for one phase of a neutral-point-clamped inverter circuit and outputs AC power of a desired number of phases with a number of power modules and capacitor units corresponding to the number of phases. Constitute. (Claim 10) Further, a closed box having a cooling fan at an upper part and having a front door, a vertical frame for dividing the box into phases,
A slide rail that is horizontally attached to the vertical frame to attach the power module so as to be able to be pulled out forward; and In a state where the capacitor unit is attached, a box divided for each phase between the power module and the capacitor unit is connected to a positive electrode, a negative electrode, and a neutral point of a DC voltage so as to vertically penetrate horizontally. Two laminated conductors,
The power module and the capacitor unit are connected to a DC voltage having a neutral point via the second laminated conductor. (Claim 11) Further, the positions of the terminal of the power module and the terminal of the capacitor unit for connecting to a DC voltage having a neutral point are flush with each other, and one end of the terminal is connected to the second laminated conductor. The other end of the tenth conductor which is connected and whose other end is flush with the position of the terminal part of the power module and the capacitor unit, the terminal part of the power module, the terminal part of the capacitor unit and the other end of the tenth conductor First to connect
By providing one conductor and removing the eleventh conductor, the power module and the capacitor unit can be pulled out. (Claim 12)

[0014]

According to the power module of the present invention, heat energy due to power loss of a plurality of semiconductor elements is transmitted to the cooling block, transmitted to the heat radiating portion via the internal coolant liquid, and efficiently radiated heat. Further, the semiconductor elements arranged in the horizontal direction are connected in series by the laminated conductor so that the semiconductor elements can be applied to the main circuit of the inverter, and the semiconductor elements arranged in the vertical direction are connected in parallel to increase the current carrying capacity. (Claim 1) Further, thermal energy is transmitted to the plurality of cooling fins by the vaporized refrigerant liquid, and is transmitted to the cooling air flowing in the vertical direction to be radiated. (Claim 2) Further, the first conductors on both sides are connected to the positive and negative poles of the DC voltage, and the second conductor is connected between the other end of the semiconductor element arranged at both ends and one end of the semiconductor element arranged inside. Connected to one end of the neutral point clamp diode, the fourth conductor is connected to the neutral point of the DC voltage, the third conductor is connected to the AC output end, and a bridge circuit for one phase of the neutral point clamp type inverter circuit is provided. Constitute. (Claim 3) Furthermore, a change in magnetic flux due to a change in current flowing through the first conductor and the second conductor is canceled, and stray inductance is reduced.
(Claim 4) Furthermore, the snubber circuit article can be tightened and connected by the first tightening screw, the second tightening screw, and the third tightening screw, and can be efficiently arranged and assembled. (Claim 5) Further, two snubber diodes and two snubber capacitors are connected in series by connecting the first terminal of the container to one end of the snubber capacitor, and the other end of the snubber capacitor is connected to the first tightening screw and The second terminal of the container is tightened and connected with the second tightening screw, and the second terminal of the container is tightened and connected with the third tightening screw. (Claim 6) Further, the fifth conductor has the same potential as the second conductor via a connection terminal which is tightened and connected by the third tightening screw, and the second terminal of the container is tightened and connected to the fifth conductor so that the second conductor is connected to the second conductor. Are connected to the semiconductor element. The fifth conductor functions as a heat sink of the snubber diode. (Claim 7) Further, the power is automatically connected to the AC output terminal via the connector of the sixth conductor, and the power is also easily removed from the joule.
(Claim 8) Furthermore, semiconductor elements are symmetrically mounted on both sides of the flat surface of the cooling block to increase the mounting density, and the ends of the eighth conductor are connected to the positive and negative terminals of the DC voltage, and the ends of the ninth conductor are connected. Section is connected to the neutral point of the DC voltage. (Claim 9) In the power converter of the present invention, the power module and the capacitor unit are paired to form a main circuit for one phase of the neutral point clamp type inverter circuit, so that a desired number of phases of AC power is output. The inverter can be a neutral point clamp type inverter having a high degree of freedom. (Claim 10) Further, since the cooling air introduced from the opening provided at the lower portion of the front door or the bottom of the box passes through the condenser unit and the power module in a linear path, the pressure loss is reduced, and the cooling effect is improved. Promoted. Further, since the power module and the capacitor unit can be easily removed via the slide rail, front maintenance is facilitated. Also,
Since the positive, negative, and neutral points of the DC voltage between the adjacent power modules and between the adjacent capacitor units are connected via the second laminated conductor, the magnetic flux change due to the current change accompanying the switching operation of the semiconductor element is offset. As a result, stray inductance is reduced, and high-speed switching operation is enabled. (Claim 11) Further, by removing the eleventh conductor, the power module and the capacitor unit can be easily separated,
Front maintenance becomes easier. (Claim 12)

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a power module according to claims 1 to 9 of the present invention will be described below. FIG. 1A is a front view of the power module 20, and FIG. 1B is a side view.
In FIGS. 1 (a) and 1 (b), reference numeral 21 denotes a plate-shaped cooling block made of a metal having good heat conductivity and having a predetermined thickness and having a hollow portion filled with a refrigerant liquid for boiling cooling. It is installed so that the surface is vertical. The cooling block 22 has a hollow portion that is continuous with the hollow portion of the cooling block 21 through the coolant liquid.
21 is a heat dissipating part to which heat energy is transmitted, and constitutes a cooling device of a boiling cooling system.

The flat plate surfaces on both sides of the cooling block 21
As shown in (a), four semiconductor elements (IGBT) 31 to
34 are mounted side by side in the horizontal direction, and a plurality of semiconductor elements (five in the present embodiment) are similarly arranged in the vertical direction. At the bottom, four neutral point clamp diodes 35 and 36 are mounted side by side in the horizontal direction. In addition,
The number of the neutral point clamp diodes 35 and 36 may be two.

As shown in FIG. 3, the heat dissipating portion 22 has a hollow portion continuous with the cooling block 21 and has a flat plate-like metal block 23 having a predetermined thickness and good heat conductivity. A plurality of tube plates 24 which are mounted on the metal block 23 so as to be perpendicular to the flat plate surface so that the cooling air flows vertically, and a plurality of corrugated fins 25 which are mounted between the tube plates 24 so that the cooling air flows vertically. And a side plate surrounding the entire heat radiating portion. The tube plate 24 has a hollow portion continuous with the hollow portion of the metal block 23, receives heat energy in the cooling block 21, transfers heat to the corrugated fins 25 by the vaporized refrigerant, and transfers heat to the cooling air flowing in the vertical direction to radiate heat. Is what you do.

Most of the power loss (thermal energy) generated from the semiconductor element and the neutral point clamp diode flows out of the mounting surface to the flat surface of the cooling block 21 by heat conduction, and the thermal energy flowing into the cooling block 21 Is transmitted to the refrigerant liquid filled therein and is thermally transported by the vaporized refrigerant to the upper heat dissipating part 22, and the tube plate 2 of the heat dissipating part 22
4. Heat is transferred to the cooling air through the corrugated fins 25 and released. The refrigerant whose temperature has dropped due to the release of the heat energy is liquefied and returned to the cooling block 21. According to the power module of the present embodiment, it is possible to emit predetermined heat energy even if the vertical dimension of the heat radiating portion 22 is reduced,
It is possible to contribute to miniaturization. Further, since the ventilation path is in the vertical direction, the pressure loss is reduced and the cooling effect is promoted. (Claim 2) The semiconductor elements 31 to 34 attached to the flat surface of the cooling block 21
As shown in FIG. 3, a stacked conductor composed of a first conductor 61 and a second conductor 62 for connecting semiconductor elements arranged in a vertical direction in parallel and connecting semiconductor elements arranged in a horizontal direction in series
A conductor 63 is provided. By using the first conductor 61 and the second conductor 62 as laminated conductors, when a current change accompanying the switching operation of the semiconductor elements 31 to 34 occurs, a change in magnetic flux due to a change in the current flowing in the first conductor 61 and the second conductor 62 occurs. They cancel each other out, reducing the stray inductance of the wiring and enabling high-speed switching operation.

The circuit connected as described above can be applied to a neutral point clamp type inverter. (Claims 1 and 3) The first conductor 61 is disposed on the flat surface of the cooling block 21 in the horizontal direction.
One end of the semiconductor elements 31 and 34 arranged at both ends of the semiconductor elements arranged side by side is connected to the positive pole P or the negative pole N of the DC voltage. The second conductor 62 includes the other ends of the semiconductor elements 31 and 34 disposed at both ends and the semiconductor elements 32 and
33 is connected to one end of neutral point clamp diodes 35 and 36. The third conductor 63 is a semiconductor element disposed inside.
Connect the other end of 32,33 to AC output terminal AC. The fourth conductor 64 connects the other ends of the neutral point clamp diodes 35 and 36 to the neutral point C of the DC voltage. Each of the conductors 61 to 63 has a plurality of connection terminals made of a metal collar 65 having a vertically long plate shape as shown in FIG. 3 or FIG. The first conductor 61 is formed in a vertically long and wide plate shape so as to cover the width of the second conductor 62, and is provided with a hole for electrically insulating and penetrating a connection terminal of the second conductor 62. The third conductor 63 is disposed at the center of the laminated conductors disposed close to each other and disposed on both sides. The surface of each conductor is subjected to an insulating coating process such as a baking process of a powdered epoxy resin. (Claim 4) Further, as shown in FIG. 4, each of the conductors 61 to 63 is connected to a terminal of each semiconductor element with a tightening screw passing through a through hole of the metal collar 65 of the connection terminal, and is disposed at both ends. Semiconductor elements 31, 34
A first tightening screw 66 of a connection terminal of a first conductor 61 for connecting one end of the first conductor, a second tightening screw 67 of a connection terminal of a third conductor 63 for connecting the other end of the semiconductor element disposed inside, and both ends. The third terminal of the connection terminal of the second conductor 62 that connects the other end of the semiconductor element disposed at
A snubber circuit component consisting of diodes 39 and 42 and snubber capacitors 37, 38, 40 and 41 is tightened and connected by a tightening screw 68. The circuit connected as described above forms a bridge circuit for one phase of the neutral point clamp type inverter circuit shown in FIG. (Claim 5) The diodes 39 and 42 of the snubber circuit article have two snubber diodes housed in one container and connected in series, and both ends thereof are adjacent to the upper part of the container as two first terminals 69. And connect two snubber diodes in series with one
The second terminals 70 are provided at the lower part of the container.

Further, as shown in FIG. 4, a third tightening screw 68 for connecting one end of the semiconductor element 32, 33 disposed inside.
, A vertically long fifth conductor 71 disposed on the first conductor 61 is tightened and connected, the second terminal 70 of the container is tightly connected to the fifth conductor 71, and the snubber capacitors 37, 38, 40 and 41 are connected. One end is connected to the first terminal 69 of the container, and the other end of the snubber capacitors 37, 38, 40, 41 is tightened and connected by the first tightening screw 66 and the second tightening screw 67. The tightening screws for connecting the other ends of the semiconductor elements 31 and 34 disposed at both ends are connected to a third screw.
It can be adopted as the tightening screw 68. Fifth conductor 71
Fix the diodes 39 and 42 and act as a heat sink. (Claim 7) Alternatively, the fifth conductor 71 may be omitted, and the shape of the second terminal of the container may be made into a plate shape that also serves as a heat radiating plate, and may be tightened and connected with the third tightening screw 68. (Claim 6) As shown in FIGS. 1 to 3, one end is connected to the upper part of the third conductor 63, and the other end has a connector 73 for automatic connection. Sixth conductor arranged
72 is provided and connected to the AC output terminal via the connector 73. (Claim 8) The plurality of semiconductor elements mounted on the flat surface of the cooling block 21 are symmetrically mounted on both surfaces of the flat surface, and an L-shaped connection portion is provided below the first conductor 61 at the same position on both surfaces. And a seventh conductor 74 for connecting between the connecting portions. The first and second conductors 61 and 74 are fastened and connected to one ends of protective fuses 53 and 54 provided below the seventh conductor 74. 53,5
4 is provided with an L-shaped eighth conductor 75 which is tightened and connected to the other end of the cooling block 21. The fourth conductor 64 connects the other ends of the neutral point clamp diodes 35 and 36 mounted on both sides of the cooling block 21.
The fourth conductor 64 is connected to the
A ninth conductor 76 having an end flush with the end of the conductor 75;
Let the ends of the eighth conductor 75 be P1 and N1, and the end C of the ninth conductor 76
Connect to a DC voltage having a neutral point potential as 1. It is also possible to omit the protective fuses 53 and 54 and to connect them with another conductor so as to be fuseless. (Claim 9) An embodiment of a power converter according to claims 10 to 12 of the present invention will be described below. The above-described power module 20 and a capacitor unit 80 having a terminal for connecting two sets of capacitors in series and connecting to a DC voltage having a neutral point.
Can be used to form a main circuit for one phase of the neutral point clamped inverter circuit, and a neutral point clamped inverter that outputs a desired number of phases of AC power can be configured.

For example, as shown in FIG.
As shown in (a), three sets of capacitors C in which voltage dividing resistors R are connected in parallel are connected in series, and two sets of capacitor blocks 81 and 82 in which four sets are connected in parallel are provided on the positive electrode side and the negative electrode side. The two capacitor blocks are connected in series to form a capacitor unit 80 having terminals P2, N2 and C2 for connection to a DC voltage having a neutral point. FIG. 7 shows FIG.
3A shows an example of a hardware configuration of the capacitor unit 80 shown in FIG. As shown in the front view of FIG. 7A, a mounting plate 86 having a hole for mounting a capacitor is provided in the middle of a frame 85 forming a rectangular space.
As shown in (2), each capacitor C is mounted with a gap so that cooling air passes in the vertical direction. Each capacitor C has two terminals on one side and is connected in series for every three capacitors, and is connected to conductors 77 and 78. Conductor 77 is connected to terminals P2 and N2
And the conductor 78 becomes the terminal C2. Then, in combination with the power module 20 described above, a main circuit for one phase of the neutral point clamp type inverter circuit is configured, and a desired number of phases of AC power is generated by the number of power modules and capacitor units corresponding to the number of phases. A neutral-point-clamped inverter that outputs power can be configured.

FIG. 6B shows an example of a neutral point clamp type inverter which outputs three-phase AC power. Each capacitor unit 80 is connected to a DC voltage via protective fuses 83 and 84. I have. (Claim 10) An embodiment of a power converter using the power module 20 and the capacitor unit 80 described above is shown in FIGS. This embodiment is an example of a power converter that outputs three-phase AC power. FIG. 8 is a front view thereof, and FIGS. 9 and 10 are right side views.

As shown in the figure, the power converter has a closed box 93 having a cooling fan 91 at the upper part and a front door 92, and a vertical section dividing the inside of the box 93 into three parts. It has a frame 94, and this vertical frame 94 has a slide rail 95
96 is mounted horizontally, and as shown in FIG. 8, the power module 20 and the capacitor unit 80 are mounted so as to be able to be pulled out forward. FIG. 8 shows a state in which the door is removed, and the left end shows a state in which the power module 20 and the capacitor unit 80 are removed. In addition, between the power module 20 and the capacitor unit 80, a box 93 divided for each phase by a vertical frame 94 is connected to the positive pole P and the negative pole N of the DC voltage and the neutral point C so as to penetrate in the horizontal direction. Second laminated conductor 97
As shown in FIG. 9, the power module 20 and the capacitor unit 80 are connected to the DC bus 98 through another conductor, and the DC module 98 is connected to the DC voltage having a neutral point through the second laminated conductor 97. Connecting. As shown in FIG. 10, a contact 99 which is connected to the connector 73 of the AC terminal of the power module 20 and is automatically connected to the connector 73 is provided on the rear side of the box 93, and is separately provided on the conductor 101 serving as an AC output (bus) terminal. Connect with conductors.

With this configuration, the cooling air taken in from the lower opening of the entire door or the bottom of the box is
After cooling from the bottom to the top of the capacitor unit 80 to cool each capacitor C, and further from the bottom to the top of the power module 20 to cool the surface of each semiconductor element, snubber circuit supplies, and conductors 61-61, The cooling block 21 is efficiently cooled by blowing through the cooling fan 23 and discharged to the outside through the cooling fan 91. Therefore, the ventilation passage is substantially linear, the pressure loss is reduced, and the cooling fan 91 can have low noise. (Claim 11) In addition, a terminal portion of the power module 20 (conductors 75 and 76 in FIG. 1A) and a terminal portion of the capacitor unit 80 (FIG. 7A) for connection to a DC voltage having a neutral point. The positions of the conductors 77 and 78) are flush with each other, and one end is connected to the second laminated conductor 97 and the other end is flush with the positions of the terminals of the power module 20 and the capacitor unit 80 as shown in FIG. Aligned L-shaped 10th conductor
An eleventh conductor 103 is connected between the terminal of the power module 20, the terminal of the capacitor unit 80, and the other end of the tenth conductor 102. This first
By removing the one conductor 103, the power module 20 and the capacitor unit 80 can be easily pulled out, and the entire maintenance can be easily performed. (Claim 12)

[0025]

According to the power module of the present invention, semiconductor elements can be mounted at a high density and heat can be efficiently radiated, the capacity can be reduced and the size can be reduced. Can be applied to Also,
Since the stray inductance of the main circuit is reduced and snubber circuit articles can be rationally arranged, a higher-speed switching operation can be performed. Further, the unit can be easily attached to and detached from the apparatus as a unit, and an efficient assembling operation can be performed.

According to the power converter of the present invention, a neutral point-clamped inverter can be configured for each phase, and the degree of freedom of the system configuration can be increased. Also,
The stray inductance of the main circuit on the DC side is reduced, and higher-speed switching operation becomes possible. Further, a complicated ventilation duct for cooling air is not required, pressure loss is reduced, a cooling fan can be downsized, and cooling efficiency is high and noise can be reduced. Further, since the power module and the capacitor unit can be easily removed, front maintenance is facilitated.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of a power module according to claims 1 to 9 of the present invention, wherein (a) is a front view and (b) is a side view.

FIGS. 2A and 2B are side views showing details of the above embodiment, in which FIG. 2A shows an arrangement of semiconductor elements, and FIG. 2B shows each conductor.

FIG. 3 is a perspective view of the embodiment.

FIG. 4 is a view showing a connection relationship between a semiconductor element and a conductor according to the embodiment.

FIG. 5 is a circuit diagram of the power module of the embodiment.

FIG. 6 is a circuit diagram showing an embodiment of a power converter according to claims 10 to 13 of the present invention, wherein (a) is a circuit diagram of a capacitor unit, and (b) is a circuit diagram of the power converter.

FIG. 7 is a hardware configuration diagram of the capacitor unit;
(a) is a front view, (b) is a side view.

FIG. 8 is a front view of a hardware configuration diagram showing an embodiment of a power converter according to claims 10 to 13 of the present invention.

FIG. 9 is a side view (a) of the power converter.

FIG. 10 is a side view (b) of the power converter.

FIG. 11 is a circuit diagram of a conventional power module.

FIG. 12 is a hardware configuration diagram of a conventional power converter.

FIG. 13 is a hardware configuration diagram of a conventional power converter.

[Explanation of symbols]

20… Power module 21… Cooling block 22… Radiator 23… Metal block 24… Tube plate 25… Corrugated fins 31 to 34… Semiconductor elements (IGBT) 35, 36… Semiconductor elements (neutral point clamp diodes) 37, 38, 40,41 snubber capacitor 39,42 snubber diode 43 to 46 gate resistance 47,48 diode 49 to 52 snubber resistance 54,55 protection fuse 61 first conductor 62 second conductor 63 third Conductor 64 Third conductor 65 Metal collar 66 First tightening screw 67 Second tightening screw 68 Third tightening screw 69 First terminal 70 Second terminal 71 Fifth conductor 72 Sixth conductor 73 Connector 74 ... Seventh conductor 75 ... Eighth conductor 76 ... Ninth conductor 80 ... Capacitor unit 81 ... Positive side capacitor block 82 ... Negative side capacitor block 83,84 ... Protective fuse 91 ... Cooling fin 92 ... Front door 93 ... Box 94 ... vertical frame 95, 96 ... slide rails 97 ... laminated conductor 98 ... DC bus 99 ... contact 100 ... current detector 101 ... AC output terminal 102 ... 10 conductors 103 ... 11 conductor

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02M 1/00 H02M 7/5387

Claims (12)

(57) [Claims] 1. A cooling plate having a predetermined thickness and having a hollow portion filled with a coolant liquid for boiling cooling and having a hollow portion filled with a metal having good heat conductivity and having a flat plate surface. A cooler comprising a block and a heat radiating portion having a hollow portion attached to an upper portion of the cooling block and continuous with a hollow portion of the cooling block, and heat energy of the cooling block is transmitted through the coolant liquid. A plurality of semiconductor elements mounted on the flat surface of the cooling block, wherein the semiconductor devices are arranged on the flat surface of the cooling block, four in a horizontal direction, and a plurality in the vertical direction;
A power module comprising a laminated conductor for connecting semiconductor elements arranged in a vertical direction in parallel and connecting semiconductor elements arranged in a horizontal direction in series. 2. The power module according to claim 1, wherein the heat radiating portion is formed in a flat metal block having a hollow portion continuous with the cooling block and having good heat conduction so that cooling air flows in a vertical direction. A power module, comprising: a plurality of cooling fins provided on both sides perpendicular to the surface of the metal block and having a hollow portion continuous with the hollow portion of the metal block, so that cooling air flows in a vertical direction. . 3. The power module according to claim 1, wherein at least one of the plurality of semiconductor elements mounted on the flat surface of the cooling block is horizontally arranged at the lowermost part. Two neutral point clamp diodes are provided, and the laminated conductor is connected to one end of a semiconductor element arranged at both ends of four semiconductor elements arranged horizontally on the flat surface of the cooling block. A first conductor connected to the positive or negative electrode,
The other end of the semiconductor element arranged at both ends and one end of the semiconductor element arranged inside are constituted by a second conductor connected to one end of the neutral point clamp diode, and the other end of the semiconductor element arranged inside And a fourth conductor connecting the other end of the neutral point clamp diode to the neutral point of the DC voltage, and a bridge for one phase of the neutral point clamp type inverter circuit. A power module comprising a circuit. 4. The power module according to claim 3, wherein the first, second, and third conductors are formed in a vertically long flat plate shape, and have a through-hole vertically protruding in front of and behind the flat plate surface. A plurality of connection terminals, wherein the first conductor has a vertically long and wide flat plate shape so as to cover the width of the second conductor, and has a hole through which the connection terminal of the second conductor passes. A power module, wherein the third conductor is disposed close to the second conductor, and the third conductor is disposed at the center of the laminated conductor disposed on both sides. 5. The power module according to claim 4, wherein the first, second, and third conductors are connected to the terminals of the respective semiconductor elements by fastening screws passing through through holes of the metal collar of the connection terminals. A first tightening screw connecting one end of a semiconductor element disposed at both ends to the first conductor, a second tightening screw connecting the other end of the semiconductor element disposed inside to the third conductor, and both ends; A snubber circuit component comprising a diode and a capacitor is tightened and connected by a third tightening screw for connecting the other end of the semiconductor element arranged at the first end or the one end of the semiconductor element arranged inside to the second conductor. Power module. 6. The power module according to claim 5, wherein said snubber circuit article comprises two snubber diodes and two snubber capacitors housed in one container and connected in series. And two second terminals disposed adjacent to each other and one second terminal disposed below the container, wherein one end of the snubber capacitor is connected to the first terminal of the container, and the snubber capacitor is connected to the first terminal of the container. The other end of the power module is tightened and connected with the first and second tightening screws, and the second terminal of the container is tightened and connected with the third tightening screw. 7. The power module according to claim 5, wherein said snubber circuit article comprises two snubber diodes and two snubber capacitors housed in one container and connected in series. And two first terminals disposed adjacent to the container and one second terminal disposed at a lower portion of the container. The first terminal is connected to the first conductor by being tightened and connected by the third tightening screw. A fifth terminal of the container is fastened to the fifth conductor, and one end of the snubber capacitor is connected to the first terminal of the container, and the other end of the snubber capacitor is connected to the fifth terminal. A power module, wherein the power module is tightened and connected with a first tightening screw and a second tightening screw. 8. The power module according to claim 2, wherein one end of the cooling block is connected to the third conductor and the other end has a connector for automatic connection. A sixth conductor arranged in parallel,
A power module connected to an AC output terminal via the connector. 9. The power module according to claim 2, wherein the plurality of semiconductor elements mounted on the flat surface of the cooling block are mounted symmetrically on both surfaces, and the semiconductor elements are located at the same position on both surfaces. L below the first conductor
A seventh conductor connecting the connection portions, an eighth conductor having an end for leading the potential of the seventh conductor to the front side, and the fourth conductor being provided with the cooling member. A U-shaped connecting the other end of the neutral point clamp diode attached to both sides of the block, and having a U-shaped end connected to the fourth conductor and flush with the end of the eighth conductor A power module comprising nine conductors, and connected to a DC voltage having a neutral potential through ends of the eighth conductor and the ninth conductor. 10. A power module according to claim 1, further comprising: a capacitor unit accommodating a positive electrode and a negative electrode of a DC voltage having a neutral point and a plurality of capacitors connected to the neutral point. To form a main circuit for one phase of the neutral point clamp type inverter circuit, and output a desired number of phases of AC power with the number of power modules and capacitor units corresponding to the number of phases. A power conversion device comprising a clamp-type inverter. 11. A power conversion device according to claim 10, wherein a closed box having a cooling fan at an upper portion and having a front door, a vertical frame dividing the box into phases, and the vertical frame. A slide rail that is horizontally mounted on the power module so that the power module can be pulled out forward, and a slide rail that is mounted below the position where the power module is mounted so that the capacitor unit can be pulled out forward, and the power module and the capacitor unit are provided. The second stack connecting the positive and negative DC voltages and the neutral point so that the box body divided for each phase runs horizontally in the horizontal direction between the power module and the capacitor unit while the power module and the capacitor unit are attached. A conductor, and the power module and the capacitor unit are connected via the second laminated conductor. Power converter, characterized in that connected to a DC voltage having a neutral point. 12. The power converter according to claim 11, wherein the terminal of the power module and the terminal of the capacitor unit for connecting to a DC voltage having a neutral point are flush with each other, A tenth conductor having one end connected to the second laminated conductor and the other end flush with the positions of the power module and the terminal of the capacitor unit;
An eleventh conductor connecting the terminal of the power module, the terminal of the capacitor unit and the other end of the tenth conductor is provided, and by removing the eleventh conductor, the power module and the capacitor unit can be pulled out. A power converter characterized by the above-mentioned.