JP3474363B2 - 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 power converter applied to a semiconductor element cooling technique.

[0002]

2. Description of the Related Art In recent years, GTOs (Gate Turn-Off Thyristors) used in power converters such as inverters have been increasing in capacity, and GTOs with a rating of 6kV-6kA or more have already been used.
Has been announced. In a power converter using a GTO, a snubber circuit that realizes a low inductance is required to suppress a surge voltage generated when a large current is cut off.

FIG. 13 shows a conventional heat sink for cooling a semiconductor element in a power converter. This heat sink is described in Japanese Utility Model Publication No. 6-39502. The spiral flow path 30 through which the refrigerant flows is inverted at the center and is directed in the opposite spiral shape toward the outside.

[0004]

However, in the heat sink in the above-mentioned conventional power converter, it is difficult to reduce the inductance of the snubber circuit added to the semiconductor element, so that it is difficult to suppress the surge voltage.
There is a problem that the capabilities of semiconductor devices cannot be fully utilized.

Therefore, in view of the above problems, it is an object of the present invention to provide a power converter having a heat sink that realizes a low inductance of a snubber circuit added to a semiconductor element.

[0006]

In order to achieve the above object, the invention according to claim 1 is a semiconductor element, and a heat sink for cooling the semiconductor element, which has a spiral flow path through which a refrigerant flows. the power converter having a parallel
A plurality of semiconductor elements connected to between the drain passage for discharging the refrigerant and the water supply passage for supplying the refrigerant, includes a plurality arranged flow paths of the spiral flow path, said plurality of semiconductor Elementary
The spiral flow for each semiconductor element is near the center of the child.
And a conductive heat sink disposed at the center of the path .

The invention according to claim 2 is characterized in that the spiral flow path and the other plurality of spiral flow paths are arranged at substantially the same distance. According to a third aspect of the present invention, the refrigerant discharged from the spiral flow passage is provided between the spiral flow passage and the other plural spiral flow passages. It is characterized in that each of the paths has a flow path for branching.

[0008]

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the present invention.
~ It demonstrates using FIG. FIG. 1 is a front view of a heat sink in the power converter of this embodiment, FIG. 2 is a side view for explaining a mounting state of a semiconductor element, and FIG. 3 is a view showing an internal structure of the heat sink, particularly a flow path 2.

As shown in FIGS. 1 and 2, the heat sink 1
The GTO 3 and the snubber diode 4 are arranged in the dotted line part of. The cooling water entered from one outlet 5 passes through the flow path 2 and cools the GTO 3 and the snubber diode 4. GTO
The two flow paths of φDGTO of the mounting portion of 3 and φDDS of the mounting portion of the snubber diode 4 are configured such that the outward path 6 and the return path 7 are alternately configured, and the center of the spiral is near the mounting center of each semiconductor element To be done. The heat sink in FIG. 3 is
The cooling water flow path block 8, the lid 9 and the outlet 5 are assembled by filtering or the like, but it is also possible to manufacture them by a method of casting a pipe of copper or the like having excellent heat conductivity.

As described above, since the forward path 6 and the return path 7 are alternately arranged, the flow of the cooling water becomes a counter flow and the heat exchange efficiency is high, and the temperatures of the heat sinks at the respective mounting portions of φDGTO and φDDS are average. And is cooled ideally for each semiconductor element. As a result, the element is not destroyed by the vicious cycle of current concentration and partial temperature rise, and the element capability can be fully utilized. The distance l shown in FIG. 1 and the distance between the centers of the GTO and the snubber diode are designed to be the minimum values that satisfy predetermined insulation.

Therefore, it becomes possible to dispose the GTO 3 and the snubber diode 4 close to each other, and when constructing the snubber circuit structure, it is possible to realize a low inductor inductance of the snubber circuit.

FIG. 4 shows a power converter having a heat sink for realizing a low inductance of the snubber circuit.
The GTO 3 and the snubber diode 4 are flat type elements, and the GTO
3 and the same potential side of the snubber diode 4 are mounted close to the heat sink 1. On one contact surface of the snubber diode 4, a thin and wide conductor 11a for connecting to the snubber capacitor 10 is attached to connect the snubber capacitor 10 to the GT.
O3 is also connected by the thin and wide conductors 11b and 11c so that the conductor 11a and the conductor 11a are close parallel conductors. Conductor 11a
11b and 11c sandwich the insulating spacer 12 and form a stack 13 integrally with the snubber diode 4 to form a snubber circuit.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 5 is a front view of a heat sink in the power converter of this embodiment, FIG. 6 is a side view for explaining a mounting state of a semiconductor element, and FIG. 7 is a view showing an internal structure of the heat sink, particularly a flow path 2.

In the heat sink 1 of FIGS. 5 and 6, one GTO 3 and two snubber diodes 4 are arranged in a portion indicated by a dotted line, and side surfaces are arranged as shown in FIG. The cooling water entered from one outlet 5 passes through the flow path 2 and GTO
3 and two snubber diodes 4 are cooled. ΦDGTO which is the mounting part of GTO3 and two snubber diodes 4
.Phi.DDS, which is the mounting portion, is formed such that the outward path 6 and the returning path 7 are alternately arranged, and the center of the spiral is located near the mounting center of each semiconductor element. The heat sink 1 is similar to the first embodiment in that the cooling water channel block 8, the lid 9 and the outlet 5 are provided.
It is assembled by filtering or the like, but it can also be manufactured by a method of casting and enclosing a pipe made of copper or the like having excellent heat conductivity.

As described above, according to the present embodiment, since the temperatures of the GTO mounting surface and the two snubber diode mounting surfaces are equalized on each mounting surface, the semiconductor element is ideally cooled, and the current concentration and the partial cooling are achieved. The element is not destroyed due to the vicious cycle of a large temperature rise, and the ability of the element can be fully utilized. Further, since the inductance of the GTO snubber circuit structure can be reduced, the surge voltage generated when the GTO shuts off the current can be suppressed to a low level, and the GTO capability can be fully utilized.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 8 shows the flow path structure of the heat sink in the power converter. The relationship between the GTO 3 and the snubber diode 4 and the relationship between 11 and 12 are the same as in the second embodiment. The difference from the second embodiment is that the two snubber diode mounting portions φDDS are divided into two parallel passages by a branch 15, and the spiral passage of the snubber diode 4 is
That is, the flow path is symmetrical with respect to the axis passing through the center of the GTO.

As described above, the two snubber diode portions have the two flow paths arranged in parallel, so that the two snubber diodes are cooled by the cooling water having the same temperature. Moreover,
Since the two snubber diode cooling spiral flow paths are parallel flow paths symmetrical with respect to the axis passing through the center of the GTO,
The flow rate of cooling water is equalized. Further, since the distances l1 and l2 are substantially the same, the current paths of the snubber diodes are also substantially the same. Furthermore, since the temperature distribution is almost the same, 2
The shunting of each snubber circuit current of the parallel snubber circuit is further equalized as compared with the second embodiment.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In FIG. 9, the flow path block 8 is divided into two. The flow path blocks 8A and 8B have a lid 9
The flexible conductor 16 is connected via A and 9B.

If there is a flexible portion between the place where the GTO is cooled and the place where the snubber diode is cooled, the following effects are obtained. This will be described using the power conversion device shown in FIG. GT
When O3 is replaced, the pressing force of the GTO stack is released. At this time, the reaction force of the disc spring incorporated in the stack causes components stacked above the disc spring, such as the heat sinks 1, 17, GTO3. , Stack insulator 18
Will move upwards. Then, since the snubber capacitor 10 is fixed to the insulator 19 and cannot move, a portion having weak strength, for example, a connection terminal of the snubber capacitor 10 may be bent and damaged. Therefore, the connection conductors 11a to 11c of the snubber circuit must be removed, and the snubber diode 4 needs to be removed from the stack 13.

However, if a flexible portion is provided between the GTO 3 of the heat sink 1 and the mounting surface of the snubber diode 4,
Since no bending moment is applied to the connection terminal of the snubber capacitor 10, the damage to the terminal can be suppressed.

Therefore, the above-described removal is not necessary, and the GTO can be used without removing the connection conductor of the snubber circuit.
Will be exchangeable. Next, a fifth embodiment of the present invention will be described with reference to FIG.

FIG. 10 shows that the pressure stud 20 of the snubber diode 4 is fixed or penetrated to the heat sink 1 of the power semiconductor device in the above-mentioned first, second, third, and fourth embodiments. A fastening hole 21 is provided.

With such a structure, the rigidity of the heat sink 1 can be used to serve as a holding frame for the pressing mechanism of the snubber diode 4, and the number of parts can be reduced.

Next, a sixth embodiment of the present invention will be described with reference to FIG.
1 and FIG. 12 will be described. FIG. 11 shows a heat sink 1 according to the second embodiment, the third embodiment, and the fourth embodiment, in which a through hole 22 for stud penetration is provided between cooling surfaces of adjacent snubber diodes. The through hole 22 is used to pass the pressurizing stud 20 through the center of the two snubber diodes 4 and allow the other studs 20 to pass through both outsides of the heat sink 1 to pressurize the snubber diode 4. . FIG. 12 shows the internal structure of the heat sink when this embodiment is applied.

With such a structure, the portion of the heat sink that does not contribute to cooling can be greatly reduced, and the weight of the heat sink can be greatly reduced. In addition, in the first to sixth embodiments, the connection terminal can be configured by extending the length of the lid 9, which is not particularly illustrated.

[0027]

As described above, according to the present invention, it is possible to provide a power converter having a heat sink that realizes a low inductance of a snubber circuit added to a semiconductor element.

[Brief description of drawings]

FIG. 1 is a front view of a heat sink of a power conversion device according to a first embodiment of the present invention.

FIG. 2 is a side view of the heat sink of the power conversion device according to the first embodiment of the present invention.

FIG. 3 is an internal structural diagram of a heat sink of the power conversion device according to the first embodiment of the present invention.

FIG. 4 is a power conversion device according to a first embodiment of the present invention.

FIG. 5 is a front view of a heat sink of a power conversion device according to a second embodiment of the present invention.

FIG. 6 is a side view of a heat sink of a power conversion device according to a second embodiment of the present invention.

FIG. 7 is an internal structural diagram of a heat sink of the power conversion device according to the second embodiment of the present invention.

FIG. 8 is an internal structural diagram of a heat sink of a power conversion device according to a third embodiment of the present invention.

FIG. 9 is a heat sink of a power conversion device according to a fourth embodiment of the present invention.

FIG. 10 is a heat sink of a power conversion device according to a fifth embodiment of the present invention.

FIG. 11 is a heat sink of a power conversion device according to a sixth embodiment of the present invention.

FIG. 12 is an internal structural diagram of a heat sink of a power conversion device according to a sixth embodiment of the present invention.

FIG. 13 is a heat sink of a conventional power conversion device.

[Explanation of symbols]

1 heat sink 2 channels 3 GTO 4 Snubber diode 5 bout 6 Outward route 7 Return 8 flow path blocks 9 lids 10 snubber capacitors 11 conductors 12 Insulation spacer 13 stack 15 branches 16 Flexible conductor 17 heat sink 18 Insulator for stack 19 Insulator 20 Pressurizing stud 21 Fastening hole 22 through hole

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Nobuhiro Takahashi               No. 1 Toshiba Town, Fuchu City, Tokyo Higashi Co., Ltd.               Shiba Fuchu Factory (72) Inventor Ryo Nakajima               No. 1 Toshiba Town, Fuchu City, Tokyo Higashi Co., Ltd.               Shiba Fuchu Factory                (56) References JP-A-63-241956 (JP, A)                 JP-A-61-102799 (JP, A)                 JP 7-30027 (JP, A)                 JP-A-8-46280 (JP, A)                 JP-A-6-273028 (JP, A)

Claims (3)

(57) [Claims] 1. A power converter having a semiconductor element and a heat sink for cooling the semiconductor element, the power converter having a spiral flow path in which a refrigerant flows, and a plurality of semiconductor elements connected in parallel, and the refrigerant. Between the water supply channel for supplying the water and the drainage channel for discharging the refrigerant, there is a channel in which a plurality of spiral channels are arranged, and the vicinity of the center of the plurality of semiconductor elements is each half
An electric power converter comprising: a conductive heat sink disposed in the center of a spiral flow path for a conductor element . 2. The power converter according to claim 1, wherein the spiral flow path and the other plurality of spiral flow paths are arranged at substantially the same distance. Power converter. 3. The power conversion device according to claim 1 or 2, wherein the refrigerant discharged from the spiral flow passage is between the spiral flow passage and a plurality of other spiral flow passages. A power conversion device comprising: a flow path that divides the above into a plurality of other spiral flow paths.