JP2008078423A - Cooling structure of semiconductor power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor power converter which can cool electrical equipment other than a semiconductor element using a common cooling passage without lowering the cooling capability of the semiconductor element. <P>SOLUTION: The semiconductor power converter 1 includes the semiconductor element 100 and a second circuit component 150 that are housed in an enclosure. The enclosure also includes a wind tunnel 20 through which cooling air is sent out of the enclosure, and a cooling unit 10 which is exposed to cooling air in the wind tunnel and transmits heat generated from the semiconductor element to cooling wind. The wind tunnel includes an opening 200 which is located closer to the downwind side than the cooling unit and leads air heated by the second circuit component into the wind tunnel. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structure of a semiconductor power conversion device including a semiconductor element that obtains a variable voltage by a switching operation, and more particularly to a structure for cooling the semiconductor element.

  The semiconductor power conversion device houses a semiconductor power conversion circuit formed by combining an inverter circuit and a converter circuit in a casing. These circuits are composed of semiconductor elements such as IGBTs (Insulated gate bipolar transistors) and MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) and other electrical components such as capacitors, and the variable voltage is changed by the switching operation of the semiconductor elements. Have gained.

  The semiconductor element and other electrical components generate heat by the operation of the semiconductor power conversion device, and raise the temperature of the entire device. In order to stably operate the semiconductor element, the semiconductor element must be maintained within a predetermined temperature range. For this reason, the semiconductor power converter usually has a device for cooling it.

  For example, inside the casing, each component is arranged separately as a semiconductor element group and other electrical component groups, and a cooling body having a heat receiving part and a heat radiating part is arranged adjacent to the semiconductor element group. . The heat dissipation part is exposed to the atmosphere outside the housing, and the semiconductor element is naturally cooled.

  Further, in the case where natural cooling alone is not sufficient for cooling the semiconductor element, a wind tunnel and a fan are provided inside the casing so that the heat radiating portion of the cooling body is exposed in the wind tunnel. In this case, since the cooling air passes through the wind tunnel by the rotation of the fan, the heat radiating portion can be actively cooled.

In addition to this, there is a document disclosing a technique related to cooling of the above-described other electrical components. The document discloses a configuration in which the ventilation path between the main circuit and the capacitor is divided into a main circuit ventilation path and a capacitor ventilation path, and the respective ventilation paths are fluidly connected in parallel. In this configuration, since the cooling air in the main circuit ventilation path and the cooling air in the condenser ventilation path are diverted, a certain cooling ability can be obtained without mutual influence of temperature (see Patent Document 1).
Japanese Patent Laid-Open No. 3-155696

  As described above, in the conventional semiconductor power conversion device, when cooling of the semiconductor element is not sufficient only by natural cooling, a wind tunnel is formed in the casing, and the cooling air is forcibly sent into the wind tunnel by a fan or the like. Thus, the lack of cooling capacity was avoided.

  However, in such a configuration, generally, only the semiconductor element is cooled through the wind tunnel, and many other electrical components rely on natural cooling. For this reason, as the calorific value of other electric parts increases, the influence of the temperature rise due to the heat increases, and it is necessary to devise such arrangement that these electric parts are arranged away from other structures. Therefore, when this configuration is used, the entire apparatus becomes large, which is a problem.

  In addition, in part, the other electrical components described above are arranged on the upper side or the lower side in the wind tunnel with respect to the heat radiating portion of the semiconductor element, and the electrical components are cooled by the cooling air taken into the wind tunnel. Some are configured. However, such a configuration also has a problem.

  For example, when the other electronic components are arranged on the upper side of the heat radiating portion of the semiconductor element, the wind poured into the heat radiating portion of the semiconductor element is hot air that has taken the heat of the other electronic components. For this reason, the problem that the capability to cool a semiconductor element will fall remarkably compared with the case where external air is poured into a thermal radiation part.

  On the other hand, when the other electronic components are arranged on the lower side of the heat radiating part of the semiconductor element, the same applies to the case where the other electronic components are arranged on the upper side. Will be blocked by. For this reason, the ventilation of the cooling air in the wind tunnel is deteriorated, and the speed of the cooling air moving in the wind tunnel is reduced. In this case, the pressure loss in the wind tunnel is high, and it is a problem because the fan must be enlarged in order to compensate for the wind speed.

Also, as in the case of the cited document 1, there is a problem in the case where separate cooling passages dedicated to the main circuit and the capacitor are separately provided because the number of parts increases and the apparatus becomes large.
Accordingly, the present invention has been made in view of the above problems, and is a semiconductor power that can forcibly cool other electrical components by using a common cooling passage without reducing the cooling capacity of the semiconductor element. An object is to provide a conversion device.

In order to solve the above problems, the present invention is configured as follows.
One aspect of the semiconductor power conversion device of the present invention includes a semiconductor element and a second circuit component (an electrical component other than the above-described semiconductor element, for example, a capacitor with a large amount of generated heat, for example) provided in the housing. Assuming that, in the casing, a wind tunnel for sending cooling air to the outside of the casing, and the cooling air being exposed to the cooling air in the wind tunnel, the heat generated from the semiconductor element is conducted to the cooling air. A cooling body, and the wind tunnel is provided with an opening for guiding the air heated by the second circuit component into the wind tunnel.

For example, the space surrounding the second circuit component may be configured to be electrically connected to the inside of the wind tunnel only at the opening.
In the present invention, the cooling air heated from the heat of the semiconductor element through the cooling body is forced out through the wind tunnel, and the heated air around the second circuit component is guided into the wind tunnel. This guided air is also forced out to the outside through the common wind tunnel (a common cooling passage, for example, a wind tunnel on the lower side excluding the upper side of the cooling body).

In the present invention, other electric components can be forcibly cooled using a common cooling passage without reducing the cooling capacity of the semiconductor element.
Further, since no other electrical components are arranged in the wind tunnel, the ventilation of the cooling air in the wind tunnel does not deteriorate. For this reason, the pressure loss in the wind tunnel can be kept low, and the size of the fan can be made extremely small.

  Therefore, the entire apparatus can be configured compactly.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an example of the internal structure of the semiconductor power conversion device of the present invention.

FIG. 1A shows the interior of the semiconductor power conversion device drawn from an oblique direction.
FIG. 1B is a front view of FIG. 1A drawn from the A direction.
In each figure, the housing | casing of a semiconductor power converter device is shown with the broken line, and the internal structure is shown with the continuous line.

The semiconductor power conversion device of the present invention includes a cooling body 10 and a wind tunnel 20 as in the semiconductor power conversion device 1 shown as an example in FIG.
The cooling body 10 includes a heat receiving portion and a heat radiating portion. In the example of the figure, one flat plate member 10-1 installed horizontally is the heat receiving portion. In addition, several radiating fins 10-2 extending downward from the lower surface of the flat plate member 10-1 are the radiating portions.

The plate-shaped member 10-1 and the heat radiating fin 10-2 are made of a material having good heat conduction.
The wind tunnel 20 is configured from the bottom of the heat receiving portion to the rear thereof (slightly upper right in FIG. 1A).

  A cylindrical wind tunnel (front wind tunnel) 20-1 having an open front and back is provided under the flat plate-shaped member 10-1 that is a heat receiving portion. In the front wind tunnel 20-1, the radiating fin 10-2 is exposed inside, and the outer peripheral surface other than the flat plate member 10-1 is covered with a sheet metal member.

  Behind the heat receiving portion, a cylindrical wind tunnel (rear wind tunnel) 20-2 having a front surface and a rear surface opened and further having an opening 200 on the side surface is provided. The semiconductor power conversion device 1 of this example has a configuration in which cooling air is taken in from the front by a fan (not shown) and exhausted from the back. For this reason, the rear wind tunnel 20-2 is designed to be larger than the front wind tunnel 20-1 so that the cooling air can easily pass through the wind tunnel 20.

FIG. 2 is an exploded view of a cooling structure constituted by the cooling body 10 and the wind tunnel 20.
As shown in the figure, the front surface 20-2A of the rear wind tunnel 20-2 is opened to be approximately the same size or slightly smaller than the rear surface 20-1B of the front wind tunnel 20-1, and the front wind tunnel By connecting the back surface 20-1B of 20-1 and the front surface 20-2A of the rear wind tunnel 20-2, the wind tunnel 20 is communicated inside the cylinder from the front to the rear.

  Then, as shown in FIG. 1, the semiconductor element group (two semiconductor elements in this example) 100 is disposed on the upper surface 10-1 </ b> A of the flat plate-shaped member 10-1, and the wind tunnel 20 at a position away from the semiconductor element group 100. Other electrical components (in this example, three capacitors) 150 are arranged outside.

The space where the capacitor 150 is exposed in the housing communicates with the space in the wind tunnel 20 only at the opening 200.
Now, the principle of cooling various electric components by the cooling air passing through the wind tunnel 20 will be described.

FIG. 3 is a view showing the direction of the cooling air flowing in the wind tunnel.
Fig.3 (a) is the figure which added the direction of the cooling air to Fig.1 (a). However, in order to make it easy to understand the air flow in the opening 200 of the wind tunnel 20-2, in the same figure, the capacitor is shifted to the side.

FIG. 3B is a view showing the air flow in the wind tunnel 20 from above the apparatus. In this figure, the upper side is omitted from the position of the line CC ′ in FIG.
A large amount of heat is always generated from the semiconductor element 100 and the capacitor 150 while the semiconductor power converter 1 is being driven. The heat generated in the semiconductor element 100 is absorbed by the flat plate member 10-1 of the cooling body 10 and is conducted to the radiation fin 10-2. Further, the heat generated in the capacitor 150 is released to the surroundings and is conducted to the air surrounding the capacitor 150.

In the wind tunnel 20, air in the atmosphere (cooling air) is guided from the front side of the wind tunnel 20 by the rotation of a fan (not shown) (arrow W1).
This cooling air first passes through the front wind tunnel 20-1 as cooling air. During this passage, heat is taken away from the radiating fin 10-2 exposed to the cooling air, so that the cooling air heated there is sent as cooling air into the rear wind tunnel 20-2 (arrow W2).

  In the rear wind tunnel 20-2, the heated cooling air is sent out as it is (arrow W3). At this time, the air outside the wind tunnel 20 heated by the capacitor 150 is drawn from the side opening 200 (arrow W4). And those hot air is discharge | released in air | atmosphere from the opening part of a back surface (arrow W5).

  In this way, the heat generated from the semiconductor element 100 and the heat generated from the capacitor 150 are always forcibly released to the outside through the common wind tunnel 20, and the temperature of the semiconductor element, the capacitor, etc. is maintained within a predetermined range. .

  Note that the structure and size of the cooling body 10, the wind force generated by the fan, the shape of the wind tunnel 20, and the like may be designed so that the semiconductor element 100 and other electrical components 150 can be sufficiently cooled.

  In particular, the opening 200 is desirably provided in the rear wind tunnel 200-2 as in this example, but may be provided in the front wind tunnel 20-1. Even in the latter case, a certain degree of effect can be obtained.

  Further, in this example, the opening 200 is provided on the side surface of the wind tunnel 20. However, since the effect can be obtained if the space where the other electrical components 150 are exposed communicates with the inside of the wind tunnel 20, the opening is formed on the other surface. 200 may be provided. At this time, the number, shape, and size of the openings 200 may be appropriately determined.

  In the present embodiment, as an example, the opening 200 is provided on the leeward side of the cooling body of the wind tunnel. For this reason, the cooling air heated through the cooling body based on the heat generated in the semiconductor element is forcibly sent to the outside through the wind tunnel, and the other electric components are provided in the opening 200 on the leeward side of the cooling body. The ambient heated air is guided into the wind tunnel. This guided air is also forced out through the common wind tunnel (common cooling passage, in this case, the wind tunnel on the lower side excluding the upper side of the cooling body).

As described above, other electrical components can be forcibly cooled using the common cooling passage without reducing the cooling capacity of the semiconductor element.
Moreover, the pressure loss in the wind tunnel can be kept low, and the inside of the apparatus can be efficiently ventilated with cooling air. This prevents the fan from becoming large.

  Moreover, since it is only necessary to provide an opening in the wind tunnel, the semiconductor power conversion device can be reduced in size and manufactured at low cost.

It is an example of the internal structure of the semiconductor power converter device of this invention. 2 is an exploded view of a cooling structure constituted by a cooling body 10 and a wind tunnel 20. FIG. It is the figure which showed the direction of the cooling air which flows through the inside of a wind tunnel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor power converter 10 Cooling body 10-1 Flat plate member 10-2 Radiation fin 100 Semiconductor element group 150 Other electrical components 20 Wind tunnel 20-1 Front wind tunnel 20-2 Rear wind tunnel 200 Opening part

Claims (2)

A semiconductor power conversion device including a semiconductor element and a second circuit component in a housing,
In the housing,
A wind tunnel for sending cooling air to the outside of the housing;
A cooling body that is exposed to the cooling air in the wind tunnel and that conducts heat generated from the semiconductor element to the cooling air;
Is configured,
An opening for guiding the air heated by the second circuit component into the wind tunnel is configured in the wind tunnel.
The semiconductor power converter characterized by the above-mentioned. The space surrounding the second circuit component is electrically connected to the wind tunnel only at the opening.
The semiconductor power conversion device according to claim 1.